If an existing EXE program has been entered in the Program edit-field then this button becomes enabled.
Clicking this button disables the RUN button, executes the program and a blinking button appears in the Status Bar.
Then the main program window is automatically hidden, so you can better watch the started program; but you can always make it reappear by clicking on the PA-RUN Tray Icon.
Then the Real-time Program Monitoring window appears in the top-left corner of the screen where you can monitor the started program in real-time.
Instead of clicking this RUN button to run the current program you could also:
• double-click the Loaded-Program button in the status-bar, or
• press CTRL+R
PA-RUN remains "attached" to the started program until the started program is terminated. Only then this RUN button becomes enabled again.
When you close the started program then the PA-RUN main window automatically reappears at its previous position.