AT&T 7400B Plus User Manual page 131

DEFINITY Communications System
7400B Plus Data Module
User´s Guide
Symptom
Commands are
displayed without error
as they are typed
(echoed), but the 7400B
Plus does not respond
to any command.
The CONNECT message
is sent without a speed
indication, but the far
end device is not set at
300 bps.
The terminal device has
its DTR lead turned on,
but the TR LED is off.
Problem
The local terminal
device is set to a speed
not supported by the
7400B Plus.
The 7400B Plus is
configured to display
only the basic set of
result codes (option
x0).
A defective or non-
standard (null-modem)
EIA-232-D cable is in
use.
CHAPTER 5: TROUBLESHOOTING
Solution
Set the terminal device for one
of the supported speeds: 300,
1200, 2400, 4800, 9600, or 19200
bps.
Configure the 7400B Plus to
send CONNECT nnnn
messages for all speeds except
300 bps by typing
atx4 ( )
Enter
Replace the EIA-232-D cable
with one that is wired correctly.
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