Plant Simulation provides a detailed help file.
Open it and look for graphics import.
Then you will find a page similar to this (s.b.),
where all the importable graphic formats are listed.
To answer your question:
*.stl is not listed, therefore apparently not importable by Plant Simulation.
In any way this list contains a lot of formats, that can be exported by NX
I guess jt should work.
And by the way:
In case an application's native format is not supported as an import format to Plant Simulation and there is the file format Jt available, try using that before others. This is our native format and thus probably the best way to import data as fast and as good as possible.
Thanks All for your help. I was able to use NX model following your points.
1. Export NX STL file in JT Format.
2. Import that file in PS as JT.
3. Now, export that as s3D file from PS.
4. Finally, we can exchange graphics of MU or other parts.