Chapter 14 Troubleshooting
14-1
Chapter 14 Troubleshooting
Here describes the contents of various errors to be occurred while operating the system, the methods to find
the causes and the actions.
14.1 Basic Procedure for Troubleshooting
It is important to use the high reliable machine to increase the system reliability but it is important to take
a prompt action when the trouble occurs as well.
To start the system promptly, it is more important to find the trouble occurring cause promptly and take
the necessary action. The basic items to comply when taking this trouble shooting are as follows.
1) Check by the naked eye
Check the following items by the naked eye.
•
Machine operation state (STOP, RUN)
•
Power supply state
•
I/O machine state
•
Wiring state (I/O cable, extended and communication cable)
•
After checking the indication state of each indicator (Power LED, Run LED, Stop LED, I/O LED
etc.), connect the peripheral device and check PLC operation state and program contents.
2) Trouble Checking
Examine how the trouble is changed by the following action.
•
Place the key switch on STOP position and apply the power ON/OFF.
3) Limit range
Estimate what is the trouble cause using the above method.
•
Is it from PLC itself ? Or external cause ?
•
Is it from I/O module ? Or other cause?
•
Is it from PLC program?
14.2 Troubleshooting
Here describes the method to find the trouble, the error code and the actions on the above by dividing
them per phenomenon.
Trouble contents
When Power LED is OFF
When ERR. LED is blinking
When RUN, STOP LED is
OFF
When I/O module operates
abnormally
When PROGRAM WRITE
does not work
Action method when Power LED is OFF
.
Action method when ERR LED is blinking
Action method when RUN, STOP LED is OFF
Action method when I/O module operates abnormally
Action method when PROGRAM WRITE does not work