Ethernet empowers fieldbus: Fieldbuses are adapting Ethernet to increase performance, cut costs

摘要

Fieldbus networks have been around for over a decade, delivering value in industrial automation applications worldwide. In most cases, a fieldbus network is used to link field devices to a host computing system in a process plant. The field devices in question are most typically instruments, analyzers, and modulating control valves. The most popular types of instruments are flow, level, temperature, and pressure transmitters--although a typical process plant will also include many other types of process variable transmitters. Common analyzer types measure the chemical composition of parameters such as moisture, carbon dioxide, methane, and other gasses and liquids. Modulating control valves provide continuous flow control of liquids and gases. The host computing systems linked to field devices include control systems, Enterprise Resource Planning (ERP) systems, and asset management systems. The control systems in question are usually basic process control or regulatory control systems. Other control systems with fieldbus links to field devices include advanced process control systems and safety systems.