Developing a class of sequential function charts from Petri nets

A fundamental problem in specifying control software is that the interaction of inputs and outputs becomes difficult to tract as the size of the control problem grows. This has led to a great deal of interest in graphical programming languages (GPL), such as the sequential function chart (SFC) or the GRAFCET approach to program documentation. These languages are based on Petri nets. In this paper we are interested in defining criteria for developing a GPL macrostep program structure from a Petri net specification of a discrete event system. This work is related to earlier work in which a methodology was developed for converting ladder logic programs to Petri nets. The combination of results is aimed at providing a methodology for automatic stepwise transformation of programs among the programming disciplines of ladder logic Petri nets and GPL