Reference Guide for the Model XM128 ISDN Digital Modem

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*#

 

 

 

Troubleshooting

10-3

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NETGEAR XM128 ISDN manual Diagnostic Command, B1/B2 Loopback with Self-test