My experience with WinCupl is that it doesn't like spaces in file paths or names.
My advice:
Make sure the path to your WinCupl program does not contain spaces
Make sure the path to your WinCupl project does not contain spaces
Make sure the name of your WinCupl project does not contain spaces
Make sure the "Name" line in your .pld file matches the name of your .pld file
I created a directory named D:\Dev\Test\BLDC and created the file BLDC.pld in that directory. I copied your source and pasted it into the BLDC.pld file. I then changed the first line from "Name BLDC Commutation ;" to "Name BLDC ;"
Here is the result of my simulation.
Let me know if this helps.
Shawn