Omron CJ2 - Non-CPU Unit Errors and Remedies; Error Causes and Remedies

6 Troubleshooting
6-26
CJ2 CPU Unit Hardware User’s Manual
6-3 Non-CPU Unit Errors and Remedies
6-3-1 Error Causes and Remedies
Input Units
No. Symptom Cause Remedy
1 Not all inputs turn ON or indica-
tors are not lit.
Power is not supplied to Input
Unit.
Supply the appropriate external
input power.
Supply voltage is low. Adjust supply voltage to within
rated range.
Terminal block mounting screws
are loose.
Tighten screws.
Faulty contact of terminal block
connector.
Replace terminal block connec-
tor.
2 Not all inputs turn ON (indicator
lit).
Input circuit is faulty. Replace Unit.
3 Not all inputs turn OFF. Input circuit is faulty. Replace Unit.
4 Specific bit does not turn ON. Input device is faulty. Replace input devices.
Input wiring disconnected. Check input wiring
Terminal block screws are loose. Tighten screws.
Faulty terminal block connector
contact.
Replace terminal block connec-
tor.
Too short ON time of external
input.
Adjust input device.
Faulty input circuit Replace Unit.
Input bit number is used for out-
put instruction.
Correct program.
5 Specific bit does not turn OFF. Input circuit is faulty. Replace Unit.
Input bit number is used for out-
put instruction.
Correct program.
6 Input irregularly turns ON/OFF. External input voltage is low or
unstable.
Adjust external input voltage to
within rated range.
Malfunction due to noise. Take protective measures
against noise, such as:
• Install surge suppressor.
• Install insulation transformer.
• Install shielded cables between
the Input Unit and the loads.
Terminal block screws are loose. Tighten screws.
Faulty terminal block connector
contact.
Replace terminal block connec-
tor.