BA-Series
Intelligent Data/Fax Modem
User Guide
Contents
Chapter 1 - Introduction and Description......................................................................... 5
1.1
1.2
1.3
Introduction...................................................................................................................................... 6
How To Use This Manual................................................................................................................. 6
Modem Features ............................................................................................................................. 7
1.3.1 2834 Series Features................................................................................................................ 8
Fax Features ................................................................................................................................... 8
Technical Specifications .................................................................................................................. 9
Power .............................................................................................................................................. 10
Modem LED Indicators .................................................................................................................... 11
Controls on PC Board ..................................................................................................................... 12
1.4
1.5
1.6
1.7
1.8
Chapter 2 - Installation and Connection......................................................................... 13
2.1
2.2
What is in Your Modem Package? .................................................................................................. 14
Installation ....................................................................................................................................... 14
2.2.1 Safety Warnings........................................................................................................................ 15
2.2.2 Installation Procedure ............................................................................................................... 15
Installing Data Communications Software ....................................................................................... 16
2.3
Chapter 3 - Software Configuration and Modem Basics .............................................. 17
3.1
3.2
Introduction...................................................................................................................................... 18
Configuring Your Software............................................................................................................... 18
3.2.1 ConfiguringSoftware for Your Modem ....................................................................................... 18
PC Initialization Strings ................................................................................................................... 18
3.4.1 Changing Default Parameters................................................................................................... 19
3.4.2 Other Parameters ..................................................................................................................... 19
Configuring Software for Your Computer ......................................................................................... 19
3.5.1 Configuring Software for the Remote System ........................................................................... 19
3.5.2 Terminal Emulation ................................................................................................................... 20
3.5.3 File Transfer Protocols .............................................................................................................. 20
3.4
3.5
Chapter 4 - Command Mode............................................................................................ 21
4.1
Introduction...................................................................................................................................... 22
4.1.1 AT Command Editing ................................................................................................................ 22
4.1.2 Functional Modes...................................................................................................................... 22
Summary of AT Commands............................................................................................................. 23
Result Codes ................................................................................................................................... 26
Dialing Commands .......................................................................................................................... 27
4.4.1 Dialing Action Commands ......................................................................................................... 27
4.4.2 Dial Modifier Commands ........................................................................................................... 28
4.4.3 Phone Number Memory Commands......................................................................................... 30
4.4.4 Configuration and Default Storage Commands ........................................................................ 31
4.4.5 Command Response (Result Code) Commands ...................................................................... 33
4.4.6 Phone Line Conditioning Commands........................................................................................ 34
4.4.7 RS-232C Interface Control Commands .................................................................................... 36
4.4.8 Error Correction Commands ..................................................................................................... 38
4.4.9 Flow Control Commands .......................................................................................................... 40
4.4.10 Compression, Error Correction, Flow Control, Pass-Through and Pacing Commands ............ 43
4.4.11 Speed Conversion Commands ................................................................................................. 44
4.4.12 Immediate Action Commands ................................................................................................... 46
4.4.13 Line Probe Commands ............................................................................................................. 48
4.2
4.3
4.4
Chapter 5 - S-Registers.................................................................................................... 49
5.1
5.2
Introduction...................................................................................................................................... 50
Reading and Assigning S-Register Values ...................................................................................... 55
5.2.1 Examples of Assigning Values .................................................................................................. 56
5.2.2 Examples of Reading Values .................................................................................................... 56
AT Command and S-Register Summary ......................................................................................... 56
5.3
Chapter 6 - Callback Security and
Remote Configuration...................................................................................................... 57
6.1
6.2
6.3
Introduction...................................................................................................................................... 58
Callback Feature Description .......................................................................................................... 58
Remote Configuration Description................................................................................................... 58
6.3.1 Initial Setup Procedures for Callback and Remote Configuration. ............................................ 58
6.3.2 Remote Configuration Procedures ............................................................................................ 61
Remote Configuration and Callback Security AT Commands ......................................................... 62
Remote Configuration/Callback Security S-Registers ..................................................................... 63
6.4
6.5
Chapter 7 - DIP-Switch Settings...................................................................................... 65
7.1
7.2
7.3
7.4
Introduction...................................................................................................................................... 66
DIP-Switch Option Settings ............................................................................................................. 66
Speaker Volume Control ................................................................................................................. 71
Recording Option Configurations .................................................................................................... 72
Chapter 8 - Warranty, Service and Tech Support .......................................................... 74
8.1
8.2
8.3
8.4
8.5
8.6
Introduction...................................................................................................................................... 75
Multi-Tech Systems, Inc. Warranty & Repairs Policies .................................................................... 75
Online Warranty Registration .......................................................................................................... 76
Replacement Parts .......................................................................................................................... 77
Technical Support ............................................................................................................................ 77
Internet Sites ................................................................................................................................... 77
Appendixes ....................................................................................................................... 78
Appendix A -- Upgrading Your Modem’s Firmware....................................................................................... 79
Appendix B - Troubleshooting ...................................................................................................................... 82
Apendix C - AT Command Summary ........................................................................................................... 87
Appendix D - V.25bis Operation ................................................................................................................... 96
Appendix E - MultiModemBA Cables ........................................................................................................... 102
Appendix F - Regulatory Information............................................................................................................ 103
Index.................................................................................106
Chapter 1 - Introduction and Description
MultiModemBA User Guide
1.1 Introduction
Welcome to the world of data communications. You have acquired one of the finest intelligent
desktop data/fax modems available today, the MultiModemII BA series modem, from Multi-Tech
Systems. This User Guide covers various models within the BA series, and unless otherwise noted,
all content should be considered relevant to all models.
Your MultiModem provides data communication at the following rates:
33,600 - 14,400 bps (Enhanced V.34 / V.32bis)
The MultiModem also provides other prevalent data communications standards and includes dial
backup with automatic lease line restoration, adaptive protocol enhancing used in typical Unix® batch
file transfers and support for IBM's AS/400TM and WindowsTM environments.
1.2 How To Use This Manual
The information contained in each chapter and appendix is as follows:
Chapter 1 - Introduction and Description
This chapter begins with a short introduction, followed by a guide (which you are now reading) to the
use of this manual. There is a discussion about what components you can expect in your modem
package. We then provide a more detailed description of the modem, including the modem’s
technical specifications. Chapter 1 includes sections covering power, LED indicators and a brief
summary of PC board controls. (Chapter 9 covers switch settings more thoroughly.)
Chapter 2 - Installation and Connection
Chapter 2 covers the procedure for connecting the modem to your computer and to the phone line.
Details are given, supported by illustrations on the modem's back panel connections as a guide to
install your modem to the point of operation. In addition, this chapter describes the installation of
PhoneTools, the communications software included with your modem.
Chapter 3 - Software Configuration and Modem Basics
Chapter 3 documents communication software configuration recommended specifically for the
MultiModem. Other issues covered include setting up initialization strings, changing default
parameters, configuring software for the remote system and file transfer protocols.
Chapter 4 - AT Command Mode Operation
Chapter 4 may be the most important chapter of this manual. It begins with an introduction and
discussion on Command Mode fundamentals. A flow chart is provided to illustrate Command Mode
and On-Line Mode operation and the methods used in each mode. Next, there is a summary of the
modem’s commands and responses. We then go into a detailed explanation of each modem
command, providing examples where applicable.
Chapter 5 - S-Registers
Chapter 5 covers the modem's S-Registers, which enable the user to establish, read, and modify
various modem options. All of the S-Registers are charted and explained, followed by instructions on
accessing the S-Registers and reading or changing their values.
6
Chapter 1 - Introduction and Description
Chapter 6 - Callback and Remote Configuration
Chapter 6 documents instructions on how to operate the modem's Callback and Remote
Configuration features; and the usage of LOGIN Passwords, Set-Up Passwords and Remote Escape
Characters as network management tools.
Chapter 7 - DIP-Switches
Chapter 7 covers the modem’s printed-circuit board options. Sixteen DIP-Switch settings and the
modem's speaker volume control are explained in detail, including all default settings.
Chapter 8- Warranty, Service & Technical Support
Chapter 8 provides statements on your five-year warranty, instructions for getting modems serviced
at the factory and the procedure for downloading firmware upgrades via FlashROM.
Appendixes
There are also several appendices at the end of this manual, most of which repeat information
contained in the chapters, but in a more condensed form. These appendices can be used as a quick
reference.
Appendix A - Upgrading Your Modem’s Firmware
Appendix B - Troubleshooting
Appendix C - AT Command Summary
Appendix D - V.25bis Operation
Appendix E - Cabling Diagrams
Appendix F - Regulatory Information
1.3 Modem Features
The MultiModem BA Series modem connections can be made on Public Switched Telephone
Networks (PSTNs) and/or point-to-point 2-wire telephone type circuits.
Your modem offers interactive automatic dialing, as well as Command Mode option configuration.
You may store up to ten command line/telephone numbers, of up to 60 characters each, in the
modem’s nonvolatile memory. The modem pulse or tone dials, and recognizes dial tones and busy
signals for reliable call-progress detection. The modem can detect AT&T calling card tones. It is
FCC-Registered for connection to telephone networks without any Data Access Arrangements
(DAA’s).
Your modem also features Callback Security to protect networks from unauthorized use, and to
manage phone line costs. By using the modem’s phone number and password directory, a host site
can, upon receipt of a call, callback to a remote site at a predetermined number.
Remote Configuration permits you to assist users at remote sites, saving you the time and trouble of
site visits and preventing misinterpretation of configuration instructions.
7
MultiModemBA User Guide
1.3.1
2834 Series Features
Your MT2834BA modem meets the proposed Enhanced V.34 ITU standard for data signalling rates
as high as 33.6/31.2K bps in full duplex mode. Enhanced V.34 is an extension of V.32/V.32bis/V34
standards, and supports and is compatible with those features, including EIA extended Automode;
adaptive line probing; automatic symbol rate and carrier frequency during start-up; and retrain and
rate renegotiation (in 2400 bps increments).
The MT2834BA features ITU V.25bis standard for synchronous dialing, ITU V.42 error correction and
V.42bis data compression, providing 100% error-free data transmission. V.42 error correction
incorporates MNP( Classes 3 and 4, and LAP-M. You may select V.42bis data compression for 4-1
throughput, or MNP Class 5 for 2-1 throughput.)
1.4 Fax Features
Your modem meets the ITU V.17 standard for sending and receiving faxes. When linked to a
compatible fax machine or modem, it can transmit faxes at 14,4 K bps. It also meets the ITU’s Group
3 Designation for sending and receiving faxes at 9600 bps; and Group 2 Designation for sending and
receiving faxes at 4800 bps. The modem is also downward-compatible with modems to speeds as
low as 300 bps, so it can send and receive faxes with any fax machine in the world.
8
Chapter 1 - Introduction and Description
1.5 Technical Specifications
Your data/fax modem meets the specifications listed below:
Tradename
MultiModemIITM
Model Numbers
MT2834BA, MT2834BAI
Data Rates (modem)
33,600, 31,200, 28,800, 26,400, 24,000, 21,600, 19,200, 16,800,
14,400, 12,000, 9600, 7200, 4800, 2400, 1200, 0-300 bps
Data Rates (fax)
Data Format
14,400, 9600, 7200, 4800 bps
Serial, binary, asynchronous at 0-300, 1200, 2400, 4800, 7200,
9600, 12,000, 14,400, 16,800, 19,200, 21,600, 24,000, 26,400,
28,800, 31,200, 33,600 bps; synchronous at 1200, 2400, 4800,
7200, 9600, 12,000, 14,400, 16,800, 19,200, 21,600, 24,000, 26,400,
28,800, 31,200, 33,600 bps
Compatibility
ITU V.42bis, V.42, Pending ITU Enhanced V.34 approval, ITU V.34,
AT&T V.32terbo, ITU V.32bis, V.32, V.21*, V.22bis, V.22,
V.23*,V.25bis, *Bell 212A and 103/113, ITU V.17, Group 3 T.4, T.30
and EIA TR-29 Class 2 (*Bell 212A and 103/113 domestic models
only; *V.21/V.23 Int'l models only)
Error Correction
V.42 (LAP-M or MNP 3 & 4) error correction
Data Compression
V.42bis, (4:1 throughput) or MNP 5 (2:1 throughput) data
compression
Speed Conversion
Serial port data rates adjustable to 300, 1200, 2400, 4800, 9600,
19,200, 38,400, 57,600 and 115,200 bps
Flow Control Options
Mode of Operation
Intelligent Features
Xon/Xoff, Hardware RTS/CTS, ENQ/ACK, Unix-to-Unix Copy
Protocol (UUCP) "Spoofing"
Full duplex over both dial-up lines and 2-wire leased lines; automatic
or manual dialing, automatic or manual answer
Fully “AT command” compatible, microprocessor controlled remote
configuration, EIA extended Automode, adaptive line probing,
automatic symbol rate and carrier frequency during start-up, retrain
and rate renegotiation, autodial, redial, repeat dial, dial linking, pulse
or tone dial, dial tone detection, dial pauses, call status display, auto-
parity and data rate selection, keyboard-controlled modem options,
nonvolatile memory and on-screen displays for modem option
parameters and up to ten telephone numbers/command lines of up
to 60 digits each, help menus
Command Buffer
Modulation
60 characters
Trellis Coded Modulation (TCM) at 33,600, 31,200, 28,800, 26,400,
24,000, 21,600, 19,200, 16,800, 14,400, 12,000 and 9600 bps,
Quadrature Amplitude Modulation (QAM) at 9600 (non-trellis), 4800
and 2400 bps, PSK at 1200 bps, FSK at 300 bps
9
MultiModemBA User Guide
Fax Modulations
Transmit Level
V.21CH2 FSK at 300 bps, V.27ter DPSK at 4800 and 2400 bps,
V.29 QAM at 9600 and 7200 bps, V.17 TCM at 14400, 12000, 9600,
and 7200 bps
-11dBm (dial-up), -9 or -15 dBm (leased-line); dBm level selectable
with DIP-Switch #3 in leased line setting
Frequency Stability
Connectors
0.01%
One DB-25 RS-232C connector; two RJ11 for phone line/telephone
set; power.
Diagnostics
Indicators
Power-on Self Test, Local Analog Loop, Local Digital Loop, Remote
Digital Loop, Back-to-Back Test.
LEDs for Transmit Data, Receive Data, Carrier Detect, Speed
Indicators, Off Hook, Terminal Ready, Error Correction, Fax, and
Error
Controls
Toggle switches for Voice/Data with Originate or Answer, Power On/
Off; and DIP Switches for various modem options.
Speaker
Speaker for call progress monitoring
Operating Temperature
Power Requirements
0° to 50° C (32° to 120° F)
115 Volts AC, 60Hz, 0.3amp (2-prong outlet-mounted transformer)
240V/50Hz optional (International).
Dimensions
Weight
6.150" x 9.00" x 1.375"
15.6 cm x 22.9 cm x 3.5 cm
1.6 pounds/0.72 Kg (without transformer)
2.6 pounds/1.18Kg (with transformer)
Limited Warranty
Five Years
1.6 Power
Power is supplied through an AC power transformer terminated with a standard two-prong plug. The
transformer supplies low voltage AC to the modem, and plugs into any conventional 115 volt AC, 60
Hz, two-prong power outlet (240 volts AC, 50Hz, .3 Amp for International modems). The power
transformer supplied with the modem is the only one that should be used. Use of any other
transformer could cause damage to the modem. A Power On/Off switch is located on the back of the
modem.
10
Chapter 1 - Introduction and Description
1.7 Modem LED Indicators
The MultiModem diagnostic LED indicators are shown in Figures 1-1
Answ
MT2834BA
Orig
Series
SD
RD CD 28.8 24.0 19.2 14.4 96
24
OH TR
EC
FX
Intelligent
Modem
Voice/
Data
Send Rcv Carr 28.8K 24.0K 19.2K 14.4K 9600 2400 Off Hk Rdy V.42 Fax
Figure 1-1. MT2834 LED Display
(SD) Send (Transmit) Data. This LED blinks when data is being transmitted, on for a space, off for a
mark. The state of this LED matches the TD circuit on Pin 2 of the RS-232C/V.24 interface.
(RD) Receive Data. This LED blinks when data is being received, on for a space, off for a mark. The
state of this LED matches that of the RD circuit on Pin 3 of the RS-232C/V.24 interface.
(CD) Carrier Detect. This LED is lit when a valid carrier tone has been detected.
When the modem is connected at 33,600 bps, the 28.8 LED rapidly blinks at approximately 5
blinks per second.
When the modem is connected at 31,200 bps, the 28.8 LED blinks slowly at approximately 1
blink per second.
(28.8) 28,800 bps. This LED is lit when the modem is connected at 28,800 bps. Note: if the modem
falls back to 26.4K bps while in V.34 mode, both the 28.8 and 24.0 LEDs light.
(24.0) 24,000 bps. This LED is lit when the modem is connected at 24,000 bps. Note: if the modem
falls back to 21.6K bps while in V.34 mode, both the 24.0 and 19.2 LEDs light.
(19.2) 19,200 bps. This LED is lit when the modem is connected at 19,200 bps.
(14.4) 14,400 bps. (2834 and 1432 models only) This LED is lit when the modem is connected at
14,400 bps. Note: if the modem falls back to 12,000 bps while in V.32bis mode, both the 14.4 and 96
LEDs light.
(96) 9600 bps. This LED is lit when the modem is connected at 9600 bps.
(24) 2400 bps. This LED is lit when the modem is connected at 2400 bps.
(OH) Off Hook. This LED is lit when the phone line is "off hook". This occurs when the modem is
dialing, on-line, or answering a call. This LED also flashes when the modem is pulse dialing in
Command mode.
(TR) Terminal Ready. When the TR LED is lit, the modem is permitted to answer an incoming call.
When it goes off, a connected modem will disconnect. The state of the TR LED matches that of the
DTR circuit on Pin 20 of the RS-232C/V.24 interface.
(EC) Error Correction. This LED is lit when the modem is set for V.42 error correction, and flashes on
and off when data compression is activated.
(FX) FAX. This LED is lit when the modem is connected in FAX mode.
11
MultiModemBA User Guide
1.8 Controls on PC Board
The MultiModem is designed on a single printed circuit (PC) board. This board contains one 16-
position DIP-Switch (numbered 1-16). The DIP-Switches are accessible through a cut-out on the side
of the modem. There is also a knob which is used to adjust the speaker volume. This knob is
accessible through the modem's rear panel. The sixteen DIP-Switches control various modem
options or set default values for Command Mode operation. There is a difference in how several of
the switches operate depending on whether you are in synchronous or asynchronous mode. Refer to
the switch label on the bottom of the modem for an exact list of the switch functions in asynchronous
and synchronous operation.
12
Chapter 2 - Installation and Connection
MultiModemBA User Guide
2.1 What is in Your Modem Package?
Your MultiModem is made up of many components. Make sure you have them all before trying to
operate your modem.
Answ
MT2834BA
Orig
SD
RD CD 28.8 24.0 19.2 14.4 96
24
OH TR
EC
FX
Series
Intelligent
Modem
Voice/
Data
Send Rcv Carr 28.8K 24.0K 19.2K 14.4K 9600 2400 Off Hk Rdy V.42 Fax
MADE IN U.S.A
U.S.A
ADE IN
M
Figure 2-1. Unpacking
Your package should include:
•
•
•
•
•
•
MT2834BA data/fax modem
RJ-11 telephone cord
AC Power Transformer
One (1) Quick Start Guide
One (1) software CD (PhoneToolsTM data communications and fax software)
This User Guide (on diskette)
If any of these items are missing, contact Tech Support.
2.2 Installation
The installation of the modem consists of making the physical connections necessary to render the
modem functional with your computer. This includes making the proper serial, phone line, and power
connections. Unless otherwise noted, these instructions apply to all models of the BA series.
14
Chapter 2 - Installation and Connection
2.2.1
Safety Warnings
1.
2.
3.
4.
Use this product only with UL and cUL listed computers.
To reduce the risk of fire, use only 26 AWG (.41mm) or larger telephone wiring.
Never install telephone wiring during a lightning storm.
Never install a telephone jack in wet locations unless the jack is specifically designed for wet
locations.
5.
Never touch uninsulated telephone wires or terminals unless the telephone line has been
disconnected at the network interface.
6.
7.
Use caution when installing or modifying telephone lines.
Avoid using a telephone during an electrical storm. There is a risk of electrical shock from
lightning.
8.
Do not use a telephone in the vicinity of a gas leak.
2.2.2
Installation Procedure
The following procedures will guide you through the physical connections required to make your
modem operational. Software loading is covered later in this guide.
Step Procedure
1
Verify that the settings for DIP-Switch #5 and DIP-Switch #10 match those of your system
configuration.
The 16-position DIP-Switch (numbered 1-16) is accessible through a cut-out on the right side (as
the LEDs are facing you) of the modem chassis. For a full description of all DIP-Switch Settings,
refer to Chapter 7.
DIP-Switch
Condition
UP*
Effect
#5
Selects Answer mode
Selects Originate mode
Selects Dial-Up operation
Selects Lease Line operation
DOWN
UP*
#10
DOWN
* indicates Factory Default setting
2
Verify that the ON/OFF switch at the rear of the modem to the OFF (Down) position.
15
MultiModemBA User Guide
3
Connect the modem to a dial-up line by attaching the RJ-11 telephone cord (provided with your
unit) to the LINE connector on the modem and to a dial-up wall jack. Refer to Figure 2-2.
PHONE
LINE
EIA RS232C
ON
OFF
POWER
VOLUME
Figure 2-2. MultiModemBA/BAI Connections
4
5
Attach the EIA RS-232C connector on the modem to the serial port on your computer or terminal
with an RS-232 (or V.24) cable (you supply). Refer to Figure 2-2.
To connect a telephone set to the modem (optional) plug one end of an RJ-11 phone cord into
the PHONE connector on the modem, and plug the other end into your telephone. Refer to
Figure 2-2.
6
7
Attach the AC Power transformer provided with your unit to the POWER connector on the
modem and to a live AC outlet. Refer to Figure 2-2.
Note: Only apply power to the modem using the power transformer provided with your unit. Use
of a power supply not designed for your unit could result in damage to your modem and will void
the warranty.
Apply power to the unit by setting the ON/OFF switch at the rear of the modem to the ON (Up)
position. Refer to Figure 2-2.
2.3 Installing Data Communications Software
Data communications software is designed to send and receive messages. Multi-Tech includes a
data communications software program, PhoneTools, with your modem. However, the modem will
work with any data communications software.
To install PhoneTools, insert the PhoneTools CD in you CD-ROM drive and click the PhoneTools
icon. You will be asked to choose your language. The software will then automatically load onto your
PC.
16
Chapter 3 - Software Configuration and Modem Basics
MultiModemBA User Guide
3.1 Introduction
Chapter 2 described the installation of PhoneTools, a communications software. If you are using a
different software package, there are some points you should take into consideration. Since your
communications software configuration is affected by the capabilities of your computer, this chapter
begins with a discussion of the limitations of some serial ports and how to identify them. It then
discusses communications configuration in general and recommends settings specifically for the
MultiModem. The last section of this chapter walks you through the basics of using your modem.
3.2 Configuring Your Software
Communications software must be configured to work with your modem, your computer, and the
remote system it is calling. Fortunately, most communications programs make the process easy by
providing a default initialization string for your modem as well as defaults for most of the other
required parameters.
3.2.1
Configuring Software for Your Modem
Because remote computers may have different connection requirements such as speed, number of
bits, parity, log-on sequences, etc., communications software is typically configured by sessions,
each session having a unique configuration for a given connection. Most communications programs,
however, have a separate modem configuration menu because modem configurations rarely change
from session to session.
The most important configuration is the modem initialization string. This is a sequence of commands
the software uses to configure the modem when the communications software is loaded or when a
session begins. Always begin the initialization string with the ATtention command AT, then follow it
with the modem reset command, &F. Issuing a reset command before other commands ensures that
you are starting with a known state.
The rest of the commands in the initialization string depend on the capabilities of the modem and
what you want it to do. Some older communications programs require you to create the initialization
string by yourself. Most modern communications programs, however, provide you with a ready-made
initialization string that is automatically selected when you choose your modem model from a list. It is
a poor idea to use an initialization string intended for another modem, especially one from another
manufacturer, because modem capabilities and command implementations vary from modem to
modem. However, if your MultiModem does not appear on a modem list, you may use the
MultiModemII initialization string.
3.4 PC Initialization Strings
We recommend the following initialization string for a MultiModem connected to a PC-compatible
computer when sharing a line with a telephone:
AT &F X4 S0=0 ^M
This string resets the modem to the factory default settings, selects extended result codes with NO
DIAL TONE and BUSY, and turns off auto-answer. ^M must end every string sent to the modem from
software. It is the ASCII code for the RETURN key on most keyboards, and the default code for the
carriage return character in the modem and most communications programs. The carriage return
character is defined in the modem in S-register S3; if you change it, you must also change the
carriage return character code used in your communications software. If you send a command
directly to the modem in terminal mode rather than indirectly through communications software, you
must end the command string by pressing the RETURN key (<CR>) instead of adding ^M to the
string.
The following initialization string is for a MultiModem on a telephone line that functions solely as a
DATA LINE:
AT &F X4 S0= 2 ^M
18
Chapter 3 - Software Configuration
3.4.1
Changing Default Parameters
By default, the modem will answer after the first ring and try to communicate with a modem on the
other end of the line. If you have one telephone line for voice, fax, and modem communications, the
modem may attempt to answer all incoming calls, voice as well as data. To change auto-answer to
default off, open your communications program and type the following string in the terminal window:
AT &F S0=0 &F9 &W0 <CR>
This string selects the factory default parameters, then turns auto-answer off and stores that setting,
along with all other current parameters, in nonvolatile memory. The &F9 command causes the
modem to load the values from nonvolatile memory the next time it receives the &F command. You
will use the same initialization string as before:
AT &F X4 ^M
But now the modem will load the values stored in nonvolatile memory when you turn on the modem
and when you issue the ATZ or AT&F reset commands.
Note: Because it clears the command buffer, you should not use ATZ in an initialization string.
3.4.2
Other Parameters
The default values for the other parameters in modem configuration menus rarely need changing.
They typically include the dialing prefix (ATDT for touch-tone service and ATDP for rotary service),
the dialing suffix (^M), the hang-up string (+++ATH0^M), and response messages (RING, NO
CARRIER, BUSY, etc.). Communications software with a host mode might also include an auto-
answer string (AT S0=1^M).
