Passing Axis Letters As Macro Parameters to M98

davidjryan

I have a non-3D printer, 13 axes CNC (M453) system.

Is it possible to send an axis letter as a macro parameter through M98 and then use it in a G1 (or any) command?

Say I want to have a single macro that will move any of my axes 5mm in the positive or negative direction. I want to use param.X and param.Y to signify axis letter and direction, respectively.

Basic G-Code for forward and reverse (what I am trying to achieve through the macro):

G91 G1 X5 F2000
or
G91 G1 X-5 F2000
based on desired axis and direction, X could be Y, W, A, B, C, D, etc...

I'd like to do this:

M98 P"jog-axis.g" X"X" Y"Pos"

or

M98 P"jog-axis.g" X"X" Y"Neg"

Contents of jog_axis.g:

echo {param.X} ^ "  " ^ {param.Y}    ;just to confirm the macro inputs
if {param.Y} = "Pos"
    echo "Positive"  ;confirm param.Y was interpreted correctly
    G91 G1 {param.X}5.0 F2000
elif {param.Y} = "Neg"
    echo "Negative"  ;confirm param.Y was interpreted correctly
    G91 G1 {param.X}-5.0 F2000

The jog_axis.g functon runs but the axis does not move and the console reports:

Error: in file jog_axis.g line 12: Illegal parameter letter '-'

So, it's interpreting the param.Y value and executing the correct condition. It's just not interpreting param.X as the axis letter for the G1 command and then, subsequently, the '-' in -5 is interpreted as a character/parameter out of place.

If I put the 5.0 and -5.0 in {}, I can get the Error to go away but the axis still does not move.

Am I doing anything wrong or am I trying to use a feature that does not currently exist?

My alternative is to write 13(x2) conditionals for all of my axes. Not the end of the world but I thought passing the axis letter would be more elegant; 6 lines of code vs. 78.

T3P3Tony

@davidjryan this is not currently possible. It has been requested in the past and we have a feature request outstanding:

https://github.com/Duet3D/RepRapFirmware/issues/708

@davidjryan said in Passing Axis Letters As Macro Parameters to M98:

My alternative is to write 13(x2) conditionals for all of my axes. Not the end of the world but I thought passing the axis letter would be more elegant; 6 lines of code vs. 78.

Unfortunately this work around is how you need to do it for now.

T3P3 created this issue in Duet3D/RepRapFirmware

open allow expressions to be used as a substitution for any part of a gcode string #708

davidjryan

@T3P3Tony Thanks, Tony!
I have the longer form implemented and all works well.