Implementation of a Control System Test Environment in UNIX

Abstract

This paper discusses how UNIX features such as shared memory, remote procedure calls, and signalling have been used to implement a distributed computational environment ideal for the development and testing of digital control systems. The resulting environment - based on features commonly available in commercial workstations - is flexible, allows process simulation and controllers development to proceed in parallel, and provides for testing and validation in a realistic environment. In addition, the use of shared memory to exchange data allows other tasks such as user interfaces and recorders to be added without affecting the process simulation or controllers. A library of functions is presented which provides a simple interface to using the features described. These functions can be used in either C or FORTRAN programs and have been tested on a network of Sun workstations and an ENCORE parallel computer.