Re: Whoa, hang on
Hell, at [redacted] we implemented an exchange between secure and nonsecure parts of the ground network where the nonsecure part would ask for new data using an SNMP packet, and the secure part would eject the data as needed. It's not rocket science!
Tsk. Just blast the data every $num seconds over a physical one-way link. And if you really need event-driven data collection, create a specific link whose binary state signals whether new data is wanted.