Ethernet in industrial automation: Overcoming obstacles

Resumo

Ethernet evolution history and data packet assembly in the OSI model are discussed. Limitations impeding Ethernet application in industrial automation are formulated. The paper notes that real-time Ethernet operation requires additional mechanisms which allow to avoid collisions. The mechanisms in Ethernet-compatible real-time protocols such as EtherNet/IP, PROFINET, EtherCAT, Powerlink, Modbus TCP, Foundation Fieldbus HSE, and SERCOS III are analyzed. The IEEE1588 standard enabling high-precision synchronization of network users’ clocks is examined. Characteristics and application fields of wireless Ethernet networks are listed. Ethernet redundancy mechanisms such as STP, MSTP, MRP, Link Aggregation, PRP, and HSR are considered. Innovative solutions such as powering over Ethernet and embedded Ethernet switches are described.