Timing analysis of reliable real-time communication in CAN networks

Abstract

The Controller Area Network (CAN) is a fieldbus network with real-time capabilities. It is generally considered that CAN guarantees atomic multicast properties, through its extensive error detection/signalling mechanisms. However, there are error situations where messages can be delivered in duplicate by some receivers or delivered only by a subset of the receivers, leading to inconsistencies in the supported applications. In order to prevent such inconsistencies, a set of atomic multicast protocols is proposed, taking advantage of CAN synchronous properties to minimise its run-time overhead. This paper presents such set of protocols, focusing on the timing analysis of the supported reliable real-time communication. It demonstrates that, in spite of the extra stack of protocols, the real-time capabilities of CAN are preserved, since the predictability of message transfer is guaranteed.