BU I LDI NG SOLUT IONS
— Architecture and configuration of a KNX system
— Area, line, device
— Physical Address
Each device in the KNX network, with the exception of power supplies, is uniquely identified by a physical address. The address consists of three numeric fields separated by a dot: • from 0 to 15, defines the area it belongs to • from 0 to 15, indicates the line • from 0 to 255, identifies the device.
A KNX system is a distributed logic network (i.e. there is no device that centralizes the logic of the entire system) whose nodes have an individual 16-bit address. In total then, theoretically, up to 65,536 devices can be addressed. The KNX technology, at line level, allows any of the star, tree and bus topologies while the ring topology is not possible. A set of up to 256 devices constitutes one line. A maximum of 15 lines can be connected by a main/line, constituting an area. A KNX installation can conta in up to 15 areas, connected together by a particular line called backbone line.
— Group address
The devices of a KNX system communicate with each other via group addresses. Normally, group addresses are structured according to a 3-level hierarchy: • The main group, normally this is the system level (e.g. lighting, temperature control, etc.). • The core group, a particular function of the system under consideration (e.g. switch, dimmer, etc.). • The subgroup, devices belonging to the same function (e.g. kitchen light, bedroom window, etc.). The group addresses are represented by separating the numerical fields that define the main group, the central group and the subgroup using the slash character (/) and can be assigned at will even though it is advisable to maintain a principle scheme that is the same for all systems. There is also a version of two-level group addressing, but it is less widely used.
— Power supply
The power supply is the device that provides power to devices connected to the bus line. The power supply is normally supplied directly to the mains voltage and provides a DC voltage of 29 V directly to the bus terminals.
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