In decentralised systems every component has intelligence. Sensors put commands directly on the bus and actuators “listen” for the commands intended for them in order to execute them independently. There is thus no central intelligent component. A power supply, input components and output components are all that are needed to build an integrated home system.

Figure 5: EIB/KNX is a typical example of a system with decentralised intelligence. Sensors and actuators are connected to one another by the bus. A number of lines (maximum of 64 components per line) can be connected together using a connector or line coupler. There is no master that controls everything. Every component can “listen” and/or “send”. (Illustration source: EIBA)
Some systems that use the decentralised principle include:

Figure 6: Some brands of decentralised systems on the market.
Example Luxom:

Figure 7: The Luxom system is decentralised. Every component has intelligence and is connected directly to the bus. At the top left of the diagram is the supply for the bus system. (Illustration source: Luxom)
Example Bticino:

Figure 8: In the Bticino “My Home” system, all operating components and actuators are connected to the same bus. There is no master. (Illustration source: Bticino)