Yamaha DTXpress/DTXplorer/DTXtreme

Hi i just borrowed a roland cy-6 from the local music store

http://www.rolandus.com/products/details.asp?
catid=5&subcatid=23&prodid=CY%2D6

and i cant get it to work for the dtxpress... it is a Dual Trigger 
Cymbal Pad but i dont get 2 sounds out of it. ive tried putting it 
to slot 9/10 and got just one sound. then i tried it at slot 7 which 
i now have a crash with stereo plug that produce 2 different sounds, 
but the roland cy-6 didnt produce 2 sounds there either. thats 
strange because it comes with a stereo plug. do need a splitter for 
port 9/10 or something. or is the roland cy-6 not compatible with 
dtxpress2?

I anyone have some experience with roland or have some suggestions i 
would really appreciate it

thanks

Andreas