Try starting with a working application here: https://support.industry.siemens.com/cs/document/109480894

Usman_emden_hs

Hi. Does anyone know, how to fill up the USS_RPM (Readout parameters from the drive) for V20.

Oh, so you didn't open the Siemens provided example that does what you are asking to do as a reference guide?

Find the instruction you want to know about within the sample project and see where it gets that information.

What does F1-Help on the instruction say? 

Usman_emden_hs

Thanks for your kind response. I already have seen it. It is more complex. I just need to know how to fill up b USS_RPM.