CAN only really works out well in a complex system if you have full control over the addressing scheme. Addressing and prioritization are one in the same. Unint

CAN only really works out well in a complex system if you have full control over the addressing scheme. Addressing and prioritization are one in the same. Unintuitively, prioritization isn't about the importance of a message so much as it is about the message's urgency. A pretty common approach is to use "rate monotonic" prioritization. The basic idea is that higher rate messages have higher priority (lower address) than lower rate messages. There's rules of thumb about never overloading a CAN bus beyond, say, 50% utilization. That's because systems with poor prioritization management tend to start falling over around there. With a well thought out scheme, it's possible to push a CAN bus fairly close to 100% utilization. I built several safety critical systems that pushed 80% utilization on average. At that level, you really need to rely on redundancy rather than simple robustness, though. A CAN bus running at 80% falls over very hard when you have a flaky physical connection somewhere.