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FIBER OPTIC CONVERTERS
4.3 Diagnostic Testing
To test one Fiber Optic Converter or a pair of Converters, as well as the
attached fiberoptic lines, first connect a Bit Error Rate Tester (BERT) in
place of the local device. Then follow the steps in
Section 4.3.1
or
Section 4.3.2
, as appropriate.
4.3.1 L
OCAL
L
OOPBACK
T
EST
Move the TEST switch on the front panel of the local Converter to the
LOCAL (left-hand) position. The ON LOCAL LED will light and the MUX
SM/MM will no longer accept signals from the Single Mode to Multimode IN
1300NM connector.
Begin sending test data from the BERT to the local Converter. The data
will travel along this path (minimally illustrated in Figure 4-3 below):
• Into the local Converter’s Multimode to Single Mode IN 850NM or IN
1300NM connector;
• Through the local Converter’s MUX SM/MM;
• Out of the local Converter’s Single Mode to Multimode OUT 850NM
or OUT 1300NM connector; and
• Back into the BERT.
The tester will compare the data received with the data stream sent
and report any discrepancies it finds.
FIBER OPTIC
EQUIPMENT
FMC-101
PTT
LINES
Figure 4-3. Local loopback.
BERT
FOC
