In: J. Soc. Instrum. Control Eng. (Japan), Vol. 27, No. 8, pages 680-687. August 1988. In Japanese.
Abstract: The programmable controller based on sequential control logic has been enhanced in functions by the addition of simple arithmetic processing functions and extended in application scope. In the mean time, it has become important for the FA controller to perform integrated control of more complicated, wider-ranging automated processes. The Petri net is an abstract model of the parallel process and it is expected that it will be used as the method of FA controller-level sequential control programming.