Bus systems are the foundation for industrial communication. With Industrial Ethernet as a consistent standard for automation, open communication is possible from the enterprise management level down to the process level. Other bus systems such as Profibus, AS-i, or CAN can be connected to Ethernet using their specific interfaces and communication protocols. To meet industrial requirements such as availability, real-time capability, and robustness, data exchange must function as smoothly and losslessly as possible. Industrial-grade connection technologies, network structures, Profinet, and Industrial Security help to meet these requirements. This book provides plant planners and operators, programmers, and commissioning engineers with the fundamentals and terminology for the use of Industrial Ethernet and communication buses in industrial automation.