843
FX
3U
/FX
3UC
Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
37 Error Check Method and Error Code List
37.1 States and Colors of LEDs PLC Operation Status
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37. Error Check Method and Error Code List
When an error occurs while the program is executing, eliminate the cause of the error in accordance with this
chapter.
For the details of errors, refer to the Data Communication Edition and the Hardware Edition of the PLC main
unit.
37.1
States and Colors of LEDs PLC Operation Status
When an error has occurred, the PLC state can be checked by the LED status lights on the PLC.
37.1.1
POWER LED [lit, flickering or unlit] [FX
3U
/FX
3UC
]
37.1.2
RUN LED [lit or unlit] [FX
3U
/FX
3UC
]
LED status
PLC status
Action
Lit
The voltage is correctly supplied to the power
terminal.
The power supply is normal.
Flickering
The following status occurred:
•
The voltage or current is incorrectly
supplied to the power terminal.
•
The wiring is incorrect.
•
There is fault inside the PLC.
•
Check the power supply voltage.
•
Disconnect cables except the power cable, turn the PLC
power ON again, and check whether the status is
changed.
If the status is not improved, consult a Mitsubishi Electric
Distributor.
Unlit
The following status occurred:
•
The power is OFF.
•
The voltage is incorrectly supplied to the
power terminal.
•
There is wire breakage in the power
cable.
When the power is not OFF, check the power supply and
power line route.
When the power is correctly supplied, consult a Mitsubishi
Electric Distributor.
LED status
PLC status
Action
Lit
Sequence program is executing.
The PLC operation status is indicated.
This LED is not lit depending on the ERROR LED status.
(Refer to Subsection 37.1.4.)
Unlit
Sequence program is stopped.
POWER(Green)
RUN(Green)
BATT(Red)
ERROR(Red)
FX
3U
PLC
FX3
UC
PLC
ERROR(Red)
POWER
(Green)
RUN(Green)
BATT(Red)
L.RUN(Green)
L.ERR
(Red)