ConvertLength

Short summary

This function can be used to convert distances from one physical length unit into another. The value will change corresponding to the conversion. Example:
1 m = 39.3701 inches = 3.28084167 feet = 1.093613889 yard = 0.00062137 miles

Return: CNM_RecipeHandling.Length: a copy of the given length converted into the desired unit

• Return type: Length

Parameters

Name	Type	Comment	Kind
lengthToConvert	Length	the length that should be converted	inout
convertTo	LengthUnit	the physical length unit it should be converted to	input
resultPrefix	MetricPrefixes	the metrical prefix (for SI units)	input

Code

Declaration

FUNCTION ConvertLength : Length
VAR_IN_OUT CONSTANT
	(* the length that should be converted *)
	lengthToConvert :Length;
END_VAR
VAR_INPUT
	(* the physical length unit it should be converted to *)
	convertTo :LengthUnit := LengthUnit.METER;
	(* the metrical prefix (for SI units) *)
	resultPrefix :MetricPrefixes := MetricPrefixes.NONE;
END_VAR
VAR
	factor :LREAL;
	exponent :INT := 1;
END_VAR
VAR CONSTANT
	(* length convertions related to meter *)
	LENGTHS : ARRAY[LengthUnit.METER..LengthUnit.US_MILE] OF LREAL := [1.0, 2.54E-5, 0.0254, 0.3048, 0.9144, 1609.34];
END_VAR

Implementation

factor := LENGTHS[lengthToConvert.unit] / LENGTHS[convertTo];
exponent := lengthToConvert.prefix - resultPrefix;
ConvertLength.prefix := resultPrefix;
ConvertLength.unit := convertTo;
IF CheckValueIsANumber(lengthToConvert.value) THEN
	ConvertLength.value := lengthToConvert.value * factor * FastPow10(exponent);
ELSE
	ConvertLength.value := lengthToConvert.value;
END_IF