LonWorks
LonWorks is an open, universal bus concept for building automation. It was included by the Comité Europeen de Normalisation( CEN) in the standardization of EN 14908 of building automation and building management.
LonWorks fulfills the requirements regarding openness and is based on the OSI reference model. The universal fieldbus concept covers all functional levels from the field level to the control level. It offers compatibility and can communicate with components from different manufacturers.
LonWorks networks can have all topologies: Ring, Star, Lines, Tree. The data rate of 1.25 Mbit/s is comparable to other building buses, as is the number of connectable devices, which is 32,000. A component of LonWorks is the Local Operating Network( LON), via which the physical transmission is realized. In contrast to other field buses, the LON network nodes operate autonomously without central network control. The so-called Neuron chips communicate directly with each other.
Further layers in the LonWorks layer model are LonMark with application-specific standards, the so-called Functional Profiles, the LonWorks Network Services( LNS) with the network operating system, the IT-based layers for client- server operation and the programming interfaces( API) as well as the layer for cross-trade building automation.