fieldbus

fieldbus
Name	fieldbus
Type	industrial network
Invented	1970s–1990s
Developer	International Electrotechnical Commission; Profibus Nutzerorganisation; ControlNet International; ODVA; OSI model

fieldbus

Fieldbus is a family of industrial digital bus protocols used for real-time distributed control and automation in process and manufacturing plants. It replaces point-to-point analog wiring by enabling multiple PLCs, DCSs, and smart instruments to communicate over a shared serial or Ethernet backbone, supporting diagnostics, configuration, and control functions. Fieldbus technologies intersect with standards from organizations such as the International Electrotechnical Commission and industry consortia like PROFIBUS and ODVA, and have been applied across sectors including petrochemical, automotive, pharmaceutical, and power generation.

Overview

Fieldbus encompasses digital communication protocols designed to interconnect sensors, actuators, controllers, and operator interfaces within industrial automation systems. Typical implementations link PLC modules, DCS nodes, and smart field devices such as Rosemount transmitters and Siemens actuators. Architectures range from serial topologies to industrial Ethernet variants used by vendors like Rockwell Automation, Schneider Electric, and Emerson; these support service layers for device descriptions, diagnostic data, and configuration via tools produced by companies such as Honeywell and ABB.

History and Development

Initiatives to create fieldbus standards emerged during the 1970s and 1980s as firms including General Electric, Siemens, and Honeywell sought to reduce wiring and improve diagnostics in plants like BP refineries and Shell facilities. Major milestones included the formation of consortia—PROFIBUS Nutzerorganisation for PROFIBUS, Fieldbus Foundation promoting FOUNDATION Fieldbus, and ODVA for DeviceNet and EtherNet/IP—alongside standardization work at the International Electrotechnical Commission and IEEE. Trials in industrial sites run by Dow Chemical and ExxonMobil demonstrated benefits that accelerated adoption through the 1990s and 2000s in sectors such as pulp and paper and mining.

Technical Architecture and Protocols

Fieldbus systems implement layered architectures inspired by the OSI model and incorporate real-time scheduling, token passing, and master-slave arrangements. Notable protocol families include FOUNDATION Fieldbus, PROFIBUS, DeviceNet, ControlNet, Modbus TCP/IP, and EtherNet/IP. Physical media span shielded twisted pair, fiber optics, and industrial Ethernet switches from vendors like Cisco Systems and Belden. Key device profiles and descriptors reference standards from IEC 61158 and IEC 61784, enabling interoperability among products from Emerson, Yokogawa, Endress+Hauser, and ABB.

Standards and Organizations

Standards bodies and industry alliances coordinate fieldbus specifications, certification, and compliance. Principal organizations include the International Electrotechnical Commission, ISO, PROFIBUS Nutzerorganisation, Fieldbus Foundation, ODVA, and OPC Foundation. Regional and national groups such as VDE in Germany and ANSI in the United States contribute to testing frameworks and conformance programs used by manufacturers like Siemens, Schneider Electric, and Rockwell Automation.

Applications and Industry Use

Fieldbus technology is widely deployed in process industries (oil and gas, chemical, water treatment), discrete manufacturing (automotive assembly, semiconductor fabrication), and utilities (power generation, transmission). Systems are integrated into control rooms in installations by ExxonMobil, Chevron, Toyota, Ford Motor Company, Intel, and Siemens Energy. Use cases include remote transmitter networks in Chevron platforms, skid-mounted control for Boeing suppliers, and distributed safety interlocks in facilities managed by BASF and DuPont.

Implementation and Integration

Implementing fieldbus requires device selection, network design, device description (DD/EDD) integration, and configuration via engineering workstations from vendors such as Honeywell Process Solutions and Rockwell Automation. Integration with enterprise systems employs gateways and protocols like OPC UA to connect to SAP MES, Siemens SCADA solutions, and historian databases from OSIsoft (now AVEVA). Cybersecurity and lifecycle management reference guidelines from NIST and industry practices used by operators including BP and Shell.

Advantages, Limitations, and Comparison with Alternatives

Advantages of fieldbus include reduced cabling, richer diagnostic data from smart devices, and deterministic behavior suited to control tasks—benefits realized in plants run by Dow Chemical, ExxonMobil, and Royal Dutch Shell. Limitations involve interoperability challenges, vendor fragmentation, and migration issues when updating legacy systems to Industrial Ethernet or WirelessHART solutions promoted by HART Communication Foundation. Alternatives and successors include MODBUS, PROFINET, EtherCAT, and WirelessHART, each adopted by companies like Siemens, Beckhoff Automation, Endress+Hauser, and ABB depending on performance, determinism, and real-time needs.

Category:Industrial automation