The Konnex bus (KNX) is a field bus for building automation. It was developed from the European Installation Bus( EIB), the BatiBUS and the European Home Systems( EHS) and further developed by the Konnex Association according to the European standardEN 50090. The Konnex bus is the successor of these fieldbuses and is downward compatible with the EIB bus. It is a flexible fieldbus used in smart homes and meets the requirements for flexible building automation.
From the EIB bus, the Konnex bus has adopted the transmission medium TP cable (TP1) and the kernel structures of the network layer, the transport layer and the application layer. The TP cable (TP0) used in the Batibus and the Powerline cable(PL132) of the European Home System can be used as alternative transmission media. In addition, there is a variant for transmission via the IP protocol with "KNX over IP " as well as infrared and radio extensions, Konnex-RF(KNX-RF). For the radio technologies, the frequency range between 868 MHz and 870 MHz is used, which is particularly suitable in buildings.
Data transfer is based on data packets and can take place on the Konnex bus as connectionless and connection-oriented point-to-point connection, in multicast and as broadcast. The Konnex bus is used in building automation and smart buildings, where it controls lighting, blinds, heating, air conditioning and ventilation, and triggers alarms. The control can be done via remote access.
The KNX bus distinguishes between three configuration categories: Devices with Automatic-Mode, A-Mode, are self-configuring, those with Easy-Mode (E-Mode) have pre-programmed functions and must be configured by the user, and those with System-Mode(S-Mode) have no basic settings and must be installed by technical personnel. The Konex bus system is standardized by the Konnex Association.