You probably don't need ladder logic. I would think that it is do-able with HAL components. Maybe latch-on the spindle-enable when spindle commanded-speed is zero until measured spindle-speed is very, very near zero.
I would need to experiment, but I am thinking setting "in" permanently to "true", clck being triggered by spindle-on ans reset triggered by spindle-off AND speed ~= 0.
(Spindle-off would be inverted spindle-on, and stopped status would use wcomp. )
