S7-300 Write to file, Read from file

Is it possible to write DB fields into a (comma separated) text file? And read them back again ... If yes, how to do it?

PLC Siemens S7-319.

Thank you.

Is this something you want to do from an HMI or from Step 7?

From Step7. But we have 7 OP-panels in the project too, connected via ethernet. I'm at home now, so I don't know the exact type, but they are two types. Bigger and smaller touchscreen panels.

Yes, that's possible easily, only not with the standard simatic software.

Where are the CSV files ?
On the OP panels, or on a PC networked with the PLCs/OPs ?

edit: And what is it that you want to achieve exactly ?

The CSV files are on a network computer. Same computer where Intouch visualisation is running.

Purpose of this thing is that customer wants a daily backup of all product data in the building (about 100 000 DB fields). These products are stored in tracks. Customer wants to be able to do a 'trackwise' restore. So write back saved data into the PLC.
This customer wish comes from their experience with a previous system where PLC data obviously disappeared once in a while.
We tried to talk them out of this option because it is probably not necessary, but they want it anyway.