Digital Port Loop-Around Test (#13)
This test is a modification of the Voice and Control Channel Local Loop test used by Digital
Station (DIG-LINE) maintenance. This test does not perform the control channel and secondary
information channel loop around tests as described for DIG-LINE, as these data paths do not
exist for the Maintenance/Test digital port. The primary information channel is tested by first
looping back the data channel onto the TDM bus, and then sending a digital count from the
Tone-Clock circuit pack and receiving the same digital count with a general-purpose tone
detector. A conference test is done
14 FAIL The primary information channel is not transmitting properly. User
impact may range from nothing to not being able to use this port.
1. Run the circuit pack tests to check the Tone Generator circuit pack
and the Tone Detector circuit pack using test board location.
2. Resolve any problems that are detected on the Tone Generator
circuit pack or Tone Detector circuit pack.
3. If the Tone Generator and Tone Detector circuit packs are
functioning properly, and the test still fails, replace the Maintenance/
Test circuit pack.