Dear SudhakarK

Thank you for your post! With this I finally managed to have a running example of a connection with OPC UA.

To your question: OpenModelica stores all files for a simulation in a specific folder, in your temp directory.
For me it is:

on Windows: C:\Users\%username%\AppData\Local\Temp\OpenModelica\OMEdit\
on Linux:  /tmp/OpenModelica_%username%/OMEdit .

There you also find a .mat file that you can open with OMEdit.