
In Linux the Nocturn appears as a standard MIDI device. The rotary knobs send relative CCs. Here is a map of what the knobs and buttons do:
Buttons: 0x70..0x7F -- send nonzero to put LED on, zero for off.
Smooth rotaries: 0x40..0x47 -- send CC to set LED ring
01 for clockwise, 7F for anticlockwise
touch: 0x60..67 for touched, 00 for not touched
Middle encoder: 0x4A
01 for clockwise, 7F for anticlockwise
send CC to 0x50 to set display
Based on this, something I've come up with is a quick hack that combines three nocturns into a single virtual device with 24+3 encoders, 48 buttons, with 48 banks of CC values.