When configured as a multipoint, the V.29 modem uses the same training sequence and
structure as a modem in fast mode. If the master does not train, it can be trained
by releasing and depressing the slave DC Bus switch.
2-11. SELF TEST AND FAULT ISOLATION
The test switches and indicators built into the V.29 Modem assembly allow a rapid
four-step check of the data terminals, modems, and telephone lines. This procedure
can be used both to verify normal system operation and to isolate faulty equipment
in the event of failure. The results of each test step immediately verify the
operational performance of each unit in the system or provide a positive indication
of equipment failure. The modem also has a self-test feature. This feature links
the data in and data out circuits sending the receiver output to the transmitter,
completing the loop.