COSMIC: a middleware for event-based interaction on CAN

Distributed factory automation systems benefit from field-busses which, in general, provide support for reliable and timely communication. These field-buses, however, provide rather low level communication objects and their features regarding quality aspects of communication are difficult to access and use for applications. The paper presents COSMIC (cooperating smart devices), a middleware architecture which allows the use of communication abstraction for high level applications based on distributed cooperating objects. The middleware supports an event-based communication model which enables spontaneous dissemination of events, maintains control autonomy of objects and allows to specify different real-time and reliability requirements on the application level. The basic abstractions presented at the middleware layer are events and event channels. As an example, the paper describes how these abstractions are mapped to CAN-Bus which constitutes a widely used field-bus standard.