Examples - OPC Data Access - Change update rate of a single subscription

.NET

// This example shows how change the update rate of an existing subscription.

using System;
using System.Threading;
using OpcLabs.EasyOpc.DataAccess;
using OpcLabs.EasyOpc.DataAccess.OperationModel;

namespace DocExamples.DataAccess._EasyDAClient
{
    partial class ChangeItemSubscription
    {
        public static void Main1()
        {
            // Instantiate the client object.
            using (var client = new EasyDAClient())
            {
                client.ItemChanged += client_ItemChanged;

                Console.WriteLine("Subscribing...");
                int handle = client.SubscribeItem("", "OPCLabs.KitServer.2", "Simulation.Random", 1000);

                Console.WriteLine("Waiting for 10 seconds...");
                Thread.Sleep(10 * 1000);

                Console.WriteLine("Changing subscription...");
                client.ChangeItemSubscription(handle, new DAGroupParameters(100));

                Console.WriteLine("Waiting for 10 seconds...");
                Thread.Sleep(10 * 1000);

                Console.WriteLine("Unsubscribing...");
                client.UnsubscribeAllItems();

                Console.WriteLine("Waiting for 10 seconds...");
                Thread.Sleep(10 * 1000);
            }
        }

        // Item changed event handler
        static void client_ItemChanged(object sender, EasyDAItemChangedEventArgs e)
        {
            if (e.Succeeded)
                Console.WriteLine(e.Vtq);
            else
                Console.WriteLine("*** Failure: {0}", e.ErrorMessageBrief);
        }
    }
}

# This example shows how change the update rate of an existing subscription.

# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc
import time

# Import .NET namespaces.
from OpcLabs.EasyOpc.DataAccess import *


# Item changed event handler
def itemChanged(sender, e):
    if e.Succeeded:
        print(e.Vtq)
    else:
        print('*** Failure: ', e.ErrorMessageBrief, sep='')


# Instantiate the client object.
client = EasyDAClient()

client.ItemChanged += itemChanged

print('Subscribing item...')
handle = IEasyDAClientExtension.SubscribeItem(client, '', 'OPCLabs.KitServer.2', 'Simulation.Random', 1000)

print('Processing item change notifications for 10 seconds...')
time.sleep(10)

print('Changing item subscription...')
IEasyDAClientExtension.ChangeItemSubscription(client, handle, DAGroupParameters(100))

print('Processing item change notifications for 10 seconds...')
time.sleep(10)

print('Unsubscribing item...')
IEasyDAClientExtension.UnsubscribeItem(client, handle)

print('Waiting for 10 seconds...')
time.sleep(10)

client.ItemChanged -= itemChanged

print('Finished.')

' This example shows how change the update rate of an existing subscription.

Imports System.Threading
Imports OpcLabs.EasyOpc.DataAccess
Imports OpcLabs.EasyOpc.DataAccess.OperationModel

Namespace DataAccess._EasyDAClient

    Partial Friend Class ChangeItemSubscription
        Public Shared Sub Main1()
            Using client = New EasyDAClient()
                AddHandler client.ItemChanged, AddressOf client_ItemChanged

                Console.WriteLine("Subscribing...")
                Dim handle As Integer = client.SubscribeItem("", "OPCLabs.KitServer.2", "Simulation.Random", 1000)

                Console.WriteLine("Waiting for 10 seconds...")
                Thread.Sleep(10 * 1000)

                Console.WriteLine("Changing subscription...")
                client.ChangeItemSubscription(handle, New DAGroupParameters(100))

                Console.WriteLine("Waiting for 10 seconds...")
                Thread.Sleep(10 * 1000)

                Console.WriteLine("Unsubscribing...")
                client.UnsubscribeAllItems()

                Console.WriteLine("Waiting for 10 seconds...")
                Thread.Sleep(10 * 1000)
            End Using
        End Sub

        ' Item changed event handler
        Private Shared Sub client_ItemChanged(ByVal sender As Object, ByVal e As EasyDAItemChangedEventArgs)
            If e.Succeeded Then
                Console.WriteLine(e.Vtq)
            Else
                Console.WriteLine("*** Failure: {0}", e.ErrorMessageBrief)
            End If
        End Sub
    End Class
End Namespace

COM

VBScript

Rem This example shows how change the update rate of an existing subscription.

Option Explicit

Dim Client: Set Client = CreateObject("OpcLabs.EasyOpc.DataAccess.EasyDAClient")
WScript.ConnectObject Client, "Client_"

WScript.Echo "Subscribing..."
Dim handle: handle = Client.SubscribeItem("", "OPCLabs.KitServer.2", "Simulation.Random", 1000)

WScript.Echo "Waiting for 10 seconds..."
WScript.Sleep 10*1000

WScript.Echo "Changing subscription..."
Client.ChangeItemSubscription handle, 100

WScript.Echo "Waiting for 10 seconds..."
WScript.Sleep 10*1000

WScript.Echo "Unsubscribing..."
Client.UnsubscribeAllItems

WScript.Echo "Waiting for 10 seconds..."
WScript.Sleep 10*1000

WScript.DisconnectObject Client
Set Client = Nothing



Sub Client_ItemChanged(Sender, e)
    If Not (e.Succeeded) Then
        WScript.Echo "*** Failure: " & e.ErrorMessageBrief
        Exit Sub
    End If

    WScript.Echo e.Vtq
End Sub

.NET

COM

Conceptual

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