System program defects and solutions for sequence control instructions in S7_200PLC

October 17, 2018

PLC has a variety of programming methods, which can be selected for different occasions. However, in solving logical sequence control with the nature of concurrency, jump or selection, the function diagram method is undoubtedly the best programming method. The function diagram belongs to a graphic language, which can simply describe more complicated control events, so it is also one of the development directions of the PLC programming language.