9.1.4 Published DataSet model

9.1.4.1 Overview

A PublishedDataSet defines the content of a DataSetMessage and the configuration of the information source for a DataSet. See 5.2 for the introduction to DataSets, 5.3 for the introduction to DataSetMessages and 5.4.1.2 for an introduction to the different source options and the parameters for sending of DataSetMessages.

Figure 46 depicts the ObjectTypes of the published DataSet model and their components.

Instances of the DataSetFolderType are used to organize PublishedDataSetType Objects in a tree of DataSetFolders. The configuration can be made through Methods or can be made by product-specific configuration tools.

The PublishedDataSetType defines the information necessary for a Subscriber to understand and decode DataSetMessages received from the Publisher for a DataSet and to detect changes of the DataSet semantic and metadata.

The types derived from the PublishedDataSetType define the source of information for a DataSet in the OPC UA Server AddressSpace like Variables or Events.

9.1.4.2 Published DataSet

9.1.4.2.1 PublishedDataSetType

This ObjectType is the base type for PublishedDataSets. It defines the metadata and the configuration version of the DataSets sent as DataSetMessages through DataSetWriters.

The PublishedDataSetType is the base type for configurable DataSets. Derived types like PublishedDataItemsType and PublishedEventsType define how to collect the DataSet to be published. For PublishedDataItemsType this is a list of monitored Variables used to create cyclic DataSets. For PublishedEventsType this is an Event selection used to create acyclic DataSets. The list of monitored Variables or the list of selected EventFields defines the content and metadata of the PublishedDataSetType Object.

If the content of the DataSet is defined by a product-specific configuration and the source of the DataSet is not known, the PublishedDataSetType can be used directly to expose the custom PublishedDataSet in the AddressSpace of the Publisher. If the Variable CyclicDataSet is not present, the custom PublishedDataSet shall create cyclic DataSets.

The PublishedDataSetType is formally defined in Table 247.

The PublishedDataSetType ObjectType is a concrete type and can be used directly. It can be used to expose a PublishedDataSet where the data collection is not visible in the AddressSpace.

The Object has a list of DataSetWriters. A DataSetWriter sends DataSetMessages created from DataSets through a Message Oriented Middleware. The link between the PublishedDataSet Object and a DataSetWriter shall be created when an instance of the DataSetWriterType is created. The DataSetWriterType is defined in 9.1.7.2. If a DataSetWriter is created for the PublishedDataSet, it is added to the list using the ReferenceType DataSetToWriter. The DataSetToWriter ReferenceType is defined in 9.1.4.2.5. If a DataSetWriter for the PublishedDataSet is removed from a group, the Reference to this DataSetWriter shall also be removed from this list. The group model is defined in 9.1.6.

The Property ConfigurationVersion is related to configuration of the DataSet produced by the PublishedDataSet Object. The PublishedDataSet parameters affecting the version are defined in the concrete types derived from this base type. The Property value shall match the ConfigurationVersion in the DataSetMetaData Property. The ConfigurationVersionDataType and the rules for setting the version are defined in 6.2.3.2.6.

The Property DataSetMetaData provides the information necessary to decode DataSetMessages on the Subscriber side if the DataSetMessages are not self-describing. The information in this Property is automatically updated if the ConfigurationVersion is changed based on DataSet configuration change. The DataSetMetaDataType is defined in 6.2.3.2.3. The Name field in the DataSetMetaDataType shall match the name of the PublishedDataSetType Object if the DataSetMetaData is not based on a DataSetClass.

The MajorVersion part of the ConfigurationVersion contained in the DataSetMessage needs to match the ConfigurationVersion of the DataSetMetaData available on the Subscriber side.

The DataSetClassId is the globally unique identifier for a DataSetClass. The optional Property shall be present if the DataSetClassId of the DataSetMetaData is not null. If the DataSetClassId is not null, the Publisher shall reject any configuration changes that change the DataSetMetaData. The Property value shall match the DataSetClassId in the DataSetMetaData Property.

The Property CyclicDataSet provides the information if the DataSets created by the PublishedDataSet are cyclic or acyclic. If the Property is provided by an instance of PublishedDataSetType, the Value shall be true. If the Property is provided by an instance of PublishedEventsType, the Value shall be false.

The ExtensionFields Object allows the configuration of fields with values to be included in the DataSet in case the existing AddressSpace of the Publisher does not provide the necessary information. The extension fields are added as Properties to the ExtensionFields Object. For PublishedDataItemsType base PublishedDataSets, an extension field is included as a Variable in the published DataSet. For PublishedEventsType base PublishedDataSets, an extension field is included into the SelectedFields for the DataSet.

9.1.4.2.2 ExtensionFieldsType

The ExtensionFieldsType is formally defined in Table 248. It allows the configuration of fields with values to be included in the DataSet in case the existing AddressSpace of the Publisher does not provide the necessary information.

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

The configured list of extension fields is exposed through Properties and managed through the Methods AddExtensionField and RemoveExtensionField. An ExtensionField is not automatically included in the DataSet. The ExtensionField can be added to the DataSet after creation.

Metadata that normally appear in message headers can be included in the body by adding extension fields with well-known QualifiedNames. These well-known QualifiedNames are shown in Table 249. The qualifying namespace is the OPC UA namespace.

If a well-known name is used, the value placed in the message body is dynamically generated from the current settings. The value set in the AddExtensionField Method is ignored. Subtypes of DataSetWriterTransportType may extend this list.

9.1.4.2.3 AddExtensionField Method

This Method is used to add a Property to the Object ExtensionFields.

The Client shall be authorized to modify the configuration for the PubSub functionality when invoking this Method on the Server.

Signature

	AddExtensionField (
		[in]	QualifiedName	FieldName,
		[in]	BaseDataType	FieldValue,
		[out]	NodeId		FieldId
		);
	

Method Result Codes

Table 250 specifies the AddressSpace representation for the AddExtensionField Method.

9.1.4.2.4 RemoveExtensionField Method

This Method is used to remove a Property from the Object ExtensionFields.

The Client shall be authorized to modify the configuration for the PubSub functionality when invoking this Method on the Server.

Signature

	RemoveExtensionField (
		[in]	NodeId		FieldId
		);
	

Method Result Codes

Table 251 specifies the AddressSpace representation for the RemoveExtensionField Method.

9.1.4.2.5 DataSetToWriter

The DataSetToWriter ReferenceType is a concrete ReferenceType that can be used directly. It is a subtype of the HierarchicalReferences ReferenceType.

The SourceNode of References of this type shall be an Object of ObjectType PublishedDataSetType or an ObjectType that is a subtype of PublishedDataSetType defined in 9.1.4.2.1.

The TargetNode of this ReferenceType shall be an Object of the ObjectType DataSetWriterType defined in 9.1.7.1.

Each DataSetWriter Object shall be the TargetNode of exactly one DataSetToWriter Reference.

Servers shall provide the inverse Reference that relates a DataSetWriter Object back to a PublishedDataSetType Object.

The representation of the DataSetToWriter ReferenceType in the AddressSpace is specified in Table 252.

9.1.4.3 Published Data Items

9.1.4.3.1 PublishedDataItemsType

The PublishedDataItemsType is used to select a list of OPC UA Variables as the source for the creation of DataSets sent through one or more DataSetWriters.

The PublishedDataItemsType is formally defined Table 253.

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

The PublishedData is defined in 6.2.3.7.1. Existing entries in the array can be changed by writing the new settings to the Variable Value. A new Value shall be rejected with Bad_OutOfRange if the array size would be changed. Entries in the array can be added and removed with the Methods AddVariables and RemoveVariables.

The index into the list of entries in the PublishedData has an important role for Subscribers and for configuration tools. It is used as a handle to reference the entry in configuration actions like RemoveVariables or the Value in DataSetMessages received by Subscribers. The index may change after configuration changes. Changes are indicated by the ConfigurationVersion and applications working with the index shall always check the ConfigurationVersion before using the index.

9.1.4.3.2 AddVariables Method

This Method is used to add Variables to the PublishedData Property. The PublishedData contains a list of published Variables of a PublishedDataItemsType Object. The information provided in the input Arguments and information available for the added Variables is also used to create the content of the DataSetMetaData Property. The mapping to the DataSetMetaData is described for the input Arguments.

Variables shall be added at the end of the list in PublishedData. This ensures that Subscribers are only affected by the change if they are interested in the added Variables.

If at least one Variable was added to the PublishedData, the MinorVersion of the ConfigurationVersion shall be updated. The ConfigurationVersionDataType and the rules for setting the version are defined in 6.2.3.2.6.

The Client shall be authorized to modify the configuration for the PubSub functionality when invoking this Method on the Server.

Signature

	AddVariables (
		[in]	ConfigurationVersionDataType		ConfigurationVersion,
		[in]	String[]					FieldNameAliases,
		[in]	Boolean[]					PromotedFields,
		[in]	PublishedVariableDataType[]		VariablesToAdd,
		[out]	ConfigurationVersionDataType		NewConfigurationVersion,
		[out] StatusCode[]				AddResults
		);
	

Method Result Codes

Operation Result Codes

Table 254 specifies the AddressSpace representation for the AddVariables Method.

9.1.4.3.3 RemoveVariables Method

This Method is used to remove Variables from the PublishedData list. It contains the list of published Variables of a PublishedDataItemsType Object.

