KNX System devices, needed to make the system alive
KNX International Catalog
The International KNX offer overview
The KNX system devices comprise of devices to feed the bus or devices, to couplers and gateways to link different parts of the system, interfaces to communicate with or program devices and devices needed only once per installation like a weather station. So it is a bundle of very different products.
Here are some devices and special features listed: