Filter
Top Products
258
Troubleshooting Problems in Modules Section 9-3
Output Errors
Error condition Probable cause Remedy
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.