MIDI input on OS X

I’m trying to get my coremidi device to control the mixer levels on OS X. I’ve tried MIDIMapper and editting ardour.rc as the ardour docs say, but I can’t figure out how to connect the physical and ardour virtual ports, then how to map certain MIDI channels to certain mixer channels. The docs seem very unclear about this.

Thanks

http://ardour.org/manual/intro/midi

Read the whole thing, but specifically see the section at the bottom of the page that covers OSX.