In: Proc. IEEE Int. Conf. on Systems, Man, and Cybernetics (SMC'2000), 8-11 October 2000, Nashville, TN, Vol. 4, pages 3051-3056. 2000.
Abstract: This paper presents a process of converting A and B contacts in the ladder diagram (LD) into the Petri net (PN). In order to represent A and B contacts in the LD program with the PN graph, the concept of preservation arc is introduced. The resulting PN is then compared with the conventional PN by using the timing chart. The state equation for A and B contacts is constructed in the transition vector. As using the equation, each state equation about the LD program is created, such as A contact function and B contact function. The state equation is validated using each example.
Keywords: LD programs, Petri nets, ladder diagrams, state equations.