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CANOGA PERKINS 2240 Fiber Optic Modem User Manual

Page 99

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2240 Fiber Optic Modem

99

Step

Symptom

Possible Cause(s)

Action

3

Cable loss exceeds

Defective

Repair or

modem loss budget.

F/O cable

replace defective
cable

4

Cable loss exceeds

Defective Fiber

Repolish or

modem loss budget.

Optic Connectors

replace defective
connector

5

Set the Remote Loopback switch on the near-end modem. Set up BERT
tester for the proper clocking, data rate and format as used with the
circuit. Use the existing interface cables if possible. Connect the BERT
tester in place of the near-end user device. Run the BERT test and go to
the next step.

6

Loopback test passes

Modem not

Verify / correct

but modems will not

configured

switch and strap

pass data.

properly

settings on modem
and devices

7

Loopback test passes

Interface cables

Repair damaged or

but modems will not

damaged or mis-

miswired cables

pass data.

wired.

8

Optically loopback
each modem and repeat
BERT test as detailed in
Step 5 of this procedure.

Modem fails BERT

Defective modem or

Replace defective

test when optically

electrical interface

modem

looped back to itself.

9

Set the Local Loop-
back switch on the
near-end modem.

Modem fails BERT

Defective modem or

Replace defective

when looped locally

electrical interface

modem