Not really sure what that means, but I'll look at the manual for changing the settings. I work with computers a lot, but every time I read something about how a PID works, my eyes kinda glaze over... :shock:
A PID is just a math calculation. Error is the difference between the temp you want and the temp you have. The calculation takes the error and calculates the output based on the P, I and D settings sometimes called gains.
P is for proportional which is just basically a muliplication factor. Proportional effectively takes that error and multiplies by a factor. The larger the error, the larger the output based on the P, the smaller the error, the smaller the output based on P. Since as you approach setpoint error decreases toward zero and multipling by a P gain approaches zero, so P alone cannot be used because while you might get close, you will not normally reach setpoint on P alone.
I is integral. This is used for consistent errors. For example as you approach setpoint and P output becomes so small that it is negligible, the output for I is used to close the error to zero when P cannot get there. It is basically a time thing where you keep adding some amount until the error gets to zero.
D is for derivative. It is usually not that helpful in these cases but it is for what is called step or sudden changes in temp. If your temp had a sudden change say downward, derivative would instantaneously add output to try to slow down the quick change.
When I say output, it is in reference to a system where you have an analog output such as a variable speed fan. In the case we are talking about, the output is discrete (on/off) fan so you have to have a range of output that will turn on the fan. For example, output above X turns on the fan.
I have left off several details in my explanation but I think you can get a basic idea of how it works from it.
