Omron FQM1-MMP21 ユーザーズマニュアル

None of the outputs will go ON.

(1) The load power is not being 

supplied.

Supply power.

(2) Load power supply voltage is 

too low.

Adjust voltage to within the 
allowed range.

(3) Faulty terminal block connec-

tor contact.

Replace terminal block connec-
tor.

(4) Output circuit is faulty.

Replace the Module.

None of the outputs will go OFF.

Output circuit is faulty.

Replace the Module.

A specific bit address’ output does not turn ON. 
(Indicator is not lit.)

(1) Output ON time too short 

because of a program error.

Correct program to increase the 
time that the output is ON.

(2) The bit’s status is controlled 

by multiple output instruc-
tions.

Correct program so that each 
output bit is controlled by only 
one instruction.

(3) Faulty output circuit.

Replace the Module.

A specific bit address’ output does not turn ON. 
(Indicator is lit).

(1) Faulty output device.

Replace output device.

(2) Break in output wiring.

Check output wiring.

(3) Faulty terminal block connec-

tor.

Replace terminal block connec-
tor.

A specific bit address’ output does not turn OFF. 
(Indicator is not lit.)

Output does not turn OFF due to 
leakage current or residual volt-
age.

Replace external load or add 
dummy resistor.

Output of a specific bit number does not turn OFF. 
(Indicator lit.)

(1) The bit’s status is controlled 

by multiple output instruc-
tions.

Correct program.

(2) Faulty output circuit.

Replace the Module.

Output turns ON/OFF irregularly.

(1) Low or unstable load voltage. Adjust load voltage to within 

proper range

(2) The bit’s status is controlled 

by multiple output instruc-
tions.

Correct program so that each 
output bit is controlled by only 
one instruction.

(3) Malfunction due to noise.

Take protective measures 
against noise, such as:
(1) Install surge suppressor.
(2) Install isolating transformer.
(3) Install shielded cables 
between the outputs and loads.

(4) Faulty terminal block connec-

tor contact.

Replace terminal block connec-
tor.

Errors occur in 8-point or 16-point blocks, i.e., for the 
same common.

(1) Faulty terminal block connec-

tor contact.

Replace terminal block connec-
tor.

(2) Faulty data bus

Replace the Module.

(3) Faulty CPU

Replace the Module.

Output indicator does not light, but output operates 
normally.

Faulty indicator or indicator cir-
cuit.

Replace the Module.