The "Error Data Nil" message on the
passenger panel means that power is applied, but no RS-485 data is received at
the passenger panel. The centre two pins of the connector and cable are used
for the communications.
This issue can be associated with the
following:
- The passenger panel RS-485 internal chip has failed. The solution is to replace
the passenger panel.
- The cable between the passenger panel and the operator panel or its
connectors are damaged. A cable fault is
less likely as the comms wires are the innermost part of the cable and less
likely to be damaged.
- The connector socket on the passenger panel or the operator panel that the
cable connects to. It is possible
someone has tried to connect this connector around the wrong way and in forcing
the connection has bent the internal spring pins on the RS-485 RJ45 connector
mounted on the PCB. This can be checked
by looking at the alignment and conditions of the pins. A good electronics service technician would
be capable of replacing this connector (de-soldering from PCB and replacing).
- Failed transmitter in the operator panel sending the data to the passenger
panel.
Tests to isolate the fault
To isolate which part is the
faulty unit, try:
- Plugging the passenger panel into another check-in desk that’s
working;
- Swap the cables over;
- Try a known working passenger panel and cable on
the faulty desk.
From these tests it
should become clear which part needs to be replaced or repaired.