Mitsubishi Electric MELSEC iQ-F FX5UC Series, User Manual

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15 TROUBLESHOOTING
15.1 Troubleshooting Procedure
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15
15
TROUBLESHOOTING
Details on errors occurring in the system, their causes, and corrective actions are explained below.
For details on troubleshooting for each module, refer to the manuals for the module.
Saving the program and devices at the time of an error helps to analyze the error cause.
(
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Page 259 Backing Up the Data)
15.1
Troubleshooting Procedure
When the system has any trouble, perform troubleshooting in the following order.
1.
Check that each module is properly mounted and wired.
2.
Check the LEDs of the CPU module. (

Page 253 Checking with LEDs)
3.
Check the LEDs of each intelligent function module and FX5 safety extension module. (

User's manuals for each
module)
4.
Connect the engineering tool and execute the system monitor. The error module can be identified. (
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Page 255
System monitor)
5.
Select the error module, and execute the module diagnostics. The error cause and the action to be taken can be
displayed. (
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Page 256 Module diagnostics)
6.
When the cause could not be specified by Module diagnostics, check the error history from the event history of the
engineering tool to identify the cause. (
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Page 257 Event history)
7.
Check the cause of the error and take corrective actions.
15.2
Checking with LEDs
Check the module status with LEDs as a means to perform the primary diagnosis.
Checking the PWR LED
When the PWR LED turns off, check the following items.
When the PWR LED still does not turn on even after the items shown above are checked, there may be a hardware issue.
Consult your local Mitsubishi Electric representative.
Checking the BAT LED
When the BAT LED is flashing, check the following items.
The LED is valid when the optional battery is installed and the LED is set to "display" for battery errors by using the parameter.
Item to check Cause and action
Measure the voltage supply to the CPU module. When the power source is not supplying the proper voltage, provide a power source that does.
Remove extension modules and all wiring other than
the one for the power supply, and turn on the power
supply. When the PWR LED turns on in this condition, the 24VDC service power supply may be shorted or
overloaded. Reconnect the modules and wire one by one to identify the cause.
Item to check Cause and action
Check the installation of the battery. Install the battery properly.
Check the battery voltage. When the battery voltage is reduced, replace the battery with a new one.
Battery voltage can be monitored with programmable controller data register SD8005.
(
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Page 248 Special relay for low battery voltage)