Thats because I was asking what that adjustment needed to be and what it was, I had found the output voltage adjust but did not know what that PRO was for.
I have now the answer :- It sets the foldback current point for the power supply when in overload, in my first write I had not got a copy of its circuit hence the addition later so now I have ordered two 1.2R 75W resistors to make a dummy load with so it can be set up.
Thank you for your response to my question anyway...
David