SetMinimumSamplingInterval Method

Sets the minimum sampling interval of this data variable.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<ExtensionAttribute()>
<NotNullAttribute()>
Public Shared Function SetMinimumSamplingInterval( _
   ByVal dataVariable As UADataVariable, _
   ByVal minimumSamplingInterval As Integer _
) As UADataVariable

'Usage
 
Dim dataVariable As UADataVariable
Dim minimumSamplingInterval As Integer
Dim value As UADataVariable
 
value = UADataVariableExtension.SetMinimumSamplingInterval(dataVariable, minimumSamplingInterval)

[Extension()]
[NotNull()]
public static UADataVariable SetMinimumSamplingInterval( 
   UADataVariable dataVariable,
   int minimumSamplingInterval
)

[Extension()]
[NotNull()]
public:
static UADataVariable^ SetMinimumSamplingInterval( 
   UADataVariable^ dataVariable,
   int minimumSamplingInterval
)

Parameters

dataVariable: The data variable that will be modified and returned.
The value of this parameter cannot be null (Nothing in Visual Basic).
minimumSamplingInterval: The minimum sampling interval that can be provided for this data variable. In milliseconds.

Return Value

Returns the , internally modified as defined by the method.

This method never returns null (Nothing in Visual Basic).

Exceptions

Exception Description

Exception	Description
System.ArgumentNullException	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.

System.ArgumentNullException

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

Setting the minimum sampling interval to System.Threading.Timeout.Infinite effectively disables the sampling.

This is an extension method (info: C#, VB.NET). In languages that have support for extensions methods (such as C# and VB.NET), you can use the extension method as if it were a regular method on the object that is its first parameter. In other languages (such as with Python.NET), you will call the extension as a static method, and pass it the object on which it acts as its first parameter.

Example

CSharp
VB.NET

// This example shows how to create a data variable and set its minimum sampling interval.
// You can use any OPC UA client, including our Connectivity Explorer and OpcCmd utility, to connect to the server. 
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client, server and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-OPCStudio-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

using System;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.NodeSpace;

namespace UAServerDocExamples._UADataVariable
{
    partial class SetMinimumSamplingInterval
    {
        public static void Main1()
        {
            // Instantiate the server object.
            // By default, the server will run on endpoint URL "opc.tcp://localhost:48040/".
            var server = new EasyUAServer();

            // Create a data variable, and specify custom minimum sampling interval.
            // The type of the data variable (Int32, in this case) is inferred from the type returned by the function.
            var random = new Random();
            server.Add(new UADataVariable("ReadThisVariable")
                .ReadValueFunction(() => random.Next())
                .SetMinimumSamplingInterval(5 * 1000));

            // Start the server.
            Console.WriteLine("The server is starting...");
            server.Start();

            Console.WriteLine("The server is started.");
            Console.WriteLine();

            // Let the user decide when to stop.
            Console.WriteLine("Press Enter to stop the server...");
            Console.ReadLine();

            // Stop the server.
            Console.WriteLine("The server is stopping...");
            server.Stop();

            Console.WriteLine("The server is stopped.");
        }
    }
}

' This example shows how to create a data variable and set its minimum sampling interval.
' You can use any OPC UA client, including our Connectivity Explorer and OpcCmd utility, to connect to the server. 
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-VBNET .
' Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
' a commercial license in order to use Online Forums, and we reply to every post.

Imports System
Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.NodeSpace

Namespace _UADataVariable
    Partial Friend Class SetMinimumSamplingInterval
        Shared Sub Main1()
            ' Instantiate the server object.
            ' By default, the server will run on endpoint URL "opc.tcp://localhost:48040/".
            Dim server = New EasyUAServer()

            ' Create a data variable, and specify custom minimum sampling interval.
            ' The type of the data variable (Int32, in this case) is inferred from the type returned by the function.
            Dim random = New Random()
            server.Add(New UADataVariable("ReadThisVariable").ReadValueFunction(Function() random.Next()).SetMinimumSamplingInterval(5 * 1000))

            ' Start the server.
            Console.WriteLine("The server is starting...")
            server.Start()

            Console.WriteLine("The server is started.")
            Console.WriteLine()

            ' Let the user decide when to stop.
            Console.WriteLine("Press Enter to stop the server...")
            Console.ReadLine()

            ' Stop the server.
            Console.WriteLine("The server is stopping...")
            server.Stop()

            Console.WriteLine("The server is stopped.")
        End Sub
    End Class
End Namespace

CSharp
VB.NET

//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client, server and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-OPCStudio-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

using OpcLabs.EasyOpc.UA.NodeSpace;
using System;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.Generic;

namespace UAServerDemoLibrary
{
    static public class DemoNodes
    {
        /// <summary>
        /// Adds nodes that demonstrate various features of the OPC Wizard.
        /// </summary>
        /// <param name="parentFolder">The folder to which to add the nodes.</param>
        static public void AddToParent(UAFolder parentFolder)
        {
            // Demonstrate that in the simplest case, the data variable can be added directly to the Objects folder.
            parentFolder.Add(new UADataVariable("Simple").ReadWriteValue(0));

            // Demonstrate the fact that nodes can be organized in folders, and that data variables can be nested.
            UAFolder demoFolder = UAFolder.CreateIn(parentFolder, "Demo");

            // Create an empty data variable.
            demoFolder.Add(new UADataVariable("Empty"));

            // Demonstrate that the data variables can be nested.
            demoFolder.Add(
                new UADataVariable("Random")
                {
                    new UADataVariable("Nested").ReadValueFunction(() => Random.NextDouble())
                }.ReadValueFunction(() => Random.NextDouble()));

