New option to end a program with % or M2

Andy,

It is briefly mentioned here...

linuxcnc.org/docs/html/gcode/overview.html#_overview

But it does not really go into the differences, I agree more detail might be nice.

I have gotten into the practice of using % at the start and end because of some of the unwanted effects (for me at times) of M2.
I do like to use M2 at the end of the day or when shutting down.

The point is of course that now we have the option with NGCGUI.

Rick G

I think there should be a section after the overview called "Format of a File" and move most of the overview into that section with a link from M2-M30 to that section as well.

JT

agreed. I think it would serve a lot of purposes to have a "gcode for dummies" into on the wiki somewhere that very very briefly mentions all the fundamental parts of good g-code, with each mention linking out to a very thurough explination of each. the detailed info already exists, it is a good summary we seem to be missing.

can NGCGUI be configured to ask for any arbritary M code? Sounds like no but I haven't looked. maybe those of us with special needs or strange workflow would be well served to modify M2 or create our own custom M code to end NGCGUI files with.

linuxcnc.org/docs/html/gcode/m-code.html#sec:M2-M30

more than a little vauge for the n00bs like myself. Someone illuminated this a bit for me on IRC a few weeks back, but I have completly forgotten what I learned at this point. fortunatly I took notes, but they are not in front of me.

You can use a postamble (such as bye.ngc) as well as a preamble with ngcgui, perhaps that will do what you want.

Rick G

Rick G wrote: You can use a postamble (such as bye.ngc) as well as a preamble with ngcgui, perhaps that will do what you want.

Rick G

that is super obvious, can't belive I didn't think of it. a % in the preamble and post will net what I want without use of an M2 it seems. Also to note in the past I got hte "this code doesn't end wit ha % or m2" error message, and since I had learend M2 wasn't what I wanted I tried using a % and iirc it still failed and I never understood why. The docs claim you need a % at the begging and end, but I think the error message will say you are lacking a % at the end of your code even if you ONLY have a % at the end. Obviously "begggining" and "end" are non-trivial things for a PC to recognize, but clear to me. Eitherway I was never aware the %s had to wrap your code due to the vague error messages.

but all of that is from memory, I'll see if I can replicate it or if it was just my greeen showing.

On the topic at hand, does a % sign simply tell the interperter "this code is complete enough to execute" and send zero commands to the machine itself? Want to understand exactly what it does, can't find anything in the documents so far.