A rule-based evaluation of ladder logic diagram and timed petri nets for programmable logic controllers

This paper describes an evaluation through a case study by measuring a rule-based approach, which proposed for ladder logic diagrams and Petri nets. In the beginning, programmable logic controllers were widely designed by ladder logic diagrams. When complexity and functionality of manufacturing systems increases, developing their software is becoming more difficult. Thus, Petri nets as a high level specification language were offered. Rule-based approach tends to a unified measurement for both ladder logic diagrams and Petri nets. The proposed approach is performed in three levels and its complexity increases level by level. We have shown that, when the levels are more complex, Petri nets are more tractable and more verifiable. Moreover, it can be concluded that Petri nets are superior to ladder logic diagrams. This feature enhances the verifiability of modeled systems. The proposed approach a net system control model, which can be directly compiled to a executable control code for designing and analysis of complex manufacturing systems.