Domain specific model-based development of software for programmable logic controllers

Procedural process control is responsible for coordination of control units that perform basic control in a typical industrial control system. Basic control, in turn, performs actions necessary for maintaining a desired state of process variables and equipment. Software in the domain of procedural process control consists of modules responsible for management of startup and shutdown sequences, exception handling and module communication. In this work we present the domain specific modeling language (DSL) ProcGraph together with its corresponding code generation tool that was designed for the development of software in the domain of procedural process control systems. The advantage of using a domain specific language is that not only the programmers, but also domain experts are able to understand and modify the code. The DSL code is self-documenting, as it is expressed in the idiom of the problem domain. In the article we present a formal description of the ProcGraph language. Furthermore, we describe how the formal model is used in the implementation of the automatic IEC 1131-3 code generator.