Hi Laura.
At first blush, I’d say four status flags may do the trick…
- Is it time to get data? (example: is it between 8:00 and 9:00)
- Has the data already been transferred? (we don’t want to keep doing it over and over again within that window)
- Trigger for the transaction group
- ACK from the tranaction group
EDIT: If you have 7.7, I think this would be a prime application for SFCs.
Here’s the workflow I’m visualizing. No doubt, it can be streamlined or generally be improved upon… 
:
