Experience or knowledge is needed to troubleshoot plc issues. In order to find the errors on the machine, it is necessary to know the machine. There may be many reasons for fault diagnosis or breakdown in PLCs.
You can use the diagnostic LEDs on the plc for errors or you can take advantage of the error codes on the indicator panel on some plc and drivers. If there is no error indication screen,
You can find the fault code by connecting with the program and by looking at the errors in the logs or the number of times the LEDs on it flash quickly or slowly.
You can find the related articles by filtering according to plc and driver at plctr.com.
In order to find the diagnosis and fault solution of the loops in the PLC, or if the codes in the plc do not perform any operation during the operation or if your machine has a very fast cycle time and you cannot see the code processed in the plc or in the sequencer the program skips some places, so the program you wrote is correct if not working; At this point, by adding counters to the lines in the plc, you can interpret which line is executed by looking at the status of these counters.
Another method is; to use trend graphs in plc. You can find information on how to add and use trends on our website.
Trends in PLC is simple to use and can keep historical records. Instead of following the fault at the beginning of the plc, you can add the relevant tags to the train and interpret them later.