THE USE OF OBJECT-ORIENTED PROGRAMMING METHODOLOGIES IN PLANT CONTROL SYSTEMS: BENEFITS OR BUZZWORDS?

摘要

This paper will examine the use of an object-oriented programming methodology to develop treatment plant control system logic. This examination will be used to determine if actual benefits are obtained or if object-oriented programming methodologies are just buzzwords. An overview of object-oriented software and its expected benefits is presented. A case study of an actual implementation of this methodology is examined to show the development and implementation of control logic for a large water treatment plant control system.The steps used during the development process are presented, including the concept of a "top down, bottom up" development methodology. This methodology consists of examining the process designer's control narratives - the "top" - and identifying the common equipment control "objects" - the "bottom." The identified objects are prototyped and tested to verify the desired functionality. These objects are then used to develop the control system logic that implements the process designer's control narratives.The results of using an object-oriented methodology are compared to implementing similar control narratives using a non-object-oriented methodology. The time required to develop, debug, and start up the two plant control systems are discussed as well as the ease of troubleshooting, maintaining, and modifying the logic for each methodology.This paper concludes with a determination of whether actual benefits are realized by using an object-oriented programming methodology in the development of treatment plant control system logic or if this methodology is just buzzwords.