3.5 Configuring Software for Your Computer
You must configure your communications software to match your computer’s configuration. If the
modem is connected to the COM2 serial port, you must tell the software you are using COM2.
Another important parameter is the serial port baud rate. This is the speed at which your modem
communicates with your computer, not the speed at which your modem communicates with another
modem. When V.42bis data compression is enabled, you must have a serial port baud rate four
times the transmission speed of the modem to fully optimize compression. So if your UART is fast
enough, you should set the serial port baud rate to a minimum of four times the top speed of your
modem.
If you have an 8250 UART, your most reliable serial port speed will be 9600 bps; if you have an
8250A or a 16450 UART, try 19,200 bps; if you have a 16550 UART or equivalent, a serial port
setting of 115,200 bps can be set reliably.
3.5.1
Configuring Software for the Remote System
You must meet the requirements of the remote system for successful communications. Though the
modem can automatically match the speed of the other modem, you must specify parameters such
as type of flow control, break length, number of data bits, number of stop bits, and parity. If you set
these parameters incorrectly with the remote system, gibberish will appear on your screen.
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MultiModemBA User Guide
3.5.2
Terminal Emulation
If you are accessing the remote computer as if from an on-site terminal, the keyboard codes used by
your computer may not match the ones used by the remote computer. To be compatible with the
remote computer, your software must be able to substitute the appropriate codes in what is known as
terminal emulation. Most communications programs can emulate the most common mainframe
terminals, including the DEC VT100, VT102, and VT52 terminals, and the basic TTY mode. If in
doubt about which to choose for a BBS, try ANSI or VT100 first.
3.5.3
File Transfer Protocols
When you upload or download files with your modem, the host computer will ask which file transfer
protocol you want to use. Most communications programs allow you to choose a default protocol.
Your software’s documentation should list the ones it can use (not all communications programs
support all protocols). Zmodem is the recommended protocol for most transfers.
20
Chapter 4 - Command Mode
MultiModemBA User Guide
4.1 Introduction
AT commands are the means by which you, and your communications software, are able to
communicate with and configure your modem. They enable you to establish, read, and modify
parameters in addition to dialing. The following provides both a summary and a detailed explanation
of the AT commands recognized by the MultiModem.
4.1.1
AT Command Editing
The BACKSPACE key on your keyboard can be used to edit characters in the AT command line. An
AT command is not executed until the RETURN key is pressed. The BACKSPACE key erases the
previous character for reentering.
The BACKSPACE key does not erase the AT characters once they are entered. If your keyboard
has no BACKSPACE key, CTRL-H does the same thing. The character recognized by the modem
as BACKSPACE may be changed to any other ASCII character with S-Register S5.
If you wish to cancel an entire command that has been entered but not yet executed, enter CTRL-X.
This also clears the command buffer. The effect is the same as backspacing to cancel the entire
command, only quicker.
Characters entered in a command are stored in the modem's Command Buffer (memory) until
executed by hitting RETURN. The Command Buffer's capacity is sixty characters. The Attention
Characters AT do not count in the sixty allowed Command characters. Spaces, which may be used
for increased display readability, may be used when entering a command, but are not stored in the
Command Buffer and are not counted in the sixty allowed characters. Hyphens, parentheses, etc. are
not allowed.
If the sixty character limit is exceeded or if invalid characters are entered, the Command Buffer
automatically erases, and an ERROR message appears. You would then re-enter your command
within the sixty-character maximum, using only the allowed characters.
4.1.2
Functional Modes
The MultiModem can be in one of two functional states (see Figure 4-1). These are "Command
mode" and "On-line mode". (There is also an in-between state, "Wait-for-Carrier", where the modem
is out of Command mode but not yet really On-Line.
When the modem is initially powered up, it is in Command mode and is ready to accept commands
from your keyboard or software. The modem enters On-line mode after dialing, making a connection
with another modem, and then detecting a valid carrier signal. If no carrier is detected within a certain
time frame, the modem abandons the call and re-enters Command mode.
Once on line, the modem exits On-line mode if one of two conditions is met. If the carrier is lost or
intentionally dropped, the modem hangs up and re-enters Command mode. Also, if the modem
recognizes the Escape sequence for which it is configured (i.e., either the Escape characters in the
serial data stream, the Remote Escape characters in the modulated data stream, or the Break
signal), the modem will exit On-line mode, retain the datacomm link, and enter Command mode.
You can force the modem into On-line mode without dialing by sending the ATD or ATA command to
the modem.
22
Chapter 4 - Command Mode
+++AT
COMMAND
MODE
HANG
UP
Dial (D or A) command,
or incoming phone call
WAIT FOR
CARRIER
No carrier
detected
Carrier detected
ON-LINE
MODE
AT0 Command
Carrier lost
Figure 41. Functional Modes
4.2 Summary of AT Commands
A wide variety of autodial operations and modem options can be controlled when the modem is in
Command Mode. Remember, nearly all commands begin with AT.
These commands are organized into several functional groups. An alphabetical summary of
commands is provided in Appendix D.
HOW TO
DIAL
COMMANDS
D
Dial
A: or : Continuous Redial
$D
$VD
N
DTR Dialing
Voice/Data Dialing
Dial a Stored Number
MODIFY DIALING
PROCEDURES
P/T
&P
,
Y
W
;
Pulse/Tone Dialing
Set Pulse Dial Ratios
Automatic Pauses in dialing
Long Space Disconnect
Wait for New Dial Tone
Return to Command Mode After Dial
Command
R
!
Reverse Mode of Operation
Flash On Hook
$
@
AT&T "Calling Card" Tones
Quiet Answer
MEMORIZE PHONE
NUMBERS
D...N Store Phone Numbers
NN
L
Number Linking
List Numbers Stored in Memory
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MultiModemBA User Guide
STORE MODEM
CONFIGURATIONS
AND DEFAULTS
&F
&W
Load Factory Defaults
Store Configuration & S-Register
Parameters
Z
Reset Modem
V
Result Code Terse/Verbose
UNIX/"Spoofing”
Synchronous/Asynchronous Mode Select
Synchronous Transmit Clock Select
$SP
&M
&X
CONFIGURE
COMMAND
RESPONSES
Q
&Q
E
Result Codes Enable/Disable Response
Result Code Selection
Echo Command Characters
V
Result Code Terse/Verbose
X
Result Code...Basic/Extended/Call Progress
CONDITION
PHONE LINE
&G
M
Guard Tones
Monitor Phone Line
&T
#T
B
Remote Digital Loop Signal
Enable/Disable Trellis Coded Modulation
Bell/V.21 Tones
#F
Fallback When On-Line
&CD Cleardown at Disconnect (2834 Series only)
#A
Auto-Speed Detect
CONTROL RS232C
INTERFACE
&C
&D
&R
&S
&RF
&SF
Carrier Detect Control
Data Terminal Ready Control
Clear To Send Control
Data Set Ready Control
CTS/RTS Control
DSR/CD Control
CONFIGURE
ERROR
CORRECTION
&E0
&E1
&E2
#L0
#L1
#L2
#L3
$A
Normal Mode
Auto-Reliable Mode
Reliable Mode
Negotiate V.42 Mode During Handshake
MNP On/LAPM Off
LAPM On/MNP Off
Direct LAPM/Phase Out Handshake
Auto-Reliable Buffering
Enable/Disable Auto-Reliable Fallback Character
Retransmit Count
$F
$R
$E
Error Correction at 300 bps
CONFIGURE
FLOW CONTROL
&E3
&E4
&E5
&E6
&E7
#X
Flow Control Disabled
Hardware Flow Control
Xon/Xoff Modem-Initiated
Xon/Xoff Modem Responds/No Pass-Through
Xon/Xoff Modem Responds/Pass-Through Allowed
Send Single/Multiple Xoff Characters
Enq/Ack Off
&E8
&E9
Enq/Ack On
&E10 Normal Mode Modem Flow Control Off
&E11 Normal Mode Modem Flow Control On
&E12 Computer-Initiated/Off
&E13 Computer-Initiated/On
&BS Maximum Block Size
$EB
#P
10/11 bit Asynchronous Format
Parity Selection
24
Chapter 4 - Command Mode
CONFIGURE DATA
COMPRESSION
&E14 Data Compression Disabled
&E15 Data Compression Enabled
CONFIGURE SPEED $BA0 Speed Conversion On
CONVERSION
$BA1 Speed Conversion Off
$MB Set modem speed (e.g.,$MB14400)
$SB
Set serial port speed (e.g.,$SB57600)
EXECUTE
IMMEDIATE
ACTION
$H
I
Help
Product Code Inquiry
I 9
L5
L6
L7
L8
H
Windows 95 Autodetect Inquiry (2834 Series only)
List Current Operating Parameters
List S-Register Values
List additional Configuration Parameters
List On-Line Diagnostics
COMMANDS
Off Hook
+++AT<CR> Escape Sequence: Entering Command Mode while On-Line
%E
A
Escape Sequence Options...Entering Command Mode while On-Line
Force Answer Mode
O
Exit Command Mode/Go Back On-Line
EXECUTE
LINE
%DF Format Line Probe Display (Graph or Table Format)
%DP Enable/Disable Reading Line Probe From DSP during handshake
PROBE
COMMANDS
(2834 Series only)
L9
L10
Display of Signal Strength Information
Display Signal to Noise Ratio (SNR)
L11 Display of Noise Information
&RP Initiates Retrain to Read Line Probe Parameters
READ AND
ASSIGN
Sr?
Sr=
Read Current S-Register Value
Assign S-Register Value
S-REGISTER
VALUES
REMOTE
#CBN Passwords for Callback Phone Numbers
CONFIGURATION
& CALLBACK
#DB
#I
Callback Security Enable/Disable
Change LOGIN Password
SECURITY
#RCBNxx
#S
Erase Password Linked with Memory Location xx
Change SETUP Password
TEST MODEM
U
Self-Test Modem (Chapter 8)
&T
Enable/Disable Digital Loopback Signal
25
MultiModemBA User Guide
4.3 Result Codes
The Command mode provides you with several responses, or “Result Codes”, that can aid you in
Command mode operation. These Result Codes are displayed on your video monitor.
You can choose result codes that closely match those of the standard AT command set, or choose
enhanced function result codes that have been used in Multi-Tech modems ("Multi-Tech" responses).
The &Q command selects which result codes will be used.
You can choose to have these Result Codes displayed in either “verbose” (full words) or “terse”
(digits) format. This is controlled by the ATV0 (terse) or ATV1 (verbose) commands. The modem
defaults to verbose format.
AT&Q0 selects Multi-Tech responses with Reliable/LAPM/Compression modifiers. The terse
response code for CONNECT 2400 is 9. AT&Q1 selects Standard AT command set responses. The
terse result code for CONNECT 2400 is 10.
The following tables define the result codes generated by the &Q command (refer to Appendix G for
Result Code Summary).
"Multi-Tech" Result Codes
TERSE
VERBOSE
TERSE
VERBOSE
0
1
2
3
4
5*
6
7
8
OK
CONNECT
RING
NO CARRIER
ERROR
CONNECT 1200
NO DIALTONE
BUSY
11*
12*
13*
19*
21*
24*
26*
28*
31*
33*
CONNECT 4800
CONNECT 9600
CONNECT 14400
CONNECT 19200
CONNECT 21600
CONNECT 24000
CONNECT 26400
CONNECT 28800
CONNECT 31200
CONNECT 33600
NO ANSWER
CONNECT 2400
9*
* With MNP error correction on, RELIABLE (or R) is added to these result codes. With LAP-M error
correction on, LAP-M (or L) is added to these result codes. With data compression on,
COMPRESSED (or C) is added. (Note these "Extended" Result Codes are displayed when your
modem is set up to do so with an X1, X2, X3, or X4 command.)
"Standard AT" Result Codes
TERSE
VERBOSE
TERSE
VERBOSE
0
1
2
3
4
5
6
7
8
10
OK
CONNECT
RING
NO CARRIER
ERROR
CONNECT 1200
NO DIALTONE
BUSY
11
12
13
19
21
24
26
28
31
33
CONNECT 4800
CONNECT 9600
CONNECT 14400
CONNECT 19200
CONNECT 21600
CONNECT 24000
CONNECT 26400
CONNECT 28800
CONNECT 31200
CONNECT 33600
NO ANSWER
CONNECT 2400
*Reliable/Compression modifiers are not displayed with Standard AT Result Codes.
26
Chapter 4 - Command Mode
4.4 Dialing Commands
4.4.1
Dialing Action Commands
Dial Command D
The letter D in a command causes the modem to dial the telephone number immediately following it.
For example, if you enter ATD5551212 and hit RETURN, the modem dials the number 555-1212.
The D command is also used in conjunction with a telephone set for manual dialing. You dial the
number on your telephone set, and after hearing the answer tone on your handset, you type ATD on
your keyboard and hit RETURN. Then hang up the headset. Unless you have a specific need to dial
in this manner, we recommend you use the first method, where the telephone number is entered on
your keyboard.
The modem gives you several choices of dialing methods. You can use tone or pulse dialing, by
inserting a letter T or a P in the command string.
You can also configure the modem to either wait for and detect dial tones and busy signals (which we
call “Wait-for-Dial-Tone” dialing or “Smart” dialing), or work with timed pauses without dial tone and
busy signal detection (which we call “Blind” dialing; see Section on “X” Command.)
Note: There is another method of dialing, called “DTR Dialing”, where by manipulating the DTR
signal on pin 20 of the RS-232C/V.24 interface, a number stored in the modem's memory is
automatically dialed. See description of $D command (in this section) for details.
Continuous Redial (not used in BAI) A: or :
If you select the Wait-For-Dial-Tone method of dialing (see X3 or X4 command), you can command
the modem to continuously redial (up to 10 re-dials for DOC units) a busy number until your call is
answered. This is done with the A: command.
This command would be used only if you had already reached a busy number after executing a
normal dial command. You simply enter A: (you need not enter AT, nor do you need to hit RETURN),
and the modem will redial the number for you. If you again reach a busy signal, it re-dials again and
again until it no longer detects a busy signal. You can stop the modem from re-dialing by pressing
any key.
Another method used to cause the modem to redial a phone number continuously is to enter a colon
: at the end of the phone number. The result is the same as if you had entered A: after personally
observing that the number was busy on the first dialing attempt. Using the colon in the dialing string is
a step saver.
Dialing a Stored Number N
A telephone number that you have stored in the modem’s number memory may be automatically
dialed by entering ATNn where n = 0, 1, 2, 3, 4, 5, 6, 7, 8 or 9. For example, a number stored at N3
would be dialed by entering ATN3 and RETURN. Do not include the letter D in this command, or the
stored number will be erased.
27
MultiModemBA User Guide
DTR Dialing $D
An alternate method of causing the modem to automatically dial is DTR Dialing. Data Terminal Ready
(DTR) is a signal that comes into the modem from the terminal or computer to which it is connected,
on pin 20 of the RS-232C interface. In DTR dialing, the modem automatically dials a stored number
as soon as it receives a high DTR Signal. The DTR dialing method is popular in synchronous
applications.
To activate DTR Dialing, enter AT$D1 and hit RETURN. The modem dials the phone number stored
in the N0 location of memory when it receives a high DTR signal. DTR must remain high for the
duration of the call, until disconnect. To deactivate DTR dialing, enter AT$D0 and hit RETURN.
Note when using DTR Dialing in a synchronous application, be sure DIP-Switch #8 is in the UP
position to disable V.25bis Command mode.
Voice/Data Dialing $VD
Another alternate method of causing the modem to automatically dial is Voice/Data Dialing. With
Voice/Data Dialing, the modem automatically dials the phone number stored in the N1 position of
memory whenever the Voice/Data switch is toggled. You must first enter AT$VD1&W0<CR>. This
command string enables Voice/Data dialing when the Voice/Data toggle switch is activated. To
disable Voice/Data Dialing (default), enter the command AT$VD0 W0<CR>.
4.4.2
Dial Modifier Commands
There are several command characters that can be included within a dialing command (following the
letter D), called “Dial Modifiers”. They have various functions, including the selection of Pulse or Tone
Dialing, pauses in the dial sequence, automatic re-dials if a number is busy, and reverting to the
Command mode or switching to the Answer mode after dialing.
Pulse or Tone Dial P T
The modem dials numbers using either pulse or tone dialing, or a combination of both methods.
Pulse dialing is a method used by rotary-dial telephones, which involves the timed opening and
closing of line relay.
Tone dialing is the method used by push-button (touch tone) telephones, and is sometimes referred
to as DTMF, or Dual-Tone Multi-Frequency dialing.
The method used is selected by including a P for Pulse or a T for Tone in the dialing command, right
before the digits you wish to have dialed in that manner.
For example, you would pulse-dial the number 555-1212 by entering ATDP5551212 and hitting
RETURN. You could tone-dial the same number by entering ATDT5551212 and hitting RETURN. If
neither Pulse nor Tone dialing is specified in the dial command, the modem uses whatever method
used last. If the modem has been reset or just powered up, it uses Pulse dialing, even if the letter P is
not included in your dial command.
Nearly all telephone systems in the U.S. are now compatible with tone dialing. Since that is the faster
method, you will probably choose the tone method for your dialing.
An example of combining pulse and tone dialing could involve a PBX system where 9 had to be
pulse-dialed first, then the rest of the number tone-dialed after pausing for a second dial tone. The
number would be dialed by entering ATDP9, T5551212 and RETURN. (The comma causes a pause,
which we’ll explain soon.)
28
Chapter 4 - Command Mode
Set Pulse Dial Ratios &P
This command sets the time ratios between the open and closed portions of the dialing pulse
frequencies. To set the dialing pulse ratio of 60 mSec to 40 mSec, enter AT&P0. To set a ratio of 67
mSec to 33 mSec, enter AT&P1. The factory default is &P0.
Automatic Pauses in Dialing ,
You can cause the modem to pause during the dialing sequence by entering a comma character
where the pause is desired. This pause lasts two seconds. If a longer pause is desired, more than
one comma may be entered consecutively, with each comma causing a two second pause. You also
have the option of changing the length of the pause caused by the comma, from two seconds to any
other value from 0 up to 255 seconds. This is done by setting S-Register S8 (refer to Chapter 6).
Each comma in a dialing command counts as one of the sixty allowed characters.
Long Space Disconnect Y
When two modems are connected in Normal mode (i.e. without error correction) there is no "polite"
means of requesting a disconnect. A link disconnect request packet is sent under reliable
connections. As a result some "garbage" may be received when a hang-up command is issued. The
Y1 command enables the modem to use the break signal which accomplishes the hang-up as an
instruction to shut off its receiver and disconnect (both modems must have Y1 enabled for this
feature to be effective). Y0 (factory default) disables this function.
Wait for New Dial-Tone W
A W inserted in the dialing command causes the modem to wait for another dial tone, and not resume
dialing until another dial tone is detected.
It is not necessary to enter a W at the beginning of the dialing command to wait for a modem dial
tone, because the modem will do that first (pause automatically).
In order for this command to work, you must select Wait-For-Dial Tone dialing with the X2 or X4
command, so that your modem will be able to detect the dial tone.
Return to Command Mode After Dial Command Execution ;
A semicolon (;), entered as the last character of a dialing command causes the modem to return to
the Command mode immediately after executing the command, instead of waiting for a carrier signal
and going on line.
For example, entering ATDT5551212; would tone-dial the number, and do nothing afterwards except
go back into Command mode. This can be useful in dialing applications where modem data transfer
is not desired, such as voice communications, or in applications involving the use of touch tones as a
data entry method, such as bank-by-phone.
Reverse the Mode of Operation R
In certain operations you may need to reverse the mode of operation for your modem from originate
to answer or answer to originate so that it would answer the phone and go into answer mode. This
command turns off the reversing function with the R0 command and turns it on with the R1 command
with the modem in either command mode. If you want to reverse from the originate mode, use R (with
no number) in the dialing string.
29
MultiModemBA User Guide
Flash On Hook !
Some switchboard systems react to a momentary On Hook. An exclamation mark inserted in the
command causes the modem to “flash” on hook for a half of a second, as if you had held the switch
hook button on a telephone down for a half second.
For example, to flash On Hook after dialing the number 555-1234 in order to transfer to Extension
#5678, you might enter ATDT5551234,,!5678. The commas cause a 4 second pause (just to be
safe).
"Calling Card" Detect Tones $
The modem has the capability to detect AT&T "calling card" tones for the purpose of utilizing the
user's calling card number to originate an on-line connection. An $ symbol placed in the dialing string
causes the modem to pause and wait for an AT&T "calling card" or a 1600 Hz tone (prevalent in the
United Kingdom). When the tone is detected, the rest of the dialing string is processed. If no tones
are detected within the time period set by S-Register S7 (default 45 seconds), the modem will abort
by indicating a NO CARRIER message. Hitting any key also aborts the $ command.
The following is an example of this command:
ATDT1028806127853500$123456789
(access/phone number) (credit card number)
Quiet Answer @
The @ command causes the modem to wait before processing the next symbol in the dialing string.
The wait is for one or more ringbacks followed by 5 seconds of silence. If the time specified by S-
Register S7 passes before the rings and silence, a NO ANSWER (R) result code is processed. The
@ command is used for accessing a system that does not provide a dial tone.
For example, ATDT5551212@6313550 causes the modem to dial the first number (555-1212) and
wait for the time specified in S7 for at least one ringback and 5 seconds of silence. If a busy signal is
detected, the modem hangs up and generates a BUSY result code. If it does not detect 5 seconds of
silence, a NO ANSWER result code is generated after hanging up. If 5 seconds of silence is
detected, the second number (631-3550) is then dialed.
4.4.3
Phone Number Memory Commands
Storing Phone Numbers D...N
A telephone number and command line of up to sixty characters may be stored in the modem’s
number memory. As many as ten of these numbers may be stored. Each number will be given a
name, using the codes N0, N1, N2 up to N9.
A phone number is stored by entering ATD, then the number as it would be dialed, along with any P,
T, R, ; or comma characters, and then entering N followed by the number’s “name,” which would be
any number from 0 through 9, and then hitting RETURN.
For example, the tone-dialed number 1-612-631-3550 would be stored as number N3 by entering
ATDT16126313550N3 and RETURN. The number is not dialed with this store command. After
storing a number, check to see that it has been stored correctly by typing ATL and hitting RETURN.
When phone numbers are stored, the entire command line is also stored so that you can effectively
create a macro for each number. For example, if you know a particular number needs to have
extended result codes, detect busy or dial tone, error correction, Xon/Xoff flow control, pacing, and
data compression enabled, the command line would be:
ATX4&E1&E5&E13&E15DT16126313550N3. This would store the entire command at location N3.
30
Chapter 4 - Command Mode
Number Linking NN
You may command the modem to dial another number automatically if the first number dialed is
busy. This would be useful in a situation where a computer can be accessed through more than one
phone number. This is called “linking”.
To link the number in N1 to the number N2, simply enter ATN1N2 and hit RETURN. Several numbers
can be linked in the same command. For example, you could link N1 to N2 to N3 to N4 by entering
ATN1N2N3N4 and RETURN or you could link N1 to N2 and back to N1 and then back to N2 by
entering ATN1N2N1N2 and RETURN.
The only limit on the number of numbers that can be linked is the 60 characters allowed in a
command line. Number linking can not be used with blind dialing, since busy signals would not be
detected. You would have to select the Wait-for-Dial tone dialing method using the X Command in
order to use the Number Linking feature.
Listing Numbers Stored in Memory L
Telephone numbers that you have stored in the modem’s memory may be listed and displayed with
the L command. It will display all ten stored N numbers in a format like that shown below. All digits
and command letters will be shown. The number’s “name” (0 thru 9) is shown first, followed by the
complete dialing command and telephone number as originally entered.
Simply enter ATL and hit RETURN to display these numbers on your video screen or printer. An
example of an L command listing is shown below:
0
1
2
3
4
5
6
7
8
9
DT14082345678
DT16125551212;
DP9,T14089876543
DT3738315,12101,16126313550
DT6313551R
DP9,4258513
DTX4&E1&E5&E13&E15DT16126313550
DT12138880123
4.4.4
Configuration and Default Storage Commands
Store Configuration & S-Register Parameters in Non-Volatile Memory &W
The modem can store configuration parameters and S-Register values in its nonvolatile read/write
Random Access Memory (RAM) memory. The &W command does this, which prevents any re-
configuration from being lost on a power-down or Reset (ATZ) condition.
&W0 (or AT&W) causes the modem to store your customized AT command settings and S-Register
values in its nonvolatile RAM. &W0 also sets the modem so that it reads your customized settings
stored in nonvolatile RAM when powered down or reset. (The &W0 command only changes the
settings stored in nonvolatile RAM that you specifically intend to alter. All other default parameters
are applicable.)
&W1 causes the modem not to store your customized settings to nonvolatile RAM so that, after
powering down or resetting the modem, it reads the factory default settings stored in ROM.
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MultiModemBA User Guide
Loading Factory Defaults &F
The &F command provides a choice between customized configuration settings in RAM and the
factory default configuration settings in ROM. The &F8 and &F9 commands define the function of the
&F command.
The modem is shipped from the factory with a pre-configured set of command and S-Register default
settings. This set of factory defaults can be recalled by issuing the &F command.
In addition to being able to recall the factory-installed defaults, the &F command can also recall those
defaults stored under &W0.
This is done using the &F9 command. If you have stored parameters with the &W0 command and
wish these settings to always be used as your defaults, you would enter &F9&W0.
To return the &F command to read factory installed defaults, enter &F8&W0. &F8 is the factory
default.
Many datacomm program issue the &F command automatically- the &F9 command allows the user
to select their own factory defaults. Note that the &F8/&F9 commands should be used with &W0.
Following is a summary of how the &F and Z reset commands interact with the &W command; note
how the &F reset command operates differently from the Z reset command:
Previous Command AT&F
Power-On and ATZ
AT&W1 (default)
AT&W0
AT&F8&W0
AT&F9&W0
ROM
ROM
ROM
NVRAM
ROM
NVRAM
NVRAM
NVRAM
Modem Reset Z
The Z command can be used to reset the entire Command Mode buffer and the result is the same as
if you had disconnected, and then reconnected power to the modem. When an ATZ command is
executed, the state of the &W command determines where the default values originate. &W0 defaults
come from RAM and &W1 defaults come from ROM.
