Initial G codes?

Is there a file where I can change the inital G codes that seem to be loaded in Linux cnc?
(tried to search for it but found nothing, maybe I search with the wrong keywords so please point me in the right direction if there is a thread on this already)
If I only want to use the mdi for example it would be good if the g codes I use most frequently is already loaded.

If you are talking about the the ngc file that is opened when Linuxcnc starts it is defined in the INI file in the display secetion.

www.linuxcnc.org/docs/html/config/ini_co...#sub:DISPLAY-section

OPEN_FILE = /full/path/to/file.ngc - The file to show in the preview plot when AXIS starts. Use a blank string "" and no file will be loaded at start up.


If you are talking about the g-codes that are initialized when Linuxcnc is started they are defined in the RS272 section of the INI file.

www.linuxcnc.org/docs/html/config/ini_co...sub:RS274NGC-section

RS274NGC_STARTUP_CODE = G17 G20 G40 G49 G64 P0.001 G80 G90 G92 G94 G97 G98 - A string of NC codes that the interpreter is initialized with. This is not a substitute for specifying modal g-codes at the top of each ngc file, because the modal codes of machines differ, and may be changed by g-code interpreted earlier in the session.

Yes it was the initial g codes I was looking for, cant belive I missed them in the ini file.

You are right BigJohnT but this is only for the most basic things, like for example to set it for mm and not inch which I will never use so that one can issue a mdi command without having to think about such simple things.

Thanks!

It might also be helpful to make a little sub program that resets everything to how you like it. Then make a little pyvcp button called "RESET" that calls it. I have something similar on most of the machines I've set up.

Thats interesting, I´l have to find out more about that when I have time

This is an old thread, so I assuming that the startup/preamble code location has changed. I don't see any of this under my ini RS272 section.
The wiki was no help, it still mentions the RS272 section. Other posts mention a work around.

Where is the hidden file that these preamble codes are loaded from?

Thanks

Not exactly sure what your asking for. Normally the "preamble" refers to one or more lines of G-code that you or your cam software inserts at the start of every G-code file to make sure that all machine settings (modal G-codes) are correct to run your g-code file correctly. It is generally considered the best practice to do it there, rather than rely on default settings that may or may not have been set correctly in the control prior to running your code. Some examples of G-codes that are often included in a preamble would be G20/G21(inch/metric), G17-19(coordinate plane selection), G54-59(machine offsets) G64Px(path blending tolerance), G80(canned cycle cancel), G91(absolute coordinates). All of these could easily result in a crash if not set correctly for the file to be ran.

linuxcnc.org/docs/stable/html/config/ini...l#gcode:ini-features

RS274NGC_STARTUP_CODE