I am trying to use my keyboard controller and wind controller at the same time. The SD40 plays accomp and lead voices very well, but I want to switch off and play my harmonica wind controller on the same song.

The SD40 recognizes and play either fine from two of the USB ports, but since they are both assigned to global ch 1, obviously, it is either or. I can change TX channel on the DM48 controller, but can't find a corresponding different receive channel on the SD40, and the manual doesn't help me.

I know nothing except the mere basics of midi, but it seems I have to transmit on two different channels, use a midi merge unit, of play one at a time.