The ADAT I/O cannot be used at the same time as the line or S/PDIF I/O. For example, ADAT channels one-six and S/PDIF cannot be used simultaneously. However, you can use the ADAT inputs and the Line outputs at the same time. In this instance the line outputs will mirror the ADAT inputs.

The S/PDIF Inputs Cannot Be Routed to Other Channels on the Line Mixer

By default, the S/PDIF I/O is ALWAYS assigned to channels seven and eight. This cannot be changed.