Y net: A new technique for modeling discrete control in industrial systems

This paper presents a new discrete control modeling technique for automated industrial systems. The proposed methodology helps to smooth the transition from specification to implementation. The technique is based on a graphical representation (Y net) that efficiently describes the operation of Programmable Logic Controllers (PLCs). The technique offers a structured way for constructing Y nets. Although Y net can be translated into any PLC language, we chose to present an automatic translation algorithm of Y net into Ladder Diagrams (LDs) - the most prevalent PLC language. The compactness of Y nets gives them an advantage over models that experience exponential explosion (e.g., state diagrams). A large part of the method can be automated. Minimum specification is required from the user, and both the Y net and the ladder diagram can be built automatically using the proposed algorithms.