A caller shall read the current Values of PublishedData and ConfigurationVersion prior to calling this Method, to ensure the use of the correct index of the Variables that are being removed.

If at least one Variable was successfully removed from the PublishedData, the MajorVersion of the ConfigurationVersion shall be updated. The ConfigurationVersionDataType and the rules for setting the version are defined in 6.2.3.2.6.

The order of the remaining Variables in the PublishedData shall be preserved.

The Client shall be authorized to modify the configuration for the PubSub functionality when invoking this Method on the Server.

Signature

	RemoveVariables (
		[in]	ConfigurationVersionDataType		ConfigurationVersion,
		[in]	UInt32[]					VariablesToRemove,
		[out]	ConfigurationVersionDataType		NewConfigurationVersion,
		[out] StatusCode[]				RemoveResults
		);
	

Method Result Codes

Operation Result Codes

Table 255 specifies the AddressSpace representation for the RemoveVariables Method.

9.1.4.4 Published Events

9.1.4.4.1 PublishedEventsType

This PublishedDataSetType is used to configure the collection of OPC UA Events.

The PublishedEventsType is formally defined in Table 256.

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

The EventNotifier is defined in 6.2.3.8.1.

The SelectedFields is defined in 6.2.3.8.2.

The index into the list of entries in the SelectedFields has an important role for Subscribers. It is used as handle to reference the Event field in DataSetMessages received by Subscribers. The index may change after configuration changes. Changes are indicated by the ConfigurationVersion and applications working with the index shall always check the ConfigurationVersion before using the index. If a change of the SelectedFields adds additional fields, the MinorVersion of the ConfigurationVersion shall be updated. If a change of the SelectedFields removes fields, the MajorVersion of the ConfigurationVersion shall be updated. The Property ConfigurationVersion is defined in the base ObjectType PublishedDataSetType.

The Filter is defined in 6.2.3.8.3. A change of the Filter does not affect the ConfigurationVersion since the content of the DataSet does not change.

9.1.4.4.2 ModifyFieldSelection Method

This Method is used to modify the event field selection of a PublishedEventsType Object.

The Client shall be authorized to modify the configuration for the PubSub functionality when invoking this Method on the Server.

Signature

	ModifyFieldSelection (
		[in]	ConfigurationVersionDataType		ConfigurationVersion,
		[in]	String[]					FieldNameAliases,
		[in]	Boolean[]					PromotedFields,
		[in]	SimpleAttributeOperand[]		SelectedFields
		[out]	ConfigurationVersionDataType		NewConfigurationVersion
		);
	

Method Result Codes

Table 257 specifies the AddressSpace representation for the ModifyFieldSelection Method.

9.1.4.5 DataSet Folder

9.1.4.5.1 DataSetFolderType

The DataSetFolderType is formally defined in Table 258.

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

Instances of the DataSetFolderType can contain PublishedDataSets or other instances of the DataSetFolderType. This can be used to build a tree of Folder Objects used to group the configured PublishedDataSets.

The PublishedDataSetType Objects are added as components to the instance of the DataSetFolderType. An instance of a PublishedDataSetType is referenced only from one DataSetFolder. If the DataSetFolder is deleted, all referenced PublishedDataSetType Objects are deleted with the folder.

PublishedDataSetType Objects may be configured with product-specific configuration tools or added and removed through the Methods AddPublishedDataItems, AddPublishedEvents and RemovePublishedDataSet. The PublishedDataSetType is defined in 9.1.4.2.1.

9.1.4.5.2 AddPublishedDataItems Method

This Method is used to create a PublishedDataSets Object of type PublishedDataItemsType and to add it to the DataSetFolderType Object. The configuration parameters provided with this Method are further described in the PublishedDataItemsType defined in 9.1.4.3.1 and the PublishedDataSetType defined in 9.1.4.2.

The settings in the VariablesToAdd are used to configure the data acquisition for the DataSet and are used to initialize the PublishedData Property of the PublishedDataItemsType.

The DataSetMetaData of the PublishedDataSetType is created from meta-data of the Variables referenced in VariablesToAdd and the settings in FieldNameAliases and FieldFlags.

The Client shall be authorized to modify the configuration for the PubSub functionality when invoking this Method on the Server.

Signature

	AddPublishedDataItems (
		[in]	String					Name,
		[in]	String[]					FieldNameAliases,
		[in]	DataSetFieldFlags[]			FieldFlags,
		[in]	PublishedVariableDataType[]		VariablesToAdd,
		[out] NodeId					DataSetNodeId,
		[out]	ConfigurationVersionDataType		ConfigurationVersion,
	[out] StatusCode[]				AddResults
		);
	

Method Result Codes

Operation Result Codes

Table 259 specifies the AddressSpace representation for the AddPublishedDataItems Method.

