The diagnostic command (atcg), Type, Ta128 responds – ZyXEL Communications Omni TA128 User Manual
Page 118: At&t11

106
OK
Type:
AT&T11
TA128 responds:
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 Diagnostic Command (ATCG)
The ATCG command can be used to test and isolate hardware
problems. Some of the tests are interactive operations, just follow
the indications prompted on the screen. If the TA128 is operating
normally, the test results will be displayed 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*#
Dialed digits detected, please hang-up the handset….
!!
On-hook action is detected, (Hook Interrupt)........
OK
Listen to the RING and then pick up phone set #2 ....
!!
Off-hook action is detected, (Hook Interrupt) .......
OK
Listen to the dial tone and then dial 1234567890*# in sequence.
!!
1234567890*#
Dialed digits detected, please hang-up the handset ..
!!
On-hook action is detected, (Hook Interrupt) ........
OK
Listen to the prompt signal of the Internal Speaker and then press the
button switch.......!!
Button switch is pushed (Button Interrupt) ..........
OK