Optelecom 9522A Installation And Operation Manual page 35

U B - BERT F
SING THE UILT IN UNCTION
The 9522A has a rudimentary BERT test feature that may be implemented off-line. While the test is being run,
no other signals may be introduced to a modem in the network. To run the test, set the Front Panel dipswitch
position 2 (center switch), for the TX1/RX1 optical ports or position 3 (bottom switch), for the TX2/RX2 port
DOWN, depending on which data path you wish to test. The BERT indicator will illuminate on all modems
properly receiving the signal for presentation at the RD (or RDE) output. It will not illuminate if the data is
only being repeated but not dropped off (via RD or RDE) by the modem. If initiated from the master in a fault
tolerant ring, and the BERT indicator on the master illuminates, it is receiving data that has traveled around
the ring. If the BERT indicator does not illuminate, inspect the BERT indicators on each modem in the ring to
determine where the ring is broken. Test both directions independently to obtain the most information.
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