Simply put, the DN9630 is an interface. It takes incoming AES50 signal and converts to USB, it can also convert from USB to AES50.
It operates on AES50 just like other AES50 devices. For example lets say you connect the AES50B port of your X32/M32 console to the DN9630. In order to send signal to the DN9630 you would open the ROUTING>AES50B menu and assign your 48 output signals. The signal would be sent out of your console via AES50, received by the DN9630 and converted to USB.
Now if you wanted to send signal from your computer into the console, you would just assign the signal to the USB outputs, the signal comes into the DN9630 and is converted to AES50 signals that you can assign to inputs just like any other incoming AES50 signal.
One thing to note is the unit only operates at 48k and 96k, so if you are using 44.1k for your system, this would not work.