A SIMPLE METHOD FOR PLC PROGRAMMING

摘要

The paper describes a simple method for the development of programs for PLC controllers. A specification of the program behaviour is defined using a formal model of finite state machine. The model is formal, unambiguous, language-independent, yet readable. The model can be verified against the behavioural and safety requirements. After the specification phase, the model can be converted directly into a program written in the form of a ladder diagram. Because the implementation of the graph is direct, no further verification of the target program is necessary.