// This example shows how subscribe to changes of multiple items and display each change, identifying the different // subscriptions by an object. using System; using System.Threading; using OpcLabs.EasyOpc.DataAccess; using OpcLabs.EasyOpc.DataAccess.OperationModel; namespace DocExamples.DataAccess._EasyDAClient { partial class SubscribeMultipleItems { class CustomObject { public CustomObject(string name) { Name = name; } public string Name { get; } } public static void StateAsObject() { // Instantiate the client object. using (var client = new EasyDAClient()) { // Hook events client.ItemChanged += client_StateAsObject_ItemChanged; Console.WriteLine("Subscribing..."); int[] handleArray = client.SubscribeMultipleItems(new[] { new DAItemGroupArguments("", "OPCLabs.KitServer.2", "Simulation.Random", 1000, new CustomObject("First")), // A custom object that corresponds to the subscription new DAItemGroupArguments("", "OPCLabs.KitServer.2", "Trends.Ramp (1 min)", 1000, new CustomObject("Second")), // A custom object that corresponds to the subscription new DAItemGroupArguments("", "OPCLabs.KitServer.2", "Trends.Sine (1 min)", 1000, new CustomObject("Third")), // A custom object that corresponds to the subscription new DAItemGroupArguments("", "OPCLabs.KitServer.2", "Simulation.Register_I4", 1000, new CustomObject("Fourth")) // A custom object that corresponds to the subscription }); for (int i = 0; i < handleArray.Length; i++) Console.WriteLine($"handleArray[{i}]: {handleArray[i]}"); Console.WriteLine("Processing item changed events for 10 seconds..."); Thread.Sleep(10 * 1000); Console.WriteLine("Unsubscribing..."); } Console.WriteLine("Waiting for 5 seconds..."); Thread.Sleep(5 * 1000); Console.WriteLine("Finished."); } // Item changed event handler static void client_StateAsObject_ItemChanged(object sender, EasyDAItemChangedEventArgs eventArgs) { // Obtain the custom object we have passed in. var stateAsObject = (