Object-oriented CAD for electro-pneumatic sequential circuit design in low cost automation

This paper describes an object-oriented CAD system for electro-pneumatic sequential circuits. The system is organised in an object-oriented manner for supporting both pneumatic power system and control system design. An algorithm is developed based on the Karnaugh mapping method to generate indexing equations to link appropriate objects to perform sequential control system design. The algorithm developed can handle an ordinary sequence, a sequence with simultaneous paths and a time delay function. A class which encapsulates this algorithm is described in detail. A prototype system (OOCADEP) written in C++ has been developed to demonstrate the concept.<>