Wiring the CAN Bus

Cabling

Use twisted-pair cable for the CAN High/Low pair — this is what gives the bus its noise immunity. A standard 4-conductor cable (CANH, CANL, GND, +12V) works well for a cockpit build, daisy-chained from device to device.

Termination

A CAN bus needs 120 Ω termination resistors at both physical ends of the bus — not at every device, and not just at one end. Getting this wrong is the most common cause of an unreliable bus (dropped frames, devices that intermittently vanish).

Setup	Termination
Two devices, bridge at one end	120 Ω at the bridge, 120 Ω at the far device
Three or more devices, daisy-chained	120 Ω at the two physical ends of the chain only — nowhere in the middle

Topology

Daisy-chain devices in a line rather than a star — CAN is designed for a linear bus topology, and stubs/branches longer than a few centimetres can cause reflections at higher speeds.

Connecting the bridge

The bridge's USB port goes to your PC; its CAN connector goes to the first device in the chain. See Adding a Device for the SimLinkHub side once everything's wired up and powered.