I've taken Daniel's suggestion and I've connected the Main ADAT outputs from one Octamic-D into my "FOH" Digiface, and I've connected the Aux ADAT outputs to a "Monitors" Digiface.

Each Digiface is connected via ADAT Out to an ADI-8 Pro, which is sending analog to PA and monitor racks

Each Digiface is connected via separate Cardbus adapters to 2 laptops running Software Audio Console.  One laptop will mix FOH and the other laptop will do monitors.

In other words, I have 2 complete, discrete systems which are sharing only the mic inputs.  The "splitter" is being provided by the Octamics.

For my FOH setup, I've been providing WC as instructed by Matthias and Jeff - the Digiface WC out to Octamic #1, with a T-connector providing WC to Octamic #2.  The ADI-8 Pro is connected via ADAT in and out and receives its sync that way.

Can you please tell me how to provide WC to the second Digiface and second ADI-8 Pro?
- Should the "FOH Digiface" also provide WC to the "Monitors Digiface" using a T-connector from Digiface #1?
- Should I use a T from the last Octamic in line and feed WC to Digiface #2 that way?
- Or will the ADAT outputs from the Octamics provide sync, and I don't need to worry about WC for Digiface #2?
- And can the second ADI-8 Pro get sync via ADAT as well?