Single step steps more than one line....

I have never seen this issue myself, but then I have never looked. Is there any pattern to it?
What happens if you hold the single step button down? (not with one of your expensive parts in place)

I tried it with the axis splash screen, and got exactly the expected result.

That was using the onscreen button. Are you doing it some other way? (There is a halui pin that could be wired to a hardware button for example)

I only have 2.5~pre working on my computer though

gtom wrote:

Well, open the 3dchips.ngc and step thru the program...
you have to press 3 times the button until you get a highlighted line in the listbox of axis and the machine begins to move.

This seems to be an issue with the line highlighting, I think that program execution proceeds one line at a time, for example the spindle starts on click 6, which is line 10 (which is correct, allowing for the 4 comment lines at the beginning) even thought the highlight is still on the M6 line. The next click causes line 11 to execute, and moves the highlight there. This is a single program step (good) but a triple line highlight jump (bad).

If you press the step button 8 times the program reaches line 12 of the nc-code. Next press jumps to line 18 of the nc-code. User expected line 13.
Edit: Think this is caused by the settings of the path mode...

Indeed, it does seem to be the G64P0.1 blending. If you program G61.1 (exact stop mode) then the behaviour is different.
What I think this means is that the interpreter treats moves within the G64 tolerance as a single blended move, and single-steps through them as a single move too.
I can see an argument that this is the correct behaviour, and also an argument that it is not the expected behaviour.

Line-highlighting on non-motion lines does seem like a bit of a bug though. If that was fixed the single-step would be rather more intuitive.

If you have G64Px in your program then EMC is grouping the moves into one move as the programmer has instructed it to do and that one move is a single step. For testing line by line change the G64Px to G61 or G61.1. I would not want a control to behave different in single step than automatic.

Imagine if you made the mistake of putting G64P100 instead of G64P.100 and the control system changed your G64 mistake to G61 for single step. You would not see the mistake when your milling your machinable wax one step at a time but only when you are in auto machining your $50,000 part.

John