OpcEventNode Members

Initializes a new instance of the OpcEventNode class accessible by the name specified as a child node of the parent node given.

C#

public OpcEventNode(IOpcNode parent, OpcName name)

Parameters

parent IOpcNode

The IOpcNode used as the parent node or a null reference (Nothing in Visual Basic) in the case there is no parent node available.

name OpcName

The OpcName through that the new event node can be accessed.

Initializes a new instance of the OpcEventNode class accessible by the name and id specified as a child node of the parent node given.

C#

public OpcEventNode(IOpcNode parent, OpcName name, OpcNodeId id)

Parameters

parent IOpcNode

The IOpcNode used as the parent node or a null reference (Nothing in Visual Basic) in the case there is no parent node available.

name OpcName

The OpcName through that the new event node can be accessed.

id OpcNodeId

The OpcNodeId through that the new event node can be identified and accessed.

Initializes a new instance of the OpcEventNode class accessible by the name specified.

C#

public OpcEventNode(OpcName name)

Parameters

name OpcName

The OpcName through that the new event node can be accessed.

Initializes a new instance of the OpcEventNode class accessible by the name and id specified.

C#

public OpcEventNode(OpcName name, OpcNodeId id)

Parameters

name OpcName

The OpcName through that the new event node can be accessed.

id OpcNodeId

The OpcNodeId through that the new event node can be identified and accessed.

Gets the default identifier which identifies the node that defines the underlying node type from that this OpcInstanceNode has been created.

C#

protected override OpcNodeId DefaultTypeDefinitionId { get; }

Property Value

OpcNodeId

The OpcNodeId of the type node from that this OpcInstanceNode has been created from. These type node defines the typical structure of an instance node of its type definition. If there exists no specific type definition node a null reference (Nothing in Visual Basic).

Gets or sets a value generated by the server to uniquely identify a particular event notification.

C#

public byte[] EventId { get; set; }

Property Value

Byte[]

The server is responsible to ensure that each event has its unique event identifier. It may do this, for example, by putting GUIDs into the ByteString. Clients can use the event identifier to assist in minimizing or eliminating gaps and overlaps that may occur during a redundancy failover. The event identifier shall always be returned as value and the server is not allowed to return a status code for the event identifier indicating an error.

Gets the OpcPropertyNode´1 of the EventId property.

C#

public OpcPropertyNode<byte[]> EventIdNode { get; }

Property Value

OpcPropertyNode<Byte>

An instance of the OpcPropertyNode´1 class.

Gets or sets the node identifier which describes the specific type of event.

C#

public OpcNodeId EventTypeId { get; set; }

Property Value

OpcNodeId

The event type shall always be returned as value and the server is not allowed to return a status code for the event type indicating an error.

Gets the OpcNodeIdPropertyNode of the EventTypeId property.

C#

public OpcNodeIdPropertyNode EventTypeIdNode { get; }

Property Value

OpcNodeIdPropertyNode

An instance of the OpcNodeIdPropertyNode class.

Gets or sets a value which defines a human-readable and localizable text description of the event.

C#

public OpcText Message { get; set; }

Property Value

OpcText

The server may return any appropriate text to describe the event. A null reference (Nothing in Visual Basic) if it is not a valid value; if the server does not have a description, it shall return the string part of the Name of the node associated with the event.

Gets the OpcTextPropertyNode of the Message property.

C#

public OpcTextPropertyNode MessageNode { get; }

Property Value

OpcTextPropertyNode

An instance of the OpcTextPropertyNode class.

Gets or sets the time the OPC UA server received the event from the underlying device of another server.

C#

public DateTime ReceiveTime { get; set; }

Property Value

DateTime

The ReceiveTime is analogous to the ServerTimestamp, i.e. in the case where the OPC UA server gets an event from another OPC UA server, each server applies its own ReceiveTime. That implies that a client may get the same event, having the same EventId, from different servers having different values of the ReceiveTime. The ReceiveTime shall always be returned as value and the server is not allowed to return a status code for the ReceiveTime indicating an error.

Gets the OpcPropertyNode´1 of the ReceiveTime property.

C#

public OpcPropertyNode<DateTime> ReceiveTimeNode { get; }

Property Value

OpcPropertyNode<DateTime>

An instance of the OpcPropertyNode´1 class.

Gets or sets an indication of the urgency of the event.

C#

public OpcEventSeverity Severity { get; set; }

Property Value

OpcEventSeverity

This value is commonly called “priority”. Values will range from 1 to 1 000, with 1 being the lowest severity and 1 000 being the highest. Typically, a severity of 1 would indicate an event which is informational in nature, while a value of 1 000 would indicate an event of catastrophic nature, which could potentially result in severe financial loss or loss of life.

