Chapter 13 Troubleshooting

(d)Wrong input at input module or no input (operation problem) The CPU runs, but the input data is not correct.

Input LED is not lit

Input is not read

NO

Input LED is lit

Input is not read

NO

Input LED is not lit

Input is read

NO

Check for input error

Check input signal source

Check input program

Malfunction due to noise

YES

Check input signals

Input signal voltage

Input power supply type

Cable disconnection

High-speed pulse is entered in a normal input

YES

Check input signals

Check input monitor

I/O assignment

Program

Input signal voltage

YES

LED error

LED replacement may not be performed by the user, so a repair request must be submitted.

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Hitachi NJI-350B manual 13-10