Main: AWS - APMonitor Option

 Type: Floating Point, Output
Default Value: 0
Description: Anti-Windup Status for a Manipulated Variable
0: Not at a limit
1: An upper or lower bound is reached


Anti-Windup Status (AWS) is terminology borrowed from classical controls such as Proportional Integral Derivative (PID) controllers. Anti-Windup refers to the integral action that is paused when the controller reaches a saturation limit. An example of a saturation limit is a valve that is limited to 0-100% open. If the controller requests -10%, the valve is still limited to 0%. The AWS indication is useful to show when a controller is being driven by an optimization objective versus constraints that limit movement. A Key Performance Indicator (KPI) of many controllers is the fraction of time that a MV is not at an upper or lower bound limit.