FAULT FINDING/TROUBLESHOOTING
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The front panel indicators should be used to assist in fault finding as follows:
5.1 COMMUNICATIONS ERROR LEDs
If the CmFlt led is lit this means that the unit detected an error in the communications param-
eters being used on the Modbus interface. Please check that the transmission protocol EXACTLY
matches the Modbus Communications Parameters in section 3.1 above.
5.2 INVALID MODBUS MESSAGE ERROR LED
If the MoFlt led is lit this means that the unit received a Modbus message that it could not carry
out. This indicates that the communications protocol is probably correct but that the message
content was invalid. This could be either the wrong Modbus command or wrong data length
request.
5.3 UNMARKED LED – PGN BECAME DATA NOT AVAILABLE
This green led comes on if any PGN that has been received is not received for a period of great-
er than 10 seconds. This led will stay illuminated until the next power ff poer on cycle occurs.
This can indicate a failing or removed NMEA2000 device on the bus.
