Not sure if this is any help to u and im sure there is a better way but this is how i have my virus set up in logic 8
I have the TI loaded in as a multi channel instrument.
Then in the enviroment (mixer window) on the channel with the virus loaded click the little + button in the bottom right of that channel below the mute and solo buttons. This then duplicates the instrument channel with the virus loaded in to it.
Name the duplicate channel virus 2 or something
Then on that duplicate channel got to the inspector on the left hand side of the enviroment
You need to change the midi channel value from 1 to 2 and so on for as many parts as u want, remembering to change the midi channel value to match. 1, 2, 3 etc
If you repeat these steps for as many channels as you want u can then play multiple parts from the virus.
However there is a problem with this method. And that is because you are basically duplicating the same instrument channel and just changing the midi channel value it means that if you say wanted to adjust the pan or volume or even add a effect to 1 part through logic it duplicate the changes to all.
I.E if i insert a compressor to a sound it inserts that same compressor across all channels i have duplicated. Hence there is a better way of setting it up but i aint got round to looking it up yet. My friend has some instructions apparently but i have not had time to see him about them yet. For now tho i get round it by using the mixer in the virus or bouncing a sound down if i want to add more extreme fx's or plugins to a sound.
P.S I only have my virus connected through USB too. Again im not sure if this is correct.....i am mearly a learner. Im sure others with more knowledge would be of greater help to you. Maybe even give me some advise on better setting up and running of my TI.
thanks