AT&T 7400B Plus User manual

AT&T 555-020-710
Issue 2
May 1991
7400B Plus Data Module
User’s Guide

Page 1
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NOTICE
While reasonable efforts were made to ensure that the information in this document was complete and
accurate at the time of printing, AT&T can assume no responsibility for any errors. Changes or corrections
to the information contained in this document may be incorporated into future reissues.
TO ORDER COPIES OF THIS MANUAL
Call: AT&T Customer Information Center on 800-432-6600
In Canada Call 800-255-1242
Write: AT&T Customer Information Center
2855 North Franklin Road
P.O. Box 19901
Indianapolis, Indiana 46219
Order: Document No. 555-020-710 Issue 2, May 1991
For more information about AT&T documents, see Business Communications Systems Publications Catalog
(555-000-010).
FCC NOTICE
This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant
to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful
interference when the equipment is operated in a commercial environment. This equipment generates,
uses, and can radiate radio frequency energy and, if not installed and used in accordance with the
instruction manual, may cause harmful interference to radio communications. Operation of this equipment
in a residential area is likely to cause harmful interference in which case the user will be required to correct
the interference at his own expense.
TRADEMARK NOTICE
Apple and the Apple Logo are registered trademarks of Apple Computer, Inc. Carbon Copy Plus is a
registered trademark of MicroCom. CROSSTALK is a registered trademark of Digital Communications
Associates. DEFINITY is a trademark of AT&T. Delphi is a registered trademark of General Videotex
Corporation. Dow Jones News is a registered trademark of Dow Jones & Company, Inc. Hayes is a
registered trademark of Hayes Microcomputer Products, Inc. Hot Line is a registered trademark of General
Information, Inc. HyperACCESS is a registered trademark of Hilgraeve, Inc. LEXIS/NEXIS are registered
trademarks of Mead Data Central, Inc. Macintosh is a trademark of McIntosh Laboratory, Inc. MicroPhone
is a trademark of Software Ventures Corporation. Microsoft and MS-DOS are registered trademarks of
Microsoft Corporation. Newsnet is a registered trademark of Newsnet, Inc. Official Airline Guide is a
registered trademark of the Reuben H. Donnelley Corporation. PC TOOLS is a registered trademark of
Central Point Software, Inc. PROCOMM is a registered trademark of Datastorm Technologies, Inc. RELAY
GOLD is a registered trademark of Relay Communications, Inc. SIDEKICK Plus is a registered trademark of
Borland International, Inc. Smartcom is a registered trademark of Hayes Microcomputer Products, Inc.
Smarterm is a registered trademark of Persoft, Inc. Smartmodem is a trademark of Hayes Microcomputer
Products, Inc. Terra Nova is a registered trademark of AT&T. White Knight is a trademark of The FreeSoft
Company.
Prepared by 1991 AT&T
AT&T Technical Publications Department All Rights Reserved
Middletown, New Jersey 07748 Printed in U.S.A.

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Contents
PREFACE: ABOUT THIS GUIDE
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Typographical Conventions i
Organization of This Guide i
Related Documentation ii
1 CHAPTER 1: INTRODUCTION
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Overview 1-1
Features 1-2
Physical Description 1-4
2 CHAPTER 2: INSTALLATION
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Hardware and Software Requirements 2-1
Hardware Installation 2-10
Initial System Checks 2-16
If You Are Using a PC 2-16
If You Are Using a Dedicated Terminal 2-17
3 CHAPTER 3: CONFIGURATION AND OPERATION
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Operating Modes 3-1
Issuing Commands 3-2
Configuration Parameters 3-6
Data Operation 3-8
Voice Operations 3-16
4 CHAPTER 4: PC APPLICATIONS
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Data Call Notes 4-1
Voice Dialing Notes 4-1
PC COMMUNICATIONS PACKAGES 4-2
Carbon Copy Plus - V 5.1 4-3
Crosstalk XVI - V3.71 4-7
Crosstalk Mk.4 - V1.1 4-10
Hot Line - V2.2 4-15
HyperACCESS - V3.32 4-19
MicroPhone - V1.5 4-26
PC Tools Deluxe - V 6 4-30
Procomm Plus - V 1.1B 4-33