Unix UUCP Spoofing $SP
The modem can be configured in a Unix environment that employs ACK flow control as a means of
monitoring data integrity. The modem can do “UUCP spoofing”, where the modem is able to generate
ACKs at the DTE interface. Data is transmitted more time efficiently because the delay of waiting for
data to be received, then for an ACK to be returned at the remote end, is eliminated. The $SP1
command enables UUCP spoofing and the default command $SP0 disables UUCP spoofing.
Async/Sync Mode Switching &M
This command can be used to set the on-line mode to either synchronous or asynchronous. AT&M0
will set the modem to Asynchronous mode, and all communications will be Asynchronous, in both
On-line and Command modes. AT&M1 causes the modem to communicate asynchronously when in
Command mode and switch to synchronous mode while on-line. The modem defaults to &M0
(asynchronous communications) on reset or power-up.
Synchronous Transmit Clock Select &X
The &X command selects the Synchronous Transmit Clock Source in conjunction with DIP-Switch
#11. DIP-Switch #11 in the UP position enables External clocking. DIP-Switch #11 in the DOWN
position enables Internal clocking (default position). External clocking is when the DTE provides
transmit clocking to the modem on pin 24 of the RS-232C interface.
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Chapter 4 - Command Mode
&X0 is the default setting, which allows DIP-Switch #11 to control Internal/External Clocking (default
Internal). Internal clocking is when the modem provides transmit clock to the DTE on pin 15 of the
RS-232C/V.24 interface. The &X1 command overrides DIP-Switch #11 and selects External clocking.
If DIP-Switch #11 is UP (External clocking), you can not override Internal clocking. &X2 enables
Slave Clocking. The &X2 Command causes the modem to generate the transmit clock timing (pin 15)
from the receive clock (pin 17) from the DTE (therefore 15 and 17 are the same). In this mode (Slave
Clocking), all timing is controlled by the receive clock.
4.4.5
Command Response (Result Code) Commands
Echo Command Mode Characters E
If the modem is connected to a full-duplex computer, it may be necessary for the modem to be
configured to echo back characters entered while in the Command Mode in order for them to be
displayed. The E command is used to configure the Command Mode echo, with ATE0 disabling the
echo and ATE1 enabling the echo (default).
Result Codes Enable/Disable and No Response Answer Q
The Q command enables or disables Result Codes and the No Response Answer mode of operation.
Result Codes may be disabled altogether in certain applications, such as computer-controlled auto
dialing, using the Q command. ATQ1 disables Result Code transmissions. ATQ0 (or ATQ) enables
Result Code transmission.
Regarding No Response Answer, you may want the answer mode handled without responses and
echo turned off, but want the originate mode still intelligent. This is called the No Response Answer
mode. ATQ2 selects the No Response Answer mode. If you do not select any mode, the factory
default setting (enable Result Codes) is automatically selected.
Result Codes ("Multi-Tech" or "Standard AT") &Q
The modem gives you a choice between the Multi-Tech Result Codes, and Result Codes that more
closely match the standard AT command set responses.
AT&Q1 selects AT responses with no Reliable/Compression modifiers. With this command, the
terse result code for CONNECT 2400 is 10.
AT&Q0 selects Multi-Tech responses with Reliable/Compression modifiers. With this command, the
terse result code for CONNECT 2400 is 9.
Result Codes (Verbose/Terse) V
The V command controls whether the modem’s result codes are displayed as word (“verbose”) or
single digit (“terse”) messages.
For example, if after dialing, no carrier signal is detected, the resulting message can be displayed
either as NO CARRIER, or as the digit 3.
Entering ATV0 (or ATV) causes the modem to display the Result Codes as digits, while ATV1
displays them as words. If you do not select a method, the factory default setting causes the modem
to display Result Codes as words.
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MultiModemBA User Guide
Result Codes (Basic and Extended) and Call Progress Selection X
The X Command is used to select one of two possible dialing methods (“dumb” or “smart”), and to
select various response combinations related to these methods. You can choose to have certain
responses suppressed, or whether or not you want speed indications along with the CONNECT
responses. You can also pick and choose certain responses in order to match up with “Standard AT”
responses.
The modem provides “Basic” and “Extended” Result Code sets. The difference between the two is
the Basic set provides one response (CONNECT) to indicate a connection, while the Extended set
provides several responses for different speeds (CONNECT, CONNECT 2400, CONNECT 4800,
CONNECT 9600, Etc.).
When the Extended set is chosen, you also have the option of matching them up with Standard AT
2400 response code sets, by including or not including the BUSY and/or NO DIAL TONE
responses while excluding the DIAL TONE response. The X command is used to select which
responses are provided.
Regarding the modem’s method of dialing, the modem can detect standard dial tones and busy
signals. This capability (“smart dialing”) allows the modem to wait for a dial tone, and when one is
detected, to begin dialing immediately.
The modem also can detect a distant busy signal, if after dialing, it reaches a busy number. This is
useful because it allows the modem to immediately abandon a call, rather than wait 45 seconds for a
carrier signal that will never come. S-Register S7 defines the wait for carrier time (refer to Chapter 6).
The modem gives you a choice between the wait-for-dial-tone (“smart”) method we just described,
and blind (“dumb”) dialing, where instead of detecting actual dial tones, the modem relies on timed
pauses. When the wait-for-dial-tone method is chosen, the busy signal detection capability is also
activated. The X command is also used to select which dialing method is used.
Five different X commands are available (X0 through X4), with five different effects on the modem’s
Result Codes.
X0 Provides the basic (short) result codes and provides “dumb” dial capabilities.
X1 Provides the extended result codes and provides “dumb” dial capabilities.
The remaining X commands affect Call Progress, and turn on Extended Result Codes.
X2 Looks for dial tone only and will not provide a busy response.
X3 Looks for busy only and not look for dial tone.
X4 Looks for dial tone and for busy.
The factory default setting is X0, which selects Basic Result Codes and the blind (“dumb”) method of
dialing.
4.4.6
Phone Line Conditioning Commands
Guard Tones (Not Used in BAI Models) &G
The &G command is used to control the presence or absence of guard tones from the transmitter
when in Answer mode, at either 1200 or 2400 bps. Guard tones are used in Europe and other areas
for the modem to function in the telephone systems. Guard tones are not used in the United States.
&G0 (default), turns off CCITT guard tones. &G1 turns on 550 Hz guard tones. &G2 turns on 1800
Hz guard tones. This command is not used in international models.
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Chapter 4 - Command Mode
Bell/V.21 Tone
B
The B command selects the frequency that the modem uses for its answer tone. (The answer tone is
the tone transmitted by a modem receiving a call to the modem that called it, which initiates the
handshaking between the two modems.) At higher speeds there is no conflict, because all use CCITT
frequencies. At lower speeds (0-1200 bps), in the U.S., some modems use the Bell frequency of
2225 Hz. However, the CCITT specification for V.22 has an answer tone frequency of 2100 Hz.
The ATB0 command enables CCITT frequencies including V.21 (300 bps) and V.23 (1200/75 bps).
The ATB1 command enables Bell frequencies including Bell 103 (300 bps). The modem default is
ATB0.
Phone Line Monitoring Speaker M
The modem has an internal on-board, speaker which functions like the speaker in a telephone
handset to enable you to monitor phone line activity. The M command can be used to determine
when the speaker is operational.
Entering ATM0 disables the speaker completely, while ATM1 causes the speaker to be on only until
a carrier signal is detected. ATM2 causes the speaker to remain on at all times. ATM3 causes the
speaker to be on during dialing and off during handshake. ATM1 is the default setting, and the one
that should be used in most applications.
Enable or Disable Recognition of Remote Digital Loop Signal &T
The modem has several self-test features (covered in Chapter 8). The tests are activated with
different U commands, such as ATU1, and so forth. The &T command is a phone line conditioning
command that enables or disables the modem’s ability to recognize the Remote Digital Loop (RDL)
test signal.
The AT&T4 command lets the modem respond to a RDL signal, and places itself in digital loop. The
AT&T5 command causes the modem to ignore the RDL signal. The factory default is &T5.
Enable/Disable Trelis Coded Modulation #T
This command enables or disables the Trellis Coded Modulation of the modem. There is usually no
need to disable (turn off) Trellis codings except under an unusual line condition called impulse noise.
AT#T0 turns Trellis coding off and AT#T1 turns Trellis coding on (factory default).
Fallback Modes When On-Line #F
If line conditions deteriorate, the modem automatically drops its transmission speed (“fallback”). The
#F command controls the different ways the modem falls back. During operation, if the error rate
becomes too great, the modem performs a retrain. If after the retrain, the error rate is still too high for
33600 bps operation, the modem initiates a retrain at 4800 bps. If after the first retrain the modem
returns on line at 33600 bps , the modem then starts a counter and a timer. If three retrains occur
within a two minute period, the modem falls back to 4800 bps.
Entering AT#F0 (or AT#F) allows no fallback when on-line.
AT#F1 allows the modem to fallback (based on the error rate or if three retrains have occurred within
a two minute period) from:
33.6K to 31.2K to 28.8K to 26.4K to 24K to 21.6K to 19.2K to 16.8K to 14.4K to 12K
to 9.6K to 4.8K bps.
The AT#F2 command enables incremental fall back, but also enables incremental fall forward if the
phone line improves. AT#F2 is the factory default setting.
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MultiModemBA User Guide
Enable/Disable Lowspeed Fast Connect $FC
Entering AT$FC0&W0<CR> sets up the data pump so that it will not transmit a 5 second 2100 Hz
signal. Entering AT$FC0&W0<CR> allows the modem to transmit a 5 second 2100 Hz signal and is
the factory default.
Cleardown at Disconnect &CD
The &CD command is used for control of cleardown at disconnect in V.32, V.32bis, V.34 and V.34
enhanced modes.
A cleardown usually adds 1-2 seconds to the time it takes for the modem to go on-hook after a
disconnect. A cleardown makes a disconnect by the remote modem easier to detect and a
subsequent re-connection more likely. Enter AT&CD0&W0<CR> to execute a cleardown at
disconnect (default); and enter AT&CD1&W0<CR> to disable the cleardown function.
Auto Speed Detect #A
The function of the #A command is to detect and select the operational data rates (the “starting”
speeds) with which the modem uses for initial handshake and speed selection.
Remember, this command does not control the originating data rate of the modem (that is done by
the Modem Baud Rate command $MBn), but only the Answer mode “starting” speeds.
Entering AT#A0 (or AT#A) causes the modem to operate starting at:
33,600 bps, with fallback to 28,800 to 19,200 to 14,400 to 9600 to 4800 to 2400 to 1200 and to 300
bps.
Entering AT#A1 causes:
33,600 bps operation only.
Entering AT#A2 causes the modem to operate at starting speeds of:
33,600 bps, with incremental fallback to 28,800, 19,200, 14,400, 9600 and 4800 bps.
The AT#A3 command causes the modem to begin operation as a V.22bis modem at 2400 bps, with
fallback to 1200 to 300 bps. AT#A0 is the factory default value.
4.4.7
RS-232C Interface Control Commands
Carrier Detect Control &C
The &C command allows you to control the status of the Carrier Detect signal (CD-Pin 8) on the RS-
232C line. You have four choices.
You can force the signal high, or allow it to act normally, or force the modem to reset when CD drops,
or set it to stay high until the modem disconnects, go low momentarily, and then go high again. The
last option is useful with some CBX phone systems and mainframe front ends, which require CD to
act in this manner.
To allow CD to act normally, enter the command AT&C1 (the factory default setting). To force CD on,
enter AT&C0. To reset the modem to its current parameters when CD drops, enter AT&C4. To set
up CD so that it drops for one second on disconnect and then comes up again, enter AT&C2. (If you
want the drop time to be something other than one second, use S-Register S24 to change this value.
Refer to the Chapter 6 instructions for S24.
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Chapter 4 - Command Mode
Data Terminal Ready Control &D
Data Terminal Ready (DTR) on pin 20 of the RS-232C interface is required in order for the modem to
operate. A high DTR signal tells the modem that the device to which it is connected is active, or
"ready" to communicate through the modem. If the signal is not being provided on the RS-232C
interface, you can force DTR high with DIP-Switch #1.
DTR has some other modem functions. DTR can be used to trigger a dialing sequence, called DTR
Dialing. The condition of DTR can also be used to cause the modem to reset to its default
parameters, just as if you had given the modem an ATZ command. To do this, enter the command
AT&D3 and hit RETURN.
The modem will now reset itself whenever DTR is dropped from On to Off, and will also go on-hook
(hang up) if it is on-line.
Entering AT&D0 or AT&D causes the modem to ignore DTR. Entering AT&D1 causes the modem to
go on-hook (hang up) with loss of DTR. The modem enters Command mode when DTR goes high
again. Auto-answer is disabled while DTR is low. Entering AT&D2 causes the modem to go on hook
with loss of DTR. The modem enters command mode when DTR goes high again.
CTS Control &R
The &R command allows you to control the Clear to Send signal (CTS-Pin 5) on the RS-232C
interface. You have three choices. You can force the CTS signal high, allow it to act normally, or set it
to stay high until the modem disconnects, go low momentarily, and then go high again. The last
option is useful with some CBX phone systems and mainframe front ends, which require CTS to act
in this manner.
To allow CTS to act normally, enter the command AT&R0. To force CTS on, enter the command
AT&R1 (this is the factory default setting). When the modem goes on-line, CTS still provides flow
control. To set up CTS so that it drops for one second on disconnect and then comes up again, enter
the command AT&R2. (If you want the drop time to be something other than one second, use S-
Register S24 to change this value.
Data Set Ready Control &S
The &S command allows you to control the status of the Data Set Ready signal (DSR - pin 6) on the
RS-232C interface. You have three choices. You can force the signal high, allow it to act normally, or
set it to stay high until the modem disconnects, go low momentarily, and then go high again. The last
option is useful with some CBX phone systems and mainframe front ends, which require DSR to act
in this manner.
To allow DSR to act normally, enter the command AT&S1 (the default setting). To force DSR on,
enter the command AT&S0. To set up DSR so that it drops for one second on disconnect and then
comes up again, enter AT&S2. If you want the drop time to be something other than one second, use
S-Register S24 to change this value.
CTS/RTS Interaction Control &RF
In typical operation, Clear to Send follows Request to Send when the modem is on-line. In other
words, if RTS goes off, CTS goes off in response. The &RF0 command enables CTS to follow RTS.
In some applications, however, it may be necessary for CTS to operate independent of RTS. &RF1
allows CTS to operate independently regardless of the state of RTS, and is the factory default. If this
is the case, refer to the &R command for control of the Clear to Send signal.
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MultiModemBA User Guide
DSR/CD Interaction Control &SF
In typical applications, Data Set Ready (DSR) follows Carrier Detect (CD). &SF0 enables DSR to
follow CD, and is the factory default. &SF1 enables DSR to operate independent of CD. If this is your
application, refer to the &S command for control of the Data Set Ready signal.
4.4.8
Error Correction Commands
You can use AT commands to place your modem one of three V.42 (error correction) modes of
operation. These are the Normal, Auto-Reliable, and Reliable modes.
Normal Mode &E0
In Normal mode of operation, the modem’s V.42 error correction capabilities are disabled, and the
modem functions as a non-error-correcting modem.
Auto-Reliable Mode &E1
In Auto-Reliable mode during the handshaking procedures at the start of the on-line connection, the
modem automatically determines whether or not the modem with which it is communicating is using
V.42 error correction. If the modem determines that the other modem is using V.42, it switches itself
into MNP or LAPM Reliable (V.42) mode and its error-correction capability is enabled. If it is
determined that the other modem is not using V.42, the modem remains in Normal mode, without
error correction. The default setting is Auto-Reliable mode (&E1).
The method the modem uses to determine if the modem it calls is a V.42 modem involves the use of
a “Link Request”.
When the modem is in Auto-Reliable mode and originates a call, it goes through normal handshaking
procedures just like any dial-up modem. After establishing the on-line connection, the modem
transmits a Link Request message to the answering modem. (The Link Request message is
generally about 33 coded characters.) If the answering modem replies with an appropriate V.42
acknowledgment response, the modem switches into Reliable mode. Otherwise it stays in Normal
mode. This V.42 Link Request handshaking procedure generally takes about five seconds.
When operating in V.42 Reliable mode, the modem uses its memory, or buffer, to store data as it is
received. During periods of error-caused retransmissions or compression slowdowns, this buffer may
fill up. To prevent buffer overflow and subsequent loss of data, the modem uses "flow control" to
signal the computer attached to its RS-232C port that the modem buffer is close to being full. This
causes the computer to pause in its data transmission until the modem is able to empty its buffer
sufficiently to accept more data, at which time the modem signals the computer that it may resume
transmission.
Reliable Mode &E2
In Reliable mode, the modem uses its V.42 error correction capabilities during all transmissions, and
must be connected to another modem with a similar protocol activated (MNP or LAP-M).
V.42 Mode Select #L
The V.42 standard implements both MNP Class 3 & 4 and LAP-M error correction methods. The V.42
Mode Select command (#L) selects which type of error correction (MNP or LAP-M) your modem
uses for transmissions.
The various #L command options are as follows.
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Chapter 4 - Command Mode
#L0 Command
The #L0 Command allows a pair of modems to negotiate which V.42
mode (MNP or LAP-M) will be used in their transmissions.
Originate Mode
a. If both modems have LAP-M capability, the modems use LAP-M
mode.
b. If one or both modems do not have LAP-M capability and both
have MNP, the modems use the MNP mode.
Answer Mode
a. The answering modem responds to either an MNP Link Request
or LAP-M Originator Detection Pattern (ODP) signal depending on
which the originating modem issues.
#L1 Command
#L2 Command
#L3 Command
The #L1 Command sets your modem to MNP error correction and
disables LAP-M. This command is for Originate mode only. In
Answer mode, the modem still accepts MNP or LAP-M.
The #L2 Command sets your modem to LAP-M error correction, and
disables MNP. This command is for Originate mode only. Answer
mode still accepts MNP or LAP-M.
In the prior commands, the modems use a two phase process to
establish a V.42 connection (detection to establish whether the
remote modem is also error correcting, and then protocol
establishment to determine parameters and to establish the error
correction connection). If you know that the other modem is a V.42
error correcting modem, and you wish to use LAP-M, the #L3
command disables the detection phase and goes directly to protocol
establishment. Both modems must have #L3 in effect.
Auto-Reliable Buffering $A
In Auto-Reliable mode, the modem is given four seconds to establish a Reliable connection. After this
four-second period, the modem drops to Normal mode. Any data which is received during this period
is typically discarded. The $A command can be used to cause the modem to buffer (save) data that
is received during this Auto-Reliable time-out period. This data will then be output by the modem after
the CONNECT message.
AT$A0 = Discard data received during auto-reliable time period.
AT$A1 = Buffer data received during auto-reliable time period.
The factory default is $A0.
Enable/Disable Auto Reliable Fallback Character $F
In Auto-Reliable mode, the modem is given four seconds to establish a Reliable connection. If a
single CARRIAGE RETURN is received from the remote modem during this four second period, the
Auto-Reliable modem assumes that the remote modem is not in Reliable mode and drops to Normal
(non-error correcting) mode. The CARRIAGE RETURN is the only character which causes the
modem to drop to Normal mode. Any other character will either be buffered or discarded.
The $F command can be used to disable this fallback-to-Normal-due-to-CARRIAGE-RETURN
feature.
The Auto-Reliable fallback character ($F) and Auto Reliable buffering ($A) commands can be used
together to cause the modem to buffer all data received up until the CARRIAGE RETURN, and then
drop to Normal mode. All data received will then be output following the CONNECT message.
AT$F0 = Do not fall back to Normal if CARRIAGE RETURN received.
AT$F1 = Fall back to Normal mode if CARRIAGE RETURN received.
The factory default is $F0.
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MultiModemBA User Guide
Retransmit Count $R
If errors are received during a Reliable connection, the modem re-sends the block of data which
contained an error. With the $R0 command, if another error occurs, the block will be re-sent again.
The modem counts the number of times that a data block is re-sent. If the same block of data is
resent 12 times and still has not been received properly, the modem assumes that the transmission
line is unsuitable for transmission, and abort the connection.
This retransmit counter is disabled by the $R1 command. When the retransmit counter is disabled,
the modem keeps trying to send data and will not abort, no matter how many times the same block is
resent.
AT$R0 = Disconnect if retransmit count is exceeded.
AT$R1 = Do not disconnect due to retransmits.
The factory default setting is $R0.
V.42 Error Correction/300bps $E
At 300 bps, error correction is not typically used. $E1 lets the modem function at 300 bps in either
Normal (&E0), Auto-Reliable (&E1) or Reliable (&E2) mode. $E0, which is the modem’s default,
disables 300 bps/V.42 error correction altogether.
AT$E0 = No V.42 Error correction at 300 bps.
AT$E1 = V.42 Error Correction at 300 bps.
The factory default setting is $E0.
4.4.9
Flow Control Commands
Flow control refers to the techniques used by computer devices to stop and restart the flow of data to
and from each other. Flow control is necessary so that a device does not receive more data than it
can handle. In the case of the MultiModem, there is a need for flow control in both directions. As
illustrated on the next page, flow control for data passing from your computer to the modem is called
Modem-Initiated Flow Control and flow control for data passing from the modem to your computer is
called Computer/Terminal-Initiated Pacing.
The MultiModem supports both hardware and software Modem Initiated Flow Control. On the
Computer/Terminal-Initiated Pacing side, it supports hardware and software flow control, and a
special version used by Hewlett-Packard compatible systems called ENQ/ACK Pacing. The modem
allows hardware and software pacing to be passed through the modem to the other end of the link so
that your computer or terminal can control data start/stop activity through your modem.
This is called Xon/Xoff Pass-Through. To state it simply, “Flow Control” is something the modem
does to the computer, while “Pacing” is something the computer does to the modem.
Modem-Initiated Flow Control
Computer
or
Terminal
RS-232/V.24
Data Flow
Modem
Computer-Initiated Flow Control Pacing
Computer
or
Terminal
RS-232/V.24
Modem
Data Flow
Figure 4-1. Flow Control and Pacing
40
Chapter 4 - Command Mode
Hardware Flow Control &E4
With Hardware Flow Control, the modem uses its RS-232C interface to control the flow of data from
the computer or terminal to which it is attached. The CTS (Clear to Send) signal on Pin 5 of the RS-
232C interface is brought low to stop the flow of data, and is brought high to restart it. When you
select Hardware Flow Control as your Modem Initiated Flow Control method, you will also be
selecting it for Pacing.
The difference between the two, however, is that Modem-Initiated Flow Control uses the Pin 5 CTS
output signal, while Pacing uses the Pin 4 RTS input signal.
Modem commands are used to select the method of flow control used by the modem when its error
correction capabilities are used. If neither method is selected, the modem defaults to no flow control
(&E3).
Xon/Xoff Flow Control &E5
Xon/Xoff is the most commonly used method of flow control. Under this method, control characters
known as “Xon” and “Xoff” are inserted by the modem into the data to start and stop the flow of data
from the computer or terminal to which the modem is attached. Xoff, which is a Control-S, stops the
flow of data, and Xon, which is a Control-Q, restarts it. With regard to Binary Data, Xon/Xoff flow
control is not recommended because an Xoff character may be part of the data and would trigger an
Xoff of the modem or software package, which would halt data flow.
Xon/Xoff Pass-Through &E7
So far, you have had three choices to make regarding pacing:
1. You can set the modem to respond to Xon/Xoff pacing.
2. You can set the modem to respond to RTS pacing.
3. You can set the modem to ignore pacing completely.
Well, we’re not done with pacing yet. There’s another choice you can make (which actually can apply
to both pacing and modem-initiated flow control, although it applies mainly to pacing) and that is
something called Xon/Xoff Pass-Through.
This means that if your modem is set to respond to Xon/Xoff commands, you can have the modem
do one of the following:
1. The modem responds to the Xon and Xoff pacing commands while at the same time allowing
these commands to pass through the modem and on to the remote location. We call this
“Respond, Pass-Through”.
2. The modem responds to Xon/Xoff pacing, but does not allow the pacing signals to pass through
the modem and on to the remote location. We call this “Respond, No Pass-Through”.
When Xon and Xoff commands are allowed to pass through the modem, the computer or terminal at
the remote site will receive these commands, and depending on how it is configured, the computer or
terminal may respond to them also.
When two MultiModems are connected in Normal mode (not using error correction), Xon/Xoff can be
used to control the flow of data between the modems. Flow Control can be turned on or off with the
Normal Mode Modem Flow Control commands. When the modems are connected in Reliable mode,
a different method of modem Flow Control is used, and the commands for Normal Mode Modem
Flow Control are ignored.
When you are using Speed Conversion in Normal Mode, you must activate the modem’s Normal
Mode Modem Flow Control.
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MultiModemBA User Guide
Send Xon/Xoff Characters #X
The #X phone interface command allows the modem to send either a single or multiple Xoff
characters at the modem's buffer full level. When the modem’s buffer reaches it's "buffer full" level,
the next character received causes another Xoff to be sent for every character subsequently received
by the modem.
The AT#X0 command (factory default setting) causes one Xoff to be sent until the buffer reaches the
Xon level. The AT#X1 command causes an Xoff to be sent for every character received after the
modem reaches its buffer full level.
Hewlett-Packard ENQ/ACK Pacing &E9
If the modem is being used with Hewlett Packard (or similar) equipment that employs ENQ/ACK
pacing, the modem can be configured to respond to ENQ/ACK commands, making it compatible with
HP systems. Doing so does not affect any other flow control or pacing already configured in the
modem.
When configured for ENQ/ACK, the ENQ (Control-E) and ACK (Control-F) signals from the HP
equipment will be accepted and responded to according to Hewlett-Packard protocol.
Normal Mode Modem Flow Control On &E11
When two MultiModems are connected in Normal mode (not using error correction), Xon/Xoff can be
used to control the flow of data between the modems. Flow Control can be turned on or off with the
Normal Mode Modem Flow Control commands. When the modems are connected in Reliable mode,
a different method of modem flow control is used, and the commands for Normal Mode Modem Flow
Control are ignored.
When you are using Speed Conversion in Normal Mode, you must activate the modem’s Normal
Mode Modem Flow Control.
