Nortel Networks CTA 500dm - Manual (Page 72)

72 Troubleshooting
CTA 500 dm On Line Guide P0873832 Issue 05
¥ If the cable is faulty or the ICS is down, the attached phone will
also not work.
AT command problem?
The CTA 500 dm does not respond to AT commands sent from
your PC.
¥
Make sure that your PC, terminal or other DTE is conÞgured
correctly.
¥ Check the DTE connection. If the DTE is conÞgured as a DCE
you may need a null modem cable.
¥ Check that your PC or DTE is conÞgured to expect CD and CTS
signals. See
ÒSerial Interface Control LinesÓ on page 56 for
more information.
¥ Check that the CTA 500dm is in the command mode.
¥ Check that your PC or DTE is conÞgured to provide a DTR
signal. See
ÒSerial Interface Control LinesÓ on page 56 for more
information.
¥ If the LED is ßashing quickly, refer to the ConÞguration section
of this document.
¥ Check that the CTA 500dm serial port is set to the correct baud
rate (115200 is required for all cases except during a software
upgrade) using
ÒSerial Interface RateÓ on page 54 .
Echoed AT commands from the CTA 500 dm do not appear
correctly on your PC, but the response messages appear
correctly.
¥
Check the echo option on your PC.
¥ Disable echo if your PC displays duplicate characters. Enable
echo if your PC does not display any characters.
¥ See ÒSet Local EchoÓ on page 38 for more information.
AT response messages do not appear correctly on your PC but
AT commands appear correctly.
¥
If numbers are being returned to the PC instead of messages,
change the message code setting on the CTA 500dm. See
ÒVerbose ControlÓ on page 40 for more information. The
numeric responses and indications are shown in ÒNumeric
CTA 500dm responsesÓ on page 83 .
¥ Make sure that your terminal is operating in full duplex mode
rather than half duplex mode.