VMC related HAL questions.

It seems to work now. What makes 1 do the difference?

There were two things. Your check was back to front (only run the tool changer if the system _is_ in preview) and the calling code was expecting a return value, so one needed to be added to the return command. (as is the case with the other return in the remap)

I load tool 1 to make Tool Touch Off. Then start the g code where tool 1 is used.
Starts a tool change sequence although the correct tool is already loaded.
Would this code fix it?

That should work.
But should probably be

Return [1]

Is it possible to make a reset button for the tool change sequence?
It is very hand-applied when something is not working and the arm is under the spindle. Must restart linuxcnc etc
If it is possible to make a button that resets as the arm goes out, the locking pin up the carousel stops positioning (resets all signals that are set high by the tool swap sequence).

Edit:
Will it be a .ngc file resetting with M66 P3. On all P # used?

CNCDoc wrote: I load tool 1 to make Tool Touch Off. Then start the g code where tool 1 is used.
Starts a tool change sequence although the correct tool is already loaded.
Would this code fix it?

Code:

o998 IF [#<tool_in_spindle> = <selected_tool>] o<toolchange> RETURN o998 ENDIF

The code below seems to work:

CNCDoc wrote: Is it possible to make a reset button for the tool change sequence?

I think so, if you can code it as a G-code subroutine.

Look at the MDI_COMMAND INI file entry:

linuxcnc.org/docs/2.7/html/config/ini-co....html#_halui_section

Though it might suffice to just use MDI to:
O<toolchange_reset> CALL