Cascading Logic: A Machine Control Methodology for Programmable Logic Controllers

Cascading Logic: A Machine Control Methodology for Programmable Logic Controllers explains how to develop a functional machine control program for industrial equipment that operates sequentially. The programming approach begins by breaking the machine into its fundamental components. These small, manageable parts help the programmer focus on major concerns before addressing details. The method then explains how to program each component and how to assemble the components into a complete machine control system.

This book aims to give the reader the confidence to make decisions and proceed with certainty that the program works as intended, without odd logic combinations causing unintended actions. The sequential order of events also assists operators and maintenance staff in troubleshooting and maintaining the equipment after deployment. Ladder logic illustrations demonstrate each section of the text. Although the ladder logic examples use the instruction set for the Allen-Bradley SLC 500 PLC, the concepts and techniques are applicable to any brand of PLC.

Gary Kirckof has spent the bulk of his twenty-year career programming automated equipment and assembly lines. Cascading Logic is a direct result of that experience. He is a mechanical engineering graduate of the University of Minnesota and as such started his career engineering process piping, heating, ventilating and air conditioning systems. The shift in focus to programming happened in stages. The first step occurred after the energy crisis when energy management system became popular. These systems were designed to reduce the operating cost of the equipment he was working with so programming them became part of his job. The next step happened while installing an energy management system in a Ford Motor Company plant. While working up in the trusses he looked down at all the automated equipment below him and decided right then and there to become a machine programmer. His affinity towards programming and his mechanical engineering background made him a natural control engineer. Gary Kirckof is currently a system engineer for Remmele Engineering in St. Paul, Minnesota and is both a registered mechanical and electrical engineer.