jaychoupp wrote:

... the plan is Digiface as Interface and Adi2Pro as ADDA for recording and monitoring！

... I don't get a “FS” version Adi2Pro，and seems the digiface don't have a “FS” version，but I have to transfer digital data between those 2 devices right？

So， should I update my Adi2Pro to the “FS” version？

And seems digiface dont have a BNC to connect external clock, so if I buy an external clock can I use it as the master clock to send signal to both Adi2Pro and Digiface？

Don‘t care about FS, the difference is of no practical relevance.
All ADI-2 versions have “Steadyclock”, just lately even improved by firmware update.

For the same reason you shouldn’t use an separate clock device, you gain nothing and lose a lot of convenience (and some money).

Use Digiface USB’s clock, set through the driver.

This way your system automatically follows sample rate changes when switching projects or playing different files, this is very important to avoid recording or playing with the wrong sample rate.

Sidenote:
Specialized separate clock devices are a pain in the ass in practical studio use.
You don’t want to baby you clock configuration all the time instead of making music!

Additionally, if run with 1:1 realtime BNC clock (instead of high speed clock) they can easily worsen clock precision by their own cable transfer jitter.
Fortunately RME’s SteadyClock filters out this garbage, but other converters might not have this ability.