Connect the AR2412 to the DSnake connection.
Go into the IO set up menu, D snake inputs and check that main inputs across the top
row (channels 1 to 16) are patched to mixer inputs (left side vertical row) channels
1 to 16.
Hit the apply button.
In any channel pre amp menu hit the source button and select channels 1 to 16 to be the D Snake (yellow)
That will get you channels 1 to 16 from the stage box to be on channels 1 to 16 at the mixer.
A few things to keep in mind that maybe helpful….
You can mix and match local mixer inputs and stage box inputs, for instance channels
1 to 14 could come from the stage box and 15 and 16 from local mixer inputs.
With the stage patching you can assign a stage box mic input to a stereo channel input
to squeeze a couple more mic input channels out of the mixer.
Input patching and routing is saved as part of a scene, so you could have stage box channels 1 to 16 set up and patched and the stage wired for the main act and then set up and patch 17 to 24 to appear on mixer channels 1 to 8 for an opening act.
Save each set up as a scene and recall as needed.
Don’t forget the outputs on the stage box, patch as needed in the set up menu under D snake outputs.