The ADA8000 and ADA8200 utilize the optical ADAT 8-channel digital audio protocol only.  A 2-channel S/PDIF connection is not available on this product.
Though there are, in fact, optical versions of the S/PDIF protocol that utilize the exact same physical connector (TOSLINK) as the ADAT optical protocol - the data contained within the data stream is completely different. However, some units/soundcards have one TOSLINK-type connector and are able to switch the data protocol used via software (e.g. switch the same physical connection to receive either ADAT or S/PDIF.)