Design and Implementation of Process Control Software Under Realistic Environment Conditions

Abstract

A software package is described which offers a systematic approach to development of industrial process control software. The procedure of con trol program implementation splits up in 3 basic steps or phases. Phase 1 covers control algorithm design and offline simulation. During phase 2 the real control programs are installed on process computer using results and experience of step one. Programs are thoroughly tested and evaluated in real time environment. The interplay of control software performance on the whole and its control behaviour can be investigated in closed loop simulation. Within phase 3 control software is tested on a dual computer system consisting of one computer simulating and a second computer controlling the plant. Both computers are coupled by realistic process interface equipment and are working asynchronously. Plant simulation and control software operate in parallel and in real-time. Phase 3 simulation supports final tuning and adapting of control algorithms and parameters. Concerning software engineering aspects an overall test and performance evaluation of the control system can be done. The system establishes a software and control engineering tool which makes control software development less costly and more reliable. Especially the transfer to real plant will become less risky after testing under realistic environment conditions.