Troubleshooting The Fiber-Optic Link - Nortel CS 1000M HG Manual

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Hardware diagnostic tools consist of:
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Test equipment
To facilitate the troubleshooting of the Fiber Remote Multi-IPE Interface and
the fiber-optic link, it is recommended to have on-hand an optical power
meter (Fotec Model M712A or equivalent) to test the signal level of the
optical transmitter and the signal level received over the fiber-optic link.
Receiver sensitivity limit of -30 dBm can be measured. An adjustable
fiber-optic attenuator can be used to test the sensitivity of the optical
receiver. The patchcords are used to connect the meter, the light source,
and to loopback the link or the Fiber Remote Multi-IPE Interface while
performing the tests. The loopback patchcords (provided with equipment)
should be attenuated by 15 dB for the single-mode and 10 dB for the
multi-mode fibers.
Troubleshooting the fiber-optic link
To identify the problem with the fiber-optic link, check the attenuation across
the entire link, the signal level at the receiver and the signal level at the
transmitter, as described in
link" (page
Procedure 35
Troubleshooting the fiber-optic link
Step
1
2
Copyright © 2007, Nortel Networks
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fiber identifier receiver
card self-tests
LED indicators
display codes
enable/disable switches
117).
Action
Unplug the connector at the receiver and using the power meter
measure the received power on the link and compare it with the
receiver signal level specification.
If the received power is low, test the optical patch panel jumper. If the
received power level is still too low, measure the transmitter. Refer to
Table 5 "Fiber-optic transmit and receive signal levels" (page
Measure the transmitter power level using a good patch cable and
the power meter.
If the power is low, the problem is in the transmitter. If the
transmitter output power level is within specifications, the
fiber-optic link has too much signal attenuation.
Nortel Communication Server 1000
Fiber Remote Multi-IPE Interface Fundamentals
NN43021-556 01.01 Standard
Release 5.0 30 May 2007
Procedure 35 "Troubleshooting the fiber-optic
Diagnostic tools 117
32).