Connecting digital out from audigy 2 zs to z5500 w/minijackconverter to coax no data

[vashht]

I am trying to hook up my audigy 2 zs to my z5500 speakers using the minijack on it, using a minijack converter to mono rca and a coax cable. I have heard this works for others but i just get no digital data when i set my control to coax. Do i have to change any settings in my creative stuff or am I using the wrong kind of adapter?
Thanks for any help