Connectivity Software User's Guide and Reference
Examples - Server OPC UA - React to server starting and stopping in push model

.NET

// This example shows how to react to events in order to initiate and finalize data collection 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 OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.NodeSpace;
using Timer = System.Timers.Timer;

namespace UAServerDocExamples._UAServerNode
{
    class Starting_Stopped
    {
        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 read-only data variable.
            var dataVariable = UADataVariable.CreateIn(server.Objects, "ReadThisVariable")
                .ValueType<int>()
                .Writable(false);

            dataVariable.Starting += (sender, args) =>
            {
                // Create a timer for pushing the data for OPC reads.
                var timer = new Timer
                {
                    Interval = 1000,
                    AutoReset = true,
                };

                // Set the read attribute data of the data variable to a random value whenever the timer interval elapses.
                // Note that this example shows the basic concept, however there is also an UpdateReadAttributeData method that
                // can be used in most cases to achieve slightly more concise code.
                var random = new Random();
                timer.Elapsed += (s, a) =>
                    dataVariable.ReadAttributeData = new UAAttributeData(random.Next(), DateTime.UtcNow);

                // Associate the timer with the data variable.
                dataVariable.State = timer;
                
                timer.Start();
            };
            dataVariable.Stopped += (sender, args) =>
            {
                // Obtain the timer associated with the data variable.
                var timer = (Timer)((UADataVariable)sender).State;

                // Stop the timer.
                timer.Stop();
            };
            
            // 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 react to events in order to initiate and finalize data collection 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 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 read-only data variable.
$dataVariable = [UADataVariableExtension]::Writable([UADataVariableExtension]::ValueType([UADataVariable]::CreateIn($server.Objects, "ReadThisVariable"), [int]), $false)

$random = New-Object System.Random

Register-ObjectEvent -InputObject $dataVariable -EventName Starting -Action {
    param ($sender, $e) 
    # Create a timer for pushing the data for OPC reads.
    $timer = New-Object Timers.Timer -property @{
        Interval = 1000
        AutoReset = $true
    }

    # Set the read attribute data of the data variable to a random value whenever the timer interval elapses.
    # Note that this example shows the basic concept, however there is also an UpdateReadAttributeData method that
    # can be used in most cases to achieve slightly more concise code.
    Register-ObjectEvent -InputObject $timer -EventName Elapsed -Action { 
        param ($sender, $e)
        $dataVariable.ReadAttributeData = New-Object UAAttributeData($random.Next(), [DateTime]::UtcNow) 
    }

    # Associate the timer with the data variable.
    $dataVariable.State = $timer

    $timer.Start()
}

Register-ObjectEvent -InputObject $dataVariable -EventName Stopped -Action { 
    param ($sender, $e) 
    # Obtain the timer associated with the data variable.
    $timer = [Timers.Timer](([UADataVariable]$sender).State)

    # Stop the timer.
    $timer.Stop()
}

# 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()

Write-Host "The server is stopped."
' This example shows how to react to events in order to initiate and finalize data collection 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 OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.NodeSpace
Imports Timer = System.Timers.Timer

Namespace Global.UAServerDocExamples._UAServerNode
    Partial Friend Class Starting_Stopped
        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 read-only data variable.
            Dim dataVariable = UADataVariable.CreateIn(server.Objects, "ReadThisVariable") _
                .ValueType(Of Integer)() _
                .Writable(False)

            AddHandler dataVariable.Starting, Sub(sender, args)
                                                  ' Create a timer for pushing the data for OPC reads.
                                                  Dim timer = New Timer With
                                                  {
                                                    .Interval = 1000,
                                                    .AutoReset = True
                                                  }

                                                  ' Set the read attribute data of the data variable to a random value whenever the timer interval elapses.
                                                  ' Note that this example shows the basic concept, however there is also an UpdateReadAttributeData method that
                                                  ' can be used in most cases to achieve slightly more concise code.
                                                  Dim random = New Random()
                                                  AddHandler timer.Elapsed, Sub(s, a)
                                                                                dataVariable.ReadAttributeData = New UAAttributeData(random.Next(), DateTime.UtcNow)
                                                                            End Sub

                                                  ' Associate the timer with the data variable.
                                                  dataVariable.State = timer

                                                  timer.Start()
                                              End Sub

            AddHandler dataVariable.Stopped, Sub(sender, args)
                                                 ' Obtain the timer associated with the data variable.
                                                 Dim timer = CType(CType(sender, UADataVariable).State, Timer)

                                                 ' Stop the timer.
                                                 timer.Stop()
                                             End Sub

            ' 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
See Also

OPC Wizard