The successful operation of any production process is dependent upon a well designed and reliable communication system. Modern communication systems that are employed within a factory use a variety of means for sending and receiving information. With time, these systems have become more and more complicated. This volume in The Industrial Electronics Handbook, Second Edition spans the full gamut of topics which are needed for engineers working with industrial communication systems. A detailed description of the numerous topics covered in this volume is outlined in the Preambles that are provided for the various sections, and readers are directed there for the detailed topics contained within. The four other volumes in the Handbook are available individually: Fundamentals of Industrial Electronics, Intelligent Systems, Power Electronics and Motor Drives, and Control and Mechatronics. Additionally, all of the volumes are available as a set.