Error Processing and Correction
Section 5-3
Output Units
Symptom
Cause
Remedy
Not all outputs turn ON
(1) Load is not supplied with power.
(2) Load voltage is low.
Supply power
Adjust voltage to within rated range.
Tighten screws
(3) Terminal block screws are loose.
(4) Faulty terminal block connector con-
tact.
Replace terminal block connector.
(5) Blown fuse
Replace fuse.
Replace Unit.
Replace Unit.
Replace Unit.
Correct program.
(6) Faulty I/O bus connector contact.
(7) Output circuit is faulty.
Output circuit is faulty.
Not all outputs turn OFF
Output of a specific bit num-
ber does not turn ON or indi-
cator is not lit
(1) Output ON time too short.
(2) Bit status controlled by multiple instruc- Correct program.
tions.
(3) Faulty output circuit.
Replace Unit.
Output of a specific bit num-
ber does not turn ON (indi-
cator lit).
(1) Faulty output device.
(2) Break in output wiring.
(3) Loose terminal block screws.
(4) Faulty terminal block connector faulty.
(5) Faulty output bit.
Replace output device.
Check output wiring.
Tighten screws.
Replace terminal block connector.
Replace relay.
(6) Faulty output circuit.
Replace Unit.
Output of a specific bit num-
ber does not turn OFF (indi-
cator unlit).
(1) Faulty output bit.
Replace relay.
(2) Bit does not turn OFF due to leakage
current or residual voltage.
Replace external load or add dummy resis-
tor.
Output of a specific bit num-
ber does not turn OFF (indi-
cator lit).
(1) Bit status controlled by multiple instruc- Correct program.
tions.
(2) Faulty output circuit.
(1) Low load voltage.
Replace Unit.
Output irregularly turns ON/
OFF.
Adjust load voltage to within rated range
(2) Bit status controlled by multiple instruc- Correct program
tions.
(3) Malfunction due to noise.
Protective measures against noise:
(1) Install surge suppressor.
(2) Install insulation transformer.
(3) Use shielded cable.
(4) Terminal block screws are loose.
Tighten screws.
(5) Faulty terminal block connector con-
tact.
Replace terminal block connector.
Error occurs in units of 8
points.
(1) Loose common terminal screw.
Tighten screws.
(2) Faulty terminal block connector con-
tact.
Replace terminal block connector.
(3) Blown fuse.
Replace fuse.
Replace Unit.
Replace CPU.
Replace Unit.
(4) Faulty data bus.
(5) Faulty CPU.
Output indicator is not lit (op- Faulty indicator.
eration is normal).
94
OMRON [ OMRON ELECTRONICS LLC ]
