APPLICATION OF GRAPHICAL SPECIFICATION METHODOLOGIES TO MANUFACTURINGCONTROL LOGIC DEVELOPMENT - A CLASSIFICATION AND COMPARISON

Robust formal specification of control logic is viral for efficient de velopment of discrete-event control software for real-time manufacturi ng systems. This paper classifies real-time control specification meth odologies into three types based on their levels of abstraction, Repre sentative methodologies in each class are briefly introduced, includin g a new methodology called discrete-event control networks (DECN). An example of a manufacturing discrete-event control system is presented and the logic is developed under each of the methodologies for compari son. The desirable characteristics and functions of real-time manufact uring systems specifications are identified. The paper then discusses the relative abilities of the representative methodologies to address these characteristics.