Specific Example Of Troubleshooting - Mitsubishi Electric A960GOT User Manual

8 ERROR CODES AND ERROR MESSAGES

8.5.3 Specific example of troubleshooting

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An example of troubleshooting the system which is used when an error occurs on the
PLC CPU is shown below.
PLC (main base module)
PLC
Extension cable
(extension base module)
Check the error code/step appearing on the PLC CPU.
(Obtain the status of the error and the location where the error occurs.)
The SP. UNIT DOWN message appears on CPU.
Turn off the power of the GOT.
Turn off the power of the PLC CPU.
Replace the faulty CPU with a new one.
Turn on the power of the PLC CPU.
Turn on the power of the GOT.
The error occurs further (not on CPU).
Turn off the power of the GOT.
Turn off the power of the PLC CPU.
Disconnect the bus-connection cable from the GOT 2) at IN side
(to further locate the error positions).
Turn on the power of the PLC CPU.
Turn on the power of the GOT.
The error occurs further
(not on the GOT 2) (bus interface module)).
Turn off the power of the GOT.
Turn off the power of the PLC CPU.
Disconnect the bus-connection cable from the GOT 1) at OUT side
(to further locate the error positions).
Turn on the power of the PLC CPU.
Turn on the power of the GOT.
The error will not occur.
The bus-connection cable connecting the GOT 1) to the GOT 2) is judged faulty.
Replace the faulty bus-connection cable with a new one.
GOT 1)
Bus-connection Bus-connection
cable cable
Start
End
MELSEC-GOT
GOT 2)
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