This is the thread with the Input-Output info, it is for Reaper but also works for Logic.

Reaper and Input-Output Assignments

You can take it a step further and use Mac's Audio-Midi Setup to create an aggregate device if you have another interface. I have both the 11R and an Apogee Duet 2 and I just leave my 11R hooked up to my FRFR monitor and have all the playback in Logic go through the Duet/studio speakers and my tracking audio go through the FRFR.