Kaulquappe

.. if you could give us some more information ..

I agree with the sentiment.

Maybe to help 76109 a little more - have a look at:
https://support.industry.siemens.com/cs/de/en/view/63696870

It is an application example for a Siemens Drive which in general terms can teach you what is done where.

The PDF you shared earlier is not helpful. That explains how the communication packages should look like.. if you would make something from scratch. The S7-1200 instructions handle the packaging and linking of data for you.

YOU need to figure out what protocol to use (Modbus RTU or Modbus ASCII) and what data registers should should be read/written. This part we cannot help you with.

Please work through the detail of the application example. This will give you much more clear idea on what is involved and what to ask about.

Good luck.