            // Demonstrate that the data values returned can also contain status codes that are not fully "Good".
            demoFolder.Add(new UADataVariable("GoodLocalOverride").ReadWrite(new UAAttributeData<int>(
                value: 0,
                UACodeBits.GoodLocalOverride,
                DateTime.UtcNow)));
            demoFolder.Add(new UADataVariable("BadNoCommunication").ReadWrite(new UAAttributeData<int>(
                value: 0,
                UACodeBits.BadNoCommunication,
                DateTime.UtcNow)));
            demoFolder.Add(new UADataVariable("Unreliable").ReadFunction(() => new UAAttributeData<int>(
                value: 42,
                (Random.Next(2) != 0) ? UACodeBits.Good : UACodeBits.BadNoCommunication,
                DateTime.UtcNow)));

            // Demonstrate that the data variable may decide to fail the write operation.
            demoFolder.Add(new UADataVariable("WriteFailure").WriteFunction<int>(_ =>
                UACodeBits.BadNoCommunication));

            // Depending on the needs, you can specify custom minimum sampling interval for the data variable.
            demoFolder.Add(new UADataVariable("SlowSampling")
                .ReadValueFunction(() => Random.Next())
                .SetMinimumSamplingInterval(5 * 1000));

            // Create a 3-dimensional array data variable.
            demoFolder.Add(new UADataVariable("Array3D").ReadWriteValue(new int[2, 4, 3]));

            // A data variable of data type BaseDataType that, in fact, only accepts float values to be written into it.
            // This is a demonstration of what how the data variable should *not* behave, because the client has no way of
            // determining the data type that the server expects.
            var variantRestrictedDataVariable = new UADataVariable("VariantRestricted");
            demoFolder.Add(variantRestrictedDataVariable
                
                .WriteValueFunction<object>(value =>
                {
                    if (value is float)
                    {
                        variantRestrictedDataVariable.UpdateWriteAttributeData(value);
                        return null;
                    }
                    return UACodeBits.BadTypeMismatch;
                })
                .ReadWriteValue((object)0.0f));
        }


        static private readonly Random Random = new Random();
    }
}

'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-VBNET .
' Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
' a commercial license in order to use Online Forums, and we reply to every post.

Imports System
Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.Generic
Imports OpcLabs.EasyOpc.UA.NodeSpace

'Namespace UAServerDemoLibrary
Public Module DemoNodes
        ''' <summary>
        ''' Adds nodes that demonstrate various features of the OPC Wizard.
        ''' </summary>
        ''' <param name="parentFolder">The folder to which to add the nodes.</param>
        Sub AddToParent(parentFolder As UAFolder)
            ' Demonstrate that in the simplest case, the data variable can be added directly to the Objects folder.
            parentFolder.Add(New UADataVariable("Simple").ReadWriteValue(0))

            ' Demonstrate the fact that nodes can be organized in folders, and that data variables can be nested.
            Dim demoFolder As UAFolder = UAFolder.CreateIn(parentFolder, "Demo")

            ' Demonstrate that the data variables can be nested.
            demoFolder.Add(
                New UADataVariable("Random") From
                {
                    New UADataVariable("Nested").ReadValueFunction(Function() Random.NextDouble())
                }.ReadValueFunction(Function() Random.NextDouble()))

            ' Demonstrate that the data values returned can also contain status codes that are not fully "Good".
            demoFolder.Add(New UADataVariable("GoodLocalOverride").ReadWrite(New UAAttributeData(Of Integer)(
                value:=0,
                UACodeBits.GoodLocalOverride,
                DateTime.UtcNow)))
            demoFolder.Add(New UADataVariable("BadNoCommunication").ReadWrite(New UAAttributeData(Of Integer)(
                value:=0,
                UACodeBits.BadNoCommunication,
                DateTime.UtcNow)))
            demoFolder.Add(New UADataVariable("Unreliable").ReadFunction(Function() New UAAttributeData(Of Integer)(
                value:=42,
                If(Random.Next(2) <> 0, UACodeBits.Good, UACodeBits.BadNoCommunication),
                DateTime.UtcNow)))

            ' Demonstrate that the data variable may decide to fail the write operation.
            demoFolder.Add(New UADataVariable("WriteFailure").WriteFunction(Of Integer)(Function() UACodeBits.BadNoCommunication))

            ' Depending on the needs, you can specify custom minimum sampling interval for the data variable.
            demoFolder.Add(New UADataVariable("SlowSampling") _
                .ReadValueFunction(Function() Random.Next()) _
            .SetMinimumSamplingInterval(5 * 1000))

            ' Create a 3-dimensional array data variable.
            demoFolder.Add(New UADataVariable("Array3D").ReadWriteValue(New Integer(1, 3, 2) {}))


            ' A data variable of data type BaseDataType that, in fact, only accepts float values to be written into it.
            ' This is a demonstration of what how the data variable should *not* behave, because the client has no way of
            ' determining the data type that the server expects.
            Dim variantRestrictedDataVariable = New UADataVariable("VariantRestricted")
            demoFolder.Add(variantRestrictedDataVariable _
                .WriteValueFunction(Of Object)(Function(value As Object) As UAStatusCode
                                                   If (TypeOf value Is Single) Then
                                                       variantRestrictedDataVariable.UpdateWriteAttributeData(value)
                                                       Return Nothing
                                                   End If
                                                   Return UACodeBits.BadTypeMismatch
                                               End Function
                ) _
                .ReadWriteValue(CType(0.0F, Object)))
        End Sub

        Private ReadOnly Random As Random = New Random()
    End Module
'End Namespace

Requirements

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

Reference

UADataVariableExtension Class
UADataVariableExtension Members

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