Figure D–2 Loopback Points for the Modem Signal Test
LKG−4912−93R
cable
Modem
cable
Adapter
DEC MicroServer
Communications
link
Loopback
points
Modem
To use a modem signal test, perform the following steps:
1.
Attach a loopback connector to one of the loop points.
2.
Enter the following command:
>>>TEST MODEM_SIGNAL/CH
n
Replace n with the number of the line on the DEC MicroServer you want
to test (0, 1, 2, or 3). Replace n with a value of 0 if you have a DEC
MicroServer-SP.
3.
If the test is successful, the following message appears on your terminal:
Successful Modem Signal Loopback on Channel
n
If the test fails, the following message appears on your terminal:
Modem Signal Loopback Failed on Channel
n
Modem signal tests can be used to isolate a faulty adapter cable. For example,
you can attach the 50-way loopback connector to the
DEC MicroServer’s synchronous port and run the modem signal test. Run the
test again, but this time use the correct loopback connector on the end of the
adapter cable. If there is a faulty adapter cable, the first test passes but the
second test fails.
D–6 DEC MicroServer Facilities for Problem Solving
