como puedo almacenar datos con fecha anterior a la creación del Tag PI?
You can enter data before the Pt Created event. Have you tried this and it failed? You can see it by using PISMT and Archive Editor and manually entering an "older" value.
Note in the past one had to reprocess past archives to make them aware of a tag newly created and you could not save into them until this was done.
This is not needed for the current version of the PI Data Archive.
Retrieving data ...