Sudden changes in control output are often undesirable or even dangerous for many control applications. For example, a sudden large change in setpoint can cause a very large change in controller output. Although in theory this large change in controller output results in fast response of the system, it also can cause unnecessary wear on actuators or sudden large power demands. In addition, the PID controller can amplify noise in the system and result in a constantly changing controller output.
You can use the PID Output Rate Limiter VI to avoid the problem of sudden changes in controller output. Wire the output value of the PID VI to the input (controller output) input of the PID Output Rate Limiter VI to limit the slew, or rate of change, of the output to the value of the output rate (EGU/min).
Assign a value to initial output to specify the output value on the first call to the VI. Use the dt (s) input to specify the same control-loop cycle time you use for the PID VI.