AIW8500 audio out question

Hi all, I am using a AIW8500 video card presently. I have a Sat Receiver
(s-video, RCA-out) connected to the purple AIW input dongle for TV.
Now, the output dongle is black and has 4 terminations; S-video out,
Composite Video (RCA) out, audio (stereo mini-DIN) out and "Digital
Audio" a black RCA style plug (female).
Is this a S/PDIF audio out ? Is it functional ?
I am using the Cat 5.13 drivers (NGO modded) and MMC 9.08 presently.
The ATI WDM Rage Theater Audio driver version is 6.14.10.6246.
I have connected it to my Audigy 2ZS Platinum Pro S/PDIF-in connection
but was unable to get audio over it.

Thanks