A publisher/subscriber architecture supporting interoperability of the CAN-Bus and the Internet

The paper describes a publisher/subscriber protocol and the respective system support tailored for systems which comprise a large number of smart sensors and actuators. These components directly interact to form a reactive control layer. To support large systems structured in clusters of lightly interacting components, we provide interoperability between the fieldbus (CAN) level and a TCP/IP network to allow cooperation between these "islands of control" over a larger area and wireless connections. This requires middleware support which enables the seamless integration of the different networks and provide a uniform communication interface. Finally, the system support requires lightweight mechanisms achieving a memory footprint and performance requirements suitable to run on a wide range of controllers.