Multitech MT2834BA User manual

MT2834BA/MT2834BL Series
Intelligent Data/Fax Modems
User Guide

User Guide
S000300B Revision B
MultiModemIIModels:
MT2834BA,MT2834BAI,MT2834BL,MT2834BLI
This publication may not be reproduced, in whole or in part, without prior expressed written permission
from Multi-Tech Systems, Inc. All rights reserved.
Copyright 2004©, by Multi-Tech Systems, Inc.
Multi-Tech Systems, Inc. makes no representations or warranties with respect to the contents hereof and
specifically disclaims any implied warranties of merchantability or fitness for any particular purpose.
Furthermore, Multi-Tech Systems, Inc. reserves the right to revise this publication and to make changes
from time to time in the content hereof without obligation of Multi-Tech Systems, Inc. to notify any person
or organization of such revisions or changes.
Record of Revisions
Rev. Date Description
A04/23/03 Initial release of this combination.
Replaces MT2834BA/MT2834BAI User Guide 88312001 Rev. B and
MT2834BL/MT2834BLI User Guide 88312100 Rev. A.
IncludedProductUpdate82076600(MT2834BLATcommands$LL).
B01/20/04 Corrected4-wireLeasedLinediagramsinAppendixE. WEEEStatementadded.
Patents
This device is covered by one or more of the following patents: 6,031,867; 6,012,113; 6,009,082;
5,905,794; 5,864,560; 5,815,567; 5,815,503; 5,812,534; 5,809,068; 5,790,532; 5,764,628; 5,764,627;
5,754,589; 5,724,356; 5,673,268; 5,673,257; 5,644,594; 5,628,030; 5,619,508; 5,617,423; 5,600,649;
5,592,586; 5,577,041; 5,574,725; 5,559,793; 5,546,448; 5,546,395; 5,535,204; 5,500,859; 5,471,470;
5,463,616; 5,453,986; 5,452,289; 5,450,425; D353,598; 5,355,365; 5,309,562; 5,301,274. Other
patents pending.
Trademarks
Trademarks of Multi-Tech Systems, Inc. are as follows: MultiModemII, Multi-Tech and the Multi-Tech logo.
All other brands and product names mentioned in this publication are trademarks or registered
trademarks of their respective companies.
Technical Support
Country By Email By Phone
France: [email protected] +(33) 1-64 61 09 81
India: [email protected] [phone]
U.K.: [email protected] +(44) 118 959 7774
U.S and Canada: [email protected] [phone]
Rest of the World: [email protected] +[phone]
Multi-Tech Systems, Inc.
2205 Woodale Drive
Mounds View, Minnesota 55112 U.S.A.
[phone] or [phone]
U. S. Fax [phone]
Technical Support [phone]
Internet Address: http://www.multitech.com

