Fieldbus, or fieldbus in English, is a data bus that has rapidly developed in the industrial field in recent years. Its main function is to solve the digital communication process between intelligent instruments, controllers, and other field devices in industrial settings, as well as the information transmission between these field control devices and higher-level control systems. Fieldbus has significant advantages such as simple operation, reliable operation, and cost-effectiveness, and therefore has been gradually promoted and widely used in the industrial field. This article will introduce several common fieldbuses, including HART, DeviceNET, ProfiBUS, and FF.
Hart (Highway Addressable Remote Transducer), developed by Rosemount, is characterized by enabling digital signal communication on existing analog signal transmission lines. It is widely used in industrial instrumentation; for example, level switches with the Hart protocol can replace traditional instruments and be integrated into DCS systems, or a complete FCS system can be built through a bus system.
DeviceNET (international standard IEC 62026 PART 3) is a low-cost, high-performance communication network developed in the mid-1990s based on an improved version of the CAN (Controller Area Network) bus. It conforms to global industry standards and was initially developed and operated by Allen-Bradley (later merged with Rockwell Automation) in the United States. Building upon CAN technology, it adds support for bus power supply and hot-swapping of devices, making it more versatile and flexible. It also incorporates object-oriented, connection-based communication technology, making application programming easier.
PROFIBUS is a fieldbus standard based on German standard (DIN19245) and European standard (EN50170). It was initiated in 1987 by fourteen companies, including Siemens in Germany, and five research institutions. In 1993, PROFIBUS DUP, with a simpler architecture suitable for automatic and discrete control systems, was proposed, achieving speeds up to 12 Mb/s. In 1996, it became part of the international fieldbus standards IEC61158/IEC61784 (TYPE3).
FF (Foundation Fieldbus) is short for Foundation Fieldbus. It comprises the ISP protocol, jointly developed by Fisher-Rousemount (USA) and over 80 other well-known companies, and the WorldFIP protocol, developed by Honeywell (Europe) and over 150 other companies. FF bus is widely used in process automation fields such as petrochemicals, metallurgy, water treatment, and papermaking, and can be considered a fieldbus with very promising development prospects.
