Automatic Translation of a Process Level Petri-Net to a Ladder Diagram

Major part of discrete industrial automation hardware is controlled by Programmable Logic Controllers (PLCs). While Petri-nets (PNs) have been proposed by many researchers for modelling shop floor discrete control, the majority of the world PLCs are programmed using ladder diagrams (LD) and significant portion of them cannot be programmed using another language. This paper proposes hierarchical approach to translating PN to LD: for describing the high level process, it introduces automatic translation technique of process level PN, while utilizing a recently developed method (for translating PN to Boolean logic) for translating the embedded tasks to a LD. Interestingly, the generated LD code enables the reconstruction of the original Petri-net.