DTS sound option is greyed out on Samsung 5 series smart tv

[jtbis]

I cannot select the option to output DTS audio to my receiver, which has the DTS digital surround audio logo on it.  The only options available are PCM, Dolby Digital and DTS Neo 2:5.  The DTS option is greyed out.  The tv is connected to the receiver via TOSLINK.

Model number: UN32J5500AFXZA 

[paul1111]

I think you need to have a DTS source like a downloaded film as the normal programs are all Dolby sound tracts or just stero.