Software architecture and framework for Programmable Logic Controllers: A case study and suggestions for research

Abstract

Programmable Logic Controllers (PLCs) are widely used for control and automation of machines and processes, so the quality of PLC software has a direct impact on production efficiency. This paper describes a PLC program for a food production line that was completely rewritten using a different software architecture and framework. The PLC hardware and the production line equipment were not changed, so this project provides an opportunity to quantify the impact of different PLC software architecture on production efficiency. The average number of cases of products produced per production hour during the first ten months with the new program was 6.1% higher than the average during the previous ten months with the old program. PLC software, unlike most other software, is often used by the end-user for troubleshooting. In this case, a relatively simple architecture and framework that favors the end-user significantly improved production efficiency over a more sophisticated architecture and framework that favors the software developer. Suggestions for further research on software architecture and framework are given.