Programmable logic controllers versus personal computers for process control

It is proposed that Personal Computers (PCs) can be used effectively for the same industrial applications as Programmable Logic Controllers (PLCs). The basic concepts related to the operation of a PLC to emulate the behavior of a relay panel are explained. This is used to build a simple model for using standard PCs in the same applications as PLCs. This is demonstrated using a simple example of an automated process. Sample code in a standard high level language is presented that can be used as a template for future developments. Finally, the potential advantages and enhancements that can result in using PCs for process control are presented.