Connectivity Software User's Guide and Reference
SystemConnectionParameters Property (EasySparkplugHostApplication)
Example 



OpcLabs.EasySparkplug Assembly > OpcLabs.EasySparkplug.System Namespace > EasySparkplugHostApplication Class : SystemConnectionParameters Property
The parameters used by the Sparkplug host application to connect to the Sparkplug system.
Syntax
'Declaration
 
Public Property SystemConnectionParameters As SparkplugConnectionParameters
'Usage
 
Dim instance As EasySparkplugHostApplication
Dim value As SparkplugConnectionParameters
 
instance.SystemConnectionParameters = value
 
value = instance.SystemConnectionParameters
public SparkplugConnectionParameters SystemConnectionParameters {get; set;}
public:
property SparkplugConnectionParameters^ SystemConnectionParameters {
   SparkplugConnectionParameters^ get();
   void set (    SparkplugConnectionParameters^ value);
}

Property Value

The value of this property cannot be null (Nothing in Visual Basic).

Exceptions
ExceptionDescription

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

 

Sparkplug is a trademark of Eclipse Foundation, Inc. "MQTT" is a trademark of the OASIS Open standards consortium. Other related terms are trademarks of their respective owners. Any use of these terms on this site is for descriptive purposes only and does not imply any sponsorship, endorsement or affiliation.

Example
// This example shows how to configure connection parameters of the Sparkplug host application.
//
// In order to publish or observe messages for this example, start the SparkplugEdgeNodeConsoleDemo program first.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
// Sparkplug 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.Collections.Generic;
using OpcLabs.EasySparkplug;
using OpcLabs.EasySparkplug.OperationModel;
using OpcLabs.EasySparkplug.System;

namespace SparkplugDocExamples.Consumer._EasySparkplugHostApplication
{
    class SystemConnectionParameters
    {
        public static void Main1()
        {
            // Note that the default port for the "mqtt" scheme is 1883.
            var hostDescriptor = new SparkplugHostDescriptor("mqtt://localhost");

            // Pre-create the host application, so that we can configure it.
            EasySparkplugHostApplication hostApplication = EasySparkplugInfrastructure.Instance.FindOrCreateHostApplication(hostDescriptor);
            
            // Configure various connection parameters of the host application.
            hostApplication.SystemConnectionParameters.MqttKeepAliveInterval = 2 * 1000; // 2 seconds
            hostApplication.SystemConnectionParameters.MqttKeepAliveIntervalDebug = 2 * 1000; // 2 seconds
            hostApplication.SystemConnectionParameters.PublishConnectionTimeout = 10 * 1000;   // 10 seconds
            hostApplication.SystemConnectionParameters.ReconnectInterval = 5 * 1000; // 5 seconds

            // Instantiate the consumer object.
            var consumer = new EasySparkplugConsumer();

            Console.WriteLine("Subscribing...");
            // Thanks to implicit conversion, EasySparkplugHostApplication can be used in place of SparkplugHostDescriptor.
            consumer.SubscribeEdgeNodePayload(hostApplication, "easyGroup", "easySparkplugDemo",
                (sender, eventArgs) =>
                {
                    // Handle different types of notifications.
                    Console.WriteLine();
                    switch (eventArgs.NotificationType)
                    {
                        case SparkplugNotificationType.Connect:
                            Console.WriteLine($"Connected to Sparkplug host, client ID: {eventArgs.ClientId}.");
                            break;
                        case SparkplugNotificationType.Disconnect:
                            Console.WriteLine("Disconnected from Sparkplug host.");
                            break;
                        case SparkplugNotificationType.Data:
                        case SparkplugNotificationType.Birth:
                            Console.WriteLine("Received birth or data message from Sparkplug host.");
                            // Display the metrics name and data for each metric delivered in the payload.
                            foreach (KeyValuePair<string, SparkplugMetricElement> pair in eventArgs.Payload)
                                Console.WriteLine($"{pair.Key}: {pair.Value.MetricData}");
                            break;
                        case SparkplugNotificationType.Death:
                            Console.WriteLine("Received death message from Sparkplug host.");
                            break;
                    }
                    if (!eventArgs.Succeeded)
                        Console.WriteLine($"*** Failure: {eventArgs.ErrorMessageBrief}");
                });

