FB_BA_Chrct32
The function block FB_BA_Chrct32 represents a linear interpolation with 32 interpolation points and can be used to generate a characteristic curve. In contrast to the "smaller" interpolation function blocks FB_BA_Chrct02, FB_BA_Chrct04 and FB_BA_Chrct07, and in the interest of clarity, the interpolation points are determined via field variables [aX[1]/aY[1] to [aX[n]/aY[n]].
The input variable nNumOfElem determines the number of interpolation points from the field ranges aX/aY.
The calculated output value fCalcVal is limited by fYMin or fYMax.
Error handling
The input values for aX[n+1] must always be greater than from aX[n].
In case of an error the variable bErr indicates this. The property ErrorDescription gives out a detailed description.
The input value for fYMin must not be greater than fYMax.
In case of an error the variable bErr indicates this. The property ErrorDescription gives out a detailed description.
Inputs
VAR_INPUT
fX : REAL;
aX : ARRAY [1..cBA_NumOfElem] OF REAL;
aY : ARRAY [1..cBA_NumOfElem] OF REAL;
nNumOfElem : DINT(2..32);
fYMin : REAL;
fYMax : REAL;
END_VAR
Name | Type | Description |
|---|---|---|
fX | REAL | Input value of the characteristic curve. |
aX | ARRAY OF REAL | X-value for the interpolation points. |
aY | ARRAY OF REAL | Y-value for the interpolation points. |
nNumOfElem | DINT | Number of interpolation points. Internally limited to the range 2 ... 32. |
fYMin | REAL | Lower limit of fCalcVal. The input for the lower limit is limited to the global parameter BAComn_Global.fMinReal from the Tc3_BA2_Common library. |
fYMax | REAL | Upper limit of fCalcVal. The input for the upper limit is limited to the global parameter BAComn_Global.fMaxReal from the Tc3_BA2_Common library. |
Outputs
VAR_OUTPUT
fCalcVal : REAL;
bErr : BOOL;
END_VAR
Name | Type | Description |
|---|---|---|
fCalcVal | REAL | Calculated output value of the characteristic curve. |
bErr | BOOL | This output is switched to TRUE if the parameters entered are erroneous. |
Properties
Name | Type | Access | Description |
|---|---|---|---|
ErrorDescription | T_MaxString | Get | Issues a detailed description of errors, see error handling. |
Requirements
Development environment | Required PLC library |
|---|---|
TwinCAT from v3.1.4024.22 | Tc3_BA2 from v5.2.5.0 |