A2 Ethernet Troubleshooting - Novatech Bitronics M660 User Manual

A2 Ethernet Troubleshooting

If the Link LED fails to illuminate, this is an indication that there is trouble with the
connection and communication will not proceed without solving the problem. If a
copper connection is used between the M66X and the hub/switch, check the following
items:
1. Verify that the connectors are fully engaged on each end.
2. Verify that the cable used is a "straight-through" cable connected to a "normal"
port. Alternatively, a "cross-over" cable could be connected to an "uplink" port
(this could later cause confusion and is not recommended).
3. Verify that both the M66X and hub/switch are powered.
4. Try another cable.
5. If a long CAT-5 cable is used, verify that is has never been kinked. Kinking can
cause internal discontinuities in the cable.
6. If a copper connection is used to an external fiber converter:
7. Verify that the LINK LED on the converter is lit on at least one side. Both sides
need to be lit for a valid connection to be established.
8. At least one brand of converters will not output an optical idle unless it receives a
forced 10 Mb copper link pulse (for some reason, auto-negotiation pulses
confuse it). Some hubs/switches will not output an optical idle unless they
receive an optical idle. This then inhibits the converter from outputting a copper
link pulse enabling the M66X to link. In this condition, no device completes the
link.
9. Verify that the fiber converter(s) and/or fiber hub/switch are matched for the
same type of fiber connections. A 100BASE-FX port will NEVER inter-operate
with the 10BASE-FL port (fiber auto-negotiation does not exist).
10. On the fiber connection, try swapping the transmit and receive connector on one
end.
11. Verify that the fiber converter(s) and/or fiber hub/switch use the proper optical
wavelength (100BASE-FX should be 1300nm).
ML0042 October 15, 2019
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