150-432-100-02, Revision 02
Troubleshooting
HLU-432 List 1
July 18, 2002
47
A1LB, A2LB, and A5LB Test Procedures
Using the codes listed in
, a network tester can activate NLOC or NREM loopbacks (or SMJK, if
enabled). A tester at the customer premises can activate CLOC or CREM loopbacks. All loopbacks shown in
can also be initiated from the HLU-432 front-panel MODE and SEL buttons (see
through MODE and SEL” on page 10
). Information specific to HiGain doublers is shown in bold type.
Table 14.
Addressable Repeater Loopback Commands (A1LB, A2LB, A5LB)
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.
ARMING or NI LPBK (inband)
Arming code
11000-11000 ...
ARMING or NI LPBK (ESF Data Link)
Arming code
1111-1111-0100-1000 (FF48)
IR LPDN or DISARM (inband)
Disarming code
11100-11100 ...
IR LPDN or DISARM (ESF Data Link)
Disarming code
1111-1111-0010-0100 (FF24)
IOR LPBK (NLOC and CREM
230-232 bit errors and 229-231 bit errors)
(b)
(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.
HLU loopup
1101-0011-1101-0011 (D3D3)
ILR-1 LPBK
(NDU1 and CDU1 10 bit errors)
(
)
HDU1 loopup
1100-0111-0100-0001 (C741)
LR-20 LPBK
(NDU2 and CDU2 200 bit errors)
HDU2 loopup
1100-0111-0101-0100 (C754)
ILR-3 LPBK
(NDU3 and CDU3 30 bit errors)
HDU3 loopup
1100-0111-0100-0011 (C743)
ILR-4 LPBK
(NDU4 and CDU4 40 bit errors)
HDU4 loopup
1100-0111-0100-0100 (C744)
ILR-2 LPBK
(NREM and CLOC 20 bit errors)
HRU loopup
1100-0111-0100-0010 (C742)
IR LPDN
Loopdown (HLU, HDU, or
HRU)
1001-0011-1001-0011 (9393)
IR QUERY LPBK
Query loopback
1101-0101-1101-0101 (D5D5)
IR ALTERNATE QUERY LPBK
Alternate query loopback
1101-0101-1110-1010 (D5EA)
TIME-OUT OVERRIDE
Loopback time-out override
1101-0101-1101-0110 (D5D6)
FAR END NI ACTIVATE
(c)
(c) Sending the Far-End NI Activate code is not required in A5LB because it is always activated.
Unblock AIS
1100-0101-0101-0100 (C554)
IOR POWER DOWN (HLU)
(d)
(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.
Removes HDSL line power
0110-0111-0110-0111 (6767)