I'm using a Focus 4 TX also , but with a USB interface, however, I don't think this makes any difference as far as your question is concerned.
The top 4 lines are for fixed wing craft and the bottom 4 are for helis. This is how I mapped my TX:
Rudder = 4 checked exp (exponential)
Elevator 2 checked both inv (reverse) and exp
Aileron 1 checked exp only
Throttle 3 checked inv only
I repeated this exactly for lines 5 through 8.
Although I have never flown a model heli for real, the FMS helis seem to fly well with the settings above, and I am able to control them to some degree until they get into a position wherein I cannot slow or recover the model without a crash. I'm sure this relates to my lack of expertise, and the little time I've put into learning to fly these models. By the way, the lack of throttle control - helis only - and the resultant constant engine noise becomes annoying after a while, but it's great for the price.
All of this and a lot more is explained in Eric Brouwer's website; check under - links - at the FMS website - home page. There are also many links to sites that have add-on models for FMS, and of course this one: http://rc-sim.de
. This site has literally hundreds of add-on models for FMS, as well as landscapes; you must register on this site now but it's free. The site is in German, but click on the splash screen that appears, and look for the download link in the box on the left side.
Hope the above is some help.