The development of process control software

Abstract

The use of on-line, real-time computers for control of industrial processes has been increasing rapidly during the past ten years. That the cost of the software necessary to implement such systems exceeds even the hardware costs became clear in the initial installations. As a consequence, much effort was devoted to the development of efficient, economical software and software approaches for use in industrial process control applications. During the past five years, there has emerged from these efforts the realization that process control software is different from software for large scale batch processing, time-sharing, message switching, or any other computer applications. It contains its own requirements and problems and leads to a distinct set of solutions. Moreover, this difference is due to more than the size of the computers involved in industrial process control. The objective of this paper is not to catalog the significant features of various software systems in existence today for this has been done very well in a number of recent survey papers. Rather, the objective is to describe the basic structure of current industrial process control software, emphasizing the unique structure of that software, how it evolved, and its current points of controversy and problems.