Section 150-231-164
Revision 04
Page 18
TABLE 4. HLU-231 A2LB TEST PROCEDURES (CONTINUED)
Step
Action
5
Using the following codes, a network tester can activate loopbacks NLOC or NREM or SMJK
(if enabled) shown in Figure 5. A customer tester can activate loopbacks CLOC or CREM.
ADDRESSABLE 2 (A2LB) REPEATER LOOPBACK COMMANDS
ARMING or NI LPBK (in-band)
Arming code
11000 11000 ...
ARMING or NI LPBK (ESF Data
Link)
Arming code
1111(F)*1111(F)0100(4)1000(8)
IR LPDN or DISARM (in-band)
Disarming code
11100 11100 ...
DISARM (ESF Data Link)
Disarming code
1111(F)1111(F)0010(2)0100(4)
IOR LPBK
(NLOC & CREM 231 errors)
HLU Loop up
1101(D)0011(3)1101(D)0011(3)
ILR-2 LPBK
(NREM & CLOC 20 bit errors)
HRU Loop up
1100(C)0111(7)0100(4)0010(2)
IR LPDN
Loop down
(HLU or HRU)
1001(9)0011(3)1001(9)0011(3)
IR QUERY LPBK
Query loopback
1101(D)0101(5)1101(D)0101(5)
IR ALTERNATE QUERY LPBK
Alternate Query
loopback
1101(D)0101(5)1110(E)1010(A)
TIME-OUT OVERRIDE
Loopback Time-
out Override
1101(D)0101(5)1101(D)0110(6)
FAR END NI ACTIVATE
Unblock AIS &
pass 2 in 5
1100(C)0101(5)0101(5)0100(4)
IOR POWER DOWN (HLU)
Removes HDSL
line power
0110(6)0111(7)0110(6)0111(7)
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. The IOR POWER DOWN code must
remain present for the duration of the power down mode. When this code is removed, the
HiGain system returns to its normal unlooped and unarmed state. This is the HEX number for
the 4-bit group.
6
After testing is complete, send the universal loopdown [IR (Intelligent Repeater) LPDN] code if
the system is to loopdown but remain ARMED. Send the disarm code 11100 if all the
equipment is to be looped down, disarmed and returned to normal operation. Note that the
ARMED mode has an automatic time-out of 120 minutes.
7
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 B Paragraph 3.09).