Terminal/Computer Initiated Pacing &E13
As mentioned earlier, the modem can initiate flow control by issuing Xon/Xoff commands or toggling
the CTS signal on the RS-232C interface. The modem can also be configured to react to similar
commands and signals from the computer or terminal to which it is attached via the RS-232C
interface. We refer to the computer or terminal initiated flow control as Pacing. When the modem is
set for Pacing On, the modem will respond to the terminal or computer pacing. When the modem is
set for Pacing Off, it will ignore pacing.
In order for the modem to be set for Pacing On, a modem-initiated method of flow control must be
previously selected. Once this is done, the modem will respond to either Xon/Xoff commands, or to
the toggling of the RTS (Request to Send) signal on Pin 4 of the RS-232C interface, depending on
what you selected earlier as your Modem-Initiated Flow Control method.
Maximum Block Size &BS
The maximum size of Reliable mode data blocks can be controlled with the &BS command. MNP 3
sends blocks of 1 to 64 characters. MNP 4 and 5 typically send blocks of 1 to 256 characters and
LAP-M typically send 128 characters. For MNP Classes 4 and 5/LAP-M, reducing the block size to
64 characters may give a smoother flow of data, and better throughput on noisy phone lines. Using
smaller block sizes over good phone lines may cause a slight loss in throughput (speed).
AT&BS0 = Maximum transmit block size of 64 characters
AT&BS1 = Maximum transmit block size of 128 characters (LAP-M) 256 characters (MNP)
The factory default setting is &BS1.
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Chapter 4 - Command Mode
Parity Selection #P
The #P command enables the setting of parity. AT#P0 selects no parity. AT#P1 selects odd parity.
AT#P2 selects even parity and is the default value. Note when setting up your data comm software, it
is critical that both your remote and local system's parity selection be set identically.
AT#P0 = no parity
AT#P1 = odd parity
AT#P2 = even parity
The factory default setting is AT#P2.
4.4.10 Compression, Error Correction, Flow Control, Pass-
Through and Pacing Commands
The modem has a variety of commands to control its error correction and data compression options.
These additional commands are listed below. (Remember to precede each command with the AT
characters.)
Normal/Auto-Reliable/Reliable Mode Commands:
&E0 = Normal Mode
&E1 = Auto-Reliable Mode*
&E2 = Reliable Mode
Modem-Initiated Flow Control Commands:
&E3 = Disables flow control (no flow control)
&E4 = Hardware flow control (CTS on/off and RTS on/off)*
&E5 = Xon/Xoff flow control
Xon/Xoff Pass-Through Commands:
&E6 = Modem responds to Xon/Xoff characters, but does not allow Xon/Xoff characters to pass
through to remote site.*
&E7 = Modem responds to Xon/Xoff characters, and allows them to pass through to remote site.
#X0 = Selects single Xoff character until Xon level returns*
#X1 = Selects multiple Xoff characters after buffer levels is full.
Enq/Ack Pacing Commands:
&E8 = Enq/Ack method of pacing off*
&E9 = Enq/Ack method of pacing on
Normal Mode Modem Flow Control Commands:
&E10 = Normal Mode Modem Flow Control off*
&E11 = Normal Mode Modem Flow Control (Xon/Xoff) on
Computer-or Terminal-Initiated Flow Control (Pacing) Commands:
&E12 = Pacing off*
&E13 = Pacing on (either RTS on/off or Xon/Xoff depending on the setting of &E4 or &E5).*
Data Compression Commands:
&E14 = Data Compression disabled
&E15 = Data Compression enabled*
*Factory Default setting
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MultiModemBA User Guide
4.4.11 Speed Conversion Commands
Speed conversion is a necessary part of data compression since data must be presented to the
modem faster than it can handle data, if data compression is to be effective.
Speed conversion allows the modem to communicate at one speed over the phone line, and at
another speed at the RS-232C interface. The speed (also referred to as “data rate” or “baud rate”)
can be fixed at the RS-232 interface independently of the baud rate of the on-line transmissions.
In addition to data compression, another popular application for speed conversion involves an auto-
answer MultiModem connected to a computer that does not have autobaud capability. This means
that the computer must be set at a fixed baud rate, regardless of the baud rate that the modem is
communicating over the phone line at. In this application, speed conversion allows the modem to
match its speed to that of the calling modem, while at the same time communicating with the
attached computer through its RS-232C port at a fixed baud rate, which can be pre-selected at 300,
1200, 2400, 4800, 9600, 19,200, 38,400, 57,600 bps or 115,200 bps.
Speed Conversion $BA
When using speed conversion, you must set the modem so that it does not adjust its speed at the
RS-232C serial port, even if the modem does adjust its data rate. To turn Speed Conversion ON,
enter the command AT$BA0 and hit RETURN.
To turn Speed Conversion OFF, enter AT$BA1 and hit RETURN. The modem will now match its RS-
232C speed to that of the computer, and will adjust its speed to any changes in the computer’s speed
in Originate mode, or to the speed of the originating modem in Answer mode. The speed at which the
modem communicates over the phone line will always be the same as the speed at which it
communicates via its RS-232C serial port.
Modem Baud Rate $MB
The $MB command presets the modem’s transmission baud rate for originate operations, (i.e., the
speed of the modem’s transmissions over the telephone lines when originating a call). With speed
conversion, this transmission speed can be a different baud rate than the serial port speed.
When the modem receives (answers) a call from another modem, it automatically switches its phone
line transmission speed to match the calling modem. However, if the modem originates a call to
another modem that is unable to connect at the same baud rate, it automatically drops to a lower
baud rate in an attempt to match the speed of that modem. For example, if the modem is set for
14,400 baud and calls another modem that has a top speed of 2400 baud, it drops to 2400 baud.
The command to set the Modem Baud Rate is AT$MBn, where n can be:
AT$MB75
AT$MB300
=
=
=
=
=
=
=
=
=
=
CCITT V.23
300 bps
AT$MB1200
AT$MB2400
AT$MB4800
AT$MB9600
AT$MB14400
AT$MB19200
AT$MB28800
AT$MB33600
1200 bps
2400 bps
4800 bps
9600 bps
14400 bps
19200 bps
28800 bps
33600 bps
The factory default is 33600 bps.
44
Chapter 4 - Command Mode
Serial Port Baud Rate $SB
The $SB command presets the speed of the modem’s serial (RS-232C) port, in both Originate and
Answer modes. Speed conversion allows you to set this serial port baud rate at a fixed speed of up to
115,200 bps for 1932 and 2834 models, and 57600 bps for 1432 models, regardless of the modem’s
transmission speed setting.
In order for this command to be effective, the modem’s Speed Conversion feature must first be
turned off with the $BA command. When Baud Adjust is on, the modem automatically adjusts its
serial port baud rate to match the speed of the computer or terminal it is connected to, as soon as it
receives its first AT command. However, in many applications, such as automatic answer, the
modem may not receive AT commands, in which case it is very useful to be able to preset the serial
port baud rate with this $SB command.
In addition to setting the modem’s serial port speed, this command also sets the speed at which the
modem issues Command mode responses.
The modem will accept AT commands at any speed, regardless of the speed preset by the $SB
command. If the modem receives such a command at a speed that is different than the preset speed,
the modem switches its serial port baud rate to match the new AT command speed, although the
baud rate value stored by the $SB command remains the same. This provides you with a convenient
way to switch the serial port speed, and still make it easy to go back to the original speed
automatically the next time the modem is powered up or reset with an ATZ command.
The command to set the Serial Port Baud Rate is AT$SBn, where n can be:
AT$SB300
=
=
=
=
=
=
=
=
300 bps
AT$SB1200
AT$SB2400
AT$SB4800
AT$SB9600
AT$SB19200
AT$SB38400
AT$SB57600
1200 bps
2400 bps
4800 bps
9600 bps
19,200 bps
38,400 bps
57,600 bps
115,200 bps
AT$SB115200 =
The factory default is for 2834 is 57,600 bps.
Note: Some serial ports, particularly those in older PC-compatible computers, may limit the
performance of a higher speed modem like the MultiModem (see Chapter 3). The limiting factor is a
circuit called a Universal Asynchronous Receiver/Transmitter, or UART. All data from your modem
flows through it. 8250, 16450, and 16550 are UARTs typically used in PC-compatible computers. The
8250 is unreliable above 9,600 bps and the 16450 is unreliable above 19,200 bps. The 16550 UART,
however, is reliable to at least 115,200 bps. With V.42bis data compression enabled, the MT2834BA
can achieve throughputs approaching 115.2K (depending on line quality and file content). If you
presently do not have a 16550 UART in your PC, we recommend that it be replaced with a Multi-Tech
high speed Intelligent Serial Interface (ISI) card. It comes in one, two and eight-port versions for
DOS/Windows and UNIX systems, and includes a 32 K buffer that eliminates data loss even at high
speeds. See your dealer for details.
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MultiModemBA User Guide
4.4.12 Immediate Action Commands
Help Screens $H
The Help command is designed to give you short explanations on how to use each modem
command. The Help command can be quite useful if your manual is not handy and you are in the
middle of a communications session. Although the explanations are quite abbreviated compared to
those in this manual, they should prove to be helpful reminders when needed.
At the time of this writing, we have three screens of Help information (Screen #1, #2 and #3), and
more screens may be added in the future. The Help commands are structured so that you can call up
one of three Help screens, as follows:
AT$H1 = Help Screen #1
AT$H2 = Help Screen #2
AT$H3 = Help Screen #3
Inquiry for Product Code I
Some systems or software packages automatically check the “identification” of the modem with which
they are communicating, by using the I command. This “read” command lets the software to
determine the type of modem with which it is communicating.
When ATI or ATI0 is entered, the modem responds with 247. When ATI1 is entered, the modem
responds with a three-digit code indicating the firmware version number. When ATI2 is entered, the
modem responds with MT2834BA, MT1432BA or MT932BA depending on model.
Windows 95 Autodetect Inquiry I9
This read command permits a Windows 95 operating system to query the MT2834BA's
characteristics. When ATI9<CR> is entered the symbols BA 28800 FAX CT are displayed; which
indicates to the Windows 95 system that your particular modem is a MT2834BA, 28,800 bps, fax
Class 2 capable modem. With autodetect support in your MT2834BA, your PC can automatically
allocate resources and configure it and other devices. The MT2834BA implements autodetect
capability in the form of a single .INF (Information) file that specifies AT Command mode and Result
Code "Registry Keys" that are specific to your MT2834BA.
Listing Current Operating Parameters L5 L7
The L5 and L7 commands list the current operating parameters of your modem. This information can
be very useful when you are changing communications software or when you are changing modem
default settings.
The command to list the modem’s current operating parameters is ATL5 for the basic parameters.
Entering ATL7 lists additional parameters on the modem.
Listing S-Register Values L6
Entering ATL6 lists the current values stored in the modem’s S-Register. This information can be
very useful if you wish to change S-Register values.
Listing On-Line Diagnostics L8
The L8 command displays the current on-line CONNECT status of the modem. This display can be
printed and used as a modem status report or as diagnostic information (such as when calling Tech
Support). To activate this command first type +++AT<CR>(on-line escape command while
maintaining command mode), then type ATL8. What then displays on your monitor is your modem's
current on-line condition (e.g., Link Type, Line Speed, Serial Speed, Type of Error Correction/Data
Compression, Number of past Retrains, etc.).
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Chapter 4 - Command Mode
Off Hook H
You can make the modem hang up (go On Hook). Entering ATH1<RETURN> brings the line Off
Hook, just as if you picked up the telephone set. You can hang up by entering ATH0 or ATH (the
default is 0 when no number is entered).
Escape Sequences- Entering Command Mode While Still On-Line +++AT<CR>
It is possible to cause the modem to enter Command mode after the modem has gone on-line with a
remote modem, without disconnecting the call. This is done by entering an Escape Code. The default
Escape Code used by the modem is three plus signs (+++) followed by the letters A and T, up to
sixty command characters (most typically “H”, to hang up), and a RETURN. The number of
command characters allowed after +++ AT<CR> , is defined by S-Register S34. S-Register S34
defaults to ten command characters.
When this is done, the modem escapes to Command Mode, executes the command (if any), and
then remain in Command mode. For example, to hang up the modem at the end of a call, enter
+++ATH and hit RETURN. There is no need to incorporate pauses before and after the plus signs,
as done in earlier modems.
BREAK AT<CR>
The modem provides an alternative Escape method, using a Break signal as the Escape Code. The
Break signal allows the start-stop DTE (data terminal equipment) to signal the modem without loss of
character transparency. With this method, a BREAK signal is used instead of the three plus signs.
The BREAK is followed by the letters A and T, up to 60 command characters, and RETURN. When
this is done, the modem executes that command, but remains in On-Line mode unless the command
was to hang up and/or reset the modem (an H or Z), in which case the modem would be in the
Command Mode after executing that command.
Escape Sequence Options - Entering Command Mode While On-Line %E
As mentioned, the default escape sequence setting is for the modem to respond to the +++ escape
method. Optional settings are for the modem to respond to the Break method, for the modem to
respond to either the +++ or the Break Methods, for the modem to ignore both methods and not
escape, for the modem to respond with no "OK" to +++, and for the modem to respond with "OK" to
+++. The %E command is used to select these options, as follows:
%E0
%E1
%E2
%E3
%E4*
%E5*
=
=
=
=
=
=
Modem Won’t Escape
+++ AT<CR> Method (default)
Break Method
Either +++ or Break Methods
No "OK" Response to +++
"OK" Response to +++
* The %E4 and %E5 commands enable or disable an "OK" response, which is required by some
software packages during an escape sequence.
Force Answer Mode A
You can force the modem into Answer mode with the modem’s A command.
Entering ATA when in Command mode immediately brings your modem off-hook, out of Command
mode and into On-Line Answer mode, and causes it to transmit its carrier signal over the phone line.
If no responding carrier tone is received by your modem within forty-five seconds (or some other time
as determined by S-Register S7), your modem stops transmitting its tone, hangs up, and goes back
into Command mode.
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MultiModemBA User Guide
Exiting Command Mode, Going Back On-Line O
You can bring the modem out of Command mode and back into On-Line mode by entering ATO
(where O is the letter O, not the number 0). In this case, the O command reverses what was done by
entering the Escape Code. The O command will bring the modem into the same On-Line mode
(Originate or Answer) that it was in prior to going into Command mode.
4.4.13 Line Probe Commands
Before V.34 negotiation takes place, remote and local modems transfer their functional capabilities
using modulated calling and answering tones; indicating the common capabilities of the modem at
each end.
Once this is done, a probing signal is passed between the modems to identify impairments in the
telephone channel (e.g., Receive Signal Strength vs. Frequency, Noise vs. Frequency and Signal to
Noise Ratio vs. Frequency). After receiving the results of the probing signal, the modem receivers
and transmitters begin with the lowest speed and move up until reaching the highest speed at which
they can exchange data. All this occurs in about five seconds.
There are a number of Line Probe Commands. These commands are configurable and can be stored
to RAM (via AT&W0).
These commands are listed below.
Enable/Disable Reading of Line Probe Information Commands:
%DP0 = Do not read Line Probe information from DSP during handshake (Default).
%DP1 = Read Line Probe information from DSP during handshake.
Format of Line Probe (Graph or Table) Commands:
%DF0 = Data is displayed in Graph format. Y axis is shown in dBms (Default).
%DF1 = Data is displayed in Table format. Numeric values are displayed for 150Hz to
3750Hz in 75HZ increments.
Immediate Action Line Probe Commands:
To activate these commands first type +++AT<CR>(on-line escape command while maintaining
command mode), then type the Command prefixed by an AT.
&RP = This command initiates a retrain that makes the processor read Line Probe
information. Valid only when on-line in V.34 mode.
L9
= Displays Signal Strength information.
= Displays Signal to Noise Ratio information (SNR).
= Displays noise information.
L10
L11
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Chapter 5 - S-Registers
MultiModemBA User Guide
5.1 Introduction
Certain Command Mode configurations are stored in memory registers called, S-Registers. The S
command is used to assign a value to, and to read the current value of an S-Register. To assign a
value to an S-Register, enter the letter S, followed by the S-Register number and an equals sign (=),
and then a decimal response to the message “ENTER THE NEW VALUE IN DECIMAL FORMAT”.
To read an S-Register value, enter the letter S followed by the S-Register number and a question
mark (?), then hit RETURN. To verify that the S-Register value was entered correctly, enter for
example, ATS8? and hit RETURN. You should receive a response of the assigned value given to
that S-Register.
S0
Number of Rings Until Modem Answers
Unit:
1 ring
Range:
Default:
Description:
0-255
1
S0 defines the number of rings the modem waits before answering an incoming call.
The default value is one ring (Decimal 1), which means that the modem answers the
call immediately after the first ring. The maximum number of rings that can be
configured is 255. Setting the value to zero (0) disables auto-answer completely.
S1
Rings Which Have Occurred
Unit:
1 ring
Range:
Default:
Description:
0-255
0
S1 counts the number of rings that have occurred. It is a “read” type of register and
is seldom, if ever, used in typical operation. Each time an incoming ring signal is
detected, S1 increases its value by one, up to a maximum of 255. If you set S1 to a
value other than its default value of zero, or if the value is increasing with rings, this
new value remains stored in S1 for eight seconds after the last ring is counted, after
which time the value reverts to zero.
S2
Escape Code Character
Unit:
ASCII Character
Range:
Default:
Description:
0-127
43 (+)
S2 defines the escape code character. The default character is the plus (+) sign
(Decimal 43), but may be set for any ASCII character. Setting an S2 value greater
than 127 results in no escape character, and therefore no means of entering
Command mode from On-line mode without breaking the on-line connection.
S3
Return Character
Unit:
ASCII Character
Range:
Default:
Description:
0-127
13 (^M)
S3 defines the character recognized as Carriage Return (RETURN) or “Enter”. S3
may be set for any ASCII character.
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Chapter 5 - S-Registers
S4
Line Feed Character
Unit:
ASCII Character
Range:
Default:
Description:
0-127
10 (^J)
S4 defines the character recognized as Line Feed. S3 may be set for any ASCII
character.
S5
Backspace Character
Unit:
ASCII Character
Range:
Default:
Description:
0-127
8 (^H)
S5 defines the character recognized as BACKSPACE. S5 may be set for any ASCII
character.
S6
Wait Time for Dial Tone
Unit:
1 second
Range:
Default:
Description:
2-255, 4-255**
2, 4**
S6 sets the time the modem waits after the RETURN key is pressed before
executing a dial command. The default setting is two seconds (Decimal 2).
S7
Time for Carrier (Abort Timer)
Unit:
1 second
Range:
Default:
Description:
1-255, 1-45*
45
S7 defines the Abort Timer (lack of carrier) delay time. The default value is 45
seconds (Decimal 45). This means that, after dialing, the modem waits for a carrier
signal for up to 45 seconds and, if none is detected, aborts the call. The maximum
S7 value is 255.
S8
Pause Time for Comma
Unit:
1 second
Range:
Default:
Description:
0-255, 4-255**
2, 4**
S8 sets the length of the pause caused by a comma inserted in a dialing command.
The default setting is two seconds, (or two units Decimal 2) or four seconds, where
each unit is one second. S8 may be set for up to 255 seconds.
S8 also sets the time the modem waits before retrying a call after detecting a busy
signal. Some computer systems need more than two seconds to reset (in which case
you should increase the value of S8).
* Value for International and DOC units
** Value for International units only
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MultiModemBA User Guide
S9
Carrier Detect Response Time
Unit:
100 mSec.
Range:
Default:
Description:
1-255
6
S9 sets the time delay between when the modem first detects a valid incoming
carrier signal and when the modem turns on its Carrier Detect circuit. The default
setting is 600 milliseconds, or six units of 100 mSec each (Decimal 6). S9 may be set
for up to 25.5 seconds.
S10
Carrier Loss Disconnect Delay Time
Unit:
100 mSec.
Range:
Default:
Description:
0-255
7
S10 sets the time a carrier signal must be lost before the modem disconnects. The
default setting is 700 mSec, or seven units (Decimal 7) of 100 mSec. Maximum delay
is 25.4 seconds (Decimal 254). Setting the S10 value to 255 causes the modem to
not disconnect with loss of carrier. (This S-Register applies at speeds of 2400 bps
and less.)
S11
Tone Dialing: Tone Spacing and Duration
Unit:
1 mSec.
Range:
Default:
Description:
1-255, 80-255*
70, 80*
S11 sets the speed of tone dialing (spacing and tone duration times). The default
value is 70 units (Decimal 7) or 80 units, where each unit is one mSec, meaning that
each tone is on for 70 mSec with a 70 mSec pause between each.
The minimum S11 value allowed by most telephone systems is 50 mSec (50 units).
Very few telephone systems can handle anything faster than that. The maximum S11
value is 255 mSec (255 units).
S13
Remote Configuration Escape Character
Unit:
ASCII Character
Range:
Default:
Description:
0-127
37 (%)
S13 defines the remote configuration escape character (which becomes your
modem’s remote configuration character). The default is three percent symbols
(%%%). When the S13 character is entered three consecutive times from a remotely
connected site, your modem responds with its Remote Configuration procedure.
* Value for International and DOC units
** Value for International units only
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Chapter 5 - S-Registers
S15
Callback Time Delay
Unit:
Seconds
10-255
20
Range:
Default:
Description:
S15 defines the time delay between Callback attempts after initial passwords have
been exchanged between modems.
S16
Callback Attempts
Unit:
1 Attempt
Range:
Default:
Description:
1-255
4
S16 defines the number of attempts allowed after initial passwords have been
exchanged between modems.
S17
Changing Break Time
Unit:
10 mSec.
Range:
Default:
Description:
0-2.5 sec
250
S17 defines the break time (space) sent to the local PC. The default is set for a 25 to
250 mSec break. The break time can be changed in 10 mSec increments by
increasing or decreasing the value of S17.
S24
PBX/CBX Disconnect Drop Time for DSR/CTS/CD
Unit:
50 mSec.
Range:
Default:
Description:
0-255
20
Some PBX and CBX phone systems require the modem’s DSR, CTS, and/or CD
signal(s) to behave in a certain manner when calls are disconnected. The modem’s
&R, &S, and &C commands cause the modem to drop these signal(s) for a specified
time period upon disconnect, and then bring the signal(s) up again. S24 defines the
length of time that the signals drop. The default setting of 20 results in a one second
drop time, which is what most PBX/CBX systems with this requirement need.
S25
DTR Dropout Time
Unit:
100 mSec.
Range:
Default:
Description:
0, 1 through 255
0
S25 defines the amount of time that DTR must be dropped before the modem
disconnects. Typically, a disconnect occurs when DTR is dropped for 50
milliseconds or more. This dropout time can be increased, up to a maximum of 25.5
seconds. The S25 unit value for zero is the default value of 50 mSec. For values
from 1 through 255, the unit value is 100 mSec.
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MultiModemBA User Guide
S26
Failed Password Attempts
Unit:
1 failed attempt
Range:
Default:
Description:
0-255
0
S26 counts the number of times there has been a failed password attempt. For
example, if you entered ATS26? the message 003 would be displayed, meaning
someone has failed three times to gain access to your modem using its password
security system.
S29
Local Inactivity Timer
Unit:
minutes
Range:
Default:
Description:
1-255
20
S29 defines the amount of idle time that can elapse between AT commands after the
SETUP password has been entered. If this timer expires, the LOGIN and SETUP
passwords will have to be re-entered. S29 only takes effect when the modem has
been sent a #DB1 command, which secures the modem from local and remote
configuration or dialing (i.e., no AT commands can be sent until the LOGIN and
SETUP passwords have been entered).
S30
Inactivity Timer
Unit:
1 min.
Range:
Default:
Description:
0-255
0
S30 causes the modem to disconnect if no data is transmitted or received for a
specified time. This timer runs during both Reliable and Normal error correction
connections. The timer restarts any time a data character is passed through the
serial port (either sent or received). If noise on the phone line causes an error to be
received during Normal mode, this also restarts the timer. The default value is off (0).
The inactivity timer is disabled by setting S30 to 0, which is the factory default
setting.
S32
Time Elapse for Escape Sequence
Unit:
1 second
Range:
Default:
Description:
0-255
20
S32 sets the time period to validate the escape sequence. If the time interval expires
before the escape sequence is employed (by hitting RETURN), the escape
sequence is aborted. The default is 20 units.
S34
Buffer Length of Command Mode...After On-line Escape Sequence
Unit:
ASCII Character
Range:
Default:
Description:
0-60
10
If the number of characters after AT exceeds the S34 buffer length value, the buffer
is cleared and the escape sequence is aborted.
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Chapter 5 - S-Registers
S36
Time Between DTR Inactive and Modem Off-Hook
Unit:
1 Second
Range:
Default:
Description:
0-255 seconds
0
The DTR Busy-out feature uses S-Register S36 to set the time between DTR
inactive (low) and the modem going off-hook. S36 can be set in one-second intervals
from 0 to 255 seconds. With the default setting of S36=0, DTR Busy-Out is disabled
(i.e., DTR won't Busy-Out).
S37
Time Between DTR Active and Modem On-Hook
Unit:
1 Second
Range:
Default:
Description:
0-255 seconds
5
S37 sets the time between DTR being active and the modem going on-hook (not
busy). S37 will only function in conjunction with S36.
S48
Program V.34bis Connect Speeds (2834 Series only)
Unit:
N/A
Range:
Default:
Description:
33, 31, 28, 26, 24, 21,19,16,14,12, 96 and 48
0
Defines which speed modem connects within the scope of Enhanced V.34 mode
(e.g., S48 = 26 means maximum connect speed is 26.4K). This register
compensates for line conditions that have trouble supporting higher Enhanced V.34
speeds (e.g., 33.6K, 31.2K, 28.8K, 26.4K, 24K...). The modem default is a value of 0,
which indicates a connection attempt of 33.6K.
5.2 Reading and Assigning S-Register Values
The S command is used to assign a value to, and to read the current value of, an S-Register. To read
an S-Register value, enter the letter S followed by the S-register number and a question mark (?),
then hit RETURN. For example, entering ATS7? and hitting RETURN displays the value of S-
Register S7 in a 3-digit decimal form. The number 8 would appear as 008, the number 30 would
appear as 030, and the number 255 would appear as 255.
To assign a value to an S-Register, enter the letter S followed by the S-Register number and an
equals sign (=), and then a decimal response to the message “ENTER THE NEW VALUE IN
DECIMAL FORMAT”. Convert all ASCII characters to their decimal equivalents before entering them.
