Dan Purgert:
...
> Getting the right layout at either end is certainly "important" -- but
> following the TIA-568B (or -568A) layout used for 10/100/1000BASE-T
> isn't necessarily the *correct* answer for the application at hand,
> assuming one is attempting to use some form of existing breakout rather
> than rolling their own.
...

For differential things like rs485/can, I'd go for one pair signal
(e.g. blue/blue-white) and the rest power. For rs232, which is single-
ended, I'd probably do blue/tx, blue-white/GND, green/rx, green-white/
GND, and the rest power or something similar.

Also I'd forget about thoose RJ-45s with their stupid wiring,
and use something like:
https://docs.rs-online.com/9241/0900766b80fd362c.pdf
a DB9
https://octopart.com/mrt8+p3.5/6-stelvio-22829230

Regards,
/Karl Hammar