Expansion of SFC expression for sequential control systems

Sequential control systems in the case of factory automation (FA) usually consist of programmable controllers (PCs). One of the authors, has been engaged in constructing material handling systems (MHS) for a long time and has been studying how its control design should be for keeping efficiency and for realizing correct control systems. Accordingly, the authors propose here a description method to express the contents of control systems as the pretreatment of making a program and a method in which such an expression is structurally easy to make. Namely, it is Total-SFC being based on SFC as the fundamental technology which exists in the IEC 1131-3 standard at present, and Total-SFC is expansion of SFC expression.