Examples - Server OPC UA - Adjust to sampling interval changes in push model

.NET

// This example shows how to adjust to sampling interval changes in the push data provision model.
// 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-ConnectivityStudio/Latest/examples.html .
// OPC client, server and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-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 System.Threading;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.NodeSpace;
using Timer = System.Timers.Timer;

namespace UAServerDocExamples._UAServerNode
{
    class SamplingIntervalChanged
    {
        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 timer for pushing the data for OPC reads. In a real server the activity may also come from other
            // sources.
            var timer = new Timer { AutoReset = true };

            // Create a read-only data variable.
            var dataVariable = UADataVariable.CreateIn(server.Objects, "SubscribeToThisVariable")
                .ValueType<int>()
                .Writable(false);
            dataVariable.SamplingIntervalChanged += (sender, args) =>
            {
                // Obtain and display the new sampling interval.
                int samplingInterval = dataVariable.SamplingInterval;
                Console.WriteLine($"Sampling interval changed to: {samplingInterval}");

                // Adjust the timer interval accordingly. If the sampling interval is infinite, stop the timer. Otherwise,
                // set the timer interval to half of the sampling interval, but at least 1 millisecond, and start the timer.
                if (samplingInterval == Timeout.Infinite)
                    timer.Enabled = false;
                else
                {
                    timer.Interval = Math.Max(samplingInterval/2, 1);
                    timer.Enabled = true;
                }
                args.Handled = true;
            };
            
            // Set the read attribute data of the data variable to a random value whenever the timer interval elapses.
            var random = new Random();
            timer.Elapsed += (sender, args) => dataVariable.UpdateReadAttributeData(random.Next());

            // 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();

            // Stop the timer.
            timer.Stop();

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

# This example shows how to adjust to sampling interval changes in the push data provision model.
# 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-ConnectivityStudio-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.

#requires -Version 5.1
using namespace System.Threading
using namespace OpcLabs.EasyOpc.UA
using namespace OpcLabs.EasyOpc.UA.NodeSpace

# The path below assumes that the current directory is [ProductDir]/Examples-NET/PowerShell/Windows .
Add-Type -Path "../../../Components/Opclabs.QuickOpc/net472/OpcLabs.ServerOpcUAComponents.dll"

# Instantiate the server object.
# By default, the server will run on endpoint URL "opc.tcp://localhost:48040/".
$server = New-Object EasyUAServer

# Create a timer for pushing the data for OPC reads. In a real server the activity may also come from other
# sources.
$timer = New-Object Timers.Timer -property @{ AutoReset = $true }

# Create a read-only data variable.
$dataVariable = [UADataVariableExtension]::Writable([UADataVariableExtension]::ValueType([UADataVariable]::CreateIn($server.Objects, "SubscribeToThisVariable"), [int]), $false)
Register-ObjectEvent -InputObject $dataVariable -EventName SamplingIntervalChanged -Action {
    param ($sender, $e) 
    # Obtain and display the new sampling interval.
    $samplingInterval = $dataVariable.SamplingInterval
    Write-Host "Sampling interval changed to: $samplingInterval"

    # Adjust the timer interval accordingly. If the sampling interval is infinite, stop the timer. Otherwise,
    # set the timer interval to half of the sampling interval, but at least 1 millisecond, and start the timer.
    if ($samplingInterval -eq [Timeout]::Infinite) {
        $timer.Enabled = $false
    }
    else {
        $timer.Interval = [Math]::Max($samplingInterval/2, 1)
        $timer.Enabled = $true
    }
    $e.Handled = $true
}

# Set the read attribute data of the data variable to a random value whenever the timer interval elapses.
$random = New-Object System.Random
Register-ObjectEvent -InputObject $timer -EventName Elapsed -Action { $dataVariable.UpdateReadAttributeData([int]$random.Next()) }

# Start the server.
Write-Host "The server is starting..."
$server.Start()

Write-Host "The server is started."
Write-Host

# Let the user decide when to stop.
Write-Host "Press Enter to stop the server..."
while(![System.Console]::KeyAvailable) { Start-Sleep -Milliseconds 20 }
[void][System.Console]::ReadKey()

# Stop the server.
Write-Host "The server is stopping..."
$server.Stop()

# Stop the timer.
$timer.Stop()

Write-Host "The server is stopped."

' This example shows how to adjust to sampling interval changes in the push data provision model.
' 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-ConnectivityStudio/Latest/examples.html .
' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-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 System.Threading
Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.NodeSpace
Imports Timer = System.Timers.Timer

Namespace Global.UAServerDocExamples._UAServerNode
    Partial Friend Class SamplingIntervalChanged
        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 timer for pushing the data for OPC reads. In a real server the activity may also come from other
            ' sources.
            Dim timer = New Timer With {.AutoReset = True}

            ' Create a read-only data variable.
            Dim dataVariable = UADataVariable.CreateIn(server.Objects, "SubscribeToThisVariable") _
                .ValueType(Of Integer)() _
                .Writable(False)

            AddHandler dataVariable.SamplingIntervalChanged, Sub(sender, args)
                                                                 ' Obtain and display the new sampling interval.
                                                                 Dim samplingInterval As Integer = dataVariable.SamplingInterval
                                                                 Console.WriteLine($"Sampling interval changed to: {samplingInterval}")

                                                                 ' Adjust the timer interval accordingly. If the sampling interval is infinite, stop the timer. Otherwise,
                                                                 ' set the timer interval to half of the sampling interval, but at least 1 millisecond, and start the timer.
                                                                 If samplingInterval = Timeout.Infinite Then
                                                                     timer.Enabled = False
                                                                 Else
                                                                     timer.Interval = Math.Max(samplingInterval / 2, 1)
                                                                     timer.Enabled = True
                                                                 End If
                                                                 args.Handled = True
                                                             End Sub

            ' Set the read attribute data of the data variable to a random value whenever the timer interval elapses.
            Dim random = New Random()
            AddHandler timer.Elapsed, Sub(sender, args) dataVariable.UpdateReadAttributeData(random.Next())

            ' 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

OPC Wizard

OPC Wizard Custom Data Subscriptions

OPC Wizard Push Data Provision Model