Checking The Err Led; Checking The P.run Led; Troubleshooting Using The Engineering Tool - Mitsubishi Electric MELSEC iQ-F FX6U Hardware User Manual

Checking the ERR LED

If the ERR LED flashing
If the ERR LED is flashing, check the following items.
Item to check
Write system parameters, CPU parameters, and
program files. Then power on the CPU module
again.
Set the CPU module to the STOP status and turn on
the power supply again.
If the ERR LED is turned on
If the ERR LED is turned on, check the following items.
Item to check
Provide a different power supply to the CPU module.
If the ERR LED still does not turn off even after the items shown above are checked, there may be a hardware issue.
Consult your local Mitsubishi Electric representative.

Checking the P.RUN LED

If the P.RUN LED is turned off, check the status of the ERR LED and take corrective actions. (Page 173 Checking the
ERR LED)
9.3

Troubleshooting Using the Engineering Tool

Check the error or history using the engineering tool, and identify the error cause. More detailed information on the error as
well as the error cause and action to be taken can be checked by using the engineering tool.
The engineering tool has the following functions for troubleshooting.
Function
Module diagnostics (CPU Diagnostics)
Event history
For details on each function, refer to the following.
GX Works3 Operating Manual
Cause and action
Programs or parameters are not written or damaged. Since a CPU module with the factory default
setting has no programs, the ERR LED flashes.
When the ERR LED turns off, a watchdog timer error has probably occurred. Take any of the following
measures.
• Review the program and avoid the maximum value (SD524, SD525) of the scan time exceeding the
the scan time monitoring time setting value set by the parameter.
• Check that the input used for input interruption or pulse catch is not being abnormally turned on and
off in one scan.
• Check that the frequency of the pulse input to the high-speed counter is within the specified range.
• Add some WDT instructions to the program and reset the watchdog timer several times in one scan.
Cause and action
If the ERR LED turns off, noise may have affected the module. Consider taking the following measures.
• Check the ground wiring, and reexamine the wiring route and installation location.
• Fit a noise filter onto the power supply line.
Description
This function diagnoses the module. (The current error and its details can be checked.) (Page 174 Module
diagnostics (CPU diagnostics))
This function displays event information including errors that occurred in the CPU module, expansion board,
expansion adapter and errors on the network. (Page 175 Event history)
9 TROUBLESHOOTING
9.3 Troubleshooting Using the Engineering Tool
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