AT&T 7400B Plus User Manual page 126

CHAPTER 5: TROUBLESHOOTING
Page 5-4
Symptom
An AT prefix is typed,
and it is displayed as
AATT.
The PC
communications
software indicates that
the call has been
disconnected, but the
DATA LED remains lit.
Problem
The command echo
option is enabled.
The 7400B Plus has
ignored the on-to-off
transition of the DTR
lead.
The 7400B Plus has
ignored the H (hang-
up) command.
DEFINITY Communications System
7400B Plus Data Module
Solution
Disable the command echo by
entering ATE0. As you type the
ATE0 command, AATTEE00
will appear, and the 7400B Plus
will send the response code OK
to your screen. The next
command that you enter should
appear in single characters.
From command mode, type the
command
at&d2 ( )
Enter
to set the DTR lead option to
disconnect on DTR lead
transition from on-to-off.
Alternatively, determine and
use the command provided by
the communications software to
implement this change.
Ensure that after the escape
sequence (+++) has been
entered to switch the 7400B Plus
to command mode, an adequate
pause before and after the +++
is allowed before issuing the H
command. In escaping to
command mode with the result
codes enabled, the 7400B Plus
must be given time to return OK
or 0 before it is ready to accept a
command.
User´s Guide