Troubleshooting By Symptom; When The Run Led Flashes Or Turns Off; When The Err Led Turns On; When The Alm Led Turns On - Mitsubishi Electric MELSEC iQ-R Series User Manual

3.3

Troubleshooting by Symptom

When the RUN LED flashes or turns off

When flashing
Check item
Check whether the module is in the offset/
gain setting mode.
Check whether the module is selected as
the target module for the online module
change.
When turning off
Check item
Check whether the power is supplied.
Check whether the capacity of the power supply module is enough.
Check whether the module is mounted properly.
Check whether the module replacement is allowed in the process of the online
module change.
The case other than the above

When the ERR LED turns on

When turning on
Check item
Check whether any error has occurred.

When the ALM LED turns on

When turning on
Check item
Check whether any alarm has occurred.
3 TROUBLESHOOTING
122
3.3 Troubleshooting by Symptom
Cause
The programmable controller power supply has
been turned off and on, or the CPU module has
been reset with "Operation mode setting" set to
"Offset/gain setting mode" in the module parameter
setting of the engineering tool.
The G(P).OFFGAN instruction has been executed
with the mode being set to be switched to the offset/
gain setting mode.
The values in 'Mode switching setting (L)' (Un\G296)
and 'Mode switching setting (H)' (Un\G297) have
been changed and the mode has been switched to
the offset/gain setting mode.
The base number and slot number of the D/A
converter module have been set in Module selection
(base unit No.) (SD1600) and Module selection (slot
No.) (SD1601).
Action
In the module parameter setting of the engineering tool,
set "Operation mode setting" to other than "Offset/gain
setting mode", and turn off and on the programmable
controller power supply or reset the CPU module.
Review the program that uses the G(P).OFFGAN
instruction to check whether the mode has been switched
erroneously.
Review the program that uses 'Mode switching setting
(L)' (Un\G296) and 'Mode switching setting' (H)
(Un\G297) to check whether the mode has been
switched erroneously.
Turn on Module selection cancellation request flag
(SM1615).
Action
Check that the supply voltage of the power supply module is within the rated
range.
Calculate the current consumption of mounted modules, such as the CPU
module, I/O modules, and intelligent function modules to check that the power
capacity is enough.
Check the mounting state of the module.
Perform the online module change. For details, refer to the following.
 MELSEC iQ-R Online Module Change Manual
Reset the CPU module, and check whether 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.
Action
Check 'Latest error code' (Un\G0) and take actions described in the list of
error codes.
Page 128 List of Error Codes
Action
Check 'Latest alarm code' (Un\G2) and take actions described in the list of
alarm codes.
Page 132 List of Alarm Codes