Effect of Jitter-Reducing Encoders on CAN Error Detection Mechanisms

It is well known that bit stuffing in CAN may interfere with error detection and, in particular, with CRC-based approaches, so that the residual error probability can be noticeably higher than the theoretical value. Encoding techniques that prevent the insertion of stuff bits in the payload of the frame are a simple remedy, which improves integrity of data exchanged over the network noticeably. A thorough experimental campaign was carried out in order to evaluate the benefits the adoption of such encoding schemes provides over plain CAN. Results confirm that, for realistic error models, the probability of having residual errors decreases by about two orders of magnitude at most payload lengths, which makes such an approach very effective. This implies that much higher reliability can be obtained from conventional CAN controllers, which resembles newer solutions like CAN FD.