How to operate the Tab-Guy tension system on my ElectriScreen???

I recently bought a Stewart ElectriScreens.
I don't know how to operate the Tab-Guy tension function, to ensure that the screen does not curl.
I cannot seem to find any in the manual about this and I don't want to make any errors trying.
I can see is that there is a screw located at the frame bottom in each side. But should I just turn these screws
clockwise/counter clockwise to make the tension tighter? Or is there another way to do it?