Ositech comm Trumpcard Data/Fax Modem - Manual (Page 83)

User’s Guide and Reference 5- 5
Modem Test Procedures
Remote Digital Loopback
This test checks the local and remote modems and the telephone circuit.
The test is only functional when the Modem is set to direct mode (&Q0)
and the COM port baud rate is set to 14400 bps (Trumpcard 14400) /
28800 bps (Trumpcard 28800) or less.
A message is sent to the remote unit by the Modem. The remote unit
loops the test message back. The received message is then compared
with the previously transmitted message to verify the connection. If the
data patterns do not match, then there is a problem with either the local or
remote Modem or the telephone circuit. If this is the case, both local and
remote stations may initiate local analog loopback tests to further isolate
the source of the problem.
To perform this test:
1. Enter AT&F&Q0 [ENTER] to put the Modem in basic asynchronous
mode.
2. Establish a connection with a remote Modem and enter +++ (the
escape sequence) to revert to command mode. The Modem will reply
with
OK .
3. Enter AT&T6 [ENTER] to begin the test. The Modem will display a
CONNECT response if the loopback data link has been successfully
completed. It will display an ERROR response if the link has failed.
If successful, key in a test message. The message will be echoed on
the local screen.
4. Enter +++ (the escape sequence). The Modem will respond with OK .
5. Enter AT&T0 [ENTER] to end the test. The Modem will respond with
OK .