OpcLabs.EasyOpc.UA.PubSub Namespace (OpcLabs.EasyOpcUA)

This namespace contains classes that facilitate easy work with OPC Unified Architecture (OPC-UA) PubSub. It also contains the most important extension classes.

Classes

	Class	Description
	EasyUASubscriberCore	The core part of the `EasyUASubscriber` object.
	EasyUASubscriberManagementCore	The core part of the `EasyUASubscriberManagement` object.
	EasyUASubscriberSelector	Describes how to select the EasyUASubscriberCore object.
	IEasyUASubscriberExtension	Contains extension methods to the IEasyUASubscriber interface.
	UADataSetData	Contains data about the received dataset message.
	UADataSetFieldData	Contains data about the received dataset field.
	UADataSetFieldDescriptor	Descriptor for a dataset field (using a dataset field Id, or field name).
	UADataSetHeader	Contains header information of the received dataset message.
	UADataSetSubscriptionDescriptor	Contains information needed to subscribe to a dataset.
	UADataSetWriterDescriptor	Descriptor for a dataset writer (using a physical Id, or logical name).
	UAGuidDataSetFieldDataDictionary	A dictionary of OPC UA dataset field data objects, keyed by the dataset field Id (a GUID).
	UAPublisherId	A unique identifier for a publisher within a message oriented middleware.
	UAPubSubCommunicationParameters	Represents communication parameters for OPC UA publisher or subscriber.
	UAPubSubConnectionDescriptor	Descriptor for a PubSub connection (using physical parameters, or logical name).
	UAPubSubGroupDescriptor	Descriptor for a PubSub group (using physical or logical information).
	UAPubSubHeader	Contains header information of the received PubSub message.
	UAPubSubLocators	Contains PubSub locator information.
	UAPubSubObjectDescriptor	Descriptor for an object in OPC UA PubSub.
	UAPubSubResolverDescriptor	Describes how the PubSub logical information should be resolved to physical.
	UAPubSubUtilities	Contains static members that facilitate work with types related to OPC Unified Architecture.
	UAStringDataSetFieldDataDictionary	A dictionary of OPC UA dataset field data objects, keyed by the field name.
	UASubscribeDataSetFilter	Specifies how the incoming PubSub messages should be filtered before being delivered to the application.
	UASubscriberCommunicationParameters	Represents communication parameters for an OPC UA subscriber.
	UAWriterGroupDescriptor	Descriptor for a writer group (using physical Id, or logical name).

Interfaces

	Interface	Description
	IEasyUASubscriber	Provides easy OPC UA PubSub subscriber functionality.
	IEasyUASubscriberSettings	Provides access to settings for IEasyUASubscriber objects.

Delegates

	Delegate	Description
	EasyUADataSetFieldMessageEventHandler	Represents the method that will handle an event raised for every dataset message field received.
	EasyUADataSetMessageEventHandler	Represents the method that will handle an event raised for every dataset message received.
	EasyUAResolverAccessEventHandler	Represents the method that handles events raised when the OPC UA PubSub resolver accesses its target.
	EasyUASubscriptionResolvedEventHandler	Represents the method that handles events raised when the OPC UA PubSub has resolved the dataset subscription descriptor.

Enumerations

	Enumeration	Description
	UAPublisherIdType	The type of the publisher Id.
	UAPubSubResolverKind	The kinds of OPC UA PubSub resolvers.

Remarks

This chapter gives guidance in implementing common tasks when dealing with data made available over OPC UA PubSub. You achieve these tasks mainly by calling methods on the EasyUASubscriber object. Depending on what you need, see:

Subscribing to Information (OPC UA PubSub)

The features discussed here, or some of them, may not be available in all editions of the product. Check the Product Editions page for differences between the editions. The trial license has all features enabled (and is limited in period for which it provides valid data), but licenses for specific commercial editions may have functionality limitations.

OPC UA PubSub is a large specification, and not all its parts are commonly used and have the same significance. OPC Data Client implements the parts that are relevant for its purpose. Some parts OPC UA PubSub functionality is not available in OPC Data Client. The parts that are not (yet) available include:

Publisher and server functionality.
JSON message mapping.
AMQP transport protocol mapping.
MQTT transport protocol mapping.
Support for message signing and encryption.
Custom data types.
PubSub discovery.
PubSub security key service model.
Write access to PubSub configuration.
Parts of PubSub configuration that relate to subscriber configuration.

Most of the OPC UA PubSub examples work with the OPC UA Demo Publisher that is installed with the product, or can be downloaded separately. It supports Windows, Linux and macOS.

Reference

OpcLabs.EasyOpcUA Assembly