ADTRAN HTU-C NB Installation And Maintenance Practice page 44

HTU-C using Narrowband/Wideband for Litespan Installation and Maintenance Practice
Table A-2. In-Band Addressable Loopback Codes
Function Code (Hex / Binary)
Arm 11000 (binary)
(also known
as a 2-in-5
pattern)
Disarm 11100 (binary)
(also known
as a 3-in-5
pattern)
HTU-C D3D3/
Network
1101 0011 1101 0011
Loop Up (2)
HRE Network C741/
Loop Up 1100 0111 0100 0001
HRE2 C754/
Network 1100 0111 0101 0100
Loop Up
Loop Down 9393/
1001 0011 1001 0011
A-4
Response (1)
The HTU-R will loop up toward the network. No AIS or
errors will be sent as a result of this loopback. The
HTU-C and HRE will arm.
The HTU-C and HRE are 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 HTU-C will loop up toward the network, 2
seconds of AIS (all 1s) will be sent, 5 seconds of data will
pass, and 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 pat-
tern 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.
If an HRE is present, the units have been armed, the HRE
will loop up toward the network, 2 seconds of AIS (all 1s)
will be sent, 5 seconds of data will pass, and 10 bit errors
will be injected into the DSX-1 signal. As long as the pat-
tern continues to be sent, 10 errors will be injected every
20 seconds. When the pattern is removed, the unit will
remain in loopback. If the pattern is reinstated, the injec-
tion of 10 bit errors will resume at 20-second
intervals.
If a second HRE is present, the units have been armed,
the HRE will loop up toward the network, 2 seconds of
AIS (all 1s) will be sent, 5 seconds of data will pass, and
200 bit errors will be injected into the DSX-1 signal. As
long as the pattern continues to be sent, 200 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 200 bit errors will resume at
20-second intervals.
Any HTU-C and HRE units currently in loopback toward
the network will loop down and will retain the armed
state.
61247002L1-5A