S-Register decimal values range from 0-127 for ASCII characters, or 0-255 for numeric values.
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MultiModemBA User Guide
5.2.1
Examples of Assigning Values
1. Let’s say you wish to have longer pauses caused by the comma in a dial command; five seconds
instead of two. Entering ATS8=5 assigns 5 as the value for S-Register S8 (meaning the modem
pauses five seconds for a comma in a dial command).
2. In a second example, let’s say that you wish to configure the modem to answer incoming calls
after the 30th ring instead of after the first ring. To configure S-Register S0 with a value of 30,
enter ATS0=30 and hit RETURN.
3. In a third example, let’s say you are calling long distance to another country code, and it is taking
a long time to connect. The S-Register S7 (Abort Timer) setting of 45 seconds, is insufficient.
The abort timer times out and cancels the call before a connection is made. To change the S7
value to 55 seconds, enter Command mode, then enter ATS7=55 and hit RETURN. Now, after
dialing, the modem allows 10 more seconds for a carrier signal before aborting the call. The
additional 10 seconds should provide enough time for international calls.
5.2.2
Examples of Reading Values
To verify that you entered the value correctly in the above examples, enter ATS8? and hit RETURN
in the first example, ATS0? in the second, and ATS2? in the third example. You should receive the
response 005 in the first example, 030 in the second example, and 055 in the third example.
When configuring the S-Registers, it is a good practice to include the verification read-entry in the
same command line as the configuration assignment-entry. In the three preceding examples, enter
ATS8=5S8?, ATS0=30S3?, and ATS7=55S7?.
5.3 AT Command and S-Register Summary
The vast majority of installations are similar, with the modem being used to dial up a remote
installation where the call is automatically answered. Your modem has a default configuration to dial
another modem that supports error correction, data compression and flow control. If the answering
modem is not compatible, the MultiModem can match protocols, provided the protocols are industry
standard (i.e., ITU or Bell) and not proprietary.
The &W command, used in conjunction with specific other AT commands and S-Registers, can re-
configure the modem to conform to a specific application. The command AT&W0 (or AT&W) causes
the modem to store its current parameters in its nonvolatile RAM. The command also sets the
modem upon power up, or when it is reset with an ATZ command, the modem reads all of its
configuration and S-Register parameters from RAM, and not from the factory settings in ROM (note
you may recall factory installed defaults by entering AT&F8&W0). The &W command changes the
configuration parameters stored in RAM that you specifically intend to alter. All other default
parameters remain unchanged.
The AT&W1 command sets the modem so that it does not store its parameters in RAM, and on
power up or when an ATZ command is issued, parameters are read from the factory default settings
in ROM.
Before using the &W command, you may want to view the modem's current operating parameters.
Use the ATL5, ATL6 and ATL7 commands to display the current modem configuration.
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Chapter 6 - Callback Security and
Remote Configuration
MultiModemBA User Guide
6.1 Introduction
This chapter describes how the MultiModem’s Callback and Remote Configuration features operate.
These features use a multilevel security system, which involves the use of LOGIN Passwords, Setup
Passwords and Remote Escape Characters.
The primary level security code is the modem’s LOGIN Password. Once this password is entered,
other passwords can be used. For instance, entering the LOGIN Password will allow you to enter the
Setup Password, which, in turn, allows you to enter Callback Passwords and dial back phone
numbers. Callback Passwords tell your modem what dial back phone number to call.
The Remote Escape Character is the key to using the Remote Configuration feature. The Remote
Escape Character lets you enter Command mode via a remote call, so that you can enter AT
commands just as if you were locally connected. You must also enter your modem’s Setup
Password. The Remote Escape Character is contained in S-Register S13.
6.2 Callback Feature Description
The Callback feature protects your network from unauthorized access and helps control long
distance costs. By use of Callback Passwords and dial back phone numbers, you can have your
modem "dial back" remote locations immediately after being called. A special command (Enable
Callback #DB) turns your modem into a Callback security modem. The Callback Password/Phone
number entry is protected by two-level security (your modem's LOGIN Password and Set-Up
Password) that keeps unauthorized personnel from changing parameters. When you first get your
modem, you need to change both security level codes to your unique settings.
The Callback Passwords and dial back phone numbers are in a special Callback Password/dial back
phone number memory (30 numbers long). You use the modem's LOGIN Password and the Set-Up
Password plus special Callback commands to access this memory. The memory is thirty numbers
long and replaces your modem's normal phone number memory.
Each number is 35 characters long and can contain commands as well as phone numbers. You need
to set up your modem with the numbers and codes as part of the dial back initialization procedures.
Your modem will also remember if the incoming call was reliable or not, and make the call back
accordingly.
6.3 Remote Configuration Description
The Remote Configuration feature is a network management tool that allows you to configure
modems remotely. This means you could configure modems anywhere in your network from one
location without having to visit the sites or rely on remote users to follow your instructions. With
Remote Configuration, which is protected by two level security, you can download new parameters,
program new V.42 capabilities and implement new features. Remote Configuration also makes
troubleshooting a remote location a lot easier.
The way Remote Configuration works is that S-Register S13 has been set up to contain the special
Remote Configuration escape code. When calling a Remote Configuration equipped modem, you
enter the proper Remote Escape code to enable entering your Set up Password. After entering it, you
can then execute AT commands as if you were connected locally. If you set S-Register S13 to zero,
Remote Configuration is disabled.
6.3.1
Initial Setup Procedures for Callback and Remote
Configuration.
Your modem was shipped with a default LOGIN Password and Setup Password (LOGIN=MULTI-
TECH and Set-up=MODEMSETUP) so that you have access to the features used for configuring the
modem. Because the defaults are in the modem owner’s manual, and anyone can find out what they
are, you should change the codes as the first step of your initialization procedure.
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Chapter 6 - Callback Security and Remote Configuration
Table 6-1. Modem LOGIN, Setup and Remote Escape Code Procedures
To change your modem’s LOGIN Password and Setup Password:
Step Procedure
Note: Passwords are upper/lower case sensitive. The case you enter here is the case that must be
used at Log-In.
1. Type AT#IMULTI-TECH and hit RETURN. Your modem will respond with:
OK (if the LOGIN Password is wrong, the modem’s response is ERROR)
2. Type AT#SMODEMSETUP and hit RETURN. Your modem will respond with the following:
OK (or ERROR if wrong Setup Password)
Note: At this point you can change the LOGIN Password and Setup Password.
3. Type AT#I=xxxxxxxxxx (with any keyboard characters used, minimum 6 maximum 10) and hit
RETURN. Your modem responds with:
OK
4. Type AT#S=yyyyyyyyyy (with keyboard characters used, minimum 6 maximum 10) and hit
RETURN. Your modem responds with:
OK
To change your Remote Configuration feature status:
5. If you want Remote Configuration off, set S-Register S13 to 0 (zero). Refer to Chapter 6 for
details on how to set S-Register values.
6. If you want Remote Configuration on and wish to change the Remote Escape Character, change
the S-Register S13 value. If you leave it at the default value, decimal 37 (% sign) will be your
modem’s remote escape character.
To turn your modem's Callback Security feature on and off:
7. If you want Callback Security with both remote and local password security, enter AT#DB1 and
hit RETURN. You must turn on Callback Security to be able to enter dial back phone numbers.
8. If you want Callback Security on with just remote password security, enter AT#DB2 and hit
RETURN. You must turn on Callback Security to be able to enter dial back phone numbers. If
you want to use your modem to call another modem that is also set for Callback, you must enter
AT#DB3 before you dial.
Note: this is for your modem if you are set for #DB1 or #DB2.
Once you have disconnected from that call, your modem will go back to its original setting.
9. If you want Callback Security turned off, type AT#DB0 and hit RETURN.
To set parity of the password/message prompt:
10. The parity default value for your modem is no parity (AT#P0). If your modem's prompt messages
use even parity, enter AT#P2 and hit RETURN. For odd parity, enter AT#P1 and hit RETURN.
11. Enter the &W0 command and hit RETURN to store parameters and S-Register values in RAM.
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MultiModemBA User Guide
Table 6-2. Callback Password and Dial Back Phone Number Entry Procedures
Step Procedure
1. Enter your modem's LOGIN Password (as selected in Table 6-1) by entering the following:
AT#Ixxxxxxxxxx<CR> (xxxxxxxxxx from Table 6-1)
Enter your modem's Setup Password (as selected in Table 6-1) by entering the following:
AT#Syyyyyyyyyy<CR>(yyyyyyyyyy from Table 6-1)
2. Enable the Callback Security feature by entering the following:
AT#DB2<CR> or AT#DB1<CR>
The following message is displayed on your monitor:
Entering Callback Mode, current phone numbers will be erased. Do you want to continue? (Y/N)
3. Enter a Y or N and hit RETURN.
Note: If this is your first time into Callback Mode, we recommend answering Y to clear all
previous Callback Passwords and phone numbers from memory.
4. Enter individual Callback Passwords for each of 30 different phone number memory locations as
follows:
AT#CBN0xxxxxxxxxx<CR>
To enter Callback Password for the first location (a minimum 6 characters, up to a maximum of
10 characters must be used).
AT#CBN1xxxxxxxxxx<CR>
To enter Callback Password for the second location...etc (a minimum 6 characters, up to a
maximum of 10 characters must be used).
Note: The first character of your first Callback Password must be non-numeric.
5. Enter individual phone numbers for each of the 30 memory locations as follows:
AT+ - DP...????N0 <CR> (number for location N0)
AT+ - DT...????N1 <CR> (number for location N1)...etc
Note: You must indicate within the command string that the modem either Pulse dial (ATDP...) or
Tone dial ATDT...).
The maximum length of the number is 35 characters. The number may include commands as
well as your number, so as to create macro-type command numbers.
The + and/or - characters entered before the phone number are optional. The + (Deposit
Number) code allows a caller to enter the number he or she wishes the Callback modem to call
back when the caller uses a particular password (Step 3 of Table 6-3). The - character enables
direct entry when the caller uses that correct password (Step 3 of Table 6-3) without the Callback
modem having to return the call.
The ??? entry at the end of the phone number is optional and indicates a subcode number to the
main phone number for that location. The ??? used to dial different extensions at the same basic
number. To use this optional feature, enter the number of ? marks where indicated equal to the
number of digits in the desired extension number, (i.e., with a 4 digit extension enter ????). When
a caller uses that particular password (Step 3 of Table 6-3), he or she then enters an extension
number directly after the password, with the same number of digits as the number of ? marks
originally entered. When calling back that particular number, your modem will also dial the
indicated extension number.
Note: To view Callback Passwords/Numbers, use the L Command.
6. To store changed parameters to memory, enter AT&W0 and hit RETURN.
Note: If you have enabled Callback Security (#DB1 in step 2 of Table 6-2), the modem will be
secured locally. To gain local access, you must again perform steps 7 and 8.
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Chapter 6 - Callback Security and Remote Configuration
7. Enter your modem's LOGIN Password (as selected in Table 6-1) by entering:
AT#Ixxxxxxxxxx<CR> (xxxxxxxxxx from Table 6-1)
8. Enter your modem's Setup Password (as selected in Table 6-1) by entering:
AT#Syyyyyyyyyy<CR> (yyyyyyyyyy from Table 6-1)
Table 6-3. Callback Operational Sequence Procedures
Perform the following steps when dialing into a dialback modem:
Step
Procedure
1. When called, the modem answers and after a slight delay, responds with:
Password>
2. Enter your modem's LOGIN Password (Table 6-1) and hit RETURN. If entered correctly, the
modem responds with:
DB>
3. Enter the Callback Password corresponding to the phone number you wish called back and hit
RETURN (Callback Passwords and phone numbers entered in Table 6-2). You can also use
special characters + and -. They must have been entered as part of the Callback phone numbers
in Step 5 of Table 6-2. If you use the - character along with your password, the Callback modem
will connect directly without hanging-up and calling back. If you use the + character along with
your password, you can also enter a phone number which you wish the Callback modem to dial
after hanging-up. The + and - characters must be entered after the Dial-back password, (i.e.,
DB>xxxxxx+). This is also the point where you enter an extension number if your Callback
number used the ??? feature (Step 5 in Table 6-2).
You have three tries at each prompt to enter the information properly, with an incorrect entry
resulting in a password retry. You must enter the requested information correctly within one
minute or the Callback modem will hang-up. When the information is entered properly, the called
modem will hang-up and after a 15 second delay, call you back. When your modem answers, the
dialback modem will respond with the following:
Password>
4. Enter the modem's LOGIN Password again (the same as in Step 1). The Callback modem
responds with:
CONNECT
You are now in Data Mode.
6.3.2
Remote Configuration Procedures
The procedures for using the Remote Configuration features are the same whether or not a call
originates from the remote modem. Once the modem is on-line, perform the procedures in Table 6-4.
Table 6-4 Remote Configuration Operation Procedures
Step
Procedure
1. Remote Escape Configuration requires %%%AT<CR> to be sent if the default value in S-
Register S13 has not been changed.
The modem responds with:
1. - DATA Mode
2. - COMMAND Mode
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MultiModemBA User Guide
2. You then select 1 or 2. With 1, the modem goes back into data mode and with 2, the modem
responds with the following:
Password>
3. Enter your Setup Password, and if the code is correct the modem responds with:
OK
You can now use any AT commands of the modem being remotely configured as if they were
being entered locally. You cannot change the setup of the LOGIN Password until you enter the
proper LOGIN Password.
4. When you are done entering AT commands and you want to exit, type AT0 and hit RETURN.
The modem responds with:
1. DATA Mode
2. COMMAND Mode
5. Enter a 1 to go back on-line with your computer, or enter 2 and the correct password to talk to
your modem.
6.4 Remote Configuration and Callback Security AT Commands
When you have callback security enabled for the modem, anyone trying to connect with the modem
will be required to furnish a password. The #CBN command allows you to enter passwords for each
of the 30 memory locations used for callback security. The length of each password can be up to 10
characters, but must be at least 6 characters. Any ASCII character can be used.
The format for this command is AT#CBNyyxxxxxxxx<CR> with xxxxxxxx representing the
password and yy being the memory location (0-29). Each callback password (xxxxxxxx) must start
with a non-numeric character.
Callback Security Enable/Disable
#DB
The purpose of this command is to enable or disable (default setting) your modem's callback security
option. Once this command is executed, you modem will undergo some significant changes. For
example, the phone number memory locations (N0 through N9) will be used for passwords and
phone numbers. In other words, you will not be able to dial from memory or use the DTR dialing
feature.
You can turn on callback security by typing AT#DB1 or AT#DB2 and pressing <CR>. If you want to
engage both remote and local password security, use the #DB1 command. This sets up the modem
so you have to provide passwords to dial into the modem and to dial out. For remote password
security only, use the #DB2 command. This allows the local operator to dial out without providing the
LOGIN and SETUP passwords. Use #DB3 when calling another modem with callback security active.
Change LOGIN Password
#I
The default LOGIN password for your modem is "MULTI-TECH". If you choose to activate callback
security, you should change the LOGIN password using this command in the following format:
AT#Ixxxxxxxxxx<CR> (where xxxxxxxxxxxxxxxx is the current LOGIN password). Your modem will
respond with "OK", indicating that you can enter the new LOGIN password as follows:
AT#I=yyyyyyyyyy<CR>
You can select any combination of keyboard characters (upper/lower case sensitive) between six
and ten characters long.
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Chapter 6 - Callback Security and Remote Configuration
Change SETUP Password
#S
The default SETUP password for your modem is "SMODEMSETUP". If you choose to activate
callback security, you should change the SETUP password using this command in the following
format:
AT#Stttttttttt<CR> (where tttttttttt is the current SETUP password). Your modem will respond with
"OK", indicating that you can enter the new SETUP password as follows:
AT#s=uuuuuuuuuu<CR>
You can select any combination of keyboard characters (upper/lower case sensitive) between six
and ten characters long.
Erase Callback Password
#RCBNxx
This command erases the single callback password specified by xx (0 through 29).
Erase Callback Phone Number #RDNxx
This command erases the single phone number specified by xx (0 through 29).
6.5 Remote Configuration/Callback Security S-Registers
The following S-Registers are used with Remote Configuration and Callback Security features.
Remote Configuration Character (S13)
S13 defines the modem’s remote configuration escape character. When the S13 character is entered
three consecutive times from a remotely connected site, your modem responds to it with its Remote
Configuration procedure.
Units:
ASCII
Range:
Default:
0-127
37 (% sign)
Callback Time Delay (S15)
S15 defines the time delay for Callback attempts after initial passwords have been exchanged
between modems.
Unit:
Range:
Default:
Seconds
10-255
20
Callback Attempts (S16)
S16 defines the number of Callback attempts after initial passwords have been exchanged between
modems.
Unit:
Range:
Default:
1 Attempt
1-255
4
Failed Password Attempts (S26)
S26 counts the number of times there has been a failed password attempt. For example, if you
entered ATS26? the message 003 would be displayed, meaning someone has failed three times to
gain access to your modem using its password security system.
Units:
1 failed attempt
Range:
Default:
0-255
0
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MultiModemBA User Guide
Local Inactivity Timer (S29)
S29 defines the amount of idle time that can elapse between AT commands after the SETUP
password has been entered. If this timer expires, the LOGIN and SETUP passwords will have to be
re-entered.
S29 only takes effect when the modem has been sent a #DB1 command, which secures the modem
from local and remote configuration or dialing (i.e., no AT commands can be sent until the LOGIN
and SETUP passwords have been entered).
Units:
Range:
Default:
Minutes
1-255
20
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Chapter 7 - DIP-Switch Settings
MultiModemBA User Guide
7.1 Introduction
There are several DIP-Switch options on the modem’s printed circuit (PC) board. The DIP-Switches
are accessible through a cut-out on the side of the modem. This chapter explains the modem’s
printed-circuit board options. Sixteen DIP-Switch settings and the modem's speaker volume control
are explained in detail, including all default settings.
Power Switch
Power Jack
LED
Indicators
RS-232/V.24
Connector
Line Jack
OPEN
OPEN
Phone Jack
1
2
3
4
5
6
7
8
9
10 11 12
13 14 15 16
16-position DIP-switch
Figure 7-1. PC Board
7.2 DIP-Switch Option Settings
Switch #1
Forced DTR -- "DTR"
(Asynchronous/Synchronous Mode/Leased Line/Dial-Up)
The modem must have a high DTR signal in order to operate. DTR is provided to the modem by the
terminal or computer to which it is attached, through pin 20 of the RS-232C/V.24 interface. If your
terminal or computer is not providing DTR to the modem, you can force the DTR signal high with DIP-
Switch #1.
DTR function normally =
DTR forced On
Factory Default Setting =
Switch #1 UP
Switch #1 DOWN
UP
=
Switch #2
Flow Control - &E4/&E5
(Asynchronous Mode/Leased Line/Dial-Up)
With Hardware Flow Control, the modem uses its RS-232C/V.24 interface to control the flow of data
from the computer or terminal to which it is attached. The CTS signal on Pin 5 of the RS-232C/V.24
is brought low to stop the flow of data, and is brought high to restart it. Place DIP-Switch #2 in the UP
position to enable Hardware Flow Control (&E4). Xon/Xoff Flow Control (&E5) is another flow control
method. Xon/Xoff characters in the data dictate the start and stop of data flow from the computer or
terminal. Place DIP-Switch #2 in the DOWN position to select Xon/Xoff Flow Control.
Hardware Flow Control (&E4)
Xon/Xoff Flow Control (&E5)
Factory Default Setting
=
=
=
Switch #2 UP
Switch #2 DOWN
UP
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Chapter 7 - DIP-Switch Settings
Switch #2
SDLC/BSC Option
(Synchronous Mode/Leased Line/Dial-Up)
Synchronous Data Link Control (SDLC) and Binary Synchronous Control (BSC) are two error
correction protocols used in the IBM Mainframe environment. Place DIP-Switch #2 in the UP position
to enable SDLC mode, and place DIP-Switch #2 in the DOWN position to enable BSC mode.
SDLC Mode
BSC Mode
Factory Default Setting =
=
=
Switch #2 UP
Switch #2 DOWN
UP
Switch #3
Enable/Suppress Responses -- "Q"
(Asynchronous Mode/Dial-Up)
In some Asynchronous mode applications, you may want to suppress all responses from the modem.
Place DIP-Switch #3 in the DOWN position to enable Result Code responses (Q0). Place DIP-Switch
#3 in the UP position, and answer mode is handled without responses and echo turned off (Q2), but
originate is still intelligent.
Enable Responses: Originate/Answer (Q0)
Suppress Responses: Answer (Q2)
Factory Default Setting
=
=
=
Switch #3 DOWN
Switch #3 UP
DOWN
Switch #3
dB Transmission Levels
(Asynchronous/Synchronous Mode/Leased Line)
DIP-Switch #3 adjusts dB transmission levels required by some phone carriers. Place DIP-Switch #3
in the DOWN position to enable -9 dB transmission. Place DIP-Switch #3 in the UP position to enable
-15 dB transmission.
-9dB Transmission
-15dB Transmission
Factory Default Setting =
=
=
Switch #3 DOWN
Switch #3 UP
DOWN
Switch #4
AS/400 Mode
(Synchronous Mode/Leased Line/Dial-UP)
The modem can function in the IBM AS/400 environment (appearing like an IBM5853 modem). First,
DIP-Switch #7 must be placed in the UP position. This establishes an RTS/CTS condition (state
typical for an IBM5853 modem in half-duplex mode). Next, place DIP-Switch #4 in the DOWN
position. This "spoofs" the modem into operating like an IBM5853 modem in AS/400 applications.
DIP-Switch #4 in the UP position disables this function. Note that the modem must be in Command
mode to allow AS/400 mode (DIP-Switch #8 DOWN); and in Synchronous mode (DIP-Switch #12
UP).
AS/400 Mode Enabled =
AS/400 Mode Disabled =
Factory Default Setting =
Switch #4 DOWN
Switch #4 UP
UP
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MultiModemBA User Guide
Switch #4
Unix UUCP Spoofing
(Asynchronous Mode/Leased Line/Dial-Up)
The modem can be configured for use with Unix equipment which employs ACK flow control to
monitor data integrity. The modem can do "UUCP spoofing", where the modem is able to generate
ACKs at the DTE interface. Data then is transmitted more time-efficiently, because the delay of
waiting for data to be received then waiting for the ACK to be returned at the remote end, is
eliminated. Placing DIP-Switch #4 in the DOWN position enables UUCP spoofing.
UUCP Spoofing Enabled
UUCP Spoofing Disabled
Factory Default Setting
=
=
=
Switch #4 DOWN
Switch #4 UP
UP
Switch #5
Enable/Disable Auto-Answer - "Ans"
(Asynchronous Mode/Synchronous Mode/Dial-Up)
In some originate-only applications, you may wish to disable the modem’s automatic answering
capabilities. This may be true if you have a telephone set attached to a modem and wish to receive
voice calls that you yourself would answer instead of the modem. Place DIP-Switch #5 in the UP
position to enable Auto-Answer. Place DIP-Switch #5 in the DOWN position to disable Auto-Answer.
Auto-Answer Enabled
Auto-Answer Disabled
(Factory Default Setting
=
=
=
Switch #5 UP
Switch #5 DOWN
UP)
Switch #5
Originate/Answer Mode
(Asynchronous/Synchronous Mode/Leased Line)
The modem functions in either Originate mode or Answer mode. Place DIP-Switch #5 in the DOWN
position to enable Originate mode. Place DIP-Switch #5 in the UP position to enable Answer mode.
Originate Mode Enabled
Answer Mode Enabled
(Factory Default Setting
=
=
=
Switch #5 DOWN
Switch #5 UP
UP)
Switch #6
Maximum Throughput Setting
(Asynchronous Mode/Leased Line/Dial-Up)
Some applications require you to dial into services with maximum throughput on, and other
applications where maximum throughput must be off (i.e., service not supporting error correction, or
the V.42 handshake interferes with logon sequence). DIP-Switch #6 is used for switching between
these two modes. This DIP-Switch controls three important parameters (error correction, speed
conversion and serial port speed), which in effect enables or disables maximum throughput.
Maximum Throughput Enabled =
Maximum Throughput Disabled =
Switch #6 UP
Switch #6 DOWN
UP
Factory Default Setting
=
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Chapter 7 - DIP-Switch Settings
Switch #6
Slave Clocking
(Synchronous Mode/Leased Line/Dial-Up)
In Synchronous mode, DIP-Switch #6 controls the option of having timing controlled by the receive
clock. The originate modem, in effect, adjusts to the answer (remote) modem. Place DIP-Switch #6 in
the DOWN position to enable Slave Clocking. Place DIP-Switch #6 in the UP position to disable
Slave Clocking.
Slave Clocking Enabled
Slave Clocking Disabled
Factory Default Setting
=
=
=
Switch #6 DOWN
Switch #6 UP
UP
Switch #7
Request To Send Forced - "RTS"
(Asynchronous/Synchronous Mode/Leased Line/Dial-Up)
If your computer or terminal uses RTS-CTS protocol (typically used in some synchronous
applications, but also if using hardware pacing for V.42 error correction or speed conversion), you
may want to set RTS to function independently of CTS (DIP-Switch #7 UP). For most applications,
especially asynchronous, this switch should be set so that RTS is forced On (DIP-Switch #7 DOWN)
RTS functions Normally
RTS forced On
Factory Default Setting
=
=
=
Switch #7 UP
Switch #7 DOWN
DOWN
Switch #8
Enable/Disable Command Mode -- "Com"
(Asynchronous/Synchronous Mode/Leased/Dial-Up)
In some applications you may want to disable the modem's Command mode so that the modem does
not recognize or react to AT or V.25bis commands. This may be true in strictly auto-answer
applications where no call origination is required. Place DIP-Switch #8 in the DOWN position to
enable Command mode. Place DIP-Switch #8 in the UP position to disable Command mode. The
factory default setting is Command mode enabled.
Disable Command Mode
Enable Command Mode
Factory Default Setting
=
=
=
Switch #8 UP
Switch #8 DOWN
DOWN
Switch #9
Digital Loopback Test
(Asynchronous/Synchronous Mode/Leased Line/Dial-Up)
When in Synchronous mode, this switch controls both Local Digital Loop and Remote Digital Loop
tests while on-line. When the Voice/Data switch is toggled to the Answer mode position (UP) and
DIP-Switch #9 is in the UP position, the modem performs the Local Digital Loopback test. When DIP-
Switch #9 is DOWN and the Voice/Data switch is toggled to Answer mode position (UP), the modem
performs the Remote Digital Loopback test.
