Hello,
I am quite curious about topic of genlocking in terms of video I/O cards (such as Blackmagic, AJA, Bluefish…) and would like to ask for more information on how it actually works at the moment.
I guess right now TD doesn’t sync to genlocked video I/O cards when using Video Device In/Out TOP, right? Therefore it means that phase of video I/O card is different from TD’s internal cooking phase (they could be set to the same refresh rate, but it doesn’t mean they are synced). When thinking about this further, I feel like this could also mean that due to some very little differences in refresh rate, phase between TD and video I/O card might be slowly shifting and after many hours it could eventually cause a frame drop.
To better illustrate what I mean lets imagine that internal clock of both TD and video I/O card isn’t perfect (I guess it never is) and that there is an extremely small deviation. For example TD is running at 59.999999 while video card is running at 60.000001. You start up your system that needs to be super stable and everything seems to be running just fine. However, half a million frames later (about 2.3 hours) phase drifts too much and frame drop happens. This could be a nightmare right?
If I am right here, it could mean that your stable system isn’t really that stable (which is a problem).
Maybe this video could better visualize what I am trying to say. 
sync_drift.zip (67.4 KB)