To set the MIDI output on a specific track (in Song or Pattern mode), simply press F3 OUTPUT and move the cursor to OUT CH on the track you would like to change (1-16 and OFF).
To set the MIDI INput on a specific track (in Song or Pattern), follow these steps:
1. with SONG or PATTERN on,
2. Press MIXING
3. Press EDIT
4. Use the TRACK SELECT buttons (on the far right) to choose the track whose input you want to set.
5. Press SF2 MODE
6. Cursor over to the Part's ReceivCH and change it (1-16 or OFF)