Black Box MX873A, Руководство пользователя

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MINIATURE LOCAL MUX-12
5. Diagnostics
5.1 Remote Loopback
Remote loopback can be performed by the Mux-12
when operated in conjunction with the single-port
Miniature Local Mux. The test is performed by pressing
the RLB button switch located on the front panel of the
single-port Mux, which results in looping data back from
the remote Mux-12’s receiver to the transmitter. The test
checks the single-port Mux’s digital circuitry as well as
both local and remote analog interfaces, the main-
channel link, and the Mux-12’s digital receiver section.
NOTE
When either local or remote loopback test is performed by
the single-port Mux, the TEST LED should be lit while all
other LEDs should be off at the remote Mux-12. At the
same time the Received Data signals (Circuit 104) at the
Mux-12’s sub-channels are set to MARK (negative voltage)
condition.
5.2 Fault Isolation and Troubleshooting
The symptoms and corresponding procedures listed in
Table 5-1
enable you to identify, isolate, and correct
faults.