RELATED ARTICLES :

Monday, March 24, 2008

Checking the maintenance and reparation of the PLC and making the report

Testing the PLC
After the PLC is repaired then do the testing by operating the PLC as according to procedure. Perceive and check, whether the PLC run normally or there is still error which emerge. If there is still error, reenact the reparation step.


Example of the Omron PLC test run procedure;
Power Supply Application
  • Check the PLC’s power supply voltage and terminal connections.
  • Check the I/O devices’ power supply voltage and terminal connections.
  • Turn on the power supply and check that the “PWR” indicator lights.
  • Use a Programming Device to set the PLC to PROGRAM mode.
I/O Wiring Checks
  • With the PLC in PROGRAM mode, check the output wiring by turning on the output bits with the force set and force reset operations.
  • Check the input wiring with the PLC’s input indicators or a Programming Device’s monitor operations.
Test Run
  • Use a Programming Device to set the PLC to RUN or MONITOR mode and check that the “RUN” indicator lights.
  • Check the sequence of operation with the force set/reset operations, etc.

Debugging
Correct any programming errors that are detected.

Saving the Program
  • Use a Programming Device to write the program to a backup floppy disk.
  • Print out a hard copy of the program with a printer.

Making the report
The report is made for documentation. Documentation of the PLC maintenance represent the equipment of maintenance administration to help the fluency of the next maintenance. With the good documentation and depository of the good administration peripheral, we will be more easy to look for the archives nor things which we need.
Documentation of the PLC maintenance usually consisted of the following matters;
  • Installation guide
  • Operation manual
  • Maintenance manual
  • Sparepart list
  • Sheet of component data
  • Layout diagram
  • Troubleshooting Questionnaire
  • Number phone of the service center
  • Last Maintenance Record or last maintenance report
  • Print out or hard copy from program listing
  • Back-up program
Example of The troubleshooting questionnaire on the LG PLC.