Mitsubishi MELSEC iQ-F, User Manual

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9 TROUBLESHOOTING
9.2 Troubleshooting by Symptom
Digital output value varies
Conversion completed flag does not turn on
When the input type is “resistance temperature detector”, and
“thermocouple”
When the RUN LED flashes or turns off
■ When flashing
■
When it is off
When the ERROR LED turns on or flashes
■
When it is on
■ When flashing
Check item Corrective action
Check whether a conversion method other than sampling processing is set. Check the setting of average processing specification from the "Module
parameter setting" screen of GX Works3.
Review the setting of average processing specification and check the state of
variation of 'CH1 Digital output value' (Un\G400) again.
Check item Corrective action
Check whether all channels are set to be conversion disabled. Check the setting of input type with GX Works3.
If there is no channel other than conversion disabled, please set the input type
setting to one other than "Conversion disabled" for one or more channels from
GX Works3 or sequence program.
Check item Cause Corrective action
Check whether the module is in offset/gain setting
mode. The programmable controller has been powered
off
→ on, or the CPU module has been reset when
the operation mode is set to offset/gain setting
mode in the module parameter setting of GX
Works3.
In the module parameter setting of GX Works3, set
the operation mode to normal mode and power
off
→ on the programmable controller, or reset the
CPU module.
The value in the mode switching setting has been
changed and the mode has been switched to
offset/gain setting mode. Review the program that uses the mode switching
setting to check whether the mode has been
switched erroneously.
Check item Corrective action
Check whether the power is supplied. Check that the supply voltage of the multiple input module is within the rated
range.
Check whether the capacity of the CPU module is enough. Calculate the current consumption of the I/O modules, and intelligent function
modules to check that the power capacity is enough.
Check whether the module is mounted properly. Check the mounting state of the module.
Cases other than the above Reset the CPU module, and check if the RUN LED turns on. If the RUN LED
still remains off, the possible cause is a failure of the module. Please consult
your local Mitsubishi representative.
Check item Corrective action
Check whether any error has occurred. Check 'Latest error code' (Un\G0) and take actions described in the list of
error codes.

Page 100 List of Error Codes
Check item Corrective action
Check whether 24 V DC external supply power shutdown has occurred. Check that FX5-8AD and 24 V DC external power supply are properly
connected.
Additionally, before turning on the system power supply, check that the voltage
supply from the 24 V DC external power supply is started to FX5-8AD.