ConvertWeight

Short summary

This function can be used to convert weights from one physical weight unit into another. The value will change corresponding to the conversion. Example:
10 g = 154,324 US grain = 0.35274 US ounces = 0.564382 US dram = 0.01 kg = 0.00220462 US pounds

Return: CNM_RecipeHandling.Weight: a copy of the given weight converted into the desired unit

• Return type: Weight

Parameters

Name	Type	Comment	Kind
weightToConvert	Weight	the weight that should be converted	inout
convertTo	WeightUnit	the physical weight unit it should be converted to	input
resultPrefix	MetricPrefixes	the metrical prefix (for SI units)	input

Code

Declaration

FUNCTION ConvertWeight : Weight
VAR_IN_OUT CONSTANT
	(* the weight that should be converted *)
	weightToConvert :Weight;
END_VAR
VAR_INPUT
	(* the physical weight unit it should be converted to *)
	convertTo :WeightUnit := WeightUnit.GRAM;
	(* the metrical prefix (for SI units) *)
	resultPrefix :MetricPrefixes := MetricPrefixes.NONE;
END_VAR
VAR
	factor :LREAL;
	exponent :INT := 1;
END_VAR
VAR CONSTANT
	(* weight convertions related to gram: gram, ton, US grain, US dram, US ounce, US pound, US ton *)
	WEIGTHS : ARRAY[WeightUnit.GRAM..WeightUnit.US_TON] OF LREAL := [1.0, 1.0E6, 64.79891E-3, 1.771845195, 28.349523125, 453.59237, 907.18474E3 ];
END_VAR

Implementation

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