Contents
Chapter 1 - Introduction and Description......................................................................... 5
1.1 Introduction...................................................................................................................................... 6
1.2 How To Use This Manual................................................................................................................. 6
1.3 Modem Features ............................................................................................................................. 7
1.3.1 MT2834BA/BL Series Features ...............................................................................................8
1.4 Fax Features ................................................................................................................................... 8
1.5 Technical Specifications .................................................................................................................. 9
1.6 Power .............................................................................................................................................. 10
1.7 Modem LED Indicators.................................................................................................................... 11
1.8 Controls on PC Board ..................................................................................................................... 12
Chapter 2 - Installation and Connection......................................................................... 13
2.1 What Is in Your Modem Package? .................................................................................................. 14
2.2 Installation ....................................................................................................................................... 14
2.2.1 Safety Warnings........................................................................................................................ 14
2.2.2 Installation Procedure ............................................................................................................... 14
2.3 Installing PhoneTools, the Data Communications Software ............................................................ 16
2.4 Is Your Modem Ready for Use? ...................................................................................................... 16
Chapter 3 - Software Configuration and Modem Basics .............................................. 17
3.1 Introduction...................................................................................................................................... 18
3.2 Configuring Your Software............................................................................................................... 18
3.2.1 ConfiguringSoftware for Your Modem ....................................................................................... 18
3.3 PC Initialization Strings ................................................................................................................... 18
3.3.1 Changing Default Parameters................................................................................................... 19
3.3.2 Other Parameters ..................................................................................................................... 19
3.4 Configuring Software for Your Computer......................................................................................... 19
3.5 Modem Basics................................................................................................................................. 20
3.5.1 Simple Operations .................................................................................................................... 20
3.6 TheAnswer/Originate - Voice/DataToggle Switch .......................................................................... 20
Chapter 4 - Manual Dial and Automatic Answer ............................................................ 21
4.1 Introduction...................................................................................................................................... 22
4.2 Dialing/On-Line/Answering .............................................................................................................. 22
4.3 Automatic Leased Line Restoral Operation.....................................................................................23
4.4 Manual Dial Backup Call Termination .............................................................................................. 23
4.5 Dial Backup and Leased Line Restoral ........................................................................................... 23
4.6 Dial-Up Operation............................................................................................................................ 24
4.7 Manual Call Origination ................................................................................................................... 24
4.8 AutomaticAnswering....................................................................................................................... 25
4.9 ManualAnswering ........................................................................................................................... 25
4.10 Handshaking Details ....................................................................................................................... 26
4.11 CallTermination............................................................................................................................... 26
Chapter 5 - Command Mode............................................................................................ 27
5.1 Introduction...................................................................................................................................... 28
5.1.1 AT Command Editing ................................................................................................................ 28
5.1.2 Functional Modes...................................................................................................................... 28
5.2 Summary of AT Commands............................................................................................................ 29
5.3 Result Codes................................................................................................................................... 32
5.4 Dialing Commands .......................................................................................................................... 33

5.4.1 DialingAction Commands......................................................................................................... 33
5.4.2 Dial Modifier Commands........................................................................................................... 34
5.4.3 Phone Number Memory Commands......................................................................................... 37
5.4.4 Configuration and Default Storage Commands ........................................................................ 38
5.4.5 Command Response (Result Code) Commands...................................................................... 40
5.4.6 Phone Line Conditioning Commands........................................................................................ 42
5.4.7 RS-232C Interface Control Commands .................................................................................... 44
5.4.8 Error Correction Commands ..................................................................................................... 46
5.4.9 Flow Control Commands .......................................................................................................... 49
5.4.10 Compression, Error Correction, Flow Control, Pass-Through and Pacing Commands ............ 52
5.4.11 Speed Conversion Commands .................................................................................................53
5.4.12 ImmediateAction Commands ................................................................................................... 55
5.4.13 Line Probe Commands ............................................................................................................. 57
Chapter 6 - S-Registers.................................................................................................... 58
6.1 Introduction...................................................................................................................................... 59
6.2 Reading andAssigning S-Register Values ......................................................................................66
6.2.1 Examples ofAssigning Values .................................................................................................. 66
6.2.2 Examples of Reading Values .................................................................................................... 66
6.3 AT Command and S-Register Summary ......................................................................................... 67
Chapter 7 - Callback Security and Remote Configuration............................................ 68
7.1 Introduction...................................................................................................................................... 69
7.2 Callback Feature Description .......................................................................................................... 69
7.3 Remote Configuration Description................................................................................................... 70
7.3.1 Initial Setup Procedures for Callback and Remote Configuration. ............................................ 70
7.3.2 Remote Configuration Procedures............................................................................................73
7.4 Remote Configuration and Callback SecurityAT Commands ......................................................... 74
7.5 Remote Configuration/Callback Security S-Registers..................................................................... 75
Chapter 8 - DIP-Switch Settings...................................................................................... 76
8.1 Introduction...................................................................................................................................... 77
8.2 DIP-Switch Option Settings ............................................................................................................. 78
8.3 Speaker Volume Control ................................................................................................................. 83
8.4 Recording Option Configurations .................................................................................................... 84
Chapter 9 - Warranty, Service and Tech Support .......................................................... 86
9.1 Introduction...................................................................................................................................... 87
9.2 Multi-Tech Systems, Inc. Warranty & Repairs Policies.................................................................... 87
8.3 Online Warranty Registration .......................................................................................................... 88
9.4 Replacement Parts.......................................................................................................................... 89
9.5 Technical Support............................................................................................................................ 89
9.6 Internet Sites ................................................................................................................................... 89
Appendixes....................................................................................................................... 90
AppendixA - Upgrading Your Modem’s Firmware........................................................................................ 91
Appendix B - Troubleshooting ...................................................................................................................... 94
Appendix C - AT Command Summary ......................................................................................................... 99
Appendix D - V.25bis Operation ................................................................................................................... 107
Appendix E - MultiModemBA Cables............................................................................................................ 113
AppendixF - RegulatoryInformation............................................................................................................. 114
Index................................................................................................................................ 117

