This new edition consists of twenty six chapters and begins with an introduction on data communication. This is followed by exposure on networking and networking in process automation, forming the basis for proper understanding of fieldbuses. Fieldbus is introduced in chapter five followed by discussions on an wide array of fieldbuses up to chapter fifteen. Common Industrial Protocol is taken up for discussion in chapter sixteen. Real time Ethernet-based fieldbuses have been taken up for discussion in the next five chapters. These newly introduced six chapters: from chapters sixteen to twenty one, are included because of their widespread applications in real time control and automation industries. Chapter twenty two deals with intrinsically safe fieldbus systems which is very important in highly flammable industries. Chapter twenty three is on wiring installation and commissioning of fieldbuses. Wireless fieldbuses have come of age with vast improvements in wireless sensor networks. To complement this, chapter twenty three deals with wireless sensor networks followed by the last two chapters on wireless fieldbuses: WirelessHART and ISA 100.11a. This book will be an invaluable resource to students, trainers and industry professionals in process and automation industries.