Hello Aivaras2

the best would be to use the tag prefix of the Screenwindow.

If you click on the IO Field or other object, open the Screen window and set the Tag prefix of the Screenwindow by script.

If you do not work with prefixes or structs then you can also use the property "User data" of the Screenwindow. you can set here any string you want to use inside the Screen window.

Inside the Screen window use a Script at Event "Open Picture" and read out the userdata. Then you have the tagname and you can use it in the same script to dynamize the trend as needed.

Perhaps there are also other ways but it should work 

Bye Murof

Hello Aivaras2

I´m not sure if it works to read out the dynamized tagname out of a faceplate interface...

There is a new feature for opening popup screens from faceplate in WinCC V8, here you can also use a structured tag for forwarding interface values.

Bye Murof