Glossary · System coordination, integration and orchestration
Centralized control
Also known as: central control architecture
German: Zentrale Steuerung
In control system architecture, centralized control is an approach in which one controller or control center makes the control decisions for a whole machine, line or plant, while field devices mainly provide inputs and execute commands.
- System integration
In one sentence
In centralized control one controller or control center makes the control decisions for a whole machine, line or plant.
Example
An older packaging line runs all motors, valves and sensors from one large PLC in the main cabinet, with remote I/O stations along the line.
How it applies
- Engineering: Centralized control keeps logic in one place, which simplifies overview and consistency. The central controller, its power supply and network become single points of failure that may need redundancy.
- Change: Modifying one machine function means changing the central program, which requires regression testing of functions that were not meant to change.
- Documentation: Documentation can describe the program structure in one place; still, map functions to physical machine sections so that service technicians find the right program part.
Centralized vs. decentralized control
In centralized control one controller decides. In Decentralized control decisions are spread over several controllers, each responsible for its section, which improves modularity but requires well-defined interfaces between them. Many real plants combine both approaches, for example a central line PLC with intelligent drives.