Getting sound from Proteus through Focusrite and Novation

[johnsf]

I'm trying to figure out how to assign my E-Mu Proteus as an external MIDI instrument using my Focusrite Scarlett 2i2 with Novation Impulse controller and Logic Pro X. In the DAW I don't see the Proteus. I have:

audio cables going from Proteus to Focusrite.
MIDI cable from Novation to Proteus.
Novation to Mac Mini, via USB.

The Focusrite does not have MIDI jacks. Only audio.

What do I need to do? I can see the LED blinking when I play keys on the controller. But can't get the sound.

Thanks.