The OPC UA ObjectType ProcessItemType is used to measure and monitor over time a process measurement point.

Figure 26 shows an overview for the ProcessItemType with related Variable. It is formally defined in Table 50.

Figure 26 – ProcessItemType overview

The ProcessItemType is formally defined in Table 50.

Table 50 – ProcessItemType Definition

Abstract	Value
BroseName	ProcessItemType
IsAbstract	False
References	Node Class	BrowseName	DataType	TypeDefinition	Modelling Rule
Subtype of BaseObjectType defined in OPC 10000-5
HasComponent	Variable	DisplayFormat	String	BaseDataVariableType	Mandatory
HasComponent	Variable	EffectivePrecision	Double	BaseDataVariableType	Mandatory
HasComponent	Variable	HH	Double	BaseDataVariableType	Mandatory
HasComponent	Variable	H	Double	BaseDataVariableType	Mandatory
HasComponent	Variable	L	Double	BaseDataVariableType	Mandatory
HasComponent	Variable	LL	Double	BaseDataVariableType	Mandatory
HasComponent	Variable	AnalogMeasurement	Double	BaseDataVariableType	Mandatory
HasComponent	Object	UIInfo		UIInformationType	Mandatory
HasProperty	Variable	0:EngineeringUnits	EUInformation	PropertyType	Mandatory

The ProcessItemType ObjectType is a concrete type and can be used directly.

Remark. The AnalogMeasurement value shall be historized and accessed via the OPC UA HistoryReadService as described in OPC 10000-11. The sampling time for the value is the same used by the OEM for machine performance analysis.


The following Properties are defined to extend the AnalogItemType.

The Variable DisplayFormat specifies how the value shall be displayed across all displays, clients and applications for uniformity. It is a string that contains one or more format specifiers, which are single characters or groups of characters that define how the string representation of that object's value should appear.

The Variable EffectivePrecision specifies the significant part of the value, e.g. 0.01 means 1% precision.

The Variable HH identifies a high limit for the variable above which an event is triggered.

The Variable H identifies a high limit for the variable during normal process.

The Variable L identifies a low limit for the variable during normal process.

The Variable LL identifies a low limit for the variable below which an event is triggered.

The Variable AnalogMeasurement represents the current value measured by the sensor.

The Property EngineeringUnits specifies the units for the AnalogMeasurement’s value (e.g., DEGC, hertz, seconds). The EUInformation type is specified in 5.6.3 OPC 10000-8.

The Object UIInfo contains graphical specifications required for creating faceplates to display information about the containing object.