I would like to find all granted German patents owned by a certain company. When I ran a Basic Search on depatisnet, the returned results were all published patent applications in Germany, but not granted German patents. Any suggestions on how to refine the search to get only granted patents? It's fine to include expired patents as well as active patents.
I have not seen a search engine without the ability to filter on granted vs application. However the way to do that did not jump out at me at DEPATIS. Looks like you might to use Kind Codes. (also your link to it has a typo).
At google patents advanced https://patents.google.com/advanced you enter info and check boxes on the left side. It produces a search string like -
assignee:IBM country:DE status:GRANT