Chapter 1 - Introduction and Description

Chapter 1 - Introduction and Description
Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide 6
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/BL series modem, from Multi-
Tech Systems.
Your MultiModem provides data communication at the following rates:
33,600 - 14,400 bps (Enhanced V.34 / V.32bis)
The MultiModem also 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
A summary of the information contained in each chapter and appendix 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 8 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 - Manual Dial and Automatic Answer
Chapter 4 covers some modem operations, but delays discussion on Command Mode operation
until Chapter 5. Automatic Leased Line Restoration, Dial backup, Manual Dial Mode, and Answer
Mode operation are covered in detail, as well as the handshaking procedures employed between
two modems in an auto-answer application.
Chapter 5 - AT Command Mode Operation
Chapter 5 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 1 - Introduction and Description
Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide 7
Chapter 6 - S-Registers
Chapter 6 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.
Chapter 7 - Callback and Remote Configuration
Chapter 7 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 8 - DIP-Switches
Chapter 8 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 9 - Warranty, Service & Technical Support
Chapter 9 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/BL Series modem connections can be made on Public Switched Telephone
Networks (PSTNs) and/or point-to-point 2-wire or 4-wire (BL only) 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.

Chapter 1 - Introduction and Description
Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide 8
1.3.1 MT2834BA/BL Series Features
Your MT2834BA/BL 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 major application for the MT2834BL is in 4-wire leased line networks with the addition of dial
backup capability. With this capability, the dial-up feature saves any down time if the leased line fails.
Since the MT2834BL operates according to ITU V.34 modulation, it can operate full-duplex over two
wires, so that the dial backup mode performs the same throughput as the leased line.
The MT2834BA/BL 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.

Chapter 1 - Introduction and Description
Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide 9
1.5 Technical Specifications
Your data/fax modem meets the specifications listed below:
Tradename MultiModemIITM
Model Numbers MT2834BA, MT2834BAI, MT2834BL, MT2834BLI
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) 14,400, 9600, 7200, 4800 bps
Data Format 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, 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, 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 Xon/Xoff, Hardware RTS/CTS, ENQ/ACK, Unix-to-Unix Copy
Protocol (UUCP) "Spoofing"
Mode of Operation Full duplex over both dial-up lines and 2-wire or 4-wire (BL only)
leased lines; automatic or manual dialing, automatic or manual
answer; For BL only: auto dial backup on separate lines in leased-
line operation
Intelligent Features 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 60 characters
Modulation 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

Chapter 1 - Introduction and Description
Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide 10
Fax Modulations 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
Transmit Level -11dBm (dial-up), -9 or -15 dBm (leased-line); dBm level selectable
with DIP-Switch #3 in leased line setting
Frequency Stability ±0.01%
Connectors One DB-25 RS-232C connector; two RJ11 (three for BL) for phone
line/telephone set; power.
Diagnostics Power-on Self Test, Local Analog Loop, Local Digital Loop, Remote
Digital Loop, Back-to-Back Test.
Indicators 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 0° to 50° C (32° to 120° F)
Power Requirements 115 Volts AC, 60Hz, 0.3amp (2-prong outlet-mounted transformer)
240V/50Hz optional (International).
Dimensions 6.150" x 9.00" x 1.375"
15.6 cm x 22.9 cm x 3.5 cm
Weight 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.

