Hi Art,
It’s all sounding very exciting and as you say, that system should certainly make greyscale working a lot easier to implement.
Just something, mentioned before and to keep in mind, which only affects laser operation and makes no noticeable difference to spindle operation…
Mach4 makes the changes to the S word (and the subsequent PWM output) considerably faster than Mach3 and as near as I can measure, changes occur up to 50mS before the completion of the preceding line of Gcode (the actual period in mS being dependant on the execution time of this Gcode line).
In the attached pic. of one of my earlier test samples, there are two changes of S word occurring when switching from an ‘engraving’ to a ‘cutting’ toolpaths and in both instances the increase in PWM pierced the work (shown by the arrows) at the end of the ‘engraving’ toolpath.
This fooled me a bit to start with but thanks to help by Craig and Scott adding a delay in the Mcode switching macro’s resolved the issue. Just how this can be resolved when using an axis direction pin for laser switching I have yet to discover but it is all part of the great learning experience.
I would just like to take this opportunity to offer a big “thank you” for setting such a low price for the Darwin pre-buy license. Keep up the good work my friend.

Tweakie.