Default axis-movement-mode (rel/abs)?

[OllisGit]

Hi,
coming from this issue SpoolManager not tracking usage · Issue #231 · OllisGit/OctoPrint-SpoolManager · GitHub I asked myself: what is the default axis-movement-mode, relative or absolut?

Or more precise: used by OctoPrint and used by the printer?

I found this post that describes also the problem:

Keeping track of position and motor mode(s)

@snoozer, the issue is that printer hosts are operating with imperfect information. Imagine running this gcode: G28 ; Home XYZ to 0,0,0 G0 X10 Y10 Z10 ; Move to 10,10,10 G0 X10 Y10 Z10 ; Do we stay in the same place or go to 20,20,20? Notice that the effect of the first G0 command will always be to move to 10,10,10, but the result of the second G0 command depends on what axis mode we are in (relative vs absolute). There are a few possible solutions WITHOUT having a gcode to query the axis …

From my understanding there is no "standard" included in the printers firmware. Could be a mix, axis=absolut, extruder=relative or the other way around.

Also, OctoPrints assumption is "absolute" for all motors (xyz and e).

IMHO a simple solution could be to "force" the user to enter the mode for each motor in the "printer profile" (and also move the G90/G91 extruder-checkbox from "Feature" to profile).
Now the "challenge" is up to the user to find out the mode. (from UI-Perspective it should not just a checkbox for rel/abs, the user needs to explicit entering a mode)

Did I missed something?

BR
Olli

[MMcLure]

You also need to keep track of any changes occurring in the gcode file being printed - different slicers or even different slicer profiles might switch between absolute and relative. And incorrect start/end gcode from a previous print might end up leaving the printer in the wrong state. So unless you've seen a G90 or G91 I don't think it's safe to depend on any profile setting.

[b-morgan]

Don't forget to track M82 and M83.