The OneButton FXCain is mapped to the Play/Pause Button of the Traktor X1 MK2.
If the deck isn't running the first press will Play the Deck.
When the Deck is playing the Button will increase Dry/Wet, Knob1,2,3 an activates the Button 1,2,3 in the first FX-Unit by holding the Button. Releasing the Button will set all parameter to an defined value.
The Button works best with Beatmasher2 on the first Knob, Filter on the second and Reverb on the third, Like in Ean Goldens Effect Tutorial.