This is how I integrate my ADI-2 PRO FS BE into my setup in kind of stand-alone mode with USB disconnected.
See my blog article: http://www.tonstudio-forum.de/blog/inde … our-Setup/
UFX II will be clock master, ADI-2 Pro FS will learn clock via either AES, ADAT or optical SPDIF, depending on how you connect it to the UFX II.
The ADI-2 Pro will receive the clock from the UFX II, refresh the clock signal and finally perform D/A conversion with its own internal FS clock for best D/A conversion quality.
Additionally you can leave ADI-2 Pro's USB connected, then the DAW can access both devices by the one ASIO driver.
Then both devices still need to be clock synched and you need to take care that you configure the same ASIO buffersize for the two devices to not get time offsets between recorded tracks of the two devices.
Ideal is to configure multi-channel mode on the ADI-2 Pro so that all ports of the device can be accessed by the ASIO driver / DAW through its USB connection.
BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14