Ok I've spent more than two hours trying to figure this out and read every relevant post on the subject.
I have two midi controllers, eventually this is what I've done:
Assigned MIDI out channel 1 on Axiom Air
Assigned MIDI out channel 2 on Roland A-49
Set the MIDI channels in the setups for the two keyboards respectively: Air=1,A-49=2, all other channels not selected.
On the instruments:
Set Mai Tai to use the Axiom Air on channel 1
Set PresenceXT to use A-49 on channel 2
Dragged Mai Tai onto track 1, and Presence onto track 2
Both keyboards can now control the instruments.
What happens is each keyboard controls both instruments at once, but I want each keyboard to control only one instrument, obviously so that I can play two different instruments independently but at the same time.
I couldn't see where to assign a channel to a track, so I conclude that what I am trying to do is not possible in Prime, only in the paid versions.
Can it be done?
I am on Mac os 10.14 and using Studio One 5 Prime
Thanks