This edition of Programmable Logic Controllers (PLCs) builds on the success of the first, not only explaining the design, structure and operation of PLCs, but also illustrating how they can be used in industry. Starting with basic concepts, the book goes on to cover programming techniques based on the new International Standard IEC 1131-3, including: instruction list, structured text, ladder diagram, function block diagram, and sequential function chart. In addition, special coding techniques for some common PLCs are covered in the appendices. Taking a practical approach, this book is aimed at undergraduate and BTEC students studying automation and process control. It will also be suitable for practicing engineers new to PLCs. The special features: covers basic concepts and components; covers power an control circuits and input devices; uses programming languages based on the new IEC 1131-3; and contains worked application programming examples.