Disadvantages to CAN?

[Levansic]

Daisy chain for physical mechanical interconnects in the typical FRC application, yes. But the nodes don't propagate the signal. It is a party-line with everybody hanging on. As you said, the short runs allow us to get away with the star, and the CANbus standard does not specify any physical layer. As long as every node is holding on to CAN-High and CAN-Low, and they are held apart by sufficient resistance, it doesn't matter.

This is like the old 10BASE2 networks being supplanted by 10BASE-T. The older co-ax 10-BASE2 could run the length of a building (with a max length around 550 ft.), but if it did, your speed would drop due to signal reflection. Also, the T-connectors that provided the daisy chain, were the weak link. Physical strain on one or some corrosion in a higher humidity environment, and you lost the entire network. Also, adding or removing a node required breaking the network for everyone. 10BASE-T had the same speed, but much higher reliability. Primarily because of the star topology.

--Len