152-402-145-02, Issue 2 | Loopback Operation |
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4Once armed, the H2TU-R-402 can be looped back by sending Intelligent Office Repeater (IOR) LPBK activation code 1101-0011-1101-0011 (D3D3) for at least 5 seconds. You should observe the following activation response pattern:
a 2 seconds of AIS (all ones pattern) b 2 seconds of returning data pattern
cLogic errors (including the frame bit) occurring in the returned pattern comprising:
–231 errors, if IOR LPBK (H2TU-R-402) was sent
–20 errors, if ILR-2 (H2TU-R) was sent
dNormal looped data
This error pattern repeats every 20 seconds as long as the IOR loopback pattern is being sent. This also applies to ILR, Time-out Override, and Query commands.
The H2TU-C is now in logic loopback if the IOR NLOC loopback command was sent. The Time-out Override command or a Loopdown command can override the selection made for the loopback time-out. If the Time-out Override code 1101-0101-1101-0110 (D5D6) is received after activating a loopback, then the automatic timed expiration of the loopback is inhibited. If this Time-out Override is sent, then the only way to loop the H2TU-R-402 down is to do one of the following:
•Issue the IR loopdown (LPDN) code 1001-0011-1001-0011 (9393)
•Issue the NI LPDN and Disarm inband code 11100 or the ESF-DL code (FF24).
The Time-out Override function is only valid for the current active loopback. The automatic time-out timer is restored during subsequent loopback sessions.
5Once the test is complete, do one of the following:
•If the system is to loop down but remain Armed, send the IR LPDN code.
•If all the equipment is to be looped down, disarmed, and returned to normal operation, send the disarm inband code 11100 or the ESF-DL code (FF24).
The Armed mode has an automatic time-out of 120 minutes, but this timer is reset to 120 for any of the following events:
•Loopback terminates (manually or time-out)
•Query
•Alternate query
•Far End activate
•Another ARM command
This timer is inhibited while any of the valid command codes are being sent. Once the codes are removed, the timer restarts at 120.