9.1.4.5.3 AddPublishedEvents Method

This Method is used to add a PublishedEventsType Object to the DataSetFolderType Object. The configuration parameters provided with this Method are further described in the PublishedEventsType defined in 9.1.4.4.1 and the PublishedDataSetType defined in 9.1.4.2.

The settings in the EventNotifier, SelectedFields and Filter are used to configure the data acquisition for the DataSet and are used to initialize the corresponding Properties of the PublishedEventsType.

The DataSetMetaData of the PublishedDataSetType is created from metadata of the selected Event fields and the settings in FieldNameAliases and FieldFlags.

The Client shall be authorized to modify the configuration for the PubSub functionality when invoking this Method on the Server.

Signature

	AddPublishedEvents (
		[in]	String				Name,
		[in]	NodeId				EventNotifier,
		[in]	String[]				FieldNameAliases,
		[in]	DataSetFieldFlags[]		FieldFlags,
		[in]	SimpleAttributeOperand[]	SelectedFields,
		[in]	ContentFilter			Filter,
		[out]	ConfigurationVersionDataType	ConfigurationVersion,
		[out]	NodeId				DataSetNodeId
		);
	

Method Result Codes

Table 260 specifies the AddressSpace representation for the AddPublishedEvents Method.

9.1.4.5.4 AddPublishedDataItemsTemplate Method

This Method is used to create a PublishedDataSets Object of type PublishedDataItemsType and to add it to the DataSetFolderType Object. The configuration parameters provided with this Method are further described in the PublishedDataItemsType defined in 9.1.4.3.1 and the PublishedDataSetType defined in 9.1.4.2.

The Client shall be authorized to modify the configuration for the PubSub functionality when invoking this Method on the Server.

Signature

	AddPublishedDataItemsTemplate (
		[in]	String					Name,
		[in]	DataSetMetaDataType			DataSetMetaData,
		[in]	PublishedVariableDataType[]		VariablesToAdd,
		[out]	NodeId					DataSetNodeId,
	[out]	StatusCode[]				AddResults
		);
	

Method Result Codes

Operation Result Codes

Table 261 specifies the AddressSpace representation for the AddPublishedDataItemsTemplate Method.

9.1.4.5.5 AddPublishedEventsTemplate Method

This Method is used to add a PublishedEventsType Object to the DataSetFolderType Object. The configuration parameters provided with this Method are further described in the PublishedEventsType defined in 9.1.4.4.1 and the PublishedDataSetType defined in 9.1.4.2.

The Client shall be authorized to modify the configuration for the PubSub functionality when invoking this Method on the Server.

Signature

	AddPublishedEventsTemplate (
		[in]	String				Name,
		[in]	DataSetMetaDataType		DataSetMetaData,
		[in]	NodeId				EventNotifier,
		[in]	SimpleAttributeOperand[]	SelectedFields,
		[in]	ContentFilter			Filter,
		[out]	NodeId				DataSetNodeId
		);
	

Method Result Codes

Table 262 specifies the AddressSpace representation for the AddPublishedEventsTemplate Method.

9.1.4.5.6 RemovePublishedDataSet Method

This Method is used to remove a PublishedDataSetType Object from the DataSetFolderType Object.

A successful removal of the PublishedDataSetType Object removes all associated DataSetWriter Objects. Before the Objects are removed, their state is changed to Disabled.

The Client shall be authorized to modify the configuration for the PubSub functionality when invoking this Method on the Server.

Signature

	RemovePublishedDataSet (
		[in]	NodeId	DataSetNodeId
		);
	

Method Result Codes

Table 263 specifies the AddressSpace representation for the RemovePublishedDataSet Method.

9.1.4.5.7 AddDataSetFolder Method

This Method is used to add a DataSetFolderType Object to a DataSetFolderType Object.

The Client shall be authorized to modify the configuration for the PubSub functionality when invoking this Method on the Server.

Signature

	AddDataSetFolder (
		[in]	String	Name,
		[out]	NodeId	DataSetFolderNodeId
		);
	

Method Result Codes

Table 264 specifies the AddressSpace representation for the AddDataSetFolder Method.

9.1.4.5.8 RemoveDataSetFolder Method

This Method is used to remove a DataSetFolderType Object from the parent DataSetFolderType Object.

A successful removal of the DataSetFolderType Object removes all associated PublishedDataSetType Objects and their associated DataSetWriter Objects. Before the Objects are removed, their state is changed to Disabled.

The Client shall be authorized to modify the configuration for the PubSub functionality when invoking this Method on the Server.

Signature

	RemoveDataSetFolder (
		[in]	NodeId	DataSetFolderNodeId
		);
	

Method Result Codes

Table 265 specifies the AddressSpace representation for the RemoveDataSetFolder Method.