OK, thanks! I did find out that it is setup to receive the Renard protocol with a 57.6K baud rate.
Okay, those settings are done in the Falcon serial output page.
Once you have a cable made, and have communication between the Falcon and the Renard board with the universe set to that serial output, xlights is easy.
And don't panic if the test mode from the Falcon doesn't do anything with the Renard board there's a bug in the Falcon serial output during testing that I'm not sure is fixed yet.