About deviation alarm checking
- Last UpdatedJul 18, 2024
- 1 minute read
Limit checking for each deviation is as follows:
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The TimeSinceTargetChange attribute timer starts counting when the object starts up. When SP is changed, set TimerExpired=FALSE, and restart timer. When timer's elapsed time exceeds SettlingPeriod, set TimerExpired=TRUE.
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If ( Absolute value ( PV - SetPoint ) > Deviation && SettlingTimerExpired ) then set Condition=TRUE.
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If ( Absolute value ( PV - SetPoint + Deadband ) <= Deviation && Condition=TRUE) then set Condition=FALSE.