This book is designed to help readers develop a good general working knowledge of programmable controllers with concentration on relay ladder logic techniques and how PLC is connected to external components in an operating control system. The book uses real world programming problems that readers can solve on any available programmable controller or PLC simulator. Later chapters relate to more advanced subjects in machine controls making this a welcome addition to a personal technical reference library. KEY TOPCIS: The authors examine ladder diagram fundamentals, the programmable logic controller, fundamental PLC programming, advanced programming techniques, mnemonic programming code, wiring techniques, analog I/O, discrete position sensors, encoders, transducers, and advanced sensors, closed loop and PID control, motor controls, and system integrity and safety. For those involved in Electrical, Automation, Control, and Process Engineering.