User`s manual

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MELSEC-A
6 TROUBLESHOOTING
6.3 When the digital output value cannot be read
Check item Corrective action
Is the "POWER" LED off? Take action as described in Section 6.2 (1).
Is the "RUN" LED flashing or off? Take action as described in Section 6.2 (2), (3).
Is the "L RUN" LED off? Take action as described in Section 6.2 (4).
Is the "L ERR." LED on?
Take action as described in Section 6.2 (7).
Check the error details according to the master
module user's manual.
Is the PLC CPU "RUN" LED flashing or off?
Check the error details according to the PLC CPU
user's manual.
Is the master module "RUN" LED off?
Check the error details according to the master
module user's manual.
Is the master module [RD] [SD] LED on?
Check the error details according to the master
module user's manual.
Is the analog input signal line disconnected, cut off,
or any errors?
Check the error area by checking the signal line
visually or by conductive check.
Remove the AJ65VBTCU-68ADV/ADI analog input
cable. Apply the test voltage (stable power supply
or battery) to this module's terminal, and measure
the digital output value.
If he AJ65VBTCU-68ADV/ADI module digital output
value is normal, the effects are being received by
noise from an external wiring. So check the wiring
and grounding method.
Lift the AJ65VBTCU-68ADV/ADI from the system,
and remove the grounding circuit. (install to the DIN
rail.)