You need a proper API if you want to do realtime dashboarding. In this case, would it not be better to display the graphs in excel itself?
Anyway, in theory you could use the FileDocumentFromFile java action from the community commons module to import the excel file at regular intervals from a scheduled event into your app, and import the data into your database using the excel importer functionality.
You will however need to store the excel file in a location that is accessible by your Mendix application. This might prove difficult or easy depending on where you run your app.
thanks for your answer.
Yes, it would be better and easier to display the graphs in excel. But the goal of my project is to devlop a dashboard in mendix for mobile devices, so you can see the necessary information everywhere. The production is fictional so we decided the data from the production is stored in an excel-file. The Mendix app will have access to this file at every time.
I will try to solve my problem with your Advice, thanks :)