Our MIDI Draw Knob Controller has a test mode that will find out the time and amount of power needed to move each draw knob. Ours sets individual pulses for each draw knob. The setting the length of the pulse is a one size fits all on the MIDIBoutique mdec128 board.
There is also a feedback sensor to guard against bounceback, compensate for a slow moving knob or to tell if the knob has been blocked from moving.
If the knob has been prevented from moving, the board will send a message back to Hauptwerk so that Hauptwerk knows it didn't move.
We put all that sensing and feedback monitoring in so that users would not have to configure them using software.
Our Draw Knob controller also generates and receives the MIDI messages for Hauptwerk. So it scans the switches; in effect it's an encoder and decoder. It's also the USB interface.
The mdec128b-sam.only drives the magnets. It's kind of like our MIDIout N and P boards.
We actually designed it for commercial use so it also integrates seamlessly with our newly updated organ control system.
You need 1/2 an amp per draw-knob so 15amps for the mdec128b-sam board is a bit low for driving 64 knobs simultaneously. (you need 32amps) otherwise you will get delays as it resets different groups multiplied by the length of the pulse you have set. You also need 2 power supplies; one for the magnets and one for the board.
Ours is designed to cancel simultaneously. So you buy the appropriate sized power supply to fit your number of switches. Ours takes the 5V off the main power supply to run the board.
Thanks for asking.