Prior to any form of communication between the modules, all modules in a system need some kind of identification. To keep the installation as simple as possible, the installer or electrician issues numbers to each bus module, using the respective software. The programmer assigns a number between 5 and 254 (that makes 250 units) to each bus module per bus line.
Subsequently, each Segment-linker module is also assigned a number between 5 and 125 (that makes 120 units). The programmer can connect the bus line to the PC with a special -PC-Linker. This can be done at any point in the network. There are no specially assigned connection points. Once joined, the programmer launches the DOS-programme -P or its Windows equivalence, -Pro. Bus modules communicate with each other by transmitting and receiving command signals. A bus module can also communicate with up to 250 groups (see Grouping), whereby there is no limit to the number of members per group! One specially assigned number is the number 3. If a command is sent to group 3, each and every module on the network reacts to the sent command. With this very useful feature, the entire lighting in a skyscraper for example can be switched off using one single button. Adding bus modules to groups also reduces programming effort and saves time.