kenttäväylä

Kenttäväylä, commonly translated as fieldbus, is a digital communication system used in industrial automation to connect field devices—such as sensors, actuators, and meters—to controllers, HMIs, and supervisory systems. It enables real-time data exchange, device configuration, and diagnostics over a shared network medium. Fieldbuses were developed to reduce complex point-to-point wiring and to improve scalability, reliability, and maintainability of automation plants. The term refers both to the concept of a shared industrial network and to specific standardized communication protocols.

Typical architectures include master-slave or client-server models, with cyclic or event-driven data transfers. Most fieldbuses use a daisy-chain or trunk-and-drop topology and provide deterministic timing for critical I/O. Layers usually separate physical transmission, data link framing, and application data, allowing interoperability across devices from different manufacturers when compatible profiles exist. Safety and redundancy features are often supported.

Historically important fieldbus families include PROFIBUS (and PROFIBUS DP) and FOUNDATION Fieldbus. In recent decades, Ethernet-based fieldbuses such as PROFINET, EtherCAT, and EtherNet/IP have become common in many industries, offering higher bandwidth and integration with IT networks. Other examples include CAN-based fieldbuses and HART, which overlays digital data on traditional analog wiring. The choice of fieldbus depends on factors such as required real-time performance, distance, environment, and ecosystem.

Today, kenttäväylä concepts underpin many process control and factory automation systems, enabling centralized monitoring, remote diagnostics, and easier integration of field devices with enterprise systems. The technology continues to evolve toward converged networks that blend field-level control with plant IT and cloud-enabled analytics.