'Declaration
 
<ExtensionAttribute()>
<NotNullAttribute()>
Public Overloads Shared Function ReadItem(Of TValue)( _
   ByVal client As IEasyDAClient, _
   ByVal serverDescriptor As ServerDescriptor, _
   ByVal nodeDescriptor As DANodeDescriptor, _
   ByVal readParameters As DAReadParameters _
) As DAVtq(Of TValue)

'Usage
 
Dim client As IEasyDAClient
Dim serverDescriptor As ServerDescriptor
Dim nodeDescriptor As DANodeDescriptor
Dim readParameters As DAReadParameters
Dim value As DAVtq(Of TValue)
 
value = IEasyDAClientExtension2.ReadItem(Of TValue)(client, serverDescriptor, nodeDescriptor, readParameters)

[Extension()]
[NotNull()]
public static DAVtq<TValue> ReadItem<TValue>( 
   IEasyDAClient client,
   ServerDescriptor serverDescriptor,
   DANodeDescriptor nodeDescriptor,
   DAReadParameters readParameters
)

[Extension()]
[NotNull()]
public:
static DAVtq<TValue^>^ ReadItemgeneric<typename TValue>
( 
   IEasyDAClient^ client,
   ServerDescriptor^ serverDescriptor,
   DANodeDescriptor^ nodeDescriptor,
   DAReadParameters^ readParameters
) 

Parameters

client

The client object that will perform the operation.

serverDescriptor

The OPC server involved in the operation.

nodeDescriptor

The OPC item involved in the operation.

readParameters

Read parameters, such as the data source or value age.

Type Parameters

TValue

The type of item value.

Return Value

The server can be local or can be remotely accessed via DCOM. Optionally, an access path can be specified or a specific data type can be requested.

The ReadItem method only waits for the first update from the server (or until the timeout elapses); it does not wait until the quality becomes "uncertain" or "good".

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