ADTRAN T200 H2TU-R Installation And Maintenance Manual page 23

(All codes listed below must be sent for a minimum of 5 seconds in order for them to be detected and acted upon.)
Function
Arm ............................................... 11000 (also known as a 2-in-5 pattern)
Disarm .......................................... 11100 (also known as a 3-in-5 pattern)
H2TU-C Network Loop Up ......... D3D3 (1101 0011 1101 0011)
Loop down ................................... 9393 (1001 0011 1001 0011)
Query Loopback ........................... D5D5 (1101 0101 1101 0101)
Loopback Time Out Override ...... D5D6 (1101 0101 1101 0110)
Span Power Disable ..................... 6767 (0110 0111 0110 0111)
A-4
If NIU is enabled, then the H2TU-R can be in network loopback when the H2TU-C loop-up codes are sent.
61222026L1-5A
Table A-2. In-Band Addressable Loopback Codes
Code and Response
The H2TU-R will loop up toward the network. No AIS or errors will be sent as a result of this
loopback. The H2TU-C will Arm.
The H2TU-C is removed from the armed state. If any of the units are in loopback when the
11100 pattern is received, they will loop down. The LBK LEDs will turn off on all units.
If the units have been armed and no units are in loopback
the network, 2 seconds of AIS (all 1s) will be sent, 5 seconds of data will pass, and then 231
bit errors will be injected into the DSX-1 signal. As long as the pattern continues to be sent,
231 errors will be injected every 20 seconds. When the pattern is removed, the unit will
remain in loopback. If the pattern is reinstated, the injection of 231 bit errors will resume at
20-second intervals.
Any H2TU-C unit currently in loopback toward the network will loop down and will retain the
armed state.
If the units are armed and the H2TU-C or H2TU-R is in network loopback, errors are injected
into the DSX-1 signal upon detection of the query loopback pattern. As long as the pattern
continues to be sent, errors are injected again every 20 seconds. The number of errors injected
each time depends on which unit is in loopback. 231 errors are injected if the H2TU-C is in
network loopback and 20 at a time if the H2TU-R is in network loopback.
If the units are armed and this pattern is sent, the loopback time out will be disabled. The time
out option will be updated on the Provisioning menu of the H2TU-R (viewable through the
RS-232 port) to "None." As long as the units remain armed, the time out will remain disabled.
When the units are disarmed, the loopback time out will return to the value it had before the
D5D6 code was sent.
If the units are armed and this pattern is sent, the H2TU-C will deactivate its span power
supply, turning off the H2TU-R. As long as the pattern continues to be sent, the span power
supply will remain disabled. When the pattern is no longer being sent, the H2TU-C will
reactivate its span power supply, turning the remote unit(s) on. All units will retrain and return
to the disarmed and unlooped state.
Section 61221026L1-5, Issue 2
A-4
, the H2TU-C will loop up toward
A-3