OPC Studio User's Guide and Reference
Start Method (EasyUAServerCore)
Example 



OpcLabs.ServerOpcUA Assembly > OpcLabs.EasyOpc.UA Namespace > EasyUAServerCore Class : Start Method
Starts the OPC UA server.
Syntax
'Declaration
 
Public Sub Start() 
'Usage
 
Dim instance As EasyUAServerCore
 
instance.Start()
public void Start()
public:
void Start(); 
Exceptions
ExceptionDescription

A method call was invalid for the object's current state.

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

Starts the OPC UA server, indicating an intent to make it available to accept connections from clients.

This method initializes the server operations, sets up its address space, and initiates listening on the configured endpoints for client connections. It is essential to call this method to make the server operational after it has been configured.

The server may not yet be ready to accept client connections on all its endpoints when this method completes. The IEasyUAServerEndpointMonitoring interface can be used to monitor the status of the endpoints.

If the server is already started, calling this method results in an System.InvalidOperationException.

Example
// This example shows how to create an OPC UA server with a single data variable, start and stop it.
// 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._EasyUAServer
{
    class Start_Stop
    {
        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();

            // Define a data variable providing random integers.
            var random = new Random();
            server.Add(new UADataVariable("MyDataVariable").ReadValueFunction(() => 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.");
        }
    }
}
' This example shows how to create an OPC UA server with a single data variable, start and stop it.
' 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 _EasyUAServer
    Partial Friend Class Start_Stop
        Shared Sub Main1()
            ' Instantiate the server object.
            ' By default, the server will run on endpoint URL "opc.tcp://localhost:48040/".
            Dim server = New EasyUAServer()

            ' Define a data variable providing random integers.
            Dim random = New Random()
            server.Add(New UADataVariable("MyDataVariable").ReadValueFunction(Function() 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
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