Troubleshooting
150-432-100-02, Revision 02
50
July 18, 2002
HLU-432 List 1
A3LB and A4LB Test Procedures
The HLU-432 can be looped back by sending the Addressable Office Repeater (AOR) LPBK activation code
1111-1111-0001-1110 (FF1E) for at least 5 seconds. This causes the HLU-432 to enter the NLOC state. The
Loopback Time-out setting (see
“Setting the Loopback Time-out Option” on page 44
) determines 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-432 down is to issue one of
the three loopdown commands listed in
. 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. Information specific to HiGain doublers is
shown in bold.
Table 15.
Addressable Repeater Loopback Commands (A3LB and A4LB)
Name
Description
Binary Code
(a)
(Hexadecimal Equivalent)
(a) The left-most bit arrives first in all sequences. The detection algorithm functions reliably with a random 10
-3
Bit Error Ratio
(BER) on the facility. The entire arming and loopback sequence can also be initiated at the remote HRU location.
NLOC
HLU-432 line unit from NI
1111-1111-0001-1110 (FF1E)
CREM
HLU-432 line unit from CI
0011-1111-0001-1110 (3F1E)
NDU1
HDU doubler 1 from NI
1111-1111-0000-0100 (FF04)
CDU1
HDU doubler 1 from CI
0011-1111-0000-0100 (3F04)
NDU2
HDU doubler 2 from NI
1111-1111-0000-0110 (FF06)
CDU2
HDU doubler 2 from CI
0011-1111-0000-0110 (3F06)
NDU3
HDU doubler 3 from NI
1111-1111-0000-1000 (FF08)
CDU3
HDU doubler 3 from CI
0011-1111-0000-1000 (3F08)
NDU4
HDU doubler 4 from NI
1111-1111-0000-1010 (FF0A)
CDU4
HDU doubler 4 from CI
0011-1111-0000-1010 (3F0A)
NREM
HRU loopup from NI
1111-1111-0000-0010 (FF02)
CLOC
HRU loopup from CI
0011-1111-0000-0010 (3F02)
SMJK
HRU loopup from NI
11000-11000-11000 ...
SMJK
HRU loopup from NI
(b)
(b) Not supported by A4LB.
100000 100000 100000 ...
SMJK
HRU loopup from NI (ESF-DL)
1111-1111-0100-1000 (FF48)
Loopdown
HLU and HRU loopdown from NI OR CI
11100-11100-11100 ...
Loopdown
HLU and HRU loopdown from NI OR CI
100-100-100 ...
Loopdown
HLU and HRU loopdown from NI OR CI (ESF-DL)
1111-1111-0010-0100 (FF24)