Local Digital Loopback Test
Remote Digital Loopback Test =
Factory Default Setting
=
Switch #9 UP
Switch #9 DOWN
DOWN
=
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MultiModemBA User Guide
Switch #10
Leased Line/Dial-Up Operation -- "DDD"
(Asynchronous/Synchronous Mode/Leased Line/Dial-Up)
The modem operates in either leased-line or dial-up modes. This switch controls leased-line/dial-up
operation. Place DIP-Switch #10 in the UP position for Dial-Up operation. Place DIP-Switch #10 in
the DOWN position for Leased-Line operation
Dial-Up Operation
Leased Line Operation
Factory Default Setting
=
=
=
Switch #10 UP
Switch #10 DOWN
UP
Switch #11
"AT" Responses/Multi-Tech Responses
(Asynchronous Mode/Leased line/Dial-Up)
In Asynchronous mode, you can set the modem to respond with Result Codes according to the
"Multi-Tech" command response set (Switch #11 in the DOWN position), or to "AT" command
response set (Switch #11 in the UP position). The &Q command performs the same function
(choosing AT or Multi-Tech Result Codes), and is explained further in Section 5.3 of this manual.
"AT" Responses (&Q1)
"Multi-Tech" Responses (&Q0
Factory Default Setting
=
=
=
Switch #11 UP
Switch #11 DOWN
DOWN
Switch #11
Internal/External Clocking
(Synchronous Mode/Leased Line/Dial-Up)
In Synchronous mode, the transmit clock can be supplied by the DTE on pin 24 of the RS-232C/V.24
interface by placing DIP-Switch #11 UP. Place DIP-Switch #11 in the DOWN position to enable DCE
to control clocking (internal clock via pins 15 and 17 of the RS-232/V.24 interface).
External Clock (pin 24)
Internal Clock (pins 15/17)
Factory Default Setting
=
=
=
Switch #11 UP
Switch #11 DOWN
DOWN
Switch #12
Asynchronous/Synchronous Operation -- "Sync"
(Asynchronous/Synchronous Mode/Leased Line/Dial-Up)
The modem can operate in either Asynchronous mode or Synchronous mode. In Synchronous mode,
start and stop bits are eliminated. The modem's internal clock circuits on the RS-232C/V.24 pins 15
and 17 are activated. The modem's Command mode is not accessible in Synchronous mode. This
switch is a means to alternate and to access either mode. In Synchronous mode, you may want to
set the RTS forcing and CTS forcing DIP-Switches so that both of signals act normally (not forced
on).
Synchronous Operation
Asynchronous Operation
Factory Default Setting
=
=
=
Switch #12 UP
Switch #12 DOWN
DOWN
70
Chapter 7 - DIP-Switch Settings
Switches #13 and #14
Speed Switches
(Synchronous Mode/Leased Line)
DIP-Switches #13 and #14 are used to set the modem’s data transmission rate. Switches #13 and
#14 are used in combination, typically in leased-line and call origination applications.
Note: The modem baud rate command ($MBn) overrides the setting of these speed selection
switches (DIP switches #13 and #14).
28800 bps Operation
19200 bps Operation
14400 bps Operation
9600 bps Operation
=
=
=
=
Switch #13 UP and Switch #14 UP
Switch #13 DN and Switch #14 UP
Switch #13 UP and Switch #14 DN
Switch #13 DN and Switch #14 DN
Factory Default Setting =
Switch #13 UP and Switch #14 UP
Switch #15
Carrier Detect/DSR Forcing -- "DSR"
(Asynchronous/Synchronous Mode/Dial-Up/Leased Line)
Some terminals react in unusual ways to the toggling of the Carrier Detect (CD - RS-232C/V.24 pin
6) signals. The most common symptom is that the modem does not respond to commands, or does
not echo characters. In these cases, it is advisable to force these two signals On in order for the
terminal to communicate properly with the modem in Command mode. This is done by setting DIP-
Switch #15 DOWN. With DIP-Switch #15 in the UP position, both CD and DSR will be either on or off,
depending on the On-Line status.
CD and DSR normal
CD and DSR forced On
Factory Default Setting
=
=
=
Switch #15 UP
Switch #15 DOWN
UP
Switch #16
(Reserved for Future Use)
7.3 Speaker Volume Control
You can adjust the volume of the modem’s phone-line monitor speaker with a volume control knob,
located on the back of the modem next to the RS-232C connector (see Figure 9-1 for location). Turn
the knob clockwise to increase the modem's volume and counterclockwise to decrease speaker
volume.
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MultiModemBA User Guide
7.4 Recording Option Configurations
This section lets you record any changes you may have made to the DIP-Switch settings. Circle the
appropriate setting and record the effect for future reference.
DIP-Switches
Switch
Function
Position
Effect
#1
Force DTR/DTR from Interface*
UP*
DOWN
DTR Dependent on Interface
DTR Forced On at All Times
#2
Flow Control &E4*/&E5
(Async/Dial-Up/Leased Line)
UP*
DOWN
Hardware Flow Control
XON /OFF Flow Control
#2
SDLC*/BSC (Sync)
UP*
DOWN
SDLC Mode On
BSC Mode On
#3
Result Codes Enable*/Disable
(Async/Dial-up)
UP
DOWN*
Command Mode Response Off
Command Mode Response ON
#3
DbM Transmit (-9db/0dB)*/(-15db/-10dB) UP
-15 dB Transmission (leased line)
-9 dB Transmission (leased line)
(Async/Sync/Lease-Line)
DOWN*
#4
UUCP Enable/Disable*
(Async/Dial-Up/Leased Line)
UP*
DOWN
UUCP Spoofing Off
UUCP Spoofing On
#4
AS/400 Enable/Disable*
(Sync/Dial-Up/Leased line)
UP*
DOWN
AS/400 Mode Off
AS/400 Mode On
#5
Auto-Answer Enable*/Disable
(Async/Sync/Dial-Up)
UP*
DOWN
Automatic Answer On
Automatic Answer Off
#5
Answer*/Originate
(Async/Sync/Leased Line)
DOWN
UP*
Answer Mode On
Originate Mode On
#6
Max-Thru Enable*/Disable
(Async/Dial-Up/Leased)
UP*
DOWN
Max Throughput On
Max Throughput Off
#6
Slave Clock Enable/Disable*
(Sync/Dial-Up/Leased)
UP*
DOWN
Slave Clocking Off
Slave Clocking On
#7
RTS/Normal/Forced*
(Sync/Async/Dial/Leased)
UP
DOWN*
RTS Dependent on Interface
RTS Forced On at All Times
#8
Command Mode Enabled*
(Sync/Async/Dial/Leased)
UP
DOWN*
Command Mode Off
Command Mode On
#9
Local/Remote* LoopBack
(Async/Sync/Dial/Leased)
UP
DOWN*
Local Digital Loopback On
Remote Digital Loopback On
#10
#11
#11
#12
Dial-Up*/Leased-Line
UP*
DOWN
Dial-Up Operation
Leased-Line Operation
"AT"/"Multi-Tech" Result Codes*
(Asynchronous)
UP
DOWN*
AT Responses
Multi-Tech Responses
Internal Clocking*/External Clocking
(Synchronous)
UP
DOWN*
External Clocking Selected
Internal Clocking Selected
Sync/Async Mode*
UP
DOWN*
Synchronous Mode On
Asynchronous Mode On
* Factory Default Setting
72
Chapter 7 - DIP-Switch Settings
DIP Switches #13-14
Note: The modem baud rate command ($MBn) overrides the setting of these speed selection
switches (DIP switches #13 and #14).
SWITCH
#13/#14
#13/#14
#13/#14
#13/#14
CONDITION
UP/UP*
EFFECT
28.8 K bps Operation
19.2 K bps Operation
14.4 K bps Operation
9600 bps Operation
DOWN/UP
UP/DOWN
DOWN/DOWN
DIP Switches #15-16
SWITCH
#15
CONDITION
UP*
EFFECT
CD/DSR from Interface
CD/DSR Forced On
Not Used
#15
DOWN
UP
#16
#16
DOWN*
Not Used
*Standard Factory Default Setting
73
Chapter 8 - Warranty, Service and Tech Support
Chapter 8 - Warranty, Service, and Technical Support
8.1 Introduction
This chapter starts out with statements about your modem's 5-year warranty. The next section, Tech
Support, should be read carefully if you have questions or problems with your modem. It includes the
technical support telephone numbers, space for recording your modem information, and an
explanation of how to send in your modem should you require service. The final four sections explain
how to use our Bulletin Board Service (BBS), upgrading the modem via Flash PROM, a brief section
on the CompuServe/Internet forums and information on Multi-Tech's Fax-Back Service.
8.2 Multi-Tech Systems, Inc. Warranty & Repairs Policies
Warranty
Multi-Tech Systems, Inc., (hereafter “MTS”) warrants that its products will be free from defects in
material or workmanship for a period of two, five, or ten years (depending on model) from date of
purchase, or if proof of purchase is not provided, two, five, or ten years (depending on model) from
date of shipment.
MTS MAKES NO OTHER WARRANTY, EXPRESS OR IMPLIED, AND ALL IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
HEREBY DISCLAIMED.
This warranty does not apply to any products which have been damaged by lightning storms, water,
or power surges or which have been neglected, altered, abused, used for a purpose other than the
one for which they were manufactured, repaired by Customer or any party without MTS’s written
authorization, or used in any manner inconsistent with MTS’s instructions.
MTS’s entire obligation under this warranty shall be limited (at MTS’s option) to repair or replacement
of any products which prove to be defective within the warranty period or, at MTS’s option, issuance
of a refund of the purchase price. Defective products must be returned by Customer to MTS’s
factory – transportation prepaid.
MTS WILL NOT BE LIABLE FOR CONSEQUENTIAL DAMAGES, AND UNDER NO
CIRCUMSTANCES WILL ITS LIABILITY EXCEED THE PRICE FOR DEFECTIVE PRODUCTS.
Repair Procedures for U.S. and Canadian Customers
In the event that service is required, products may be shipped, freight prepaid, to our Mounds View,
Minnesota factory:
Multi-Tech Systems, Inc.
2205 Woodale Drive
Mounds View, MN 55112
Attn: Repairs, Serial # ____________
A Returned Materials Authorization (RMA) is not required. Return shipping charges (surface) will be
paid by MTS.
Please include, inside the shipping box, a description of the problem, a return shipping address (must
have street address, not P.O. Box), your telephone number, and if the product is out of warranty, a
check or purchase order for repair charges.
For out of warranty repair charges, go to www.multitech.com/documents/warranties
Extended two-year overnight replacement service agreements are available for selected products.
Please call MTS at (888) 288-5470, extension 5308 or visit our web site at
http://www.multitech.com/programs/orc/ for details on rates and coverage’s.
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MultiModemBA User Guide
Please direct your questions regarding technical matters, product configuration, verification that the
product is defective, etc., to our Technical Support department at (800) 972-2439 or email
ping, billing, etc., to our Repair Accounting department at (800) 328-9717 or (763) 717-5631, or email
Repairs for damages caused by lightning storms, water, power surges, incorrect installation, physical
abuse, or user-caused damages are billed on a time-plus-materials basis.
Repair Procedures for International Customers (Outside U.S.A. and Canada)
Your original point of purchase Reseller may offer the quickest and most economical repair option for
your Multi-Tech product. You may also contact any Multi-Tech sales office for information about the
nearest distributor or other repair service for your Multi-Tech product.
http://www.multitech.com/COMPANY/offices/DEFAULT.ASP
In the event that factory service is required, products may be shipped, freight prepaid to our Mounds
View, Minnesota factory. Recommended international shipment methods are via Federal Express,
UPS or DHL courier services, or by airmail parcel post; shipments made by any other method will be
refused. A Returned Materials Authorization (RMA) is required for products shipped from outside the
U.S.A. and Canada. Please contact us for return authorization and shipping instructions on any
International shipments to the U.S.A. Please include, inside the shipping box, a description of the
problem, a return shipping address (must have street address, not P.O. Box), your telephone num-
ber, and if the product is out of warranty, a check drawn on a U.S. bank or your company’s purchase
order for repair charges. Repaired units shall be shipped freight collect, unless other arrangements
are made in advance.
Please direct your questions regarding technical matters, product configuration, verification that the
product is defective, etc., to our Technical Support department nearest you or email
[email protected]. When calling the U.S., please direct your questions regarding repair
expediting, receiving, shipping, billing, etc., to our Repair Accounting department at
+(763) 717-5631 in the U.S.A., or email [email protected].
Repairs for damages caused by lightning storms, water, power surges, incorrect installation, physical
abuse, or user-caused damages are billed on a time-plus-materials basis.
Repair Procedures for International Distributors
Procedures for International Distributors of Multi-Tech products are on the distributor web site.
http://www.multitech.com/PARTNERS/login/
Copyright ã Multi-Tech Systems, Inc. 2001
10-Sep-01
8.3 Online Warranty Registration
If you have access to the World Wide Web, you can register your Multi-Tech product online at http://
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Chapter 8 - Warranty, Service, and Technical Support
8.4 Replacement Parts
SupplyNet, Inc., can supply you with replacement power supplies, cables and connectors for selected
Multi-Tech products. You can place an order with SupplyNet via mail, phone, fax or the Internet at the
following addresses:
Mail:
SupplyNet, Inc.
614 Corporate Way
Valley Cottage, NY 10989
Phone: 800 826-0279
Fax: 914 267-2420
Email: [email protected]
Internet:
8.5 Technical Support
Multi-Tech Systems has an excellent staff of technical support personnel available to help you get the
most out of your Multi-Tech product. If you have any questions about the operation of this unit,
please call 800 972-2439 (USA and Canada) or 763 785-3500 (international and local). Please have
modem information available. You can also contact Technical Support by e-mail at the following
addresses:
Country
France:
India:
U.K.:
U.S.A., Canada
Rest of world:
Email
Telephone
+(33) 1-64 61 09 81
+91 (124) 6340778
+(44) 118 959 7774
800 972-2439
+763 717-5863
Please note the status of the modem before contacting Technical Support. Status information can
include the state of the LED indicators, screen messages, diagnostic test results, problems with a
specific application, etc.
8.6 Internet Sites
Multi-Tech is a commercial provider on the Internet. Multi-Tech has a Web site at
and an ftp site at ftp://ftp.multitech.com
77
Appendixes
Appendix A - Upgrading Your Modem’s Firmware
Appendix A -- UpgradingYour Modem’s Firmware
Your modem is controlled by semi-permanent software, called firmware, which is stored in flash
memory. Firmware is nonvolatile; that is, it remains stored in memory when the modem is turned off.
However, it can be changed by either the manufacturer or the user as bugs are fixed or new features
are added.
Since the firmware in your modem is stored in flash memory, you can upgrade it yourself in a few
minutes by using the following procedures.
Upgrade Overview
The upgrade procedure consists of the following steps, which are described in greater detail in the
following sections.
1. Identify the model number and firmware version of your modem.
2. Identify the current version of the firmware at the Multi-Tech Web site or BBS. If your modem already
has the current firmware, there is no need to update it.
3. Download the upgrade file and the appropriate Flash Wizard for your modem.
4. Install the Flash Wizard and extract the firmware .HEX file from the file you downloaded.
5. Document and clear your stored parameters.
6. Upgrade the modem’s firmware using the .HEX file and the Flash Wizard.
7. Restore your parameters.
Step 1: Identify the Modem Firmware
You must know the model number and firmware version of your Multi-Tech modem to know whether
or not you should update it.
1. Run your favorite terminal program. If you are using Windows 95 or above, you can use Windows
HyperTerminal.
2. In the program’s terminal window, type AT&F. Even if you cannot see the AT&F command on your
screen, be sure to type it completely, and then press ENTER. If the modem does not respond with OK,
repeat the AT&F command.
3. Now type ATI, press ENTER, and record your results. The model number and firmware version should
appear .
Step 2: Identify the Current Firmware Version
Identify the current version of the firmware at the Multi-Tech Web site. If your modem already has the
current firmware, there is no need to update it.
2. Scroll down to your modem model number.
3. Look at the firmware version number for your modem.
4. If the firmware version number matches the firmware version number found in “Step 1: Identify the
Modem Firmware,” you have the current firmware version and do not need to be update.
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MultiModemBA User Guide
5. If the firmware version number is greater than the firmware version number found in “Step 1: Identify
the Modem Firmware,” your modem has an older firmware version. Continue with “Step 3: Download
the Upgrade File.”
Warning: The first digit of the new firmware must match the first digit of the old firmware, or the
modem may not work properly. E.g., if your current firmware version is 4.16, replace it only with 4.xx
firmware, not 6.xx firmware.
Step 3: Download the Upgrade File
procedure in “Step 2: Identify the Current Firmware.”
2. Download the upgrade file for your modem by clicking its name, and save the file in a temporary
folder on your hard disk.
3. In the same section of the Web page, click the Flash Wizard utility for your operating system to
download it, and save it in the same folder.
Step 4: Extract the Upgrade Files
1. Install the Flash Wizard utility by double-clicking the file name in Windows Explorer.
2. Extract the upgrade files by double-clicking the file name. The extracted files include a .HEX file,
which contains the upgrade data, and a Readme file.
3. Copy the upgrade .HEX file into the Flash Wizard folder, which, in a default installation, is at
C:\Program Files\MultiTech Systems\Flash Wizard\.
Step 5: Clear Your Stored Parameters
Before you flash your modem, you should record the parameters that are currently stored in it, so you
can reprogram it after flashing. After you have recorded them, send the AT&W1Z command to the
modem to clear the stored parameters.
1. Run your favorite terminal program. If you are using Windows 95 or above, you can use Windows
HyperTerminal.
2. In the program’s terminal window, type AT&V and press ENTER to list your modem’s current
parameters.
3. Record your parameters by saving the screens and sending them to your printer.
4. Type AT&W1Z and press ENTER to clear your stored parameters and reset your modem to factory
default.
5. Close the terminal program.
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Appendix A - Upgrading Your Modem’s Firmware
Step 6: Upgrade the Modem’s Firmware
Before you begin the following procedure, read the README.TXT file extracted from the upgrade
archive file. Note the file name for the new firmware (example: ARQG125A.HEX).
WARNING: Never install an older version of firmware over a newer version. Doing this WILL
DESTROY THE FLASH PROM! If the flash PROM is destroyed, the modem must be sent in for
repair.
1. Run Flash Wizard by double-clicking its icon or file name, or by selecting it from the Start menu. The
Identifying Devices dialog box is displayed as Flash Wizard locates and identifies the devices
connected to your system.
Note: If the message ERROR: No valid devices detected is displayed, verify that the modem is
turned on and that all cables are correctly and securely attached.
2. Click the modem to be upgraded, and then click Next to proceed.
3. Select the port to be upgraded from the Port list, select the appropriate .HEX file from the Hex File
list, and then click Next to continue.
Note: Do not use FLASHLDR.HEX. This file is used internally by Flash Wizard.
4. The Progress dialog box appears, showing a status bar that indicates the progress of the upgrade.
Caution: Any disruption of the program during this stage of the upgrade can cause your modem to
become inoperable. Wait for the Next button to become active before proceeding.
5. When the flash upgrade is complete, the message Programming Complete appears. Click Next to
continue.
6. The Results dialog box appears next. Click Finish to exit Flash Wizard.
Step 7: Restore Your Parameters
Your modem has been updated. You can now open your terminal program to reprogram your modem
parameters or to confirm the update by typing ATI in the terminal window and pressing ENTER.
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MultiModemBA User Guide
Appendix B - Troubleshooting
Your modem was thoroughly tested at the factory before it was shipped. If you are unable to make a
successful connection or if you experience data loss or garbled characters during your connection, it
is possible that the modem is defective. However, it is more likely that the source of your problem lies
elsewhere. Problems you may encounter include the following:
•
•
•
•
•
•
•
•
•
None of the LEDs light when the modem is on.
The modem does not respond to commands.
The modem dials but is unable to make a connection.
The modem disconnects while on-line.
The modem cannot connect when answering.
File transfer is slower than it should be.
I am losing data.
I am getting garbage characters on the monitor.
I can’t run my fax and communications software at the same time.
If you experience problems, please check the following possibilities before calling Tech Support.
None of the LEDs Light When the Modem Is On
When you turn on the modem, the LED indicators on the front panel should flash briefly as the
modem runs a self-test. If the LEDs remain off, the modem is probably not receiving power.
•
•
•
•
Make sure the modem’s power switch is on, especially if you normally turn on the modem by
turning on a power strip.
If the power supply is plugged into a power strip, make sure the power strip is plugged in and its
power switch is on.
Make sure the power supply module is firmly connected to the modem and to the wall outlet or
power strip.
If the power strip is on and the modem switch is on, try moving the modem power supply to
another outlet on the power strip.
•
•
Test that the outlet is live by plugging a lamp into it.
The modem or power supply may be defective. If you have another Multi-Tech modem, try
swapping modems. If the problem goes away, the first modem or power supply may be defective.
Call Tech Support for assistance.
CAUTION: Do not under any circumstances replace the power supply module with one designed for
another product, as it may damage the modem and void your warranty.
The Modem Does Not Respond to Commands
•
Make sure the modem is plugged in and turned on. (See “None of the LEDs Light When the
Modem Is On.”)
•
Make sure you are issuing the modem commands from the data communications software, either
manually in terminal mode or automatically by configuring the software. (You cannot send
commands to the modem from the DOS prompt.)
•
•
Make sure you are in terminal mode in your data communications program, then type AT and
press ENTER. If you get an OK response, your connections are good and the problem likely is in
your phone book entry or session settings.
Try resetting your modem by turning it off and on. Make sure there is a reset command (&F) in
your initialization string, or your modem may not initialize correctly.
82
Appendix B - Troubleshooting
•
If you don’t get an OK, the problem may still be in the communications software. Make sure you
have done whatever is necessary in your software to make a port connection. Not all
communications programs connect to the COM port automatically. Some connect when the
software loads and remain connected until the program terminates. Others can disconnect
without exiting the program (make sure the Connect icon looks plugged in). If the terminal reports
that it cannot make a connection, yet the modem’s TR indicator is on, click on the Window menu
to see if more than one terminal is open. The modem’s TR indicator shows that the software has
made a connection with the modem through the COM port.
•
•
Your communications software settings may not match the physical port the modem is connected
to. The serial cable may be plugged into the wrong connector—check your computer
documentation to make sure. Or you may have selected a COM port in your software other than
the one the modem is physically connected to—compare the settings in your software to the
physical connection.
If the modem is on, the cable is plugged into the correct port, the communications software is
configured correctly, and you still don’t get an OK, the fault may be in the serial cable. Make sure
it is firmly connected at both ends.
•
•
Is this the first time you have used the cable? If so, it may not be correct. Check the cable
description on the packaging to make sure the cable is the right one for your computer.
Peripheral expansion cards, such as bus mouse and sound cards, may include a serial port pre-
configured as COM1 or COM2. The extra serial port, or the card itself, may use the same COM
port, memory address, or interrupt request (IRQ) as your communications port. Be sure to
disable any unused ports.
To look for address or IRQ conflicts if you use Windows 3.1x, select File, Run in Program
Manager, type MSD, and press ENTER. Then select Mouse, COM Ports, and IRQ Status and
note the addresses and IRQs that are in use. If you find an IRQ conflict, note which IRQs are not
being used, then change one of the conflicting devices to use one of the unused IRQs. If you find
an address conflict, change the address of one of the conflicting devices.
To change a port address or IRQ in Windows 3.1x, double-click the Control Panel icon, then the
Ports icon. Click on the port you want to change, click Settings, click Advanced, and select the
new port address and/or interrupt. If you wish to use COM3 or COM4, note that COM3 shares an
IRQ with COM1, as does COM4 with COM2, so you should change their IRQs to unused ones, if
possible.
If you use Windows 95, right-click on My Computer, select Properties from the menu, click on the
Device Manager tab, double-click on Ports, then double-click on the Communications Port your
modem is connected to. In the port’s Properties sheet, click on the Resources tab to see the
port’s Input/Output range and Interrupt Request. If another device is using the same address
range or IRQ, it will appear in the Conflicting Device List. Uncheck Use Automatic Settings to
change the port’s settings so they do not conflict with the other device, or select the port the
conflicting device is on and change it instead. If you need to open your computer to change
switches or jumpers on the conflicting device; refer to the device’s documentation.
•
•
The serial port may be defective. If you have another serial port, install the modem on it, change
the COM port setting in your software, and try again.
The modem may be defective. If you have another Multi-Tech modem, try swapping modems. If
the problem goes away, the first modem is possibly defective. Call Tech Support for assistance.
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MultiModemBA User Guide
The Modem Dials But Cannot Make a Connection
There can be several reasons the modem fails to make a connection. Possibilities include
•
•
•
•
•
•
•
lack of a physical connection to the telephone line.
a wrong dial tone.
a busy signal.
a wrong number.
no modem at the other end.
a faulty modem, computer, or software at the other end.
incompatibility between modems.
You can narrow the list of possibilities by using extended result codes. To enable them, enter
ATV1X4 and press ENTER while in terminal mode, or include V1X4 in the modem’s initialization
string. When you dial again, the modem will report the call’s progress.
•
If the modem reports NO DIALTONE, check that the modem’s telephone line cable is connected
to both the modem’s LINE jack (not the PHONE jack) and the telephone wall jack. If the cable
looks secure, try replacing it. If that doesn’t work, the problem may be in your building’s
telephone installation. To test the building installation, plug a telephone into your modem’s
telephone wall jack and listen for a dial tone. If you hear a dial tone, your modem may be
installed behind a company phone system (PBX) with an internal dial tone that sounds different
from the normal dial tone. In that case, the modem may not recognize the dial tone and may treat
it as an error. Check your PBX manual to see if you can change the internal dial tone; if you
can’t, change your modem’s initialization string to replace X4 with X3, which will cause the
modem to ignore dial tones.
•
If the modem reports BUSY, the other number may be busy, in which case you should try again
later, or it may indicate that you have failed to add a 9, prefix to the phone number if you must
dial 9 for an outside line.
