A new approach to PLC software design.

This paper presents a model-based approach to PLC software development. The essence of this approach is the introduction of a new procedural modeling language called ProcGraph. In contrast to commonly used methods, ProcGraph deals with the procedural aspect of the control system and allows software specification at a higher level of abstraction. The modeling language has been supported with the development of a software tool which facilitates graphical model design and automatic code generation. The specification notation has been tested in the development of software for industrial applications. The supporting tool has been tested in a laboratory environment.