Re: [CAD_CAM_EDM_DRO] solution for optoisolator 3.3 or 5 volt

Yes, you will need to put resistors on the feed to the LED's anyway and you
should be able to cover the saturation region on the output for both 3.3v and
5v.
Either ways you should put a buffer on the output to be sure everything is
running with clean, logic level signals and has plenty of current. Something
like a 74HC244 would be ok and allow a good length of cable to be used.
cheers