Chapter 3: Configuration And Operation; Operating Modes - AT&T 7400B Plus User Manual

DEFINITY Communications System
7400B Plus Data Module
User´s Guide

CHAPTER 3: CONFIGURATION AND OPERATION

OPERATING MODES

This chapter describes how to change, store, and recall
configuration parameters, outlines how to create and save custom
configuration profiles, and discusses more advanced command
usage with example command lines.
This chapter also provides some basics on the 7400B Plus
operation, describes how to use a few ''AT'' commands that are
essential for most voice-data communications operations, and
then outlines a typical
on-line session.
Note: The commands for the 7400B Plus are referred to as ''AT''
commands because you must type the letters AT as the
first characters on the line for most commands.
Except when a test condition has been initiated, the 7400B Plus is
always in one of two states: command mode or data mode. When
power is first applied, the 7400B Plus initializes to command
mode.
In command mode, the 7400B Plus looks at everything you type
on your keyboard. When you type in something that the 7400B
Plus recognizes as a valid command with a valid parameter (if
required), it will execute the action requested. A valid command
with an invalid parameter will produce the ERROR result code.
An invalid command will also produce the ERROR result code,
and is ignored.
In data mode, everything you type is passed as data without
interpretation by the 7400B Plus, except the escape sequence. The
escape sequence, described in later paragraphs, provides a way of
switching the 7400B Plus back to command mode without
disconnecting a data call.
CHAPTER 3: CONFIGURATION AND OPERATION
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