Connecting to a CNC machine, pros and cons of USB vs PP vs Ethernet etc.

[Jon.]

Really id say its down to personal preference. I think if your using an Ethernet controller over usb because of noise its because you haven't taken the correct steps to shield the controller and that you are also happy to have your controller bombarded with noise, just because it can it doesn't mean it should. You may be correct in that ethernet has better protection against noise but that is providing the noise is entering via its ports. If your talking about noise that is infact capable of entering a grounded enclosure then there's no telling how that noise is going to enter the board, but you say it does fair better but with the correct steps either can work so again personal preference.

Bearing in mind a pc usually has multiple usb ports, but can only handle a single ethernet port so its restrained in that respect.