How do I select the index/year to retrieve data from - there's just "Default" as the only option?

You don't need to!!! And that's good news ;-)

The Archiver Appliance does not need an index to be specified, but has all data available as "the" archive.

So queries covering several years are now easily possible (but may take time - depending on the amount of data to be processed).

Also, the "current week" archives are no longer needed, since all data is more or less instantaneously available.

Do I need to start another instance to query data from another archive?

No, you may switch archives any time from within the runnning application by selecting New Connection from the File menu!

How do I convert saved configuration files to use another archive?

1. Load the file that you want to convert
2. Select New Connection from the File menu and select the appropriate new archive to use
3. Select/highlight all PVs in your list and select Assign Selected Archive from the Tools menu
4. Save your configuration