Section 150-231-164
Revision 04
Page 42
TABLE 16. HLU-231 A3LB TEST PROCEDURES
Step
Action
1
The HLU-231 List 6D can be looped back (NLOC in Figure 14) 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-231 List 6D to enter its NLOC state shown in Figure 14. The display on the HLU-231
List 6D alternates between NLOC (network local loop) and the margin displays. The Loopback Time-
out option, which is user settable to NONE, 20, 60 or 120 minutes, 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-231 List 6D
down is to issue one of the three loop-down commands listed in Step 2. The automatic time-out mode
is restored during subsequent loopback sessions.
2
The following list summarizes the codes required to execute all the HiGain system loopbacks shown in
Figure 14. Note that all code sequences must be present for at least five seconds.
ABBREVIATIONS USED BELOW:
LU = LoopUp
LD = LoopDown
NI = Network Interface
CI = Customer Interface
ESF-DL = Extended Super Frame Data Link
ADDRESSABLE 3 (A3LB) REPEATER LOOPBACK COMMANDS
Position
Name
Code
HLU-231 LU FROM NI
NLOC
1111(F)*1111(F)0001(1)1110(E)
HLU-231 LU FROM CI
CREM
0011(3)1111(F)0001(1)1110(E)
HDU-451 DOUBLER 1 FROM NI
NDU1
1111(F)*1111(F)0000(0)0100(4)
HDU-451 DOUBLER 1 FROM CI
CDU1
0011(3)*1111(F)0000(0)0100(4)
HDU-451 DOUBLER 2 FROM NI
NDU2
1111(F)*1111(F)0000(0)0101(6)
HDU-451 DOUBLER 2 FROM CI
CDU2
0011(3)*1111(F)0000(0)0101(6)
HRU-412 LU FROM NI
NREM
1111(F)1111(F)0000(0)0010(2)
HRU-412 LU FROM CI
CLOC
0011(3)1111(F)0000(0)0010(2)
HRU-412 LU FROM NI
SMJK
11000 11000 11000 ...
HRU-412 LU FROM NI
SMJK
100000 100000 100000 ...
HRU-412 LU FROM NI (ESF-DL)
SMJK
1111(F)1111(F)0100(4)1000(8)
HLU & HRU LD FROM NI OR CI
11100 11100 11100 ...
HLU & HRU LD FROM NI OR CI
100 100 100 ...
HLU & HRU LD FROM NI OR CI
(ESF-DL)
1111(F)1111(F)0010(2)0100(4)
Note: 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. This is the HEX number for the 4-bit group.
3
All of the above loopbacks can also be initiated from the front panel of the HLU-231 List 6D with the
MODE and SEL push-buttons (Section C Paragraph 3.10).