150-388-125-01, Revision 01
Loopback Operation
HLU-388 List 2E
September 15, 1998
45
A3LB and A4LB Test Procedures
The HLU-388 can be looped back by sending the Addressable Office Repeater (AOR) LPBK activation code
1111(F) 1111(F) 0001(1) 1110(E) for at least five seconds. This causes the HLU-388 to enter the NLOC state.
The Loopback Time-out option can be set by the user to:
•
NONE (0 minutes)
•
20 minutes
•
60 minutes
•
120 minutes
These selections determine the duration of this loopback, unless it is overridden by the reception of a second
identical 16-bit loop-up command before the timer expires. When this time-out override state exists, the only way
to loop the HLU-388 down is to issue one of the three loopdown commands listed in Step 2. The automatic
time-out mode is restored during subsequent loopback sessions.
summarizes the codes required to execute Addressable 3 and 4 (A3LB and A4LB) repeater loopback
commands. All code sequences must be present for at least 5 seconds. The abbreviations used in
are as
follows:
•
LU = LoopUp
•
LD = LoopDown
•
NI = Network Interface
•
CI = Customer Interface
•
ESF-DL = Extended SuperFrame Data Link
