Specifications
Section 520-10S-WI3-203
030-101591 Rev. B
R
15
0806I3RB
vated. After the 120-minute time frame, loopback
automatically releases and the unit returns to normal opera-
tion.
- NOTE -
If the 120-minute Loopback Timeout feature is not enabled,
loopback remains in effect until the front-panel MLB button is
pressed or until the loop-down code is received.
5.3.4 Remote Loopback Deactivation
Loopback deactivation is accomplished by sending the NIU
Loop-down code 11100 for five seconds minimum or four con-
secutive patterns of the 16-bit ESF DataLink Loop-down code
0010 0100 1111 1111 for 16ms to the Side 1 transmission path.
Loopback can also be deactivated by momentarily pressing the
front-panel MLB button or via the 120-minute Loopback
Timeout feature, if enabled.
- NOTE -
16-bit inband code can be sent in either unframed, SF or ESF formats.
5.3.5 Remote Loopback Timeout Disable
While in the Loopback mode of operation (single or dual) and
if the 120-minute Loopback Timeout feature is enabled, the
Timeout feature can be disabled remotely, if required (see
Paragraph 5.1.3 for local loopback timeout disable). Loopback
Timeout Disable is accomplished by sending the 16-bit code
1101 0101 1101 0110 (D5D6 HEX) for a minimum of five sec-
onds to the Side 1 input transmission path. The 120-minute
Loopback Timeout feature is automatically restored after the
unit returns to normal operation.
- NOTE -
The 120-minute Loopback Timeout feature can be permanently
disabled, if necessary, via the front-panel MLB button and the Local
Provisioning feature as described in Section 4 of this document.
5.4 Remote Loopback (NIU Mode)
When configured as an NIU, and loopback is activated from
the Network side (single loopback), the unit loops the signal re-
ceived from the Network on Side 1 back to the Network on Side
2. At the same time, AIS is sent toward the CPE. The Loopback
path is provided with signal regeneration. Refer to Figure 11a.
In the dual loopback mode (i.e., looping back both the Network
and CPE side, the unit loops the signal received from the Net-
work on Side 1 back to the Network on Side 2 and loops the
signal received from the CPE on Side 2 back to the CPE on Side
1. Both loopback paths are provided with signal regeneration.
Refer to Figure 11b.
5.4.1 Remote Loopback Activation (NIU Mode)
Loopback is accomplished by sending NIU loop-up code 11000
from the distant end (SSC or Digital Test location) for a mini-
mum of five seconds or four consecutive patterns of the 16-bit
ESF DataLink code 0001 0010 1111 1111 for a minimum of
16ms to the Side 1 transmission path.
- NOTE -
16-bit inband code can be sent in either unframed, SF or ESF formats.
After receiving the code for the specified time frame, the front-
panel LPBK LED illuminates and the 120-minute Loopback
Timeout feature (if enabled) is activated. At the same time, an
all 1s AIS is sent toward the CPE. After the 120-minute time
frame, loopback automatically releases and the unit returns to
normal operation.
- NOTE -
If the 120-minute Loopback Timeout feature is not enabled,
loopback remains in effect until the front-panel MLB button is
pressed or until the loop-down code is received.
5.4.2 Remote Dual Loopback Activation (NIU Mode)
Before the dual loopback can be activated, the unit must first
be put into the single loopback mode (see paragraph 5.4.1).
Once single loopback is established, dual loopback is accom-
plished by sending the 16-bit inband code 1100 1010 1111 0010
(CAF2 HEX) for a minimum of five seconds to the Side 1 trans-
mission path.
- NOTE -
16-bit inband code can be sent in either unframed, SF or ESF formats.
After receiving this code for the specified time frame, the
front-panel LPBK LED flashes and the 120-minute Loopback
Timeout feature (if enabled) is activated. After the 120-minute
time frame, loopback automatically releases and the unit re-
turns to normal operation.
- NOTE -
If the 120-minute Loopback Timeout feature is not enabled,
loopback remains in effect until the front-panel MLB button is
pressed or until the loop-down code is received.
5.4.3 Remote Loopback Deactivation (NIU Mode)
Loopback deactivation is accomplished by sending the NIU
loop-down code 11100 for five seconds minimum or four con-
secutive patterns of the 16-bit ESF DataLink loop-down code
0010 0100 1111 1111 for 16ms to the Side 1 transmission path.
Loopback can also be deactivated by momentarily pressing the
front-panel MLB button or via the 120-minute Loopback
Timeout feature, if enabled.
- NOTE -
16-bit inband code can be sent in either unframed, SF or ESF formats.
5.4.4 Remote Loopback Timeout Disable (NIU Mode)
While in Loopback (single or dual) and if the 120-minute Loop-
back Timeout feature is enabled, the Timeout feature can be
disabled remotely, if required (see Paragraph 5.1.3 for local
loopback timeout disable). Loopback Timeout Disable is ac-
complished by sending the 16-bit code 1101 0101 1101 0110
(D5D6 HEX) for five seconds minimum to the Side 1 transmis-
sion path. The 120-minute Loopback Timeout feature is
automatically restored after the unit returns to normal opera-
tion. See Paragraph for local/manual loopback timeout disable.
- NOTE -
The 120-minute Loopback Timeout feature can be permanently
disabled, if necessary, via the front-panel MLB button and the Local
Provisioning feature as described in Section 4 of this document.
5.4.5 Remote Loopback Deactivation During CLOS
When the CPE Loss Of Signal (CLOS ID) operation is optioned
for Loopback (i.e., LPBK Upon CLOS) and if the unit enters