Rate Limiter (RLIM)

Operand	Type	Format	Description
RLIM tag	RATE_LIMITER	structure	RLIM structure

Input Parameter	Data Type	Description
EnableIn	BOOL	Enable input. If false, the instruction does not execute and outputs are not updated. Default is true.
In	REAL	The analog signal input to the instruction. Valid = any float Default = 0.0
IncRate	REAL	Maximum output increment rate in per-second units. If invalid, the instruction sets IncRate = 0.0 and sets the appropriate bit in Status. Valid = any float 0.0 Default = 0.0
DecRate	REAL	Maximum output decrement rate in per-second units. If invalid, the instruction sets DecRate = 0.0 and sets the appropriate bit in Status. Valid = any float 0.0 Default = 0.0
ByPass	BOOL	Request to bypass the algorithm. When true, Out = In. Default is false.
TimingMode	DINT	Selects timing execution mode. 0 = Period mode 1 = oversample mode 2 = real time sampling mode Valid = 0 to 2 Default = 0
OversampleDT	REAL	Execution time for oversample mode. Valid = 0 to 4194.303 seconds Default = 0
RTSTime	DINT	Module update period for real time sampling mode Valid = 1 to 32,767ms Default = 1
RTSTimeStamp	DINT	Module time stamp value for real time sampling mode. Valid = 0 to 32,767ms Default = 0

Output Parameter	Data Type	Description
EnableOut	BOOL	Indicates if instruction is enabled. Cleared to false if Out overflows.
Out	REAL	The calculated output of the algorithm.
DeltaT	REAL	Elapsed time between updates. This is the elapsed time in seconds used by the control algorithm to calculate the process output.
Status	DINT	Status of the function block.
InstructFault (Status.0)	BOOL	The instruction detected one of the following execution errors. This is not a minor or major controller error. Check the remaining status bits to determine what occurred.
IncRateInv (Status.1)	BOOL	IncRate < 0. The instruction uses 0.
DecRateInv (Status.2)	BOOL	DecRate < 0. The instruction uses 0.
TimingModeInv (Status.27)	BOOL	Invalid TimingMode value. For more information about timing modes, see Function Block Attributes.
RTSMissed (Status.28)	BOOL	Only used in real time sampling mode. Set to true when ABS(DeltaT – RTSTime) > 1 millisecond.
RTSTimeInv (Status.29)	BOOL	Invalid RTSTime value.
RTSTimeStampInv (Status.30)	BOOL	Invalid RTSTimeStamp value.
DeltaTInv (Status.31)	BOOL	Set to true in oversample mode if either DeltaT <= 0 or DeltaT > 4194.303.

Operand	Type	Format	Description
RLIM tag	RATE_LIMITER	structure	RLIM structure

Condition	Action
ByPass is true	Out n = In n Out n-1 = In n
ByPass is false and DeltaT > 0

Condition/State	Action Taken
Prescan	EnableIn and EnableOut bits are cleared to false.
Tag.EnableIn is false	EnableIn and EnableOut bits are cleared to false.
Tag.EnableIn is true	EnableIn and EnableOut bits are set to true The instruction executes.
Instruction first run	N/A
Instruction first scan	Initialize Out with the value of In.
Postscan	EnableIn and EnableOut bits are cleared to false.

Condition/State	Action Taken
Prescan	See Prescan in the Function Block table.
Normal Execution	See Tag.EnableIn is true in the Function Block table.
Postscan	See Postscan in the Function Block table.