Metrodata FM4900, User Manual

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TEST & TROUBLESHOOTING
76-02-011F 56
9. 4 Troubleshooting
Step 1: Establish and verify the E3 Link
Check the power LED at both ends. If power is not present, check the mains fuse. Set both
units to
UNFRAMED mode using the WAN PORT SET-UP menu:
If the MAJOR alarm LED is on, try swapping the BNC connections at one end.
If the MAJOR alarm remains on, try looping the BNC connections on the unit with a short
piece of cable. If the MAJOR alarm LED goes off then the cabling is faulty. Check for cable
continuity and network connections, etc.
If the MAJOR alarm LED goes off, you may now enable framing if required. Make sure you
do it at both ends or the MAJOR alarm will come on again.
Step 2: Establish and verify the DTE Links
If the MINOR alarm LED is on, check that the Bridges/Routers are switched on.
If the MINOR alarm LED remains on, check that the DTE connections are in place and
secure.
If the MINOR alarm LED is still on check the Bridge/Router configuration. Check to see
whether the Bridge/Router's port status is up or down.
If the MINOR alarm LED goes out but problems persist, check the DTE cabling configuration.
Transmit and Receive data connections may be crossed, as may any of the handshaking or
signalling lines. Also check that line protocol, data scrambling or data/clock inversion are
correct at both ends.
Step 3: Bridge/Router Configuration
As the FM 4900 is used in a variety of locations and with many different manufacturer’s
equipment it is impossible for us to cover all eventualities here, so please consult other
manufacturer’s operating manual for further information.