FEATURES variable in INI file RS274NGC section

Hi all,

Firstly, mad props to all the devs for making LinuxCNC such a piece of wizardry! I've been refitting my Chinese CNC router due to problems with the RichAuto hand-held controller, and have just recently got the machine to a useful working state.

While working on a Z-probe routine based around G38, I recognised that I should use custom variables in the machine INI file for things like the probe plate thickness and probing feedrate. It seems that in order to refer to INI file variables (and HAL values) from within G-code, you have to add FEATURES=12 to the INI file, in the RS274NGC section, a la:

I found this nugget in a forum/list discussion. I was thinking it would be helpful if this requirement was mentioned in the documentation on custom sections and variables:
linuxcnc.org/docs/2.6/html/config/ini_co...sub:custom-variables

FEATURES itself should probably also be described in the section on the RS274NGC INI file section:
linuxcnc.org/docs/2.6/html/config/ini_co...sub:RS274NGC-section

(I'm using LinuxCNC 2.6 at present but the 2.7 and development docs are the same in this regard.)

Indeed, is there any reason not to enable FEATURES=12 by default? I was curious about this variable and wondered what possible values there are.

Thanks!

Thanks, Andy. I think it's safe to say I don't understand the consequences. So FEATURES is a bitmask for enabling experimental functionality? I'd wondered if it might be a sort of version number for LinuxCNC's G-code dialect. Is it documented somewhere in the user docs, or is it more something for developers and testers?

I can imagine that reading HAL signals from G-code would be tricky! I did find some more information here, which clarifies that accessing INI-file vars as named parameters is still experimental:
linuxcnc.org/docs/html/remap/remap.html#...to-inifile-variables

This will be a very useful feature once stabilised/merged.

Ah, I see. I've been watching MachineKit's progress with interest; I wasn't exactly sure how amicable the relationship with LinuxCNC was, to be honest. It was confusing at least for me as a new MachineKit user not being sure if it was LinuxCNC or not.

Ha - and had I scrolled up just a little from the location from my last message, I would have found exactly what I was looking for:
linuxcnc.org/docs/html/remap/remap.html#...i_file_configuration


So, as you say, FEATURES=4 would make sense in my case of just wanting to access INI file vars from G-code.

Still, is there a case for documenting this in the INI Configuration section? Even just an extra sentence or two and/or a link to the Remap docs would help. I'm happy to do some editing, if that's permissible.

Thanks again!

Grand, thank you. I've cloned, branched, and made some changes - do I need privs to push the branch before I can issue a pull request? Computer says no, at the moment. My username on GitHub is also screwtop.

Perhaps you could also confirm that I'm using the right markup for chapter and section references (the HTML docs I've built don't seem to come out with the correct inter-page links):

For another chapter:
<<cha:remap,Remap Extending G-Code>>

For a section in another chapter/page:
<<cha:remap#remap:ini-features,Optional Interpreter Features>>
or perhaps just
<<remap:ini-features,Optional Interpreter Features>>

I did some more reading...without push privileges, I think I would need to fork the repo first, clone that, branch, modify, commit, push, and then use the forked repo to initiate the pull request. Apparently the parent repo devs will be notified. I'll give that a try...

...and there we go:
github.com/LinuxCNC/linuxcnc/pull/214

With any luck, I did that right!