Oh my!
There are plenty of CNC systems where an ethernet cable is the only connection between the CNC machine and the computer. So now [
allegedly] the
evil ethernet cable (when the computer is on its own circuit from the breaker panel) is going to result in ground loops! Really???
While in my opinion, an ethernet cable connection is a better choice for a CNC machine, as Catahoula has
not specified (in this thread) how his intended computer is to be set up, there are people using WiFi connections to a CNC machine. And in that case, there is absolutely NO physical connection between the computer and the CNC machine. So how does a separate power circuit for the computer cause a ground loop when there is NO physical connection?
And then there are systems that are permanently separated, and data etc is transferred by a "sneaker net" (walking a disk or flash drive etc from one device to another). So no physical electrical connection there either.
My point is that one cannot
reasonably make such harsh judgments with the situation as presented in this thread due to incomplete information.
(group)