Feldbus

Feldbus, or fieldbus, is a family of digital communication networks used in industrial automation to connect controllers with field devices such as sensors and actuators. It enables real-time data exchange and distributed control across a plant, reducing wiring complexity and enabling diagnostics and configuration at the device level.

Key features include deterministic communication, support for input/output data exchange, device addressing, and the ability to supply power to certain devices over the bus. Topologies commonly use a master-slave or multi-master arrangement, with devices connected along a trunk or bus and spurs. Fieldbus systems are designed for harsh industrial environments and include mechanisms for error detection, fault confinement, and network redundancy where supported.

Major standards historically associated with Feldbus include Profibus (with Profibus-DP for field devices and Profibus-PA for process automation) and Foundation Fieldbus. Other fieldbus families include CANopen, Interbus, and DeviceNet. These standards differ in data formats, cycle times, device addressing, and power delivery on the bus, as well as their target application domains.

In the late 1990s and 2000s, many industrial networks began to migrate toward Ethernet-based protocols, such as PROFINET, EtherNet/IP, and EtherCAT, which often replace or complement traditional fieldbuses. Nevertheless, fieldbus technology remains in use in existing installations where deterministic performance and established device catalogs are still valued.

See also: industrial automation, Profibus, Foundation Fieldbus, CANopen.