This text sets out to provide the reader with a sound understanding of the principles and elements of automated machine control systems. It extensively illustrates and explains how programmable logic devices (PLCs) are programmed and interfaced to hydraulic and pneumatic motion actuators and electric motors. The approach and coverage is ideally suited for students studying mechatronics in further or higher education, whether at technician diploma or undergraduate level. Most of the chapters include several case study problems which are fully solved and explained and which reflect real industrial PLC applications.