Siemens MICROMASTER 411 - Manual (Page 124)

10 Engineering Information Issue 03/01
MICROMASTER 411 & COMBIMASTER 411 Operating Instructions
124 6SE6400-5CA00-0BP0
10.2.2.5 PI Controller Proportional and Integral terms
The user can tune the performance of the PI controller to suit the process demands
by adjusting P and I terms, P2280 and P2285. The demands of the process will
determine the optimal type of response, from a rapid recovery response with
overshoot to a damped response. By adjusting the P and I parameters it is possible
to achieve different types of response.
Example:
The following figures show how different responses to a 5% PI setpoint step
change on a pressure control system. The traces show the PI feedback signal, with
1 V = 10%. The different responses are achieved by varying the settings of P2280
and P2285.
Figure 10-4 Quick response with overshoot: P2280 = 0.30; P2285 = 0.03 s
Figure 10-5 Quick response with overshoot, but instability:P2280 = 0.55; P2285 = 0.03 s