You can adjust the value in the Proportional Band field to control how sensitive the PID block is to process changes. For example, decreasing the proportional band generates a high gain and provides sensitive, but unstable control. With this narrow proportional band, a relatively small change in measurement causes a 100% change in the block's output travel. This method generally allows the set point to be reached faster, but with more severe fluctuations, as the following picture shows:
Conversely, increasing the proportional band generates a low controller gain and provides stable, but insensitive control. With this wide proportional gain, a relatively large change in measurement causes a small change in the block's output travel. This method generally takes longer to reach the set point, but causes fewer fluctuations, as the following picture shows:
