Practical issues with the timing analysis of the Controller Area Network

The Controller Area Network (CAN) bus is widely used and has been studied in several research works to determine the worst-case response time of messages. More results are being added to study systems that are not constructed according to the ideal behavior of the message queuing and CAN controller assumed in the past. In this paper, we provide an assessment on the practical relevance of several of those results. We also present theory and empirical studies on the relative importance of several implementation issues that are quite common in real systems and further deviate from the ideal behavior. In addition, we propose a heuristic for the design of multiple software queues when using TxObjects without preemption, and derive an upper bound on the worst case response time when message output at the CAN driver is polling based.