A Microprocessor-Based Control System

An industrial process control system based on a general-purpose microprocessor is described. The system employs the M6800 microprocessor, RAM, ROM, PROM, and peripheral interfaces in the hardware portion. Software includes an algorithm incorporating proportional, integral, and derivative control functions, plus multiplication, conversion, and timing sub-routines, and performance evaluation routines. An electronic analog to an industrial plant is controlled by the system. The performance of the controller with several plant models, control criteria, and sampling intervals is investigated.