OPC Studio User's Guide and Reference
TestConnectionAsync(IEasyUASubscriber,UAPubSubConnectionDescriptor,Int32) Method



OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA.PubSub.Extensions Namespace > IEasyUASubscriberExtension2 Class > TestConnectionAsync Method : TestConnectionAsync(IEasyUASubscriber,UAPubSubConnectionDescriptor,Int32) Method
The subscriber object that will perform the operation.
Descriptor for a PubSub connection (using physical parameters, or logical name).
Number of milliseconds to wait before the connection test can pass.
Tests whether an OPC UA PubSub connection can be successfully established. Asynchronous.
Syntax
'Declaration
 
<ExtensionAttribute()>
<AsyncThrowsAttribute(OpcLabs.EasyOpc.UA.OperationModel.UAException)>
<NotNullAttribute()>
Public Overloads Shared Function TestConnectionAsync( _
   ByVal subscriber As IEasyUASubscriber, _
   ByVal pubSubConnectionDescriptor As UAPubSubConnectionDescriptor, _
   ByVal waitMilliseconds As Integer _
) As Task
'Usage
 
Dim subscriber As IEasyUASubscriber
Dim pubSubConnectionDescriptor As UAPubSubConnectionDescriptor
Dim waitMilliseconds As Integer
Dim value As Task
 
value = IEasyUASubscriberExtension2.TestConnectionAsync(subscriber, pubSubConnectionDescriptor, waitMilliseconds)
[Extension()]
[AsyncThrows(OpcLabs.EasyOpc.UA.OperationModel.UAException)]
[NotNull()]
public static Task TestConnectionAsync( 
   IEasyUASubscriber subscriber,
   UAPubSubConnectionDescriptor pubSubConnectionDescriptor,
   int waitMilliseconds
)
[Extension()]
[AsyncThrows(OpcLabs.EasyOpc.UA.OperationModel.UAException)]
[NotNull()]
public:
static Task^ TestConnectionAsync( 
   IEasyUASubscriber^ subscriber,
   UAPubSubConnectionDescriptor^ pubSubConnectionDescriptor,
   int waitMilliseconds
) 

Parameters

subscriber
The subscriber object that will perform the operation.
pubSubConnectionDescriptor
Descriptor for a PubSub connection (using physical parameters, or logical name).
waitMilliseconds
Number of milliseconds to wait before the connection test can pass.

Return Value

The method returns a task that executes normally when the test passes. The task throws a OpcLabs.EasyOpc.UA.OperationModel.UAException when there is an error establishing the connection.
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.

The value of an argument is outside the allowable range of values as defined by the invoked method.

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

Due to asynchronous nature of some communication channels, successful test outcome does not always imply that a connection has been fully established.

The waitMilliseconds parameter is not a timeout in its traditional sense, i.e. a maximum time allowed for the operation. Here, this method actually waits for the time given by waitMilliseconds parameter unless a failure occurs.

This is an asynchronous method. For a synchronous alternative, see TestConnection(IEasyUASubscriber,UAPubSubConnectionDescriptor,Int32).

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