MKS 640B - Figure 17: Controller Response with Increased P Term; Figure 18: Controller Response with Increased I Term

Chapter Three: Overview Tunin
g
the 640B Series Pressure Controlle
r
37
Controller Response with Increased P Term
Increasing the P term to 1 while holding the I term at 0 yields:
Figure 17: Controller Response with Increased P Term
The controller responds much faster, however some overshoot occurs.
Controller Response with Increased I Term
Reducing the P term to 0 and increasing the I term to 5 yields:
Figure 18: Controller Response with Increased I Term
The response of the controller is quick, yet no overshoot occurs. This combination of P term and
I term yields the best control for our example system.
P = 1
I = 0
Settling Time
Settling Time
Set Point
Signal
4
2
6
8
Pressure, (Torr)
Time
P = 0
I = 5
Settling Time Settling Time
Set Point
Signal
4
2
6
8
Pressure, (Torr)
Time