            Console.WriteLine("Processing notifications for 60 seconds...");
            System.Threading.Thread.Sleep(60 * 1000);

            Console.WriteLine("Unsubscribing...");
            consumer.UnsubscribeAllPayloads();

            Console.WriteLine("Waiting for 5 seconds...");
            System.Threading.Thread.Sleep(5 * 1000);

            Console.WriteLine("Finished.");
        }
    }
}
' This example shows how to configure connection parameters of the Sparkplug host application.
'
' In order to publish or observe messages for this example, start the SparkplugEdgeNodeConsoleDemo program first.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
' Sparkplug 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.

Imports OpcLabs.EasySparkplug
Imports OpcLabs.EasySparkplug.OperationModel
Imports OpcLabs.EasySparkplug.System

Namespace Global.SparkplugDocExamples.Consumer._EasySparkplugHostApplication
    Class SystemConnectionParameters
        Public Shared Sub Main1()
            ' Note that the default port for the "mqtt" scheme is 1883.
            Dim hostDescriptor = New SparkplugHostDescriptor("mqtt://localhost")

            ' Pre-create the host application, so that we can control it.
            Dim hostApplication As EasySparkplugHostApplication = EasySparkplugInfrastructure.Instance.FindOrCreateHostApplication(hostDescriptor)

            ' Configure various connection parameters of the host application.
            hostApplication.SystemConnectionParameters.MqttKeepAliveInterval = 2 * 1000 ' 2 seconds
            hostApplication.SystemConnectionParameters.MqttKeepAliveIntervalDebug = 2 * 1000 ' 2 seconds
            hostApplication.SystemConnectionParameters.PublishConnectionTimeout = 10 * 1000 ' 10 seconds
            hostApplication.SystemConnectionParameters.ReconnectInterval = 5 * 1000 ' 5 seconds

            ' Instantiate the consumer object.
            Dim consumer = New EasySparkplugConsumer()

            Console.WriteLine("Subscribing...")
            ' Thanks to implicit conversion, EasySparkplugHostApplication can be used in place of SparkplugHostDescriptor.
            consumer.SubscribeEdgeNodePayload(hostApplication, "easyGroup", "easySparkplugDemo",
                Sub(sender, eventArgs)
                    ' Handle different types of notifications.
                    Console.WriteLine()
                    Select Case eventArgs.NotificationType
                        Case SparkplugNotificationType.Connect
                            Console.WriteLine($"Connected to Sparkplug host, client ID: {eventArgs.ClientId}.")
                        Case SparkplugNotificationType.Disconnect
                            Console.WriteLine("Disconnected from Sparkplug host.")
                        Case SparkplugNotificationType.Data,
                            SparkplugNotificationType.Birth
                            Console.WriteLine("Received birth or data message from Sparkplug host.")
                            ' Display the metrics name and data for each metric delivered in the payload.
                            For Each pair As KeyValuePair(Of String, SparkplugMetricElement) In eventArgs.Payload
                                Console.WriteLine($"{pair.Key}: {pair.Value.MetricData}")
                            Next
                        Case SparkplugNotificationType.Death
                            Console.WriteLine("Received death message from Sparkplug host.")
                    End Select
                    If Not eventArgs.Succeeded Then
                        Console.WriteLine($"*** Failure: {eventArgs.ErrorMessageBrief}")
                    End If
                End Sub)

            Console.WriteLine("Processing notifications for 60 seconds...")
            System.Threading.Thread.Sleep(60 * 1000)

            Console.WriteLine("Unsubscribing...")
            consumer.UnsubscribeAllPayloads()

            Console.WriteLine("Waiting for 5 seconds...")
            Threading.Thread.Sleep(5 * 1000)

            Console.WriteLine("Finished.")
        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