User`s manual

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MELSEC-A
6 TROUBLESHOOTING
6.2 Using the LED Indications to Check Errors
This section explains how to check errors using the LED indications of the
AJ65VBTCU-68ADV/ADI.
Refer to the PLC CPU and master module user's manual for issues regarding the PLC
CPU and master module.
(1) When the AJ65VBTCU-68ADV/ADI "POWER" LED is off
Check item Corrective action
Is 24VDC power on? Check the external power supply.
Is the voltage of the 24VDC power supply within the
specified value?
Set the voltage value to within the range 20.4 to
26.4V.
(2) When the AJ65VBTCU-68ADV/ADI "RUN" LED is flashing
Check item Corrective action
Is the LED flickering at 0.1s intervals in the normal
mode?
1. Check that the mode select switch is in the
position other than 0.
2. Check the error code (RWrn+8) to confirm the
channel where the input rang setting error
occurred.
3. Make correction to the sequence program or GX
Developer setting.
Is the LED flickering at 0.5s intervals in the mormal
mode?
1. Check the error code (RWrn+8) to confirm the
channel where the average number of times
setting or average time setting error occurred.
2. Make correction to the sequence program or GX
Developer setting.
Is the LED flickering at 0.5s intervals in the test
mode?
Change the offset/gain adjustment to within the
available setting range.
(3) When the AJ65VBTCU-68ADV/ADI "RUN" LED is off
Check item Corrective action
Has the watchdog timer error occurred?
Using the link special registers (SW0084 to
SW0087) of the master module, check the
watchdog timer error and power on the
AJ65VBTCU-68ADV/ADI again.
If the "RUN" LED is not lit after power is switched
on again, the possible cause is a hardware fault.
Contact your nearest Mitsubishi representative.
(4) When the AJ65VBTCU-68ADV/ADI "L RUN" LED is off
Communications are broken.
For details, refer to troubleshooting in the user's manual of the master module
used.
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