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Relay Gold - Release 3.0 4-37
SideKick Plus 4-40
Smartcom II - prior to Version 3.1 4-43
Smartcom II - V 3.1 4-49
Smartcom II - V 3.1 (Macintosh) 4-55
Smartcom III - V 1.1 4-57
Smarterm 240 - V3.0a 4-62
AT&T Terra Nova - V1.1.1 4-65
White Knight - V 11 4-69
5 CHAPTER 5: TROUBLESHOOTING
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How to Use This Chapter 5-1
A APPENDIX A: AT COMMAND SET
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B APPENDIX B: DIAL MODIFIERS
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C APPENDIX C: S-REGISTERS
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D APPENDIX D: LOOPBACK DATA TESTS
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Loopback Data Test D-1
E APPENDIX E: QUICK-REFERENCE SUMMARIES
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GLOSSARY
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DEFINITY Communications System PREFACE: ABOUT THIS GUIDE
7400B Plus Data Module
User´s Guide Page iii
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PREFACE: ABOUT THIS GUIDE
The purpose of this guide is to provide information for installing,
operating, and maintaining the 7400B Plus Data Module.
Note: The 7400B Plus Data Module will be referred to as the
"7400B Plus" throughout this guide.
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TYPOGRAPHICAL
CONVENTIONS Throughout this guide, command lines that you type are shown in
typewriter-style characters, and responses that the 7400B Plus
returns are shown in italics. The following is an example.
at h
(Enter )
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OK
Note the following characteristics of the display representation:
d
The first line is a command line as it should be typed. The
(Enter )
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symbol, when shown, indicates that you must press
the Enter or Return key to complete the command line.
d
Spaces are used to separate commands in some examples
shown in this guide. In actual use, the spaces may be typed,
but they are not required.
d
The second line in the example shows a typical response
returned by the 7400B Plus.
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ORGANIZATION OF THIS
GUIDE The following paragraphs summarize the chapters and
appendices contained in this guide.
Chapter 1: Introduction. Discusses the basic operating
features of the 7400B Plus and describes the external
indicators and connectors.
Chapter 2: Installation.Describes the hardware and software
required for installing the 7400B Plus, and outlines
procedures for preparing the 7400B Plus for operation.
Chapter 3: Configuration and Operation.Describes how to
issue commands to your 7400B Plus. In addition, it describes
how to change, store, and recall configuration parameters,
and outlines how to create and save custom configuration
profiles. It also provides some basics on 7400B Plus
operation, outlines a typical on-line data session, and
discusses more advanced command usage with example
command lines. If you are not familiar with the ‘‘AT’’
command interface and you are not using your 7400B Plus
with a PC communications package, you will need to
familiarize yourself with this chapter.

PREFACE: ABOUT THIS GUIDE DEFINITY Communications System
7400B Plus Data Module
Page vi User´s Guide
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Chapter 4: PC Applications.Contains notes on how to
configure some popular voice and data PC communications
packages for use with the 7400B Plus.
Chapter 5: Troubleshooting.Describes procedures for
troubleshooting problems that may be encountered while
configuring and operating the 7400B Plus.
Appendix A: AT Command Set.Contains an explanation of
each AT command accepted by the 7400B Plus.
Appendix B: Dial Modifiers. Contains an explanation of
each Dial Modifier accepted by the 7400B Plus.
Appendix C: S-Registers. Contains an explanation of each
S-register used by the 7400B Plus.
Appendix D: Loopback Data Tests.Provides information on
how to perform loopback tests and how to isolate problems
using the 7400B Plus.
Appendix E: Quick-Reference Summaries.Contains quick-
reference summaries of AT commands, S-registers, result
codes, factory-default configuration settings, EIA-232-D
connector
pin-outs, ASCII character set.
A glossary and an index are provided at the rear of this guide.
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RELATED
DOCUMENTATION The following is a list of other manuals that may provide helpful
information while installing and using the 7400B Plus. Since each
user may have different equipment and software preferences or
availability, only generic titles are given for the manuals.
If you are using a terminal device other than a PC:
User’s guide for your terminal device. You may need
information about the configuration and capabilities of your
terminal device from this manual during the installation and
preliminary operation of the 7400B Plus.
If you are using a PC as your terminal:
User’s guide for MicrosoftMS-DOS. You may need this
reference for explanations of commands used by your PC to
install, configure, and run your PC communications package.
User’s guide for your PC communications package. You may
need this guide for information on how to configure your
terminal emulation software to access the 7400B Plus.

