Glossary · System coordination, integration and orchestration
Distributed control
Also known as: distributed control architecture
German: Verteilte Steuerung
In control system architecture, distributed control is an approach in which control functions are spread over several networked controllers located close to the process, each executing part of the control task, while operation, engineering and coordination are typically provided centrally.
- System integration
- Process industry
In one sentence
In distributed control, control functions run on several networked controllers near the process, with central operation and engineering.
Example
A chemical plant runs its reactor, distillation and utilities on separate controllers of a distributed control system, all operated from one control room.
How it applies
- Engineering: Distribution limits the effect of a single controller failure and reduces cabling. Control loops that span controllers need deterministic communication and defined behavior on communication loss.
- Process industry: Distributed control systems (DCS) are the typical architecture for continuous and batch processes, with integrated engineering, alarm management and historian functions. IEC 61499 offers a vendor-neutral model for distributing function blocks across devices.
- Documentation: System documentation should show which functions run on which controller and how controllers communicate. Operating instructions refer to process units, not controllers, but service documentation needs both.
Distributed vs. decentralized control
Decentralized control emphasizes local autonomy with little coordination. Distributed control emphasizes that control is spread across nodes, which can still be engineered and coordinated as one system.