11 TROUBLESHOOTING

11.2.6 When the "RUN" LED is flickering

MELSEC-Q

If the "RUN" LED flickers, follow the steps below.

The High Performance model QCPU flickers the "RUN" LED when the RUN/STOP switch is set from STOP to RUN after the programs or parameters are written in the CPU module during the stoppage.

Though this is not the trouble with the CPU module, the operation of the CPU module is stopped.

To bring the CPU module into RUN status, reset the CPU module with the RESET/L.CLR or set the RUN/STOP switch again from STOP to RUN. The "RUN" LED turns on.

11.2.7 Flowchart for when the "ERR." LED is on/flickering

The following shows the flowchart to be followed when the "ERR." LED of the CPU module turns on or flickers at PLC power-on, at operation start or during operation.

Hardware fault

Please consult your local Mitsubishi service center or representative, explaining a detailed description of the problem.

"ERR." LED is on/flickering.

Confirm details of error by GX Developer.

(Refer to Section 11.3.)

Set the RUN/STOP switch to STOP.

Modify error details. (Refer to Section 11.3.)

Reset by the RESET/L. CLR switch.

Set the RUN/STOP switch to RUN.

Can the "ERR." LED

NO

be turned off?

 

 

YES

 

 

 

 

 

 

Completion

 

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11 - 7