Local Loopback Tests; Line Loopback (Llb); Payload Loopback (Plb); Dte Loopback (Dlb) - Paradyne 3150 Operator's Manual

8. Testing

Local Loopback Tests

The Local Loopback tests enable you to conduct circuit testing and fault isolation
for the digital line. The supported local loopback tests are:
T
T
T
T
The Line Loopback command can be activated and deactivated in response to
commands received over the network interface. The Network Interface
configuration option NET LLB controls whether the CSU responds to the
commands transmitted on the network interface to initiate LLBs (see
Configuration Options
Local loopback tests can be aborted (Abort Command) at any time.
No more than two local loopbacks can be active at any one time. An additional
restriction prohibits certain loopbacks from running at the same time. Valid
loopback combinations listed in
identified by YES.
Table 8-2.
8-6
3. From the Rem Loopback screen, press F1 to select LLBUP (Line Loopback
Up), or press F2 to select LLBDN (Line Loopback Down).
Rem Loopback:
LLBUP LLBDN
F1
The Line Loopback sequence is sent up or downstream to the far-end CSU for
10 seconds. During this time, Sending appears on Line 2 of the LCD,
followed by Command Complete when 10 seconds have elapsed.
You can press any function key to restore the Rem Loopback screen without
affecting transmission of the loopback code.

Line Loopback (LLB)

Payload Loopback (PLB)

DTE Loopback (DLB)

Repeater Loopback (RLB)

).
Valid Loopback Combinations
LLB
LLB
N/A
PLB NO
DLB
YES
RLB
YES
March 2001
F2 F3
Table 8-2, Valid Loopback
PLB DLB
NO YES
N/A YES
YES N/A
NO NO
Appendix C,
Combinations, are
RLB
YES
NO
NO
N/A
3150-A2-GB24-10