West Control Solutions Pro-EC44 - Manual (Page 115)

Pro-EC44 2-Loop Graphical Profile Controller & Recorder
Pro-EC44 Product Manual - 59540-1 October 2013 Page 108
Anti Wind-up
If after fully optimising the tuning, there is an overshoot of the setpoint at start-up or in
response to large setpoint changes, the reset wind-up inhibit point can be reduced to
suspend integral action until the process is closer to setpoint. If set too low control deviation
can occur (the process settles, but is offset above or below the setpoint). It this is observed,
increase the value until the deviation error is removed.
Anti Wind-up
Too Small: Overshoots setpoint before
settling
Too Short: Slow to setpoint or offset
above/below setpoint
Manual Reset
For proportional only control, after making all other adjustments, if a positive control deviation
error exists (process is offset above the setpoint) reduce the manual reset until the error is
eliminated. If there is a negative error (process is offset below the setpoint) increase manual
reset until the error is eliminated.
For PID or PI control, typically set manual reset to approximately 80% of power needed to
maintain setpoint, but lower values can be used to inhibit start-up overshoot if required.
Manual Reset
Too High: Overshoots setpoint at start-up Too Low: Slow to setpoint