FB_CTRL_LIN_INTERPOLATION
This block performs linear interpolation to obtain values on the basis of a table of interpolation points.
Behaviour of the output:
fIn | fOut |
|---|---|
arrTable[1,1] := 10; | arrTable[1,2] := 7; |
arrTable[2,1] := 15; | arrTable[2,2] := 10; |
arrTable[3,1] := 21; | arrTable[3,2] := 9; |
arrTable[4,1] := 22; | arrTable[4,2] := 2; |
arrTable[5,1] := 30; | arrTable[5,2] := 3; |
arrTable[6,1] := 40; | arrTable[6,2] := 6; |
VAR_INPUT
VAR_INPUT
fIn : FLOAT;
fManValue : FLOAT;
bExtrapolate : BOOL;
eMode : E_CTRL_MODE;
END_VAR
fIn : Input variable for the interpolation block.
bManValue : Input variable whose value is output in manual mode.
bExtrapolate : If this input is FALSE, then the value of the last interpolation point is output if the limits of the table are exceeded. If, however, it is TRUE, then extrapolation is performed on the basis of the last two interpolation points.
eMode : Input that specifies the block's operating mode.
VAR_OUTPUT
VAR_OUTPUT
fOut : FLOAT;
bInIsGreaterThanMaxElement : BOOL;
bInIsLessThanMinElement : BOOL;
eState : E_CTRL_STATE;
eErrorId : E_CTRL_ERRORCODES;
bError : BOOL;
END_VAR
fOut : Table value from linear interpolation.
bInIsGreaterThanMaxElement : A TRUE at this output indicates that the magnitude of the input is greater than the largest interpolation point.
bInIsLessThanMinElement : A TRUE at this output indicates that the magnitude of the input is smaller than the smallest interpolation point.
eState : State of the function block.
eErrorId : Supplies the error number when the bError output is set.
bError : Becomes TRUE, as soon as an error occurs.
VAR_IN_OUT
VAR_IN_OUT
stParams : ST_CTRL_LIN_INTERPOLATION_PARAMS;
END_VAR
stParams : Parameter structure of the interpolation element. This consists of the following elements:
TYPE
ST_CTRL_2POINT_PARAMS :
STRUCT
tCtrlCycleTime : TIME := T#0ms; (*
controller cycle time [TIME] *)
tTaskCycleTime : TIME := T#0ms; (* task
cycle time [TIME] *)
pDataTable_ADR : POINTER TO FLOAT := 0;
nDataTable_SIZEOF : UINT := 0;
nDataTable_NumberOfRows : UINT := 0;
END_STRUCT
END_TYPE
tCtrlCycleTime : Cycle time with which the control loop is processed. This must be greater than or equal to the TaskCycleTime. The function block uses this input value to calculate internally whether the state and the output values have to be updated in the current cycle.
tTaskCycleTime : Cycle time with which the function block is called. If the function block is called in every cycle this corresponds to the task cycle time of the calling task.
pDataTable_ADR : Address of the n x 2 array on which linear interpolation is to be carried out
pDataTable_SIZEOF : Size of the n x 2 array.
pDataTable_NumberOfRows : Number of rows of the array.