Process Control Instructions
194 Rockwell Automation Publication 1756-RM006K-EN-P - November 2018
CVROCNegAlarm REAL CV rate of change alarm indicator. TRUE
when the calculated rate of change for CV
exceeds CVROCNegLimit.
SP REAL Current setpoint value. The value of SP is
used to control CV when in the Auto, the
CascadeRatio, or the PV Tracking mode,
scaled in PV units.
SPPercent REAL The value of SP expressed in percent of
span of PV.
SPPercent = ((SP − PVEUMin ) * 100) /
PVSpan
where
PVSpan = PVEUMax − PVEUMin
SPHAlarm BOOL SP high alarm indicator. TRUE when the SP
≥ SPHLimit.
SPLAlarm BOOL SP low alarm indicator. TRUE when the SP
≤ SPLLimit.
PVPercent REAL PV expressed in percent of span.
PVPercent = (( PV − PVEUMin ) * 100) /
PVSpan
PV Span calculation: PVSpan =
( PVEUMax − PVEUMin )
E REAL Process error. Difference between SP and
PV, scaled in PV units.
EPercent REAL The error expressed as a percent of span.
InitPrimary BOOL Initialize primary loop command. TRUE
when not in CasRat mode or when
CVInitializing is TRUE. This signal normally
would be used by the CVInitReq input of a
primary loop.
WindupHOut BOOL Windup high indicator. TRUE when either a
SP high or CV high/low limit has been
reached. This signal will typically be used
by the WindupHIn input to limit the
windup of the CV output on a primary loop.
WindupLOut BOOL Windup low indicator. TRUE when either a
SP or CV high/low limit has been reached.
This signal will typically be used by the
WindupLIn input to limit the windup of the
CV output on a primary loop.
Ratio REAL Current ratio multiplier, no units.
RatioHAlarm BOOL Ratio high alarm indicator. TRUE when
Ratio > RatioHLimit.
RatioLAlarm BOOL
Ratio low alarm indicator. TRUE when Ratio
< RatioLLimit.
ProgOper BOOL Program/Operator control indicator. TRUE
when in Program control. FALSE when in
Operator control.
CasRat BOOL CascadeRatio mode indicator. TRUE when
in the CascadeRatio mode.
Auto BOOL Auto mode indicator. TRUE when in the
Auto mode.
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