Instructing Industrial Controls Using Ladder Diagrams on an IBM PC

Because of the increased use of programmable controllers in industry, educational institutes should teach the basic principles of these types of industrial computers. However, the cost of procuring hardware for laboratories is usually prohibitive. This paper describes the simulation of a programmable controller on an IBM PC. Special software allows the control logic to be described to the computer using ladder diagram logic. An overview of the software architecture is given and use of the simulator in a laboratory environment using real I/O is described.