There in lies the question!

The unit in question is an Allen & Heath ZED R16 using this:

"TC Applied Technologies JetPLL™ jitter reduction technology.
• Ensures our analogue/digital converters work to their optimum level, and allow         
     great separation between channels.
• Filters jitter by 100dB, preventing audio artefacts caused by interference patterns    
     between timing clocks.
• Allows fast synchronisation to other networked devices and compatibility with
     a wide range of audio equipment."

The unit can operate as a free standing master device, but n order to slave sync the unit, it must first be connected via FW and the DICE control panel used. Doing so and sync it it to the ADAT from a Digiface, shows this value when the software reports 'Sync Lock.'

DF