QuickOPC User's Guide and Reference
EasyUAMonitoredItemArguments Constructor(EasyUADataChangeNotificationEventHandler,Object,UAEndpointDescriptor,UANodeDescriptor,UAMonitoringParameters,UASubscriptionParameters,Boolean)



OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA.OperationModel Namespace > EasyUAMonitoredItemArguments Class > EasyUAMonitoredItemArguments Constructor : EasyUAMonitoredItemArguments Constructor(EasyUADataChangeNotificationEventHandler,Object,UAEndpointDescriptor,UANodeDescriptor,UAMonitoringParameters,UASubscriptionParameters,Boolean)
A callback method to be invoked for each significant monitored item change.
User-defined state object.
Endpoint descriptor. Identifies the OPC-UA server.
Node descriptor. Identifies the node in OPC server's address space.
Contains monitoring parameters (such as the sampling interval, and optional data change filter).
Contains subscription parameters (such as the publishing interval).
When set, a ConditionRefresh will be automatically performed when needed to keep the condition information up-to-date.
Initializes a new instance of the class.
Syntax
'Usage
 
Dim dataChangeCallback As EasyUADataChangeNotificationEventHandler
Dim state As Object
Dim endpointDescriptor As UAEndpointDescriptor
Dim nodeDescriptor As UANodeDescriptor
Dim monitoringParameters As UAMonitoringParameters
Dim subscriptionParameters As UASubscriptionParameters
Dim autoConditionRefresh As Boolean
 
Dim instance As New EasyUAMonitoredItemArguments(dataChangeCallback, state, endpointDescriptor, nodeDescriptor, monitoringParameters, subscriptionParameters, autoConditionRefresh)

Parameters

dataChangeCallback
A callback method to be invoked for each significant monitored item change.
state
User-defined state object.
endpointDescriptor
Endpoint descriptor. Identifies the OPC-UA server.
nodeDescriptor
Node descriptor. Identifies the node in OPC server's address space.
monitoringParameters
Contains monitoring parameters (such as the sampling interval, and optional data change filter).
subscriptionParameters
Contains subscription parameters (such as the publishing interval).
autoConditionRefresh
When set, a ConditionRefresh will be automatically performed when needed to keep the condition information up-to-date.
Exceptions
ExceptionDescription

A null reference (Nothing in Visual Basic) is passed to a method that does not accept it as a valid argument.

This is a usage error, i.e. it will never occur (the exception will not be thrown) in a correctly written program. Your code should not catch this exception.

Remarks

If dataChangeCallback is a null reference, only the OpcLabs.EasyOpc.UA.EasyUAClientCore.DataChangeNotification event is generated, and no callback method is invoked.

You can obtain nodeDescriptor e.g. by calling one of the browsing methods on OpcLabs.EasyOpc.UA.EasyUAClientCore object.

Requirements

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2016, Windows Server 2022; .NET: Linux, macOS, Microsoft Windows

See Also