Chapter 5 - Troubleshooting and Diagnostics HCD-E1
Installation & Operation Manual
5-26 Diagnostic Tests 01/01/01 08:15
This test checks the connections to the DTE connected to the data channel
of the local HCD-E1, all the circuits of the remote unit, the functions of the
remote unit and local HCD-E1, and the transmission path connecting the
two units. During the loopback, the DTE connected to the tested channel of
the remote unit continues to receive data.
Figure 5-8 LP R R CH 1 Loopback
LP INBAND CH X
The in-band activated channel loopback (see Figure 5-9) is similar to the
channel data remote remote loopback, except for the way it is connected.
This loopback is activated and deactivated by transmitting special sequences
for approximately two seconds, in contrast to the LP R R CH loopback,
where the command arrives with e.o.c.
Figure 5-9 LP INBAND CH 1 Loopback
LP BERT CH X
BER testing (see Figure 5-10) does not represent a loopback in itself; to be
performed, it requires one of the channel or line loopbacks to be already
activated, towards your BERT.
BER testing can be performed on one channel at a time. To perform the test
over the whole link, end-to-end, you may use the LP R R CH loopback on
the same channel; for a local test, use the LP L LINE loopback.