Remarks

It is expected that very few server implementations will support 1 000 distinct severity levels. Therefore, server developers are responsible for distributing their severity levels across the 1 to 1 000 range in such a manner that clients can assume a linear distribution.

In many cases a strict linear mapping of underlying source severities to the OPC severity range is not appropriate. The server developer will instead intelligently map the underlying source severities to the 1 to 1 000 OPC severity range in some other fashion. In particular, it is recommended that server developers map events of high urgency into the OPC severity range of 667 to 1 000, events of medium urgency into the OPC severity range of 334 to 666 and events of low urgency into OPC severities of 1 to 333.

Some servers might not support any events which are catastrophic in nature, so they may choose to map all of their severities into a subset of the 1 to 1 000 range (for example, 1 to 666). Other servers might not support any events which are merely informational, so they may choose to map all of their severities into a different subset of the 1 to 1 000 range (for example, 334 to 1 000).

The purpose of this approach is to allow clients to use severity values from multiple servers from different vendors in a consistent manner.

Gets the OpcPropertyNode´1 of the Severity property.

C#

[CLSCompliant(false)]
public OpcPropertyNode<ushort> SeverityNode { get; }

Property Value

OpcPropertyNode<UInt16>

An instance of the OpcPropertyNode´1 class.

Gets or sets a description of the source of the event.

C#

public string SourceName { get; set; }

Property Value

String

A value which can be a string-part of the DisplayName of the event source using the default locale of the server, if the event is specific to a node, or some server-specific notation.

Gets the OpcPropertyNode´1 of the SourceName property.

C#

public OpcPropertyNode<string> SourceNameNode { get; }

Property Value

OpcPropertyNode<String>

An instance of the OpcPropertyNode´1 class.

Gets or sets the node identifier which identifies the node that the event originated from.

C#

public OpcNodeId SourceNodeId { get; set; }

Property Value

OpcNodeId

If the event is not specific to a node the value is a null reference (Nothing in Visual Basic); otherwise the OpcNodeId of the node that the event originated from. Some subtypes of this OpcEventNode may define additional rules for the SourceNodeId.

Gets the OpcNodeIdPropertyNode of the SourceNodeId property.

C#

public OpcNodeIdPropertyNode SourceNodeIdNode { get; }

Property Value

OpcNodeIdPropertyNode

An instance of the OpcNodeIdPropertyNode class.

Gets or sets the time the event occurred.

C#

public DateTime Time { get; set; }

Property Value

DateTime

This value is set as close to the event generator as possible. It often comes from the underlying system or device. Once set, intermediate OPC UA servers shall not alter the value.

Gets the OpcPropertyNode´1 of the Time property.

C#

public OpcPropertyNode<DateTime> TimeNode { get; }

Property Value

OpcPropertyNode<DateTime>

An instance of the OpcPropertyNode´1 class.

Creates a new instance of the OpcEvent class which represents a snapshot of this OpcEventNode.

C#

public OpcEvent CreateEvent(OpcContext context)

Parameters

context OpcContext

The OpcContext to use.

Returns

OpcEvent

A new immutable instance of the OpcEvent class representing a snapshot of the event node data at the time this method has been called.

Creates a new instance of the OpcEvent class representing the specified snapshot of this OpcEventNode.

C#

protected virtual OpcEvent CreateEventCore(OpcContext context, OpcEventNodeSnapshot snapshot)

Parameters

context OpcContext

The OpcContext used to create the snapshot.

snapshot OpcEventNodeSnapshot

The OpcEventNodeSnapshot taken from the current state of this OpcEventNode from that the new OpcEvent is to be created.

Returns

OpcEvent

A new instance of the OpcEvent representing an immutable snapshot of this OpcEventNode.

Remarks

In case there this method is not overridden the method will determine the type of OpcEvent to use using the OpcEventTypeAttribute of the OpcEventNode and will use this one to create a new OpcEvent using the snapshot specified.

Initializes the default values used by the OpcEventNode.

C#

protected override void InitializeDefaults()

Remarks

This method is used to ensure the availability of appropriate node specific default values. For more information like when this method is to be overwritten see InitializeDefaults.

Produces an event using the data represented by this OpcEventNode.

C#

public void ReportEvent(OpcContext context)

Parameters

context OpcContext

The OpcContext to use.

Exceptions

ArgumentNullException

The context is a null reference (Nothing in Visual Basic).

Produces an event using the data represented by this OpcEventNode using the source as initiator of the event reported.

C#

public void ReportEventFrom(OpcContext context, IOpcNode source)

Parameters

context OpcContext

The OpcContext to use.

source IOpcNode

The IOpcNode instance its Id is used for the SourceNodeId property and its SymbolicName is used for the SourceName property to define the origin of the event produced.

Exceptions

ArgumentNullException

The context or source is a null reference (Nothing in Visual Basic).