Communication between modules
Every LCN module requires an address for it to be responsive. This is a number between 5 and 254 and is issued in seconds by the LCN-PRO. A data telegram can be sent to this address from any point in the entire bus. Group addressing is used if several subscribers need to be contacted with one telegram. 250 group numbers ranging from 5 to 254 can be issued for each LCN bus segment. The number of members of each group is unlimited. Every module can be a member of 12 groups.

In the LCN system, groups are only formed if several loads need to be addressed at the same time. By contrast, modules are addressed directly when using point-to-point transmission (“to module 55: ground floor WC light”); the process is intuitive, as you would expect to be.
More reasons for direct addressing
Besides clarity, there is another important reason for direct addressing: modules can directly send each other information for processing, which creates a “neuronal” network which becomes more and more intelligent and powerful when more and more modules are added to it. This is important for future automation tasks.
