ADC HiGain HLU-200 User Manual page 41

150-200-114-03, Issue 03
Step
1 Send into the HLU-200 List 1D the inband ARMING and NI (Network Interface) 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-200 List 1D 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-200 List 1D and HRU-412 units have been ARMED. 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-200 List 1D can be looped back (NLOC in Figure 7 for non-doubler loopback
configuration, NLOC in Figure 8 for doubler loopback configuration) by sending IOR (Intelligent Office
Repeater) 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 bits) occur in the returned pattern [10 errors if ILR-1
(Doubler 1) was sent, 200 errors if ILR-20 (Doubler 2) was sent, and 20 errors if ILR-2 (HRU)
was 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 in Figure 7 for non-doubler loopback
configuration, NLOC in Figure 16 for doubler loopback configuration). 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-200 down is to issue the IR (Intelligent Repeater) LPDN (loopdown)
code 1001 0011 1001 0011 (9393) or to issue the NI (Network Interface) 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-200 List 1D. The unit remains armed however, as indicated by the flashing of the HRU-412
LOOPBACK LED.
HLU-200 List 1D
Table 16. HLU-200 A5LB Test Procedures (Continued)
November 22, 1996
Action
Continued
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