General-Purpose I/O Function; Interrupt Input Function - Mitsubishi MELSEC L Series User Manual

15.3.6

General-purpose I/O function

(1) An input signal does not turn on.
If an input signal does not turn on, check the following items.
The general-purpose input function is not set to the input
signal.
A voltage greater than or equal to the input on voltage is not
applied between the input terminal and the COM terminal.
If the input signal does not turn on even after taking the above actions, the possible cause is a hardware failure.
Please consult your local Mitsubishi service center or representative, explaining a detailed description of the
problem.
(2) The OUT LED does not turn on.
If the OUT LED does not turn on, check the following items.
The general-purpose output function is not set to the output
signal.
The device (Y) is not on in the monitor screen of a
programming tool.
The output number is incorrect.
When forced output is performed from a programming tool
while the CPU module is in the STOP status, the OUT LED
corresponding to the output turns on.
If the OUT LED does not turn on even after taking the above actions, the possible cause is a hardware failure.
Please consult your local Mitsubishi service center or representative, explaining a detailed description of the
problem.
15.3.7

Interrupt input function

If an interrupt program does not run, check the following items.
The interrupt input function is not set to the input signal.
A voltage greater than or equal to the input on voltage is not
applied between the input terminal and the COM terminal.
The interrupt pointer (I) number is incorrect.
The EI instruction is not executed.
The interrupt program is set to be disabled by the IMASK
instruction.
If the interrupt program does not run even after taking the above actions, the possible cause is a hardware failure.
Please consult your local Mitsubishi service center or representative, explaining a detailed description of the problem.
Check item
Check item
Check item
CHAPTER 15 TROUBLESHOOTING
Action
Correct the parameter.
Check wiring with external devices and correct it.
Action
Correct the parameter.
Correct the program.
Correct the output number.
Correct the program.
Action
Correct the parameter.
Check wiring with external devices and correct it.
Correct the program.
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