AT&T 7400B Plus User Manual page 125

DEFINITY Communications System
7400B Plus Data Module
User´s Guide
Symptom
Call disconnects
immediately after an
attempt to connect; NO
CARRIER may be
displayed on the local
terminal device; CHECK
SPEED LED lights.
Call disconnects
immediately after an
attempt to connect;
BUSY or NO CARRIER
may be displayed on the
local terminal device;
CHECK SPEED LED
does not light.
Problem
The speed of the far end
device is higher than the
speed of the local
terminal device.
The far end device is set
up for half-duplex or
synchronous operation.
The far end device is
busy with another call.
The telephone number
was dialed incorrectly.
The far end device is
not busy, but the PBX
has restricted access to
the called device.
The S7 register value
does not allow enough
time for the call to
complete.
CHAPTER 5: TROUBLESHOOTING
Solution
Change the speed of the local
terminal device to match that of
the far end device. If the speed
of the far end device is not
known, set the local terminal
device to the highest speed
available.
The 7400B Plus cannot
communicate with a far end
device that is operating half-
duplex or synchronous. This
problem can be resolved only if
the far end device can be
reconfigured for full-duplex,
asynchronous operation.
Try the call again.
Check the number of the far end
device that you wish to call and
try the call again.
This situation can only be
resolved by having the PBX
readministered to remove the
access restriction.
Set the S7 register to a larger
value.
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