DEFINITY Communications System CHAPTER 1: INTRODUCTION
7400B Plus Data Module
User´s Guide Page 1-1
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CHAPTER 1: INTRODUCTION
This chapter discusses the basic operating features of the 7400B
Plus and describes the external indicators and connectors.
The 7400B Plus is a new version of the 7400B Data Module. It is
fully compatible with the 7400B and supports all of its
functionality and applications. In addition, the 7400B Plus has the
following benefits:
d
the ability to dial voice calls from your terminal device, and
d
enhanced support for calls that utilize higher speed modems
(9600 V.32 modems) in a modem pool.
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OVERVIEW Congratulations on the addition of the AT&T 7400B Plus.
Following our tradition of excellent quality and high reliability,
we have designed this new 7400B Plus with the latest advances in
telecommunications technology.
The 7400B Plus is a full-duplex asynchronous, Hayes Compatible
data module. It provides integrated voice-data communications
at the desktop over standard twisted pair wiring. At the desk, the
7400B Plus provides asynchronous communication speeds
ranging from 300 bps to 19.2 Kbps. The 7400B Plus’s ability to
emulate Hayes compatible modems, makes it compatible with the
many standard PC communications packages that use Hayes
Command sets. In addition, the 7400B Plus provides a voice dial
capability that allows you to initiate voice calls from a PC using
industry standard "auto-dialer" PC communications packages.
The 7400B Plus is a data service link between a Data Terminal
Equipment (DTE) device and the following AT&T digital PBX
equipment:
d
DEFINITYCommunications System Generic 1
d
DEFINITYCommunications System Generic 2
d
System 75
d
System 85
Note: Unless a specific DTE device is intended, the words
terminal device shall be used throughout this guide to
represent any applicable DTE device, including a dumb
terminal, a printer, a plotter, or a personal computer (PC)
with an appropriate PC communications package.

CHAPTER 1: INTRODUCTION DEFINITY Communications System
7400B Plus Data Module
Page 1-2 User´s Guide
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FEATURES A terminal device is connected to the 7400B Plus through a
standard EIA-232-D interface (formerly called the RS-232-C), and
a Digital Communications Protocol (DCP) interface (using a type
D8W modular telephone cord) is used to connect the 7400B Plus to
the digital PBX.
An internal DIP-switch allows the 7400B Plus to be optioned for
use either with or without a telephone. In the stand-alone case,
the 7400B Plus supports data service only, otherwise, the 7400B
Plus provides simultaneous data and voice service. The 7400B
Plus will work with all of the 7400 series DCP voice terminals in
providing simultaneous data and voice service.
The voice dial feature allows you to dial a voice call without
touching the telephone, and depending on the communications
package, you can store telephone numbers on a PC and recall
them for dialing, log phone calls for easy billing, and take notes
for later reference during a telephone conversation.
In addition, the 7400B Plus can be used to automatically turn on
the speakerphone of the voice terminal when a voice call is dialed
from your terminal device. The 7400B Plus voice dial feature can
be used with all DCP voice terminals, except for the following:
d
7403D (all models)
d
7404D (all models)
d
7405D (all models)
d
7407D01A
Note: If a 7400 series voice terminal with data features is used
with the 7400B Plus, data service is provided by the 7400B
Plus and the data features of the voice terminal cannot be
used.