Chapter 1 - Introduction and Description
Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide 11
1.7 Modem LED Indicators
The MultiModem diagnostic LED indicators are shown in Figure 1-1 and Figure 1-2.
FX
EC
TR
OH
24
96
14.4
19.2
24.028.8
CD
RD
SD MT2834BA
Series
Intelligent
M dem V ice/
Data
Answ
Orig
Fax
V.42
Rdy
2400
9600
14.4K
19.2K
24.0K
28.8K
Carr
Rcv
Send
Off Hk
Figure 1-1. MT2834BA LED Display
Figure 1-2. MT2834BL 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.
(ERR) ERROR. When this LED is lit, either the leased line is down and the modem is in dial backup
mode, or else the self-test has failed.

Chapter 1 - Introduction and Description
Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide 12
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. Chapter 8 provides detailed instruction for configuring the modem’s PC
board.

Chapter 2 - Installation and Connection

Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide
Chapter 2 - Installation and Connection
14
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. Your package should include:
·MT2834BA or MT2834BL data/fax modem
·RJ-11 telephone cord or BS-6312 plug (UK models)
·AC Power Transformer
·One Quick Start Guide
·One MT2834BA/BL CD. This CD contains PhoneToolsTM ( a data communications and fax
software program), the User Guide, and Adobe Acrobat Reader.
If any item is 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.
2.2.1 Safety Warnings
1. Use this product only with UL and cUL listed computers.
2. To reduce the risk of fire, use only 26 AWG (.41mm) or larger telephone wiring.
3. Never install telephone wiring during a lightning storm.
4. 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. Use caution when installing or modifying telephone lines.
7. 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.
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 Effect
#5 UP* Selects Answer mode
DOWN Selects Originate mode
#10 UP* Selects Dial-Up operation
DOWN Selects Lease Line operation
* Factory Default setting

Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide
Chapter 2 - Installation and Connection
15
2. Verify that the ON/OFF switch at the rear of the modem to the OFF (Down) position.
3. For BA: 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.
PHONE LINE ON
OFF
POWER
EIA RS232C
VOLUME
Figure 2-1. MultiModemBA Connections
The LINE connector can be used for a dial-up connection or a 2-wire leased-line connection.
3. For BL: Connect the modem to either a dial-up line or lease-line.
To connect the modem to a dial-up phone line, attach the RJ-11 telephone cord (provided with
your unit) to the PSTN connector on the modem and to a dial-up wall jack.
To connect the modem to a leased line, attach the RJ-11 telephone cord (provided with your unit)
to the LEASE connector on the modem and to a leased line wall-jack.
PHONE PSTN
ON
OFF
POWER
EIA RS232C
VOLUME
LEASE
Figure 2-2. BL Connections
The PSTN connector is used for a dial-up connection.
The LEASE connector can be used for a 2-wire or 4-wire leased-line connection.
4. 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).
5. 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.
6. Attach the AC Power transformer provided with your unit to the POWER connector on the
modem and to a live AC outlet.
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.
7. Apply power to the unit by setting the ON/OFF switch at the rear of the modem to the ON (Up)
position.

Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide
Chapter 2 - Installation and Connection
16
2.3 Installing PhoneTools, the 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 MT2834BA/BL 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.
2.4 Is Your Modem Ready for Use?
As soon as you have connected power to the modem, if you are an experienced modem user, you
may simply want to check your modem’s settings for data compression, error correction, and so on.
You may find that you can get moving quite quickly if you just issue an ATL5, ATL6 and an ATL7
command. These commands list how your modem is currently configured. If you come across a
setting you’re unsure of, refer to Chapters 5 and 6 of the User Guide for AT command and S-Register
explanations and defaults.
If you’re a novice, refer to Chapter 3 of the User Guide to learn about the basics of data
communications.

