A-2
Section 61179512L2-5, Issue 1
61179512L2-5A
Loop Down/9393 (1001 0011 1001 0011)
All units currently in loopback will loop down, but
remain in the armed state.
Query Loopback/D5D5 (1101 0101 1101
0101)
If the units are armed and the ICOT, HRE, or HLIU
are 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 ICOT is in network loopback, 20 at a time if the
HLIU is in network loopback, 10 at a time if the
HRE is in network loopback.
Query Loop Parameters/DBDB (1101 1011
1101 1011)
If the units are armed, errors are injected into the
DSX-1 signal upon detection of the query loop
parameters pattern. As long as a pattern continues
to be sent, errors are injected again every 20
seconds. The number of errors injected each time
depends on the current status of signal quality and
pulse attenuation parameters on each loop. 111
errors are injected if all HDSL receiver points
(ICOT LP1/LP2, HRE#1 NET LP1/LP2, HRE #1
CST LP1/LP2, and HLIU or Total Access 1000 RT
LP1/LP2) indicate pulse attenuation is 30 or lower
and signal quality (margin) is 6 dB or higher. 11
errors at a time are injected if any of the 8 receiver
points indicate pulse attenuation is greater than 30
dB and/or signal quality (margin) is less than 6 dB.
Loopback Time Out Override/D5D6 (1101
0101 1101 0110)
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 ICOT (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.
Span Power Disable/6767 (0110 0111 0110
0111)
If the units are armed and this pattern is sent, the
ICOT will deactivate its span power supply, turning
off the HLIU and HRE (if present). 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 ICOT will reactivate its span power
supply, turning the remote unit(s) on. All units will
retrain and return to the disarmed and unlooped
state.
