@Diamondback This is one of the features i would really love.

I am using RRF 3.3 and the macro:

; Engage the toolchanger lock. RepRap Firmware V3.3RC3 version. 
G91                  ; Set relative mode
G1 U10 F5000 H0      ; Back off the limit switch with a small move

G1 U200  F5000 H3    ; Perform up to one rotation looking for the torque limit switch Y0.5 
					 ; H3 will modify axis limits they must be reset with M208 see below (use your axis limits)

;Pickup success detection | Aborts if no Tool picked up

M400                    ; Make sure moves are complete

if {abs(move.axes[3].machinePosition) > 90 || abs(move.axes[3].machinePosition) < 20}  ;if tool is not picked up | (Change 20 (half pickup) and 90 (no Pick up) to the value you need)
	echo move.axes[3].machinePosition ;debug output of the reached position 
	M208 U0:201         ;restore axis limits (see above H3)
	set global.tool_change_Aborted = true ;send error condition
	M98 P"/macros/tool_change/tool_unlock.g" ; Unlock the tool
	G1 Y-20				;back off 
	M291 P"Werkzeug nicht richtig geladen. Ursache gefunden und behoben? Erneut versuchen!" R"Warnung Werkzeug nicht aufgenommen" S3 T-1 x1 Y1 U1
	set global.tool_change_Aborted = false
	T{state.currentTool}
	if{job.duration != null}
		M25 ;pause job
		echo "Paused"
	else 
		abort "Aborted"

;Behaviour after successful pick up
echo "Picked up Tool",{state.currentTool} ;success message
set global.tool_change_Aborted = false ;reset error condition
M208 U0:201         ;restore axis limits (see above H3)
G90                 ; Set absolute mode

I will look into using M0 /M1 .

@Diamondback This is one of the features i would really love.

I am using RRF 3.3 and the macro:

; Engage the toolchanger lock. RepRap Firmware V3.3RC3 version. 
G91                  ; Set relative mode
G1 U10 F5000 H0      ; Back off the limit switch with a small move

G1 U200  F5000 H3    ; Perform up to one rotation looking for the torque limit switch Y0.5 
					 ; H3 will modify axis limits they must be reset with M208 see below (use your axis limits)

;Pickup success detection | Aborts if no Tool picked up

M400                    ; Make sure moves are complete

if {abs(move.axes[3].machinePosition) > 90 || abs(move.axes[3].machinePosition) < 20}  ;if tool is not picked up | (Change 20 (half pickup) and 90 (no Pick up) to the value you need)
	echo move.axes[3].machinePosition ;debug output of the reached position 
	M208 U0:201         ;restore axis limits (see above H3)
	set global.tool_change_Aborted = true ;send error condition
	M98 P"/macros/tool_change/tool_unlock.g" ; Unlock the tool
	G1 Y-20				;back off 
	M291 P"Werkzeug nicht richtig geladen. Ursache gefunden und behoben? Erneut versuchen!" R"Warnung Werkzeug nicht aufgenommen" S3 T-1 x1 Y1 U1
	set global.tool_change_Aborted = false
	T{state.currentTool}
	if{job.duration != null}
		M25 ;pause job
		echo "Paused"
	else 
		abort "Aborted"

;Behaviour after successful pick up
echo "Picked up Tool",{state.currentTool} ;success message
set global.tool_change_Aborted = false ;reset error condition
M208 U0:201         ;restore axis limits (see above H3)
G90                 ; Set absolute mode

I will look into using M0 /M1 .

Is it possible to abort a tool change when the pickup fails? Currently i run a tool locking macro that checks wether or not the tool is locked, if not it should put the printer into a safe state so i can manually do the things needed to manually dock the tool or sort the stuff out. But right now the duet thinks the tool is attached even if the macro detects the failure i have no idea how to abort the tool change and e.g pause the print. Is there or will there be an option for that? i think it can be very helpful.

@phaedrux Is it possible to call the original g code the macro is replacing from within the macro, or whill it recursively use the macro? I am trying to replace the M3 command with a custom one for one specific spindle,which needs special treatment but if i want to use other spindles i want to use M3 as intended.