PairGain 150-1143-42, Manual

Page: 18 / 46

Functional Description 150-451-142-04, Revision 04
10 October 8, 1998 HDU-451 List 4B
L
OOPBACK
D
ESIGN
D
ESCRIPTION
Figure 4 shows the complete family of loopbacks that a HiGain system can
execute. Four of these loopbacks (NDU1, NDU2, CDU1, and CDU2) occur
in the doubler. These loopbacks can be initiated from the HLU maintenance
port, the HLU front panel push-button, and from a family of Special
Loopback (SPLP) in-band loopback commands.
Figure 4 lists the Generic,
SPLP, in-band loop-up command set for the four doubler loopbacks: 110000
(2 in 6) for NDU1, 111000 (3 in 6) for NDU2, 111100 (4 in 6) for CDU1 and
111110 (5 in 6) for CDU2. Refer to the appropriate HLU practice for more
details regarding the other doubler loopback commands.
Figure 4. HiGain Loopbacks.