Advanced Real-Time Languages for Distributed Industrial Process Control

IHigher level programming languages for general scientific and technical applications have become increasingly sophisticated in program safety, production economics, and hardware independence. These languages, such as Algol 68, PL/1, and Pascal, are designed primarily to form computational tasks for sequential and off-line execution. Distributed industrial computer control systems impose new programming requirements, such as true parallelism; on-line, real-time task execution; intertask communication via an explicit communication system; and programmed support of fault tolerance. This article outlines the requirements of suitable programming languages for distributed industrial process control, starting with an investigation of the features of distributed systems. In the context of these features, a general concept of the required language elements is discussed, and an example of a modern real-time programming language, that fulfills some of these requirements is given as a basis for a higher level multicomputer real-time programming language. The application of this multicomputer language to a problem involving the control of a soaking pit furnace plant shows its contribution to distributed industrial process control.