Specifications

2240 Fiber Optic Modem

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