Figure 9: Example of an addressing group assignation to devices.

Figure 8: Group Addressing Scheme in KNX/EIB

Diagram 4: Addressing Example for Devices

The addressing method is very important in order to correctly identify devices within the system. There are two types of addressing:

- Physical Addresses

- Group Addresses

The physical address indentifies the device with correspondence to the physical location within the topology of the system. The physical address is composed by 3 sections, the first one identifies the area where the device is located, followed by the line and ending by the number of the device (area-secondary line-device). For example the address given by 1.15.2 indicates that the device is located within area 1, Line 15 and is the 2^nd device in the Line 15 as shown in Diagram 4.

The group address is used to define specific functions of the system. It is a format as shown in figure 8. Its assignation is of free design for the installer. For example, the main group can represent general functions such as lights, HVAC, Motors, etc. The intermediate group can represent a physical location of the house, living room, kitchen, bathroom, etc. The last group of 8 bits can represent the number of device located within that room. Even if the design is free, it is strongly recommended to keep the same design for all the projects, as it becomes simplifies future control check-ups.

KNX/EIB has an application program ETS, where several parameters and communication objects can be pre-defined.