Siemens SIMATIC S5 Manual page 198

Notes on Controller Settings
The output variable of I control elements is the integral of the input variable, i.e. the controller totals
the deviation from the setpoint over time. This means that the controller continues to correct until
there is no deviation from the setpoint. In practice, a combination of the various time elements is
ideal, depending on the requirements of the control action. The dynamic response of the individual
elements can be described using the controller parameters proportional band X , integral action
p
time T (I action) and derivative action time T (D action).
n v
PID controller
IP244
4–132
C79000–B8576–C860–02