HERESY USED TO USE THE XP I DONT KNOW IF HE STILL DOES BUT HE SHOULD BE ABLE TO HELP YOU OUT BEYOND THE OBVIOUS MIDI OUT OF THE DR-5 TO MIDI IN ON XP50
I use an xp60 not an xp50, but you basically answered his question phil. Also, you may need to put the dr5 on device ch 17, and make sure to make teh appropriate TX and RX settings within both units.