ADC Soneplex Broadband System - Manual (Page 284)

ADCP-61-471 • Issue 4 • June 2000 • Section 2: Operation and Maintenance
2-261
© 2000, ADC Telecommunications, Inc.
TAD-102
Page 4 of 5
Transition from Armed to Loopup State
A specific HDSL unit moves from the armed state into the loopup state when commanded by an
inband control code sequence. There is a unique 16-bit activation control code sequence for each
HDSL unit as shown previously in
Table 102-1 .
As part of the loopup activation process, each of the HDSL units will respond with a loopup
identification signature that consists of a burst of bit errors in the looped payload. Upon
receiving three or more seconds of the specific activation code sequence, the addressed HDSL
unit will respond as follows:
• Loopback of the received payload data for five seconds.
• A burst of bit errors in the looped payload.
• Continued loopback of the received payload.
The number of bit errors returned in this loopup identification signature is specific to each HDSL
unit as follows:
• HLXC – 231 bit errors
• HRX – 10 bit errors
• HLXR – 20 bit errors
Note : The bit errors inserted for the loopup identification signature may occur in the
frame bit position as well as the payload in a looped SF or ESF framed data signal.
Transition from Armed to Disarmed State
The standard 5-bit inband disarming sequence used for CPE smartjack loopdown is a command
for all HDSL units to go from the armed state into the disarmed state. Each HDSL unit disarms
after receiving the command for five seconds.
The ESF data link disarming sequence used for CPE smartjack loopdown is a command for all
HDSL units to go from the armed state into the disarmed state. The ESF disarm sequence is
repeated four times.
All HDSL units go from the armed state into the disarmed state when the default time-out value
of two hours is reached.