Flowchart For When The "Run" Led Is Turned Off - Mitsubishi MELSEC- Q Q12PHCPU User Manual

11 TROUBLESHOOTING

11.2.5 Flowchart for when the "RUN" LED is turned off

Reset the CPU module RESET/
L.CLR switch.
Set the CPU module's RUN/STOP
switch to STOP and write
END to address 0 with the GX
Developer.
Set the RUN/STOP switch
to RUN and enter to the monitor
mode with the GX Developer to be
operated.
Considered to be a sequence
program error.
Check the program and modify the
program error location.
NO
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The following shows the flowchart to be followed when the "RUN" LED of the CPU
module turns off during PLC operation.
"RUN" LED is turned off.
Is the "POWER"
LED of the power supply
module lit?
YES
Is "ERR." LED
on/flickering?
NO
"RUN" LED is off.
"RUN" LED is on.
Can "RUN" LED
be turned on?
YES
Completion
Proceed to Section 11.2.4,
NO
"Flowchart for when the "Power" LED
is turned off."
Proceed to Section 11.2.7,
YES
"Flowchart for when the "ERR." LED
is on/flickering."
"RUN" LED
is on. (1) PLC part/connection fault
(2) By excessive noise
For the case of (1)
Please consult your local Mitsubishi
service center or representative,
explaining a detailed description
of the problem.
"RUN" LED does
not turn on.
Connect a surge protector circuit
such as CR to the noise source.
MELSEC-Q
For the
case of (2)
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