If you must dial 9 to get an outside line, the easiest way to dial it automatically is to include it in
the modem’s dial prefix, e.g., ATDT9,. Note the comma, which inserts a pause before the
number is dialed. By inserting 9, into the dial prefix, you do not have to include it in each directory
entry in the terminal.
To change the dial prefix in Windows Terminal, select Settings, Modem Commands. To change it
in Windows 95 HyperTerminal, select Call, Connect from the menu bar, click Dialing Properties,
and type 9 in the local and long distance boxes in How I Dial from This Location.
•
•
If the modem reports NO ANSWER, the other system has failed to go off-hook, or you might
have dialed a wrong number. Check the number.
If the modem reports NO CARRIER, the phone was answered at the other end, but no
connection was made. You might have dialed a wrong number, and a person answered instead
of a computer, or you might have dialed the correct number but the other computer or software
was turned off or faulty. Check the number and try again, or try calling another system to make
sure your modem is working. Also, try calling the number on your telephone. If you hear harsh
sounds, then another modem is answering the call, and the modems may be having problems
negotiating because of modem incompatibilities or line noise. Try connecting at a lower speed.
84
Appendix B - Troubleshooting
The Modem Disconnects While On-line
•
If you have call waiting on the same phone line as your modem, it may interrupt your connection
when someone tries to call you. If you have call waiting, disable it before each call. In most
telephone areas, you can disable call waiting by preceding the telephone number with *70 (check
with your local telephone company).
You can automatically disable call waiting by including the disabling code in the modem’s dial
prefix (e.g., ATDT*70,—note the comma, which inserts a pause before the number is dialed). To
change the dial prefix in Windows Terminal, select Settings, Modem Commands. To change it in
Windows 95 HyperTerminal, select Call, Connect from the menu bar, click Dialing Properties,
check this location has Call Waiting, and select the correct code for your phone service.
•
•
If you have extension phones on the same line as your modem, you or someone else can
interrupt the connection by picking up another phone. If this is a frequent problem, disconnect the
extension phones before using the modem, or install another phone line especially for the
modem.
Check for loose connections between the modem and the computer, the telephone jack, and AC
power.
The Modem Cannot Connect When Answering
•
Auto-answer may be disabled. Turn on auto-answer in your datacomm program or send the
command ATS0=1 to your modem in terminal mode.
File Transfer Is Slower Than It Should Be
•
•
•
•
•
You may have an older UART. For best throughput, install a 16550AFN UART or a Multi-Tech ISI
serial port card. See the “Quick Start” chapter for information on how to identify your UART.
If you are running under Windows 3.1 and have a 16550AFN UART, you must replace the
Windows serial driver, COMM.DRV, to take full advantage of the UART’s speed.
If you are using a slow transfer protocol, such as Xmodem or Kermit, try Zmodem or Ymodem/G
instead.
Is your line noisy? If there is static on your line, the modem has to re-send many blocks of data to
insure accuracy. You must have a clean line for maximum speed.
Are you downloading a compressed file with MNP 5 hardware compression enabled? Since
hardware data compression cannot compress a file already compressed by an archiving
program, the transfer can be marginally slower with data compression enabled than with it
disabled.
•
Try entering the L8 (List Online Diagnostics) command in on-line mode, making a screen print of
the diagnostics listing, and checking for parameters that may be unacceptable (number of
retrains, round trip delay, etc.).
I Am Losing Data
•
•
•
If you are using data compression and a high speed serial port, set the serial port baud rate to
four times the data rate.
Make sure the flow control method you selected in software matches the method selected in the
modem. If you have a Macintosh, you may have the wrong cable for hardware flow control.
Try entering the L8 (List Online Diagnostics) command in on-line mode, making a screen print of
the diagnostics listing, and checking for parameters that may be unacceptable (number of
retrains, round trip delay, etc.).
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MultiModemBA User Guide
I Am Getting Garbage Characters on the Monitor
•
Your computer and the remote computer may be set to different word lengths, stop bits, or
parities. If you have connected at 8-N-1, try changing to 7-E-1, or vice-versa, using your
communications software.
•
•
You may be experiencing line noise. Enable error correction, if it is disabled, or hang up and call
again; you may get a better connection.
At speeds above 2400 bps, the remote modem might not use the same transmission or error
correction standards as your modem. Try connecting at a slower speed or disabling error
correction. (With no error correction, however, line noise can cause garbage characters.)
•
Try entering the L8 (List Online Diagnostics) command in on-line mode, making a screen print of
the diagnostics listing, and checking for parameters that may be unacceptable (number of
retrains, round trip delay, etc.).
My Fax and Communications Software Won’t Run at the Same Time
Communications devices can be accessed by only one application at a time. Under DOS or Windows
3.1x, you can run either your fax software or your datacomm software, but not both at the same time,
unless you have a special communications device management application, such as Multi-Tech’s
Virtual Modem Driver. In Windows 95, you can have data and fax communication applications open
at the same time, but they cannot use the same modem at the same time.
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Appendix C - AT Command Summary
Apendix C - AT Command Summary
Command
AT
Values
Description
Attention Code that precedes most command strings
except A/, A: and Escape Codes.
RETURN
$
Pressing RETURN key executes most commands.
This symbol placed in dialing string enables the
modem to detect AT&T's "call card" tones for
accessing user's calling card to originate an on-line
connection.
A
Answer call, even if no ring present. Repeat last
command. (Do not precede this command with AT.
Do not hit RETURN to execute.)
A:
Continuous redial (10 redials in DOC units) of last
number until answered. (Not used Internationally.)
$An
#An
n = 0 or 1
*
*
$A0 discards data during auto-reliable time period.
$A1 buffers data during auto-reliable time period.
n = 0 thru 3
#A0 selects initial handshake at:33,600 to 31,200 to
28,800 to 24000 to 21,600 to 19,200 to 16,800 to
14,400 to 12,000 to 9600 to 4800 to 2400 to 1200 to
300 bps.
#A1 selects initial handshake at 33,600 bps only.
#A2 selects initial handshake at 33,600 to 31,200 to
28,800 to 24000 to 21600 to 19,200 to 16,800
19,200 to 14,400 to 9600 to 4800 bps.
#A3 selects initial handshake at 2400 to 1200 to 300
bps.
* Factory Default Setting
Bn
n = 0 or 1
n = 0 or 1
n = 0 or 1
*
*
B0 selects V.21 answer tone.
B1 selects Bell answer tone.
&Bn
&BSn
&B0 means normal transmit buffer size.
&B1 means reduced transmit buffer size.
&BS0 means maximum transmit block size of 64
characters.
*
*
&BS1 means maximum transmit block size of 256
characters.
$BAn
n = 0 or 1
$BA0 means speed conversion is on.
$BA1 means speed conversion is off.
&Cn
n = 0,1,2,4
&C0 forces Carrier Detect on.
*
*
&C1 lets Carrier Detect act normally.
&C2 lets Carrier Detect drop S24 time on
disconnect.
&C4 resets modem when Carrier Detect drops.
&CDn
n = 0 or 1
&CD0 execute cleardown on disconnect.
&CD1 do not execute cleardown on disconnect.
Ds
s = phone #
Dial a telephone number “s,” where s may include
up to 60 digits or T, P, R, comma and ; characters.
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MultiModemBA User Guide
Command
Values
Description
DsNd
s = phone #
Store telephone number. To store, phone d = 0 thru
9 number ”s“ is entered and followed by N and then
Directory Number “d.”
&Dn
n = 0 thru 3
&D0 DTR is ignored
&D1 means modem returns to command mode.
&D2 lets modem react to DTR normally.
&D3 causes modem to reset to modem default
parameters.
*
%DFn
n = 0 or 1
n = 0 or 1
*
*
%DF0 Line Probe Data in Graph Format.
%DF1 Line Probe Data in Table Format.
%DPn
%DP0 do not read Line Probe Information from DSP
during handshaking.
%DP1 read Line Probe Information from DSP during
handshaking.
$Dn
En
n = 0 or 1
*
$D0 disables DTR Dialing.
$D1 enables DTR Dialing.
n = 0 or 1
E0 means do not echo Command Mode Character.
E1 means do echo Command Mode characters.
*
*
&En
n = 0 thru 15
&E0 means no error correction.
&E1 means V.42 Auto-reliable Mode.
&E2 means V.42 Reliable Mode.
&E3 means no modem-initiated flow control.
&E4 means CTS modem-initiated flow control.
&E5 means Xon/Xoff modem-initiated flow control.
&E6 means Xon/Xoff not passed through.
&E7 means Xon/Xoff passed through.
&E8 means Enq/Ack pacing off.
*
*
*
*
&E9 means Enq/Ack pacing on.
&E10 means Normal Mode flow control off.
&E11 means Normal Mode flow control on.
&E12 means Pacing off.
*
&E13 means Pacing on.
&E14 means data compression disabled.
&E15 means data compression enabled.
*
*
$EBn
n = 0 or 1
n=0 thru 5
$EB0 enables 10 bit mode.
$EB1 enables 11 bit mode.
%En
% E0 = Modem Won’t Escape.
% E1 = +++ Method (default setting).
% E2 = Break Method.
*
% E3 = Either +++ or Break Method.
% E4 = No "OK" Response to +++
% E5 = "OK" Response to +++
#Fn
n = 0 thru 2
#F0 means no fallback when on-line.
#F1 means fallbackwhen on-line (increments of
2400 bps).
*
#F2 means fallback to 4800 bps/fall forward if line
improves (increments of 2400 bps).
88
Appendix C - AT Command Summary
&Fn
n = 0, 8 or 9
&F loads factory default values from ROM.
*
&F8 reads factory default values and switch settings
when &F is issued.
&F9 reads parameters stored in non-volatile
memory when &F is issued.
$Fn
n = 0 or 1
$F0 means do not fall back to normal connect if CR
received.
*
*
$F1 means fall back to normal connect if CR
received.
&Gn
n = 0, 1 or 2
&G0 turns off CCITT guard tones.
&G1 turns on CCITT 550 Hz guard tone.
&G2 turns on CCITT 1800 Hz guard tone.
Hn
n = 0 or 1
H0 means Hang Up (go on hook).
H1 means Go Off Hook.
$Hn
n = 1 thru 3
$H1 brings up Help Screen #1.
$H2 brings up Help Screen #2.
$H3 brings up Help Screen #3.
In
n = 0,1or 2
Read Only
I0 requests modem ID #.
I1 requests firmware revision #.
I2 for MTS internal use.
I9
Command enables display of Windows 95
Autodetect characteristics
L
Lists all stored telephone numbers in memory.
L5 lists all current operating parameters.
L6 lists all current S-Register values.
L7 lists additional parameters.
L5
L6
L7
L8
L8 lists On-Line Diagnostics.
L9
L9 Displays Signal Strength Information.
L10 Displays Signal to Noise Ratio Information.
L11 Displays Noise Information.
L10
L11 (
#Ln
n = 0 thru 3
n = 0 thru 3
*
*
#L0 means modems negotiate V.42 Mode.
#L1 means MNP on and LAP-M off.
#L2 means LAP-M on and MNP off.
#L3 means no detection phase but go directly to
LAP-M.
Mn
M0 means Monitor speaker always Off.
M1 means Monitor speaker On until carrier detected
M2 means Monitor speaker always On.
M3 Monitor speaker on during dialing/off during
handshaking.
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MultiModemBA User Guide
$MBn
n = speed
$MB75 selects CCITT V.23 mode.
$MB300 selects 300 bps on-line.
$MB1200 selects 1200 bps on-line.
$MB2400 selects 2400 bps on-line.
$MB4800 selects 4800 bps on-line.
$MB9600 selects 9600 bps on-line.
$MB14400 selects 14400 bps on-line
$MB19200 selects 19200 bps on-line
$MB28800 selects 28800 bps on-line
$MB33600 selects 33600 bps on-line
*
*
&Mn
Nd
n = 0 or 1
&M0 selects Async when on-line.
&M1 selects Sync when on-line.
d = 0 thru 9
Dial stored telephone number “d” (Do not include the
letter D in this command.)
NdNe
d = 0 thru 9
e = any other
number 0
thru 9
Number Linking. If first number dialed is
busy, another stored number may be
automatically dialed. In example, stored
number d is dialed, and if busy, stored
number e is dialed.
O
Exit Command Mode and go into On-Line Mode.
Modem will pulse-dial numbers following the P.
P
*
*
&Pn
n = 0 or 1
&P0 means 60-40 pulse ratio.
&P1 means 67-33 pulse ratio.
Qn
n = 0, 1 or 2
*
Q0 means Result Codes sent.
Q1 means Result Codes will be suppressed (quiet).
Q2 means Dumb Answer Mode.
&Qn
Rn
n = 0 or 1
n = 0 or 1
n = 0, 1 or 2
*
*
&Q0 selects Multi-Tech command set.
&Q1 selects AT command set.
R0 means modem will not reverse modes.
R1 means modem will reverse modes.
&Rn
&R0 lets Clear to Send act normally.
&R1 forces Clear to Send on.
*
&R2 drops for 1 second on disconnect.
&RP
Command Initiates a Retrain that makes the
processor read Line Probe Information (valid only in
V.34 mode).
$Rn
n = 0 or 1
n = 0 or 1
*
*
$R0 means disconnect after 12 retransmits.
$R1 means do not disconnect after 12 retransmits.
&RFn
Sr=n
&RF0 selects CTS follows RTS.
&RF1 selects CTS to act independently
r = 0-11, 13,
Sets value of Register “r” to value of “n”,
15-19, 24-26,
29, 30, 32, 34...
where “n” is entered in Decimal format.
Sr?
r = 0-11, 13,
15-19, 24-26,
30, 32 or 34...
Reads value of Register “r” and displays
value in 3-digit Decimal format.
90
Appendix C - AT Command Summary
$SBn
n = speed
$SB300 selects 300 bps at serial port.
$SB1200 selects 1200 bps at serial port.
$SB2400 selects 2400 bps at serial port.
$SB4800 selects 4800 bps at serial port.
$SB9600 selects 9600 bps at serial port.
$SB19200 selects 19,200 bps at serial port.
$SB38400 selects 38,400 bps at serial port.
$SB57600 selects 57600 bps at serial port.
$SB115200 selects 115200 bps at serial port.
*
*
*
*
&SFn
n = 0 or 1
&SF0 selects DSR follows CD.
&SF1 selects DSR independent.
&Sn
n = 0, 1 or 2
&S0 forces Data Set Ready On.
&S1 lets Data Set Ready act normally.
&S2 Data Set Ready drop is regulated by S24 on
disconnect.
$SPn
n = 0 or 1
n = 4 or 5
$SP0 disables UUCP Spoofing
$SP1 enables UUCP Spoofing
T
Modem will tone-dial numbers following the T.
&Tn
&T4 means Enable Response to Request for
Remote Digital Loopback.
*
*
&T5 means Disable Response to Request for
Remote Digital Loopback.
#Tn
n = 0 or 1
#T0 turns off Trellis Coded Modulation
#T1 turns on Trellis Coded Modulation
Un
n = 0, 1, 2, or 3
U0 places modem in Analog Loop Originate Mode.
U1 places modem in Analog Loop Answer Mode.
U2 places modem in Remote Digital Loopback test
mode.
U3 places modem in Local Digital Loopback test
mode.
$VDn
n= 0 or 1
n = 0 or 1
*
*
$VD0 disables Voice/Data Dialing
$VD1 enables Voice/Data Dialing
Vn
V0 means Result Codes sent as digits (terse
response).
V1 means Result Codes sent as words (verbose
response).
W
Wait for new dial-tone.
&Wn
n = 0 or 1
&W0 causes modem to store its current parameters
in non-volatile RAM, and modem will load these for
future sessions instead of reading factory ROM
defaults, unless &F command used.
*
&W1 causes modem to not store parameters.
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MultiModemBA User Guide
Xn
n = 0,1,2,3 or 4
*
X0 selects Basic Result Codes (w/o CONNECT
1200, CONNECT 2400).
X1 selects Extended Result Codes (w/CONNECT
1200, CONNECT 2400).
X2 selects Standard AT Command set with NO
DIAL TONE.
X3 selects Standard AT Command set with BUSY.
X4 selects Standard AT Command set with NO
DIAL TONE and BUSY.
#Xn
Yn
Z
n= 0 or 1
n = 0 or 1
*
*
#X0 selects single XOFF character sent until XON
level returns.
#X1 selects multiple XOFF characters after buffer
level is full.
Y0 disables sending or responding to long space
“break”.
Y1 enables sending or responding to long space
“breaks”.
All configuration parameters are reset to default
values.
,
In Dial Command
In Dial Command
In Dial Command
In Dial Command
Causes pause during dialing.
;
Causes return to Command Mode after dialing.
Causes modem to flash On-Hook.
!
@
Causes modem to wait for ringback, then 5 seconds
of silence before processing next part of command.
+++AT<CR>
In-band Escape Sequence. Places modem in
Command Mode while still remaining On-Line. Enter
+++ followed by the letters A and T, up to ten
command characters, and a RETURN.
BREAK AT<CR>
Out-of-band Escape Sequence. Places modem in
Command mode while still remaining On- Line.
Enter a BREAK signal, followed by the letters A and
T, up to sixty command characters, and hit
RETURN.
* Factory Default Setting
92
Appendix C - AT Command Summary
Callback Security/Remote Configuration Command Summary
Command
#DBn
Description
#DB0 disables Callback Security and answering Yes
to the prompt turns off Callback Security and erases
stored phone numbers and passwords. Answering
No to the prompt aborts the command.
#DB1 activates remote and local password security.
#DB2 activates remote password security.
#CBNyyxxxxxx
Callback password with xxxxxx being callback
password and yy being the memory location.
Callback password xxxxxx must start with a non-
numeric character and upper/lower case sensitive.
Callback password xxxxxx must be a minimum of 6
and maximum of 10 characters. yy memory
locations are from 0 to 29. Must specify P (pulse) or
T (tone) dialing in string.
+ - Dxxxxxx???Nxx
Callback Phone Numbers xxxxxx with the +
preceding the phone number indicating the callback
modem phone number for the corresponding
password at the same memory location. The (-)
preceding the phone number enables direct entry
when the caller uses the correct password without
the callback modem having to return the call. The
??? entry at the end of the phone number
represents an extension added to the main phone
number. The Nxx is the memory location of the
callback phone number and password.
#Pn
Parity of the prompt messages sent by the callback
modem.
#P0 is no parity
#P1 is odd parity
#P2 is even parity
#RCBNxx
#RDNxx
Erases the callback password stored at memory
location xx. Memory locations are 0 to 29.
Erases the callback phone number stored at
memory location xx. Memory locations are 0 to 29.
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MultiModemBA User Guide
Password Command Summary
Command
Description
#Ixxxxxxxxxx
Login Password is any keyboard characters (x)
(upper/lower case sensitive), minimum 6 and
maximum 10 characters. The default Login
Password is #IMULTI-TECH.
#Syyyyyyyyyy
Setup Password is any keyboard characters (y)
(upper/lower case sensitive), minimum 6 and
maximum 10 characters. The default Setup
Password is #SMODEMSETUP.
94
Appendix C - AT Command Summary
V.25bis Commands
Command
Description
$Vn
$V0 returns modem to AT command mode when in
V.25bis mode.
$V1 enables V.25bis mode of operation.
$V2 allows modem to receive one V.25bis command
while in AT command mode without leaving AT
command mode.
$V5 DSR follows DTR in V.25bis mode.
$V6 DSR does not follow DTR in V.25bis mode.
Changes the serial bps rate.
CSPs
CSP0300 - 300 bps
CSP1200 - 1200 bps
CSP2400 - 2400 bps
CSP4800 - 4800 bps
CSP9600 - 9600 bps
CSP19200 - 19200 bps
CSP38400 - 38400 bps
CSP57600 - 57600 bps (2834
CSP115200 - 115200 bps
CRNdd
Dials phone number dd where dd can be up to 20
characters (0 through 9, *, #, P, T and :). Phone
number is checked against the Delayed and
Forbidden Number lists before dialed.
CRIdd;nn
DIC or CIC
Dials dd same as CRN Command and ignores nn
identification string. The disregard or connect to
incoming calls commands are used for auto-answer
operations.
DIC stops the modem from answering incoming
calls.
CIC causes the modem to answer incoming calls.
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MultiModemBA User Guide
Appendix D - V.25bis Operation
Chapter 4 described a set of commands which let the modem dial, hang-up, and be configured for
various applications. However, these commands, the AT command set, are only functional when the
DTE transmits data asynchronously. That is, they cannot be used with synchronous equipment such
as that found in IBM's Binary Synchronous Communications (BSC) and Synchronous Data Link
Control (SDLC)* environments.
The ITU V.25bis commands provide you with an alternate set of commands and responses to those
described in Chapter 5 for applications in which the DTE is synchronous. V.25bis commands support
dialing functions in asynchronous or synchronous mode according to the recommendations of the
ITU; however, the AT commands are understood to reign in the asynchronous world, while the
V.25bis commands are relegated to the synchronous world of datacomm. If you need to establish a
datacomm link over Public Switched Telephone Network (PSTN) dial-up services, and your
equipment outputs a synchronous data stream, V.25bis commands are essential. V.25bis mode AT
commands do not include any modem configuration commands. You can execute normal AT
commands in V.25bis mode for modem configuration.
Delayed and Forbidden Numbers
V.25bis provides the facility to delay failed call retry attempts by putting numbers that failed to
connect on a special Delayed Number list. Subsequent dialing of these numbers will be delayed (time
specified by a country regulation) and an appropriate message displayed. If the number is retried
more than the maximum allowed number of times (number is also specified by country regulation), it
is placed on the Forbidden Numbers list, and no further retries will be allowed. When the Forbidden
Numbers list is full, no dialing is allowed and a CFIFF indication is given. The modem in AT command
mode will respond with NO CARRIER. If country regulations require that the Forbidden Numbers list
be checked in AT mode, then NO CARRIER will be the response to a dial attempt in AT mode.
Numbers will also be put on the Forbidden Numbers list if the Delayed Numbers list is full and a new
number fails for the first time. In that case, the new number will be added to the Delayed Number list
and the oldest existing number added to the Forbidden Numbers list. Numbers are removed from the
Forbidden Numbers list by after a certain time has past (also by country regulation).
Some country regulations have numbers remain on the Forbidden Numbers list permanently. The
Delayed Number and Forbidden Numbers lists are eight numbers long (20 characters each).
V.25bis Operation
Operation in V.25bis mode is similar to AT command mode in that certain DIP-Switch functions are
important to its operation. V.25bis does not include any speed detection for asynchronous mode, so
when you are giving commands, you must stay in your initial speed (i.e., if you change your terminal
speed while entering an AT command, you will get no responses). In synchronous mode, the modem
supplies the clock, so the synchronous terminal “knows” the speed.
You must be in V.25bis mode for the commands described here to function. Most AT commands will
also function, except those associated with dialing such as ATD, ATN, ATO, and ATU. To get into
V.25bis mode, you type AT$V1. At this point your modem does no more speed or parity detection
(things associated with asynchronous operation). To get out of V.25bis mode and back into AT
command mode, enter AT$VO. The AT$V2 command allows you to run one V.25bis command from
AT command mode without
leaving AT command mode.
There is no command to select between asynchronous and synchronous V.25bis operation. The
position of DIP-Switch #12 selects between modes. For synchronous mode, DIP-Switch #12 must be
UP, and the AT command mode enabled.
96
Appendix D - V.25bis Operation
Another asynchronous mode concern is the problem of connecting at a different speed than the
speed at which the serial port is set. If your modem port speed is different from the serial port speed,
you must either:
1)
2)
Enable speed conversion and have flow control on, or
Enable connect responses (with the ATX1 command) and change the serial baud rate
after receiving a connect message.
If the $VD1 command is entered when in Auto-Answer mode, the modem answers immediately upon
receiving the first ring.
There is no disconnect message (NO CARRIER) if a normal connection is made.
V.25bis Set-Up and Initialization
Before you operate your modem in the V.25bis mode, you need to make sure it is set up properly
(various RS-232 lines such as DSR and CTS act as specified in the V.25bis standard). Setup
involves proper DIP-Switch settings and soft-switches (software controlled conditions).
V.25bis DIP-Switches
#1
#2
#3
#4
#5
#6
Unforced DTR
NA
NA
NA
Auto-Answer enabled
Async - Max throughput set
Sync - Slave Clocking unforced
Command Mode forced
Digital Loopback Off
Dial-Up
#8
#9
#10
#11
#12
Async - AT/Multi-Tech Resp.
Async/Sync mode set per requirements
V.25bis Mode AT Commands
The following commands will either alter standard V.25bis behavior (so you must be careful in their
use) or they are not allowed, as indicated. All other commands can be used in V.25bis operation.
A
Not Allowed
A/
Not Allowed
A:
Not Allowed
D
Not Allowed
D...N
Not Allowed
$D
Alters Operation ($D1 in V25bis is direct call mode)
E
Alters Operation
&F
Alters Operation (removes modem from asynchronous V.42bis mode)
N
Not Allowed
N...N
Not Allowed
O
Not Allowed
P
Not Allowed
T
Not Allowed
U
Not Allowed
W
Not Allowed
X
Alters Operation (X0 no connect message, X1 connect message)
,
;
!
@
Not Allowed
Not Allowed
Not Allowed
Not Allowed
Not Allowed
+++AT<CR>
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MultiModemBA User Guide
V.25bis Responses (Result Codes)
When in V.25bis mode (the AT$V1 command executed), your modem provides you with several
responses which can help you follow the progress of V.25bis operations. These are similar to the
Result Codes associated with AT Command mode operation. The V.25bis responses are in the form
of three-character mnemonics as listed below:
INC
Incoming Call (same as RING indicator)
A valid V.25bis command has been attempted
Call delayed for t minutes (number on Delayed list)
Call failure indicator where rr equals:
et - Engaged tone (same as BUSY)
nt - Call Answered but No Answer Tone
ab - Call Not Answered
VAL
DLCt
CFlrr
fc - Number on Forbidden List
ns - Number not stored in memory
ua - User Abort
nd - No Dialtone
ff - Forbidden List full
LSNmm;dd...dd
LSDmm;dd...dd
LSFmm;dd...dd
CON ssss
Phone number in V.25bis memory
Phone number on the Delay list
Phone number on the forbidden list
Connection at ssss speed (if X1 in effect)
V.25bis AT Commands
The AT commands associated with V.25bis mode are described as follows. Note that one command
enables and disables V.25bis mode and the rest are only operable in the V.25bis mode.
