YArrayItemTyperepresents a single-dimensional array of numerical values used to represent spectra or distributions where the x axis intervals are constant. YArrayItemTypeis formally defined in Table 8.

Table 8– YArrayItemType definition

Attribute

Value

BrowseName

YArrayItemType

IsAbstract

False

ValueRank

1

DataType

BaseDataType

ArrayDimensions

{0} (0 = UnknownSize)

References

NodeClass

BrowseName

DataType

TypeDefinition

ModellingRule

Subtype of the ArrayItemType defined in 5.3.4.1

HasProperty

Variable

XAxisDefinition

AxisInformation

PropertyType

Mandatory

The Valueof the YArrayItemcontains the numerical values for the Y-Axis. Engineering Unitsand Rangefor the Valueare defined by corresponding Propertiesinherited from the ArrayItemType.

The DataTypeof this VariableTypeis restricted to SByte, Int16, Int32, Int64, Float, Double, ComplexNumberTypeand DoubleComplexNumberType.

The XAxisDefinition Propertyholds the information about the Engineering Unitsand Rangefor the X-Axis.

The StatusCode SemanticsChangedbit shall be set if any of the following five Propertiesare changed: InstrumentRange, EURange, EngineeringUnits, Title orXAxisDefinition(see 5.2for additional information).

Figure 3shows an example of how Attributesand Propertiesmay be used in a graphical interface.

image006.png

Figure 3– Graphical view of a YArrayItem

Table 9describes the values of each element presented in Figure 3.

Table 9YArrayItemitem description

Attribute / Property

Item value

Description

Magnitude Response (dB)

axisScaleType

AxisScaleEnumeration.LINEAR_0

InstrumentRange.low

-90

InstrumentRange.high

5

EURange.low

-90

EURange.high

2

EngineeringUnits.namespaceUrl

http://www.opcfoundation.org/UA/units/un/cefact

EngineeringUnits.unitId

2N

EngineeringUnits.displayName

“en-us”, “dB”

EngineeringUnits.description

“en-us”, “decibel”

Title

Magnitude

XAxisDefinition.EngineeringUnits.namespaceUrl

http://www.opcfoundation.org/UA/units/un/cefact

XAxisDefinition.EngineeringUnits.unitId

kHz

XAxisDefinition.EngineeringUnits.displayName

“en-us”, “kHz”

XAxisDefinition.EngineeringUnits.description

“en-us”, “kilohertz”

XAxisDefinition.Range.low

0

XAxisDefinition.Range.high

25

XAxisDefinition.title

“en-us”, “Frequency”

XAxisDefinition.axisScaleType

AxisScaleEnumeration.LINEAR_0

XAxisDefinition.axisSteps

null

Interpretation notes:

  • Not all elements of this table are used in the graphic.
  • The X axis is displayed in reverse order, however, the XAxisDefinition.Range.lowshall be lower than XAxisDefinition.Range.high. It is only a graphical representation that reverses the display order.
  • There is a constant X axis