NETGEAR XM128 ISDN - Manual (Page 91)

Reference Guide for the Model XM128 ISDN Digital Modem
Troubleshooting 10-3
B1/B2 Loopback with Self-test
An AT and T11 command is designed for testing the readiness of your ISDN line that uses one
B channel (B1) to place a call to itself and uses the other B channel (B2) to receive the call. This
test is a modem loopback test.
To make your test call, follow these steps:
1. Enter the command AT&ZOI=your_isdn_number.
Your Model XM128 modem responds with:
OK
2. Enter the command AT&T11.
Your Model XM128 modem responds with:
OK
Dial your_isdn_number
Loop from B1 to B2 through the switch established!
Sending and receiving data.....
B1/B2 loopback test successed.
Disconnecting.....
NO CARRIER
The modem loopback test is complete.
The Diagnostic Command
The ATCG command is used to test and isolate fault if there are any hardware problems in the
Model XM128 modem. Some of the tests are interactive operations. Follow the instructions
prompted on the screen to carry out the tests. If the modem is in the normal condition, the test
results printed on the screen are as follows:
System address & data bus test .......................OK
Layer 1 hardware test ............................... OK
Layer 2 hardware test ............................... OK
Layer 1 activation test.............................. OK
First B channel hardware test ....................... OK
Second B channel hardware test....................... OK
Listen to the Ring and then pick up phone set #1..... !!
Off-hook action is detected, (Hook Interrupt) ....... OK
Listen to the dial tone and then dial 1234567890*# in sequence.!!
1234567890*#