M291 Not Blocking

BeefyMcLargeHuge

I want to setup a macro that pauses my print, waits for me to change the filament, and continues with the print after I confirm that the changeover is complete. From what I've been able to find, M291 would be the way to do that. However, when my macro is called, the printer moves to a clearance plane, displays the message, and continues to print at the elevated plane. When I confirm the message, it goes back down to the original printing height, and continues to print. Am I using M291 incorrectly? See macro code below:

 M83          		; relative extruder moves
G1 E-1.5 F3600 		; retract
G91          		; relative positioning
G1 Z50 F360   		; lift Z by 50mm
G60 S5	     		; save current position to slot 5 	
M98 P"/macros/print_scripts/goto_front_middle.g"      ; move to front for filament change
M400			; Wait for all moves to complete
M226			; PAUSE AND WAIT
M291 P"Change and purge filament. Resume when changeover complete" R"Mid-print Filament Change" S2;
G0 R5		; move back to saved position 
G91 		; relative positioning
G0 Z-50		; drop back down to printing height
M83		; relative extruder moves
G1 E1.5 F3600	; unretract
G90		; absolute positioning

fcwilt

@beefymclargehuge

How are you executing that code?

From the docs:

M226 is intended for use in the GCode file being printed, for example to pause after a particular layer has completed. So it waits until all the moves in the queue have been completed. M25 is intended for use from a different source of GCodes (such as the web interface console, PanelDue or a Macro), so if you need to pause from those use M25 instead.

Frederick

OwenD

@beefymclargehuge
What firmware version?
I vaguely remember some earlier versions had an issue with M291 not blocking if it was called in nested macros.
So if the macro shown is being called from another macro that may apply.

Phaedrux

M600 would be the proper way to do a filament change.

https://docs.duet3d.com/en/User_manual/Reference/Gcodes#m600-filament-change-pause

Your macro would go in filament-change.g. M600 would be inserted into your gcode file where you want the change to occur.

You wouldn't use M226 in your macro, because the M600 would already do the pausing.

BeefyMcLargeHuge

Thanks for the replies all!

@phaedrux that was it! Thank you very much. This condensed my macro down to this:

G91          		; relative positioning
G1 Z50 F360   		; lift Z by 50mm
M98 P"/macros/print_scripts/goto_front_middle.g"      ; move to front for filament change
M291 P"Change and purge filament. Resume when after complete." R"Mid-print Filament Change" S2;
G0 Z-50		; drop back down to printing height
G90		; absolute positioning