The Proportional Band is used by some controller manufacturers in preference to Proportional Gain, which may be why it is used in print sometimes. I used it in controlers, and it took me a while to get my head around Kc, especially if you roughly know what PB values you are expecting for a system!
I have never had much luck with the AutoTune option, but it may be worth a go?
There are several websites that graphically show the effects of changing each of the parameters in turn (search wiki PID or PID tuning), if you have a specific issue that may give a clue as to what to vary.
You may also need to determine if 'steady state stability' or 'swift changes in setpoints' are your priority, as often tuning for one can adversely affect the other.
I will tend to attempt to tune either using autotune, or one of the theoretical methods, and then tweak values on the live system.
Message Edited by BlueTwo on 03-13-2010 02:25 PM
