Processing Performed By Q64Tc At Error Occurrence - Mitsubishi Electric MELSECSystem Q User Manual

8 TROUBLESHOOTING

8.2 Processing Performed by Q64TC at Error Occurrence

The Q64TC performs processing as explained below if an error occurs in the
Q64TC/PLC CPU or when the PLC CPU is switched from RUN to STOP.
Status
Control output setting for CPU stop
error
PID continuation flag
When PLC CPU is switched from RUN
to STOP
At PLC CPU stop error occurrence
At Q64TC write error occurrence
At Q64TC hardware error occurrence
During PLC CPU reset
• Be extremely careful when setting the PID continuation flag which controls the
DANGER
• Abnormal output may be provided due to a failure of an output element or its internal
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REMARK
1) The error code "4" is stored if data outside the setting range is written to the input
range area or alert mode setting area in the setting mode.
If you switch the setting mode to the operation mode without making error reset,
the error code changes to "3".
In this case, perform the error processing of the error code "3".
2) The errors have the following priorities.
If a higher-priority error occurs during occurrence of a lower-priority error, the
error code and error occurrence address of the lower-priority error is overwritten
by those of the higher-priority error.
[Priority]
Between errors 2 and 4, the error whose error
6 1 5 2/4
occurrence address is lower has higher priority.
Higher Lower
CLEAR
Stop
In accordance with
stop mode setting
Operation is stopped and external output is
turned off.
In accordance with operation to be performed at error in Table 8.1 Error code list
Depending on hardware error condition
Module itself becomes inoperative and external output is not provided.
external output.
circuit.
Install an external monitoring circuit for the output signals which may lead to serious
accidents.
Processing
Continue
Operation is continued
In accordance with
and external output is
stop mode setting
provided.
In accordance with
stop mode setting
MELSEC-Q
HOLD
Stop Continue
Operation is continued
and external output is
provided.
Operation is continued
and external output is
provided.
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