Worst Case Response time analysis for CAN messages with offsets

Scheduling messages with offsets is proved to be an effective method to reduce the Worst Case Response time (WCRT) for messages on the CAN bus. But there is no method available in related literatures except some commercial tools to calculate WCRT for messages with offsets. Conventional method assumes that a so-called critical instant exists, but it doesn´t happen at most case. This paper proposes an algorithm to compute the WCRT of messages with offsets. It is based on the creation of the worst case scenario for the analyzed message, and the result is although not exact but safe enough. The analysis is expected to be useful to assess an offset assignment algorithm.