i'm not sure i understand what's being asked for here.. i have a Rain8 UPB controlling my sprinklers and tied into my HAI OmniPro 2. As lupinglade mentioned above, it shows up under my list of 'Control' units, just like any other UPB device. I also have written a few lines of programming on the HAI that's activated when I press a Button.
Both the Button and the Units appear in PCAccess, my Omnitouch 5.7e touchscreens, HAI SnapLink, and of course my Haiku and HaikuHelper screens.
I haven't used the Rain8 units that connect via serial, but I imagine it's not too different: note IIUC you'll need a few more lines of HAI programming to handle the serial communication, and you won't see them under Units.