I use RJ45 for CAN communication in CAMSim. It has many advantages over classic DSUB, I even believe there no better cable for my CAN tasks. The 100Ω differential resistance of RJ45 is close enough to the 120Ω required by CAN, and RJ45 is cheap and easy to handle.
Both signal and power is delivered with RJ45. In theory the power should not be delivered in the same cable, but in practice I never had any problem with it and it’s much more convenient setup. CAT5E should handle up to 1.5A power total which is enough for 10-12 instruments, especially with several wires dedicated to power and ground.
I use 12V across CANSim for power delivery. Each device then responsible for proper 5V / 3V conversion, depending on their needs.
Each instrument has two RJ45 sockets, so daisy chaining is extremely easy with only a few cables needed. Alternative design with RJ45 splitters also makes sense for smaller instruments.
“
| N | Purpose |
|---|---|
| 1 | CAN_H bus line |
| 2 | CAN_L bus line |
| 3 | GND |
| 4 | GND (optional) |
| 5 | V+ 12V (optional) |
| 6 | GND (optional) |
| 7 | GND (optional) |
| 8 | V+ 12V |