Enable/Disable V.25bis Mode ($V) Command
The function of the $V command is to select the V.25bis mode in asynchronous mode. (Synchronous
mode is set up with switches. For example, the modem could be in AT command mode, (AT$V1),
and if synchronous mode is enabled with AT Command mode enabled, then V.25bis mode is
selected). Prior to executing this command, make sure that your modem is properly set up to perform
the type of operation you will be performing. Refer to the initialization section of this appendix for
information about modem set-up. When in V.25bis mode, most normal AT commands will also
function (except D,N,O and U). V.25bis operates in asynchronous or synchronous modes (depending
on the position of DIP-Switch #12), and does not check for terminal speed (so do not change speeds
while in this mode) or parity. In synchronous mode, speed is not important since the internal clocks
provide synchronization.
To place your modem in V.25bis mode from asynchronous mode, enter the AT$V1 command. To
return to AT command mode, enter the AT$V0 command. AT$V2 allows you to run one V.25bis
command from AT command mode without leaving AT command mode (the V.25bis command
follows $V2 on the command line).
Change Serial Baud Rate (CSP) Command
The CSP command will change the serial baud rate of your modem by entering CSPsssss where
sssss can equal:
0300
1200
2400
4800
9600
19200 =
38400 =
57600 =
115200 =
=
=
=
=
=
300 bps
1200 bps
2400 bps
4800 bps
9600 bps
19200 bps
38400 bps
57600 bps
115200 bps
98
Appendix D - V.25bis Operation
Dial Phone Number Provided (CRN) Command
The CRN command permits the dialing of the phone number immediately following it (from the
command line). It is similar to the D command of the AT command set, except that the number is first
checked against the Delayed Number and Forbidden Number list. If permitted, depending on the
country regulations in effect, the number will then be dialed. For example, if you enter CRN7859875
and hit RETURN, your modem will check the two lists. If the number is on the Delayed Numbers list,
you can dial that number again after t minutes have passed. If the number is on the Forbidden list, a
CFIFC message will be displayed.
You can use various commands from the AT command set within the CRN command line to facilitate
the dialing process, such as P, T, or : for pulse dialing, tone dialing and wait for dial tone. V.25bis
supports “smart” dialing.
To dial a phone number, enter CRNdd...dd where dd...dd is the phone number, which can be up to
20 characters long using any character on the telephone pad (0 through 9, *, #, P, T, and :).
Some additional dialing characters may be available, based on country regulations.
Listing Delayed Phone Numbers (RLD) Command
When a phone number is dialed by a CRN command and a connection is not made, the number is
entered in the modem's V.25bis Delayed Number list along with the number of retry attempts. Any
further dialing attempts will be delayed some amount of time (determined by the regulations of each
country). While the delay is in progress, the modem will give a DLC indication. The list contains eight
numbers. When filled, the next number failing “bumps” off the oldest number on the list onto the
Forbidden Number list. Numbers on the Delayed Number list that succeed in a connect attempt are
removed. If a certain number of failed attempts occur (the number of failed attempts is specified by
each country), the number is entered into the V.25bis Forbidden Phone Number List. Forbidden
phone numbers cannot be dialed at all. To list the phone numbers on the V.25bis Delayed Phone
Number List, enter RLD and hit RETURN.
Listing Forbidden Phone Number (RLF) Command
Those phone numbers that have failed to connect the required number of times as specified by
country regulations are removed from the Delayed Number list and entered onto the V.25bis
Forbidden Number list. Numbers on the Forbidden Number list cannot be dialed at all for some
maximum amount of time, which is also specified by country regulations. In some countries, the time
might be one hour, and in others the number may never be dialed again. The forbidden list is eight
numbers long, with the newest number replacing the oldest if the memory is full. To list the numbers
in the Forbidden list enter RLF and hit RETURN.
Disregard or Connect to Incoming Calls (DIC or CIC) Command
The Disregard or Connect to Incoming Calls commands are used for Auto-Answer operations.
Depending on the country regulations, your modem will wait some amount of time or number of rings
before answering the call. During that time, you can stop the modem from answering the call by
entering the DIC (Disregard Incoming Calls) command. CIC (Connect to Incoming Calls) command
will cause your modem to answer the call (either reversing the effect of a DIC command or simply
have your modem answer the call immediately without waiting the regulation time before answering).
99
MultiModemBA User Guide
DTR Dialing ($D) Command
DTR Dialing is an alternate method of causing the modem to automatically dial a number. Data
Terminal Ready (DTR) is a signal that comes into the modem from the terminal or computer to which
it is connected via pin 20 of the RS-232 interface. In DTR Dialing, the modem will automatically dial a
stored number as soon as it receives a high DTR signal. The DTR Dialing method is popular when
using the modem in synchronous applications.
To enable DTR Dialing, enter command AT$D1 and hit Return. The modem will now dial the phone
number you have stored as N0 when it receives a high DTR signal.
DTR must remain high for the duration of the call, until disconnect. To disable DTR Dialing, enter the
command AT$D0 (or AT$D) and hit RETURN.
When you use DTR Dialing, be sure that DIP-Switch #1 is in the UP position, so that DTR is not
forced on. In addition, when using DTR Dialing in a synchronous application, be sure that DIP-Switch
#8 is in the UP position to disable V.25bis Command mode.
ITU V.25bis Country Specific Information
Due to the flexibility of the V.25bis standard, each country may establish specific regulations
governing the way operations are handled. The purpose of this document is to detail each country's
specific regulations that affect operation of V.25bis in Multi-Tech modems.
1. Italy
a)
b)
c)
Command/Indicationmodifications
1. Phone number indications include status ;ZPSTTT
a)
b)
c)
d)
Z - U, D, or F, for Unrestricted, Delayed or Forbidden
P - Delay time if delayed
S - Number of retries so far
TTT - Interdiction time to further attempts
Delayed and Forbidden list behavior
1.
2.
3.
4.
5.
5 retries without delay
2 minute delay between next 4 retries
After 9 retries the number is put on the forbidden list
120 minute timer is started on entry to delay list
When it runs out, the number is removed from which ever list it is on
Auto-Answer mode behavior
1.
2.
3.
Auto-Answer in 5 seconds if no DIC
Get 10 seconds after DIC to enter CIC
If 10 seconds times out then no connection is possible
2. Switzerland
a)
Command/Indicationmodification
1.
2.
3.
4.
Modem must remain on-hook for 5 seconds after disconnect
Modem must remain on-hook for 5 minutes after 4 consecutive failed calls
If modem must remain on-hook, then it is “paused”
If the modem is paused and a call is attempted a PAU indication is given.
a) PAUt Modem is paused for t minutes
b)
c)
Delayed and Forbidden list behavior
1.
2.
3.
2 minute delay between 4 retries
After 4 retries the number is put on the forbidden list
The number remains on the forbidden list forever
Auto-Answer behavior
1. Auto-Answer mode after 2 rings if no DIC
100
Appendix E - MultiModemBA Cables
3.
Austria
a)
b)
Command/Indication modification (none)
Delayed and Forbidden list behavior
1.
2.
No delay between retries
After 2 retries to numbers that answer, but give no answer tone (CFINT), the
number is put on the forbidden list
3.
After 10 retries with busy or no dialtone, the number is put on the forbidden
list
4.
5.
The number remains on the forbidden list forever
Delayed and Forbidden Numbers lists are checked when dialing in AT mode.
If dialing is not possible then NO CARRIER is the response.
c)
Auto-Answer behavior
1.
Auto-Answer in 5 seconds if no DIC
4. France
a)
b)
Command/Indication modification (none)
Delay and Forbidden list behavior
1.
2.
3.
4.
2 min. delay after 1st call, 4 after 2nd, 6 after 3rd, etc.
After 5 retries, the number is put on the forbidden list
The number remains on the forbidden list forever
Delayed and Forbidden Numbers lists are checked when dialing in AT
command mode. If dialing is not possible then No Carrier is the response.
c)
Auto-Answer mode behavior
1.
Auto-Answer in 5 seconds if no DIC
5. Belgium
a)
b)
Command/Indication modification (none)
Delay and Forbidden list behavior
1.
2.
3.
1 min. delay between calls
After 4 retries, the number is put on the forbidden list
The number remains on the forbidden list for 1 hour after entry to forbidden
list
4.
Delayed and Forbidden Numbers lists are checked when dialing in AT
command mode. If dialing is not possible then No Carrier is the response.
c)
Auto-Answer behavior
1.
Auto-Answer in 5 seconds if no DIC.
6. Singapore
a)
Command/indicationmodifications
1.
Dialing digit ‘=’ means wait for dialtone (acts the same as ‘:’ in dialing string).
b)
Delay and Forbidden list behavior
1.
2.
3.
4.
5.
5 retries without delay
2 minute delay between next 4 retries
After 9 retries the number is put on the forbidden list
120 minute timer is started on entry to delay list
When it runs out, the number is removed from whichever list it is on.
101
MultiModemBA User Guide
Appendix E - MultiModemBA Cables
These cables connect your modem to your terminal or computer’s serial port.
25-PIN DTE
Connector
25-PIN DCE
Device
TD
RD
2
3
2
3
4
5
6
7
8
TD
RD
RTS 4
CTS 5
DSR 6
GND7
RTS
CTS
DSR
GND
CD
CD
8
DTR20
RI 22
20 DTR
22 RI
Figure E-1. RS232 Cable (IBM PC)
1
2
3
4
5
6
RED (Tip)
GREEN (Ring)
To Terminal
Block Screws
(Transmit and Receive)
RJ-11 Type
Modular Plug
Figure E-2. Two Wire Leased Line Connection
102
Appendix F - Regulatory Information
Appendix F - Regulatory Information
FCC Part 15
This equipment has been tested and found to comply with the limits for a Class B digital device,
pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection
against harmful interference in a residential installation. This equipment generates, uses, and can
radiate radio frequency energy, and if not installed and used in accordance with the instructions, may
cause harmful interference to radio communications. However, there is no guarantee that
interference will not occur in a particular installation. If this equipment does cause harmful
interference to radio or television reception, which can be determined by turning the equipment off
and on, the user is encouraged to try to correct the interference by one or more of the following
measures:
•
•
•
Reorient or relocate the receiving antenna.
Increase the separation between the equipment and receiver.
Plug the equipment into an outlet on a circuit different from that to which the receiver is
connected.
•
Consult the dealer or an experienced radio/TV technician for help.
This device complies with Part 15 of the FCC rules. Operation of this device is subject to the
following conditions: (1) This device may not cause harmful interference, and (2) this device must
accept any interference that may cause undesired operation.
WARNING: Changes or modifications to this unit not expressly approved by the party responsible for
compliance could void the user’s authority to operate the equipment.
Industry Canada
This Class B digital apparatus meets all requirements of the Canadian Interference-Causing
Equipment Regulations.
Cet appareil numérique de la classe B respecte toutes les exigences du Reglement Canadien sur le
matériel brouilleur.
FCC Part 68 Telecom
1. This equipment complies with part 68 of the Federal Communications Commission Rules. On
the outside surface of this equipment is a label that contains, among other information, the FCC
registration number. This information must be provided to the telephone company.
2. The suitable USOC jack (Universal Service Order Code connecting arrangement) for this
equipment is shown below. If applicable, the facility interface codes (FIC) and service order
codes (SOC) are shown.
3. An FCC-compliant telephone cord and modular plug is provided with this equipment. This
equipment is designed to be connected to the telephone network or premises wiring using a
compatible modular jack that is Part 68 compliant. See installation instructions for details.
4. The ringer equivalence number (REN) is used to determine the number of devices that may be
connected to the telephone line. Excessive RENs on the telephone line may result in the device
not ringing in response to an incoming call. In most, but not all, areas the sum of the RENs
should not exceed 5.0. To be certain of the nuber of devices that may be connected to the line,
as determined by the total RENs, contact the local telephone company.
5. If this equipment causes harm to the telephone network, the telephone company will notify you
in advance that temporary discontinuance of service may be required. But if advance notice is
not practical, the telephone company will notify you as soon as possible. Also, you will be
advised of your right to file a complaint with the FCC if you believe it is necessary.
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MultiModemBA User Guide
6. The telephone company may make changes in its facilities, equipment, operations, or
procedures that could affect the operation of the equipment. If this happens, the telephone
company will provide advance notice in order for you to make necessary modifications in order
to maintain uninterrupted service.
7. If trouble is experienced with this equipment (the model of which is indicated below) please
contact Multi-Tech Systems, Inc. at the address shown below for details of how to have repairs
made. If the trouble is causing harm to the telephone network, the telephone company may
request you remove the equipment from the network until the problem is resolved.
8. No repairs are to be made by you. Repairs are to be made only by Multi-Tech Systems or its
licensees. Unauthorized repairs void registration and warranty.
9. This equipment should not be used on party lines or coin lines.
10. If so required, this equipment is hearing-aid compatible.
11. Manufacturer:
Multi-Tech Systems, Inc.
Trade Name: MultiModem
Model Number: MultiModemBA
FCC Registration No: AU7USA-65363-MD-E
Ringer Equivalence No: 0.5B
Modular Jack (USOC): RJ-11C or RJ-11W (single line)
Service Center in USA:
Multi-Tech Systems, Inc.
2205 Woodale Drive
Mounds View, MN 55112
U.S.A.
(763) 785-3500
(763) 785-9874
U.S. Fax 763-785-9874
Canadian Limitations Notice
Notice: The ringer equivalence number (REN) assigned to each terminal device provides an
indication of the maximum number of terminals allowed to be connected to a telephone interface. The
termination on an interface may consist of any combination of devices subject only to the requirement
that the sum of the ringer equivalence numbers of all the devices does not exceed 5.
Notice: The Industry Canada label identifies certificated equipment. This certification means that the
equipment meets certain telecommunications network protective, operational and safety
requirements. The Industry Canada label does not guarantee the equipment will operate to the user’s
satisfaction.
Before installing this equipment, users should ensure that it is permissible to be connected to the
facilities of the local telecommunications company. The equipment must also be installed using an
acceptable method of connection. The customer should be aware that compliance with the above
conditions may not prevent degradation of service in some situations. Repairs to certified equipment
should be made by an authorized Canadian maintenance facility designated by the supplier. Any
repairs or alterations made by the user to this equipment or equipment malfunctions may give the
telecommunications company cause to request the user to disconnect the equipment.
Users should ensure for their own protection that the electrical ground connections of the power
utility, telephone lines and internal metallic water pipe system, if present, are connected together.
This precaution may be particularly important in rural areas.
Caution: Users should not attempt to make such connections themselves, but should contact the
appropriate electric inspection authority, or electrician, as appropriate.
104
Appendix F - Regulatory Information
International Modem Restrictions
Some dialing and answering defaults and restrictions may vary for international modems. Changing
settings may cause a modem to become non-compliant with national telecom requirements in
specific countries. Also note that some software packages may have features or lack restrictions that
may cause the modem to become non-compliant.
EMC, Safety, and R&TTE Directive Compliance
The CE mark is affixed to this product to confirm compliance with the following European Community
Directives:
•
•
•
Council Directive 89/336/EEC of 3 May 1989 on the approximation of the laws of Member States
relating to electromagnetic compatibility;
and
Council Directive 73/23/EEC of 19 February 1973 on the harmonization of the laws of Member
States relating to electrical equipment designed for use within certain voltage limits;
and
Council Directive 1999/5/EC of 9 March on radio equipment and telecommunications terminal
equipment and the mutual recognition of their conformity.
105
MultiModemBA User Guide
COMM.DRV .......................................................85
Command Buffer ..................................................9
"Command mode" ..............................................22
Command string .................................................18
Command Summary ..........................................87
Commands
Attention code.................................................18
Load default configuration ..............................19
Modem reset...................................................18
Compatibility.........................................................9
Computer-or Terminal-Initiated Flow Control (Pacin
43
Connectors .........................................................10
Continuous Redial (A or :) ..................................27
Controls ..............................................................10
CTS Control (&R) ...............................................37
CTS/RTS Interaction Control (&RF) ...................37
Index
A
AbortTimer.........................................................51
Answer Mode .....................................................39
AS/400 Mode .....................................................67
ASCII code .........................................................18
Asynchronous Word Lenth Selection ($EB) .......43
Asynchronous/Synchronous Operation..............70
AT .......................................................................18
AT Command and S-Register Summary ............56
AT Commands....................................................23
"AT" Responses/Multi-Tech Responses .............70
Auto-answer ................................................ 18, 19
Auto-Reliable Buffering ($A)...............................39
Auto-Reliable Mode (&E1)..................................38
D
Data Compression ...............................................9
Data Compression Commands ..........................43
Data Format .........................................................9
Data Rates ...........................................................9
Data Set Ready Control (&S) .............................37
Data Terminal Ready Control (&D) .....................37
Datacomm software ...................... 18, 19, 20, 82
Configuration ........................................... 18, 19
dB Transmission Levels .....................................67
Delayed and Forbidden Numbers ......................96
Diagnostics.........................................................10
Dial (D) ...............................................................27
Dial Phone Number Provided (CRN) Command 99
Dialing a Stored Number (N) ..............................27
Digital Loopback Test .........................................69
Dimensions ........................................................10
DIP-Switches......................................................72
Disregard or Connect to Incoming Calls (DIC or CIC
99
B
Backspace Character .........................................51
Basic Result Code..............................................34
Basic/Extended Result Codes............................34
Baud Adjust ($BA) ..............................................44
Baud rate
Serial port .......................................................19
Bell/V.21 Tone ....................................................35
BREAK AT<CR> ................................................47
Buffer Length of Command Mode...After On-line
Esca ...................................................................54
Bulletin board systems .......................................20
C
Call waiting .........................................................85
Callback Attempts ..............................................53
Callback Operational Sequence Procedures .....61
Callback Password and Dial Back Phone Number
Entry ...................................................................60
Callback Retry Attempts .....................................63
Callback Security Enable/Disable (#DB) ............62
Callback Time Delay ................................... 53, 63
"Calling Card" Detect Tones ($).........................30
Canadian Limitations Notice.............................104
Carrier Detect Control (&C) ................................36
Carrier Detect Response Time ...........................52
Carrier Detect/DSR Forcing ...............................71
Carrier Loss Disconnect Delay Time ..................52
Change LOGIN Password (#I) ...........................62
Change Serial Baud Rate (CSP) Command ......98
Change SETUP Password (#S) .........................63
Changing Break Time .........................................53
Cleardown at Disconnect ...................................36
COM ports
DSR/CD Interaction Control (&SF).....................38
DTR Dialing ($D) ................................................28
DTR Dialing ($D) Command ............................100
DTR Dropout Time .............................................53
Dual-Tone Multi-Frequency dialing .....................28
“dumb” dialing.....................................................34
E
echnical Specifications .........................................9
EMC, Safety, and R&TTE Directive Compliance105
Enable/Disable Auto-Answer..............................68
Enable/Disable Auto-Reliable Fallback Character39
Enable/Disable Command Mode.......................69
Enable/Disable V.25bis Mode ($V) Command ...98
Enable/Suppress Responses .............................67
Erase Callback Password (#RCBNxx) ...............63
Erase Callback Phone Number (#RDNxx) .........63
Error Correction....................................................9
COM2 .............................................................19
106
Index
Escape Code Character .....................................50
Escape Sequence Options (%E)........................47
Escape Sequences (+++AT<CR>).....................47
Examples of Assigning Values ...........................56
Examples of Reading Values .............................56
Exiting Command Mode, Going Back On-Line (O)48
Extended Result Codes .....................................34
L
Leased Line/Dial-Up Operation ..........................70
Limited Warranty ................................................10
Line Feed Character...........................................51
“Link Request” ....................................................38
Listing Current Operating Parameters (L5 L7) ..46
Listing Delayed Phone Numbers (RLD) Command99
Listing Forbidden Phone Number (RLF) Command99
Listing Numbers Stored in Memory (L)...............31
Listing On-Line Diagnostics (L8) ........................46
Listing S-Register Values (L6) ............................46
Loading Factory Defaults (&F) ...........................31
Local Inactivity Timer..........................................64
Long Space Disconnect (Y) ...............................29
Losing Data ........................................................85
F
Failed Password Attempts..................................63
“fallback”.............................................................35
Fallback Modes When On-Line (#F) ..................35
Fax .....................................................................19
Fax and Communications Software Won't Run ..86
Fax Modulations .................................................10
FCC Part 68 Telecom regulation ......................103
File transfer protocols.........................................20
firmware
upgrading ................................................79–105
flash memory......................................................79
Flash On Hook (!) ...............................................30
Flash Wizard upgrade utility ...............................80
Flow Control .......................................................66
Flow control ........................................................85
Flow Control - &E4/&E5 .....................................66
Force Answer Mode (A) .....................................47
Forced DTR........................................................66
Frequency Stability.............................................10
Front panel .........................................................82
Functional States ...............................................22
M
Maximum Throughput Setting ............................68
Memory
Nonvolatile (NVRAM) .....................................19
MNP 5 ................................................................85
Model Numbers ....................................................9
Modem Baud Rate ($MB)...................................44
Modem Cannot Connect When Answering ........85
Modem Dials But Cannot Make a Connection....84
Modem Disconnects While Online .....................85
Modem Does Not Respond to Commands.........82
Modem Reset (Z) ...............................................32
Modem-Initiated Flow Control Commands .........43
Modulation............................................................9
MT1432BL Connections .....................................16
MT2834BL Cables............................................102
Multi-Tech Internet sites .....................................77
G
Garbage Characters...........................................86
Guard Tones (&G) ..............................................34
N
H
noise information ................................................48
Normal Mode (&E0) ...........................................38
Normal Mode Modem Flow Control (&E11) ........42
Normal/Auto-Reliable/Reliable Mode Commands43
Number of Rings Until Modem Answers...... 50, 55
Hardware Flow Control (&E4) ............................41
Help Screens ($H)..............................................46
HOW TO ................................................................
COMMANDS ......................................................23
I
O
Immediate Action Line Probe Commands ..........48
Inactivity Timer ...................................................54
Indicators............................................................10
Initialization strings ........................ 18, 19, 82, 84
PC-compatible ................................................18
initiating Line Probe ............................................48
Intelligent Features...............................................9
Intelligent Serial Interface (ISI) ...........................45
Internal/External Clocking ..................................70
International Modem Restrictions .....................105
Internet addresses .............................................77
"On-line mode" ...................................................22
ordering replacement parts ................................77
Originate Mode...................................................39
Originate/Answer Mode ......................................68
P
Parameters.................................................. 18, 19
Changing defaults ...........................................19
Defaults ..........................................................19
Parity ..................................................................18
Parity Selection (#P) ..........................................43
Password Command Summary ........................94
107
MultiModemBA User Guide
Pause Time for Comma......................................51
Summary ............................................................56
PBX/CBX Disconnect Drop Time for DSR/CTS/CD53 Synchronous Transmit Clock Select (&X) ..........32
PBX/CBX systems .............................................53
T
Power .................................................................10
Power supply......................................................82
Program V.34bis Connect Speeds .....................55
Program V34 Connect Speeds...........................55
Protocols ..................................................... 20, 85
Pulse or Tone Dial (P T) ....................................28
Telephone line ....................................................84
Terminal mode ....................................................82
Terminal/Computer Initiated Pacing (&E13) .......42
Testing ......................................................... 82, 84
self-test ...........................................................82
Time Elapse for Escape Sequence ....................54
Time for Carrier (Abort Timer) ............................51
Tone Dialing: Tone Spacing and Duration ..........52
Tradename ...........................................................9
Transmission speed ...........................................19
Transmit Level ....................................................10
Two Wire Leased Line Connection...................102
Q
Quiet Answer (@) ...............................................30
R
Reading of Line Probe Information Commands .48
registering your product .....................................76
Reliable Mode (&E2) ..........................................38
Remote Configuration Character........................63
Remote Configuration Escape Character...........52
Remote System Configuration ...........................19
replacement parts ..............................................77
Request To Send Forced....................................69
Result codes ............................................... 18, 84
Result Codes Enable/Disable and No Response (Q)
33
Result Codes Verbose/Terse (V) ........................33
Retransmit Count ($R) .......................................40
Return Character................................................50
Return character ................................................18
Return to Command Mode After Dial Execution (;)29
Reverse the Mode of Operation (R) ...................29
Rings Which Have Occurred ..............................50
U
UART .................................................................45
UARTs ................................................................19
16450..............................................................19
16550....................................................... 19, 85
8250................................................................19
8250A .............................................................19
Unix UUCP Spoofing ..........................................68
Unix UUCP Spoofing ($SP)................................32
upgrading the modem ................................79–105
V
V.25bis Mode AT Commands ............................97
V.25bis AT Commands .......................................98
V.25bis Operation ...............................................96
V.25bis Responses (Result Codes)....................98
V.25bis Set-Up and Initialization .........................97
V.42 Mode Select (#L) ........................................38
V.42bis................................................................19
S
S-Registers
S3 ...................................................................18
Safety Warning Telecom ....................................15
SDLC/BSC Option..............................................67
Send Xon/Xoff Characters (#X)..........................42
Serial cable ........................................................83
Serial port ............................................. 18, 19, 83
Serial Port Baud Rate ($SB) ..............................45
serial ports..........................................................45
servicing your modem ......................................104
Sessions.............................................................18
Set Pulse Dial Ratios (&P) .................................29
Signal Strength information ................................48
Signal to Noise Ratio information (SNR) ............48
Slave Clocking ...................................................69
Slow File Transfer ..............................................85
smart dialing .......................................................34
Speaker ..............................................................10
Speed Conversion ($BA) ...................................44
Speed Switches .................................................71
Storing Phone Numbers (D...N) .........................30
W
Wait for New-Dial-Tone (W)................................29
Wait Time for Dial Tone ......................................51
"Wait-for-Carrier" ................................................22
warranty ...........................................................104
Weight ................................................................10
Windows 3.1.......................................................85
serial port driver ..............................................85
Windows 95 Autodetect Inquiry Command (I9) ..46
Windows 95 HyperTerminal................................85
X
Xmodem .............................................................85
Xon/Xoff Flow Control (&E5) ..............................41
Xon/Xoff Pass-Through (&E7)............................41
Xon/Xoff Pass-Through Commands...................43
108
Index
Y
Ymodem/G .........................................................85
Z
Zmodem .............................................................85
109
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