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.

Figure 3– Graphical view of a YArrayItem

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

Table 9– YArrayItemitem 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