ADTRAN FT1 User Manual
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Section 61245211L1-5, Issue 1
61245211L1-5A
4. MAINTENANCE
The ADTRAN Single-Wide FT1 Repeater requires
no routine maintenance. In case of equipment
malfunction, perform an in-band loopback from the
central office (CO), as described in Appendix A of
this practice. If a malfunction is confirmed, replace
the Single-Wide FT1 Repeater.
FT1 Repeater Loopbacks
The Single-Wide FT1 Repeater has looping
capability through the channel which allows for
digital loopback to help isolate faults. The looping
is accomplished remotely from the CO switch as
described in Appendix A.
The FT1 Repeater network loopback is a digital
loopback toward the CO, as illustrated in Figure 3.
This loopback is initiated by the DDS latching
loopback code for NEI Position 1 (N1000001). The
NEI Position 1 latching loopback is detected in the
primary DS0 of the FT1 circuit (the channel in
which the FT1-DP is physically installed) to control
the looping of the FT1 circuit. When the FT1
circuit is looped, all DS0s in use will be looped.
The DS0s in use will also be transmitted on to the
customer. This loopback is also initiated from the
craft interface or the LB push-button at the FT1-DP.
FT1 Self-Test
When a self-test is initiated at the FT1-DP, a
repeater failure will be indicated as an FNID failure
on the craft interface screens. Likewise, if a
self-test is initiated at the FNID, a repeater failure
will be indicated as an FT1-DP failure on the craft
interface screens.
Replacement of Circuit Packs
When testing indicates a faulty circuit pack, refer to
the apparatus case installation/maintenance practice
for the entry and pressurization control. Replace the
faulty circuit pack. Request a loopback test from
the CO, per Appendix A.
ADTRAN does not recommend field repair of the
circuit pack. Repair services may be obtained by
returning the defective unit to the ADTRAN Repair
Department.
Testing the FT1 Repeater at the CO
The ADTRAN Single-Wide FT1 Repeater performs
the loopback described in Appendix A.
Figure 3. FT1 Repeater Network Loopback
DSX-1
Interface
Central
Office
FT1 DP
D4
Channel Bank
FT1-NID
HDSL
Local Loop
DS1
Interface
Customer
Premises
FT1
Repeater