A Building-Block Approach to Industrial Controls Laboratories Using Programmable Logic Controllers

Abstract

Industrial control systems design often incorporates reusable sections of prior design that can easily be adapted for new machine and process control systems. For instance, inclusion of a tri-mode control structure (Manual, Automatic and Set-up modes) often becomes a ‘cut and paste’ section from a previous control system design. The prior design is already proven, and development time is available for the newer aspects of the control system. This building-block method can also be used to structure university laboratory exercises for EET (Electrical Engineering Technology) industrial controls design courses. Reusing software sections from previous laboratories can enhance the student’s design capability by focusing lab time on the new problem instead of recreating the old structures. This paper describes a semester-long industrial controls laboratory using programmable logic controllers (PLC) as the primary lab equipment. It describes twelve increasingly difficult PLC laboratory experiments that generally build on the components of the prior labs. The final lab assignment is an open-ended team project to design a complete system for a typical industrial machine or process. All of the PLCs are networked to provide the students with communications content within the lab experience. The pedagogical features of the laboratory exercises are illustrated and results from student comments and numerical ratings of the effectiveness of the lab exercises and equipment are also included in the paper.