Hello, I'm currently building a Logic editor for an old Yamaha 4-OP FM synth. Everything is going great, except I can't figure out how to make buttons that affect the relative value of another fader, which sends a Sysex string (43 10 12 5D xx) for turning each operator on and off. There are possible 16 states total, so I have made a fader that goes from 0 to 15, and it works fine. There is an iOS app that does this with "bit changers": http://mididesigner.com/qa/3386/what-are-bit-changers-in-midi-designer The patch I made with MIDI Designer has 4 buttons (one for each operator) that affect the relative value of the Sysex fader. But I can't wrap my head around this problem in Logic. Any help is appreciated!