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Troubleshooting
A1LB, A2LB, and A5LB Test Procedures
Using the codes listed in
enabled). A tester at the customer premises can activate CLOC or CREM loopbacks. All loopbacks shown in
Table 14
can also be initiated from the HLU-231 front-panel MODE and SEL buttons (see
through MODE and SEL" on page
Table 14. Addressable Repeater Loopback Commands (A1LB, A2LB, A5LB)
Name
ARMING or NI LPBK (inband)
ARMING or NI LPBK (ESF Data Link)
IR LPDN or DISARM (inband)
IR LPDN or DISARM (ESF Data Link)
IOR LPBK (NLOC and CREM
230-232 bit errors and 229-231 bit errors)
ILR-1 LPBK
(NDU1 and CDU1 10 bit errors)
ILR-20 LPBK
(NDU2 and CDU2 200 bit errors)
ILR-3 LPBK
(NDU3 and CDU3 30 bit errors)
ILR-4 LPBK
(NDU4 and CDU4 40 bit errors)
ILR-2 LPBK
(NREM and CLOC 20 bit errors)
IR LPDN
IR QUERY LPBK
IR ALTERNATE QUERY LPBK
TIME-OUT OVERRIDE
(c)
FAR END NI ACTIVATE
(d)
IOR POWER DOWN (HLU)
(a) The left most bit arrives first in all sequences. The detection algorithm functions reliably with a random 10
(BER) on the facility. The entire arming and loopback sequence can also be initiated at the remote HRU location.
(b) The HRU identifies CREM (and the HLU identifies NLOC) with 231 bit errors, including the frame bits. When framed data is
being sent in the AUTO framing mode, the number of the 231 bit errors detected by the test set varies from 229 to 231,
depending on whether or not the test set counts frame errors as bit errors, and on the number of frame bits contained in the
block of 231 error bits. The HRU and HLU generate this bit pattern in a series of discontinuous bursts containing 20-bit errors
each, including frame bits. Those test sets that do not count frame error bits as data bit errors will indicate fewer bits than the
HRU and HLU transmit for a CI and NI loopback.
(c) Sending the Far-End NI Activate code is not required in A5LB because it is always activated.
(d) 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.
48
Table
14, a network tester can activate NLOC or NREM loopbacks (or SMJK, if
11). Information specific to HiGain doublers is shown in bold type.
Description
Arming code
Arming code
Disarming code
Disarming code
HLU loopup
(b)
HDU1 loopup
(b)
HDU2 loopup
HDU3 loopup
HDU4 loopup
HRU loopup
Loopdown (HLU, HDU, or
HRU)
Query loopback
Alternate query loopback
Loopback time-out override
Unblock AIS
Removes HDSL line power
September 13, 1999
150-231-185-05, Revision 05
"Setting Options
(a)
Binary Code
(Hexadecimal Equivalent)
11000-11000 ...
1111-1111-0100-1000 (FF48)
11100-11100 ...
1111-1111-0010-0100 (FF24)
1101-0011-1101-0011 (D3D3)
1100-0111-0100-0001 (C741)
1100-0111-0101-0100 (C754)
1100-0111-0100-0011 (C743)
1100-0111-0100-0100 (C744)
1100-0111-0100-0010 (C742)
1001-0011-1001-0011 (9393)
1101-0101-1101-0101 (D5D5)
1101-0101-1110-1010 (D5EA)
1101-0101-1101-0110 (D5D6)
1100-0101-0101-0100 (C554)
0110-0111-0110-0111 (6767)
-3
Bit Error Ratio
HLU-231 List 8E
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Table of Contents
Troubleshooting
