Specifications
Section 520-10S-WI3-203
030-101591 Rev. B
R
13
0806I3RB
4-second timer time out. The LPBK T.O. LED remains
off and the unit returns to normal operation.
5.1.3 Manual Loopback Timeout Disable
The 120-minute Loopback Timeout feature can be disabled lo-
cally, if required, via the front-panel MLB button and using the
Local Provisioning feature (see Sections 4, 6, and 7).
5.1.4 Manual Loopback Deactivation During CLOS
When CPE Loss Of Signal (CLOS ID) is set for Loopback (i.e.,
LPBK Upon CLOS, NIU Mode) and if the unit enters this con-
dition because of a loss of signal from the customer, an override
of this condition can be accomplished by pressing the front-
panel MLB button (i.e., less than 3 seconds). In the override
mode, the unit stays in the override mode for three minutes. If
the override mode times out and if the CPE signal is still absent,
the unit returns to the CPE LOS LPBK state. If the override
mode times out and the CPE signal is present, the unit returns
to normal operation.
5.2 Remote Loopback (Office Repeater Mode)
When configured as an office repeater, and when loopback is
activated from the Network side (single loopback), the unit
loops the signal received from the Network on Side 1 back to
the Network on Side 2. At the same time, AIS is sent toward the
CPE. Refer to Figure 12.
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. Refer to Figure 13.
5.2.1 Remote Loopback − Arming
When configured as an office repeater, and before loopback
can be activated, the unit must first be armed. This is accom-
plished by sending the NIU loop-up code 11000 from the
distant end (SSC or Digital Test location) for five seconds mini-
mum or four consecutive patterns of the 16-bit inband ESF
DataLink code 0001 0010 1111 1111 for 16ms.
Upon receiving the appropriate inband code for the specified
time frame, the front-panel LPBK LED begins flashing at 1-sec-
ond intervals.
- NOTE -
The Arming condition remains in effect for a period of 120 minutes.
If no action is taken during this 120-minute time frame, the unit times
out and returns to normal operation.
5.2.2 Remote Loopback Activation
When the unit is armed, actual loopback activation is accom-
plished by sending the 16-bit inband code 1100 1010 1111 0011
(CAF3 HEX) for a minimum of five seconds to the Side 1 input
transmission path.
- NOTE -
16-bit inband code can be sent in either unframed, SF or ESF formats.
After receiving the 16-bit inband code for the specified time
frame, the front-panel LPBK LED illuminates and the
120-minute Loopback Timeout feature (if enabled) is acti-
vated. At the same time, AIS is sent toward the CPE indicating
the unit is in the single loopback mode. 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.
5.2.3 Remote Dual Loopback Activation
Before the dual loopback can be activated, the unit must first
be put into the single loopback mode (see paragraphs 5.2.1
through 5.2.2). Once single loopback is established, the dual
loopback mode of operation is accomplished by sending the
16-bit inband code 1100 1010 1111 0010 (CAF2 HEX) for a
minimum of five seconds to the Side 1 transmission path.
- NOTE -
16-bit inband code can be sent in either unframed, SF or ESF formats.
After receiving this 16-bit inband code for the specified time
frame, the front-panel LPBK LED begins flashing and the
120-minute Loopback Timeout feature
(if enabled) is activated.
After the 120-minute time frame, loopback automatically re-
leases 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.
5.2.4 Remote Loopback Deactivation
Loopback deactivation is accomplished by sending the NIU
Loop-down code 11100 for five seconds minimum or the 16-bit
ESF DataLink Loop-down code 0010 0100 1111 1111 for a
minimum of 16ms to the Side 1 transmission path. Loopback
can also be deactivated by momentarily pressing the front-pan-
el 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.
5.2.5 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.