Chapter 3 - Software Configuration and Modem Basics

18
Chapter 3 - Software Configuration
Multi-Tech Systems, Inc. MT2834BA/BL Series 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 initializationstring.
3.3 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

19
Chapter 3 - Software Configuration
Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide
3.3.1 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.
3.3.2 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).
3.4 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.

20
Chapter 3 - Software Configuration
Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide
3.5 Modem Basics
You control your modem by issuing AT commands, setting S-Registers, and setting DIP-Switches.
You can easily change the settings of your DIP-Switches, as they are located on the right side of
your modem’s chassis. Right now your modem is set up for the most typical user application, that is,
as a traditional modem set to make a dial-up call to a remote installation where the call is answered
automatically; therefore, you shouldn’t need to change the DIP-Switches. (If however, you know that
your application does not follow this profile, please refer to Chapter 8 for full details on DIP-Switch
settings.)
While you may operate your modem manually, it is more likely that you will use your data
communications software to either:
•enter “terminal” mode, where you can “speak most directly” to the modem by issuing AT
commands, or to
•launch a datacomm session through a set of modem configurations which you select and then
associate with a target telephone number. Once you have created, saved, and named this set of
information according to your connection needs and your datacomm software’s conventions, the
software then simplifies your dialing because you needn’t re-configure your modem, nor run the
risk of mistakenly keying-in incorrect information.
Either way, you need to understand that an AT command is the method by which your modem is
controlled, and must therefore prefix nearly all commands. AT stands for attention, and alerts the
modem that a command follows. You may enter these commands with either upper- or lowercase
characters. Entering AT automatically sets the modem’s serial baud rate to match your computer’s
and also sets the modem’s parity. It also clears the modem’s command buffer.
Once you’re in terminal mode, enter AT followed by <CR> to check whether your modem is
operational. If everything’s fine, your modem will respond OK. (Note: refer to Chapter 4 for additional
details on Dialing, Automatic Answering, Dial Back-Up and Automatic Leased Line Restoral.)
3.5.1 Simple Operations
You can dial a number by using the ATD command and the phone number of the modem with which
you wish to connect, e.g., ATD6127853500. Your modem will dial the number, and hear a
“scrambling” noise as the modem negotiates the kind of connection it can make, and once the
modems have settled on a common connection, you will receive a connect message on your
computer’s video display. As the modem dials and connects, you may notice changes across its front
LED panel: the OH (Off Hook) LED lights to let you know the modem is operating as if you had
picked up the handset to a phone. The CD (Carrier Detect) LED lights to let you know the modem
has detected a device it can connect to. A speed LED lights to let you know at which speed the
connection has been made.
To hang up a call, enter +++ATH<CR>. Your modem will return on hook, just as if you had returned a
phone’s handset to its cradle. Notice also that the OH, CD and speed LED’s are no longer lit. Your
video now displays OK, signifying that your modem is ready for your next command.
3.6 The Answer/Originate - Voice/Data Toggle Switch
Located on the front of the modem is a Voice/Data "toggle" switch with Originate/Answer capabilities.
This switch enables the modem to automatically dial a phone number stored in the N1 location of
memory whenever this switch is toggled. (Note that you must first enter AT$VD1&W0<CR>. This
command string enables Voice/Data dialing when the Voice/Data toggle switch is activated.)
If you are "Manually" dialing with an attached telephone device (and not with your keyboard), your
modem originates when toggled in that position (DOWN); and if you are "Manually" answering
(modem is not configured to automatically answer via S-Register S0 setup), the modem answers an
incoming call when toggled in that position (UP).