Thanks for your reply mflux,
I doubt I can claim the Omron relays should be included since the board is pictured without them at the fadalcnc web site
PCB-0137
It is quite weird though as one would think a PCB is either completely populated or sold as a bare board. Good to know the M!8 is not needed. I thought perhaps it was needed to condition the signal or something.
I also have a probe arm I had planned to install on a CNC lathe so the M18 will be put to use for that.
BTW do you know the full part number for the Omron ice cube relays? I did a search for Omron MY4N and that is just the size and pin configuration. The rest of the part number tells the voltage.
Andy