I have been facing the same problem but yes unfortunaltely, DataConnect is no longer available in ThingWorx 8.1 (Is DataConnect not available in ThingWorx 8.1?).
I am also looking to get a work around to just get the JSON and CSV files generated. I will update here if I am able to find a workaround and please do let me know if you find it before me
Also how are you able to generate JSON and CSV files with the AnalyticsServer Thing?
I'm working on a workaround. I generate a json and a csv file with some services. To send the json and the csv file via AnalyticsServer_DataThing I need the absolute path to the generated json and csv file. How can I get the path to a repository? (the link to the files via Repository.GetFileListingWithLinks() will not work). I think I need the absolute path in filesystem.