CNT-APG002-EN 9
®
Chapter 2
PID settingsThis chapter describes some of the key variables used to set up and tune
PID loops. The variables discussed here are:
•Throttling range
•Gain
•Sampling frequency
•Action
•Error deadband
Throttling range
The throttling range is the amount of error it takes to move the output of
a system from its minimum to its maximum setting. For example, a throt-
tling range of 4°F (2.2°C) means that a controller fully opens or closes an
actuator when the error is ±2°F (1.1°C) or greater, as illustrated in
Figure 8. Note how the controller response (actuator position) lags behind
the space temperature.
Figure 8: Throttling range
Time
Space temperature (°F)
Actuator position
Space temperature
Setpoint = 75°F
Actuator position (%)
Throttling range = 4°F