Ladder diagram language (LD) is a common programming language in industry to develop control algorithms of discrete event systems (DESs). Besides, it is one of the five programming languages supported by the International Electrotechnical Commission through the IEC-61131-3 standard. On the other hand, Petri net (PN) theory is both a graphical and mathematical tool used to model discrete event systems, particularly in this study, control lines used in industrial algorithms. Control algorithms in LD are generally developed based on the experience of control system programmers. Therefore, it is still a relevant problem how to formalize the current and new control algorithms. In this chapter, are analyzed lines in LD used more frequently in control algorithms. Additionally, an element-to-element transformation methodology from a LD program to a PN model is proposed.
Part of the book: Petri Nets in Science and Engineering