Examples - OPC Data Access - Change percent deadband of a subscription

// This example shows how change the percent deadband of an existing subscription.

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

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

                Console.WriteLine("Subscribing with 10% deadband...");
                int handle = client.SubscribeItem("", "OPCLabs.KitServer.2", "Simulation.Ramp 0:100 (10 s)",
                    VarTypes.Empty, requestedUpdateRate:100, percentDeadband:10.0f, state:null);

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

                Console.WriteLine("Changing subscription to 0% deadband...");
                client.ChangeItemSubscription(handle, new DAGroupParameters(100, 0.0f));

                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_PercentDeadband(object sender, EasyDAItemChangedEventArgs e)
        {
            if (e.Succeeded)
                Console.WriteLine(e.Vtq);
            else
                Console.WriteLine("*** Failure: {0}", e.ErrorMessageBrief);
        }
    }
}

# This example shows how change the percent deadband 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.BaseLib.ComInterop import *
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 with 10% deadband...')
handle = IEasyDAClientExtension.SubscribeItem(client, '', 'OPCLabs.KitServer.2', 'Simulation.Ramp 0:100 (10 s)',
                                              VarType(VarTypes.Empty), requestedUpdateRate=50, percentDeadband=10.0,
                                              state=None)

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

print('Changing item subscription to 0% deadband...')
IEasyDAClientExtension.ChangeItemSubscription(client, handle, DAGroupParameters(50, 0.0))

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 percent deadband of an existing subscription.

Imports System.Threading
Imports OpcLabs.BaseLib.ComInterop
Imports OpcLabs.EasyOpc.DataAccess

Namespace DataAccess._EasyDAClient

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

                Console.WriteLine("Subscribing with 10% deadband...")
                Dim handle As Integer = client.SubscribeItem("", "OPCLabs.KitServer.2", "Simulation.Ramp 0:100 (10 s)", VarTypes.Empty, 100, 10.0F, Nothing)

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

                Console.WriteLine("Changing subscription to 0% deadband...")
                client.ChangeItemSubscription(handle, New DAGroupParameters(100, 0.0F))

                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_PercentDeadband(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

Conceptual

Changing Existing Subscription (OPC Data)