A-3
Section 61222004L2-5, Issue 1
61222004L2-5A
The designated HDSL2 element will loop up after
receiving the proper activation sequence.
If the NIU loopback feature for the HDSL2 circuit is
enabled (see
H2TU-C Switch Options
), the 5-bit
in-band arming sequence (11000) or the 16-bit ESF
data link sequence (0001 0010 1111 1111) will
activate the NIU loopback in the H2TU-R.
Transition from Armed to Disarmed State
: All
HDSL2 elements can be commanded to move from
the armed state into the disarmed state by the standard
5-bit in-band disarming sequence used for NIU
Smartjack loop down. Each HDSL2 element must
disarm after receiving the following code for five
seconds per element:
Disarm Sequence ............................. 11100
The disarming process ensures race-free operation of
HDSL2 element disarming and Smartjack loop down.
Duration of the disarm sequence may need to exceed
24 seconds to allow detection and loop down of up to
three HDSL2 elements and the Smartjack.
All HDSL2 elements can be commanded to move
from the armed state into the disarmed state by the
ESF DATA LINK disarming sequence used for NIU
Smartjack loop down as follows:
ESF Disarm Sequence ..................... 0010 0100 1111 1111
for four repetitions per
element in loopback
The disarming process ensures race-free operation of
HDSL2 element disarming and Smartjack loop down.
Duration of the disarm sequence may need to exceed
16 repetitions to allow detection and loop down of up
Table A-1. HDSL2 Loopback Control Codes
Name
Arming (In-band)
Arming (ESF)
Activation
(H2TU-C)
Activation
(H2TU-R)
Deactivation
(all HDSL2 elements)
Disarming (In-band)
Disarming (ESF)
Arming Time out
Loop up Time out
Detection Time
5 Seconds
4 Repetitions
> 4 Seconds
> 4 Seconds
> 5 Seconds
5 Seconds
4 Repetitions
2 Hours
Programmable from H2TU-C:
None, 20, 60, or 120 minutes
Code
11000
0001 0010 1111 1111
1101 0011 1101 0011
1100 0111 0100 0010
1001 0011 1001 0011
11100
0010 0100 1111 1111
N/A
N/A
Comments
Signal sent in-band or over ESF data link.
HDSL2 elements in disarmed state make
transition to armed state. Detection of either
code results in Smartjack loop up, if NIU
loopback is enabled.
Signal sent in-band. HDSL2 elements in
armed state make transition to loop up state.
Loop up state time out is programmable from
the H2TU-C.
Signal sent in-band. HDSL2 element in loop
up state makes transition to armed state.
Signal sent in-band or over ESF data link.
HDSL2 elements in any state make transition
to disarmed state.
HDSL2 element in loop up makes transition to
armed state.
>5 Seconds
>5 Seconds
Loopback Time out
Override
Span Power
Disable
1101 0101 1101 0110
0110 0111 0110 0111
Signal sent in-band. Sets Loopback Time out
to NONE. Time out will return to previous
value when pattern is removed. Arming
pattern (11000) must precede this pattern.
Signal sent in-band. Disables span powering
of remotes. Span power will return when
pattern is removed. Arming pattern (11000)
must precede this pattern.
