A transformation algorithm from ladder diagram to SFC using temporal logic

Summary form only given. A ladder diagram (LD) has been widely used in industries as a language for sequential controls. However, LD can not represent sequential flows of control logics explicitly. This leads to difficulties in understanding the control logics for other engineering. To overcome this problem, a sequential function chart (SFC) has been proposed. As the SFC can represent the sequential flow explicitly, it is expected to be used more widely. As many know-hows have been required in the LD, it is necessary to develop transformation algorithm from the LD to the SFC. In this paper, a technique to transform the LD to the corresponding SFC by using temporal logic is proposed. In the closed-loop system which consists of the LD and the controlled plant, informations in the sequence including parallel path divergences are extracted to develop the transformation algorithm. An example is shown verify feasibility of the proposed algorithm.