Reply to S4 faders don't work when connected to DJM900 NXS

Aloha- Just hooked up my new DJM900 NXS and am using it as the soundcard rather than the S4's card. Is there a way to get the faders to work on the S4 with the 900 as the soundcard? I want to use the effects on the 900 for each channel as well as the Traktor effects on each channel through the S4. Thx!
V