Chapter 7 Maintenance
7-6
7-2
Cause of the failure
Poor operation during PLC operation may be caused by the following causes.
(1)
Power supply problem for the system including the PLC
・
Power is not supplied
・
Power supply voltage is low.
・
Turn off the power instantaneously
・
Be powered by a large amount of noise
Measure
Investigate the cause using the AC analyzer and take countermeasures.
(2)
Damage to equipment due to accidents or mistakes
・
High pressure applied to the power supply (lightning strike, etc.)
・
Load short
・
Damage to power equipment due to mechanical failure (valves, motors, etc.)
・
Detector damaged due to mechanical failure
Measure
Replacement of the relevant equipment
Replacing the fuse
(3)
Defective control circuit
・
The timing of the control circuit (PLC program, etc.) and the machine is not correct.
・
There is an unexpected situation in the control circuit.
・
Aging
Measure
Timing adjustment
(4)
Deterioration and wear and tear of machinery and parts
・
Poor contact (welding and life of limit switches, relays, electromagnetic switches, etc.)
・
Drop in the cell voltage of the CPU
・
Degradation of PLC due to high pressure noise
・
Aging
・
Changes in the characteristics of analog devices
Measure
Replacement of applicable machines and parts
(5)
Program changes due to noise or mistakes
・
The program was rewritten by mistake through monitor operation, etc.
・
Module plugged and unplugged when power is turned on.
・
Program memory changed due to large noise
Measure
Restore the program or memory backup.
Summary of Contents for Kostac SJ-Ether Series
Page 1: ...English version of the KOSTAC SJ Ether series user s manual SJ ETHER USER M...
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Page 113: ...3 24 Note Refer to 6 3 3 Module Assembly for connections and locks between modules...
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Page 156: ...flashing OFF Not sent H W RX Green flashing Receiving H W OFF Not received H W...
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