ADC HiGain H2TU-C-388 List 7F Manual page 67

LTPH-UM-1214-02
To perform the A2LB loopback test procedures:
1 Send the inband Arming and NI LPBK code 11000 to the H2TU-C for at least 5 seconds.
2 Monitor the output of the H2TU-C for the return of the pattern. Return of the pattern indicates one of the
following:
• The H2TU-R has looped up, if the SMJK Loopback option is enabled.
• An external NID has looped up, if the SMJK Loopback option is disabled, and the H2TU-C and H2TU-R
have been armed.
If the Arming code is not returned after 5 seconds, the system may be armed, but there is no
active loopback.
3 Once armed, the H2TU-C 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
c Logic errors (including the frame bit) occurring in the returned pattern comprising:
–
231 errors, if IOR LPBK (H2TU-C) was sent
–
20 errors, if ILR-2 (H2TU-R) was sent
d Normal 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
method to loop the H2TU-C down is 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.
4 Once the test is complete, do one of the following:
•
If the system is to loopdown but remain Armed, send the IR (Intelligent Repeater) LPDN code for
universal loopdown.
•
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).
H2TU-C-388 List 7F July 21, 2003
Testing
57