KNX is a standardized, open-source communication protocol for residential and commercial building automation. It is designed to control various functions such as lighting, shutters, security systems, energy management, and HVAC systems. KNX evolved from three earlier standards: the European Home Systems Protocol (EHS), BatiBUS, and the European Installation Bus (EIB). This protocol allows devices from different manufacturers to communicate with each other seamlessly.
The system operates on a decentralized network structure, meaning there is no central controller. Each device has its own intelligence and can communicate directly with other devices on the network. This enhances the reliability of the system; if one device fails, the others continue to operate. Communication can be carried out over various media, including Twisted Pair (TP) wiring, Powerline (PL), Radio Frequency (RF), and IP/Ethernet. This flexibility makes KNX suitable for both new constructions and retrofitting existing buildings. The configuration and commissioning of a KNX system are done using a vendor-independent software tool called ETS (Engineering Tool Software), which simplifies the design, installation, and maintenance of the network.