PairGain PLANT Series, Руководство пользователя

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Issue 1, Section 150-231-164
Revision 04
Page 17
TABLE 4. HLU-231 A2LB TEST PROCEDURES
Step Action
1 Send into the HLU-231 List 6D the in-band ARMING and NI LPBK code 11000 for at least
five seconds, or at least four repetitions of the 16-bit ESF Data Link ARMING code 1111
1111 0100 1000 (FF48). (Left bit arrive first)
2 Monitor the output of the HLU-231 List 6D for the return of the pattern. Return of pattern
indicates that either the HRU-412 has looped-up (if the SMART-JACK LOOPBACK option is
ENABLED) or that an external NI has looped up (if the SMART-JACK LOOPBACK option is
DISABLED) and that the HLU-231 List 6D and HRU-412 units have been ARMED. Verify
that the HLU-231 List 6D display intermittently indicates “ARM” and also “SMJK” if the HRU-
412 is in loopback. Also verify, if possible, that the LOOPBACK LED of the HRU-412 is
flashing, indicating that the HRU-412 is armed or that it lights steadily, indicating that it is
both armed and in loopback.
3 Once armed the HLU-231 List 6D can be looped back (NLOC in Figure 5) by sending IOR
LPBK activation code 1101 0011 1101 0011(D3D3) for at least five seconds. The tester
observes the following activation response:
•
Two seconds of AIS (all ones), followed by:
•
Five seconds of returning data pattern, followed by:
•
231 logic errors (including the frame bit) occur in the returned pattern (10 errors if ILR-1
were sent), followed by:
•
Normal looped data. Note that this error pattern will repeat every 20 seconds as long as
the IOR loopback pattern is being sent. This same 20 second repeat scenario also
applies to ILR, Time-Out Override and Query commands.
The HiGain Line Unit is now in Logic Loopback (NLOC of Figure 5). The display on the HLU-
231 List 6D periodically shows NLOC (network local loop) and ARM (the HLU-231 List 6D is
still armed) in addition to 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 TIME-OUT OVERRIDE command or a loop down command is sent. If
the Time-out Override code 1101 0101 1101 0110 (D5D6) is received, the “activation
sequence” described in “3” above is repeated and the automatic timed expiration of the
loopback is inhibited. If this Time-out Override is sent, then the only way to loop the HLU-
231 List 6D down is to issue the IR (Intelligent Repeater) LPDN (loop-down) code 1001 0011
1001 0011 (9393) or to issue the NI LPDN and Disarm code 11100. The automatic time-out
timer is restored during subsequent loopback sessions.
4 Upon completion, the tester sends IOR LPDN code 1001 0011 1001 0011 (9393) to loop-
down the HLU-231 List 6D. The unit remains armed however, as indicated by the ARM
message on the HLU-231 List 6D and the flashing of the HRU-412 LOOPBACK LED.
Table continued on next page