DEFINITY Communications System CHAPTER 1: INTRODUCTION
7400B Plus Data Module
User´s Guide Page 1-3
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Additional features of the 7400B Plus include the following:
d
non-volatile, read-write memory for storing two data
options profiles and up to four telephone numbers
d
an ‘‘AT’’ command interface that emulates a Hayes 2400
Smartmodem and supports the following:
storage of the wait time for carrier detect interval (S7
register)
voice call origination using the ‘‘ATDP’’ command
d
automatic speed and parity adjustment
d
even, odd mark, space or no parity
d
automatically adjusts data throughput
d
power-up self-test
d
local and remote loopback tests with test duration timers
d
voice terminal powered by the PBX is not affected if ac
power is removed from the 7400B Plus

CHAPTER 1: INTRODUCTION DEFINITY Communications System
7400B Plus Data Module
Page 1-4 User´s Guide
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PHYSICAL DESCRIPTION The external features of the front and rear panels of the 7400B Plus
and the separate power supply unit are described in this section.
The 7400B Plus has a removable access panel on top of the unit,
which is described further in the hardware installation section of
Chapter 2, "Installation."
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Front Panel The front panel of the 7400B Plus is shown in Figure 1-1, and the
10 LEDs on the front panel are described in Table 1-1. In addition
to indicating the status of the set during normal operation, the
LEDs also indicate the result of the self-tests when initially
powered.
Artwork to be supplied
Figure 1 Front Panel

DEFINITY Communications System CHAPTER 1: INTRODUCTION
7400B Plus Data Module
User´s Guide Page 1-5
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TABLE 1-1
Front Panel LED Indicator Descriptions
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Connector Description
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POWER/
TEST This red LED normally indicates that power is applied to the 7400B Plus.
This LED flashes during any test mode, except the start-up self-test. It
also flashes along with the DATA LED when the 7400B Plus is unable to
communicate with the PBX.
DATA
METERING This red LED indicates that the Data Metering option is enabled, and will
indicate the state of the CTS (Clear To Send) lead when metering.
AA Automatic Answer. This red LED lights continuously when Automatic
Answer is enabled, and flashes when there is an incoming call.
CD Carrier Detect. This red LED lights as long as communication is
established with the far end device.
RD Receive Data. This red LED lights when received data is being
transferred from the 7400B Plus to the local terminal device.
SD Send Data. This red LED lights when transmitted data is being
transferred from the local terminal device to the 7400B Plus.
TR Terminal Ready. This red LED normally indicates the state of the DTR
lead. The LED is always on when the 7400B Plus is optioned to ignore
the DTR lead.
OH Off Hook. This red LED lights continuously from the time a data
communications call is initiated until the call is terminated.
CHECK
SPEED This red LED lights when a call set up fails because of an incompatibility
between the configuration of the local terminal device and the far end
device. The incompatibility will usually occur if a common operating
speed cannot be achieved between the two endpoints. Chapter 5,
"Troubleshooting," provides information about this and other conditions
that may cause this LED to light.
DATA This green LED lights to indicate that a data call is in progress. This LED
flashes along with the POWER/TESTLED when the 7400B Plus is unable
to communicate with the PBX.

CHAPTER 1: INTRODUCTION DEFINITY Communications System
7400B Plus Data Module
Page 1-6 User´s Guide
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Rear Panel The rear panel of the 7400B Plus is shown in Figure 1-2, and the
connectors located on the rear panel are described in Table 1-2.
Artwork to be supplied
Figure 2 Rear Panel
TABLE 1-2
Rear Panel Connector Descriptions
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Connector Description
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PHONE This connector accepts one end of the D8W telephone line cord used to
connect a telephone or voice terminal to the 7400B Plus.
LINE This connector accepts one end of the D8W telephone cord that connects
between the 7400B Plus and the PBX wall jack.
POWER This connector accepts the output cable of the separate power supply
unit used with the 7400B Plus.
PORT 1 This connector accepts a male plug from the EIA-232-D (or RS-232-C)
cable that connects between the 7400B Plus and the terminal device.

DEFINITY Communications System CHAPTER 1: INTRODUCTION
7400B Plus Data Module
User´s Guide Page 1-7
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Power Supply Unit A separate power supply unit is shipped with the 7400B Plus.
This unit connects between a grounded AC outlet and the
‘‘POWER’’ connector at the rear of the 7400B Plus. This power
supply unit provides the necessary operating voltages for the
7400B Plus.
Caution: Make certain that the AC outlet to which you connect
the power supply is unswitched (for example, not
controlled by a wall switch or light dimmer).
Instructions for installing the power supply unit with an
illustration are provided in the hardware installation section of
Chapter 2, "Installation."

DEFINITY Communications System
7400B Plus Data Module
User´s Guide
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DEFINITY Communications System CHAPTER 2: INSTALLATION
7400B Plus Data Module
User´s Guide Page 2-1
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CHAPTER 2: INSTALLATION
This chapter describes the equipment required for installing the
7400B Plus, and outlines procedures for preparing the 7400B Plus
for operation. If you are using the 7400B Plus with a PC, you will
be ready to use a PC communications package after reading this
chapter. You should continue reading this guide, if you are using
the 7400B Plus with a terminal, printer, or host, or if you want to
learn about the ‘‘AT’’ interface and operations of the 7400B Plus.
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HARDWARE AND
SOFTWARE
REQUIREMENTS
This section provides information on the equipment packaged
with your 7400B Plus, and the additional items required for
installation. It uses illustrations to show how equipment is
arranged for installations with and without a voice terminal, and
with adjunct equipment.
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What You Have Your 7400B Plus package should contain the following:
d
7400B Plus Data Module
d
a 7-foot D8W telephone cord for the Data
Communications Protocol (DCP) connection between the
7400B Plus ‘‘LINE’’ jack and the PBX wall jack
d
power supply
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What You Need To install and operate the 7400B Plus, you will need the following
items:
d
an asynchronous data terminal or personal computer (PC)
with a communications package
d
an EIA-232-D interface (formerly RS-232-C) cable to
connect between the terminal device and the 7400B Plus
d
(optional) 7400 series DCP voice terminal (optional for
data, required for voice), and associated adjunct
equipment, if applicable
Note: The following list identifies those voice terminals
that cannot be used with the 7400B Plus voice dial
feature:
d
7403D (all models)
d
7404D (all models)
d
7405D (all models)

CHAPTER 2: INSTALLATION DEFINITY Communications System
7400B Plus Data Module
Page 2-2 User´s Guide
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d
7407D01A

DEFINITY Communications System CHAPTER 2: INSTALLATION
7400B Plus Data Module
User´s Guide Page 2-3
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If you are not using the voice dial feature, the above
mentioned voice terminals can be used to provide
simultaneous voice and data operation.
d
(optional) a second type D8W cord to connect between the
7400B Plus ‘‘PHONE’’ jack and optional voice terminal
(you may need an adjunct power supply, adapter, and
D6AP cord, if applicable)
Figure 2-1 illustrates the required hardware items for an
arrangement without a telephone, Figure 2-2 shows the set up for
using a telephone without adjunct equipment, and Figure 2-3
shows a similar setup with some typical adjunct equipment.

CHAPTER 2: INSTALLATION DEFINITY Communications System
7400B Plus Data Module
Page 2-4 User´s Guide
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Artwork to be supplied
Figure 1 Typical Standalone Installation

DEFINITY Communications System CHAPTER 2: INSTALLATION
7400B Plus Data Module
User´s Guide Page 2-5
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Artwork to be supplied
Figure 2 Typical Installation with Telephone

CHAPTER 2: INSTALLATION DEFINITY Communications System
7400B Plus Data Module
Page 2-6 User´s Guide
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Artwork to be supplied
Figure 3 Typical Installation with Telephone and Adjunct
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