Chapter 13 Troubleshooting

(f)Wrong output from output module or output module will not output (operation problem) The CPU operates, but output signals are not correct.

Output LED is not lit

Will not output

NO

Output LED is lit

Will not output

NO

Output LED is not lit

Will output

NO

Check for output error

Check the output power supply

Check the output program

Malfunction due to noise

YES

Check the output area

Forced output

I/O assignment

Program

YES

Check output signals

Output signal voltage

Power supply voltage for load

Terminal block wiring

Terminal block connector connection

Voltage between the common and the bit

Wiring

Especially for the S terminal on the transistor

The drive power supply for the relay is not connected

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 13-13