Quote Originally Posted by mmcp42 View Post
is there a standard way of using unused Mcodes - or do you just get on with it?
The simple answer is - I don't know. The problem with standards is that there are so many of them. I've referred to NIST - but this doesn't mean it's the only one (googlify gcode standards!) - a lot of implementations for example take the view - if it's good enough for Fanuc - it's good enough for me. Certainly some m codes are "standard" in the sense that they mean the same thing in "most" implementations. BUT as far as I'm aware there is no "standard" for using the "unused" codes.