Conversion between ladder diagrams and PNs in discrete-event control design-a survey

Modern manufacturing systems have challenged the use of LDs for PLCs to design their discrete-event controllers. Researchers are constantly pursuing integrated tools that eliminate the limitations of LDs. These tools are aimed not only for control but also for system analysis, evaluation, and simulation. For the past decades, Petri nets (PNs) have emerged as an important tool to provide an integrated solution for modeling, analysis, simulation, and control of industrial automated systems Different types of PN-based controllers in academia are intended for application in industry. There is a need for more benchmark studies of PN and LD methods in order to form a structured and integrated framework for logic control software development. The paper surveys work on these methods with focus on the conversion methods between PNs and LDs.