CurveLin

 Function Block - Linear interpolation on a curve.

Inputs

Input	Data Type	Range	Unit	Default	Description
X	REAL				X coordinate of the point to be interpolated.
XAxis	REAL[ ]				X coordinates of the known points of the X axis.
YVal	REAL[ ]				Y coordinate of the points defined on the X axis.

Outputs

Output	Data Type	Range	Unit	Description
ERR	DINT			Error code if failed. 0 (zero) if OK.
OK	BOOL			TRUE if successful.
Y	REAL			Interpolated Y value corresponding to the X input.

Remarks

• This function performs linear interpolation in between a list of points defined in the XAxis single dimension array.
  • The output Y value is an interpolation of the Y values of the two rounding points defined in the X axis.
  • Y values of defined points are passed in the YVal single dimension array.
• Values in XAxis must be sorted from the smallest to the biggest.
  • There must be at least two points defined in the X axis.
    • YVal and XAxis input arrays must have the same dimension.
• If the X input is less than the smallest defined X point:
  • The Y output takes the first value defined in YVal.
  • An error is reported.
• If the X input is greater than the biggest defined X point:
  • The Y output takes the last value defined in YVal.
  • An error is reported.

If the function fails, the ERR output gives the cause of the error:

Error Code	Meaning
0	OK
1	Invalid dimension of input arrays
2	Invalid points for the X axis
4	X is out of the defined X axis

FBD Language Example

Not available.

FFLD Language Example

Not available.

IL Language Example

Not available.

ST Language Example

Not available.