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Guy McBride wrote
Can the pistons be controlled by midi messages?
Certainly. They show up on a special page (or "window") in the Customizer, and that's where you associate them with the physical piston switches. You click on the piston's cell and then operate the actual piston. The Customizer registers the MIDI message for each piston as you go through that routine, including the "Set" piston. For a stop switch, you do that for both ON and OFF, but for a piston it would just be ON. However, you can also register it as TOGGLE, if you need to.