OptoDataLink connects your controller data to files it's PC can access. But OptoDataLink cannot access files on your controller. Here's a link to a video about OptoDataLink.
You might also consider using PAC Display's logging features, see form 1702 (PAC Display User's Guide).
Personally, especially since you mention you're already using FTP (I'm assuming ftp comm handles), I think you'd find writing a strategy to use a file comm handle would be easy. In fact, if you don't have PAC Project Pro/SoftPAC already, you could try this out with PAC Sim since PAC Sim has supported file comm handles for years. That way you'd have complete control over exactly what/when/where you write to your files. You could include each of your R1s as I/O Units in the strategy that runs on this SoftPAC controller/PC to easily access I/O on those controllers or their memory maps.
Also remember that our product support is FREE! and they may have some ideas and thoughts for you I might've missed here.
Hope that helps!