Each of the different engines have slightly different functions for the encoders but this should give you a list of the most common ones.

You can change them but this will give you a point of reference.

D0/D1 = LFO Rate
D2/D3 = Envelope Release
D4/D5 = LFO Depth
D6/D7 = Menu

D0/D1 = Oscillator Sustain
D2/D3 = Envelope Decay
D4/D5 = Oscillator Release
D6/D7 = Envelope Sustain

D0/D1 = Oscillator Attack
D2/D3 = Envelope Depth
D4/D5 = Oscillator Decay
D6/D7 = Envelope Attack

D0/D1 = ????
D2/D3 = Filter Cutoff
D4/D5 = Oscillator Delay
D6/D7 = Filter Resonance