Apart from the 2 configuration modes, the KNX standard includes several communication media. Each communication medium can be used in combination with one or more configuration modes, which allows each manufacturer to choose the right combination for the target market segment and application.
TP (Twisted Pair)
This communication medium, twisted pair, bitrate 9600 bits/s, has been taken over from EIB. The EIB and KNX TP1 certified TP1 products will operate and communicate with each other on the same busline.
This communication medium, power line, bitrate 1200 bits/s, has also been taken over from EIB. The EIB and KNX PL110 certified products will operate and communicate with each other on the same electrical distribution network.
RF (Radio frequency)
KNX devices supporting this communication medium use radio signals to transmit KNX telegrams. Telegrams are transmitted in the 868 MHz (Short Range Devices) frequency band, with a maximum radiated power of 25 mW and bitrate of 16.384 kBit/sec. The KNX RF medium can be developed with off the shelf components, allows uni- and bidirectional implementations, is characterized by low power consumption and for small and medium size installations only requires retransmitters in exceptional cases.
As documented in the KNXnet/IP specifications, KNX telegrams can also be transmitted encapsulated in IP telegrams. In this way, LAN networks as well as Internet can be used to route or tunnel KNX telegrams. In this way, IP routers are an alternative to USB data interfaces respectively TP line or backbone couplers. In the latter case, the normal TP backbone is replaced by a fast Ethernet based line.