well, my initial experiment seems to have worked. (at least from the StudioOne screen anyway) - I admit i have not tried "actually" playing anything yet...
Overview: Create many individual "instruments" with the same midi "Port" but isolate each instrument as a "single midi channel"
Simplest description: Each midi channel for each module is a new "instrument" with the "same port", but with a "singular midi channel"
Note also: These external instruments will NOT appear in the right-hand "browser", they can only be found when creating a "track" as
Add tracks/Output/Existing Instruments - drop-down menu.
Procedure.
1. Under the Options/External Devices Menu, Create a "New Instrument"
2. Name and identify the instrument with the "Manufacturer" and "Device Name" so, in my case this would be "Roland" and "U220-01-01"
Note: I have several U220s so each new "instrument" is identified as U220-01, U220-02. etc. BUT
Each MIDI channel within the instrument also needs to be easily seen on the "Track Display"
so "module one midi channel one and two" are specifically named. - U220-01-01, U220-01-02 etc.
AND each consecutive "Physical Instrument" needs to be isolated through a separate Midi plug on your interface.
so each instrument must be identified as eg.
U220-01-01 for "Module One", "Midi channel 1"
U220-01-02 for "Module One", "Midi channel 2"
U220-01-03 for "Module One", "Midi channel 3"
then
U220-02-01 for "Module Two", "Midi Channel 1"
U220-02-02 for "Module Two", "Midi Channel 2"
and of course each new instrument should be addressed through your midi interface TO A SINGLE PORT.
so again, each channel of U220-01 is a separate instrument BUT ALL OF THEM FOR THAT MODULE are addressed to the same "port"
U220-01-01 Port 1 - First Module, Midi Channel 1
U220-01-02 Port 1 - First Module, Midi Channel 2
U220-01-03 Port 1 - First Module, Midi Channel 3
etc
U220-02-01 Port 2 - Second Module, Midi Channel 1
U220-02-02 Port 2 - Second Module, Midi Channel 2
U220-02-03 Port 2 - Second Module, Midi Channel 3
Simplest description: Each midi channel for each module is a new "instrument" with the "same port but consecutive midi channels."
Note also again: These external instruments will NOT appear in the right-hand "browser", they can only be found when creating a "track" as
Add tracks/Output/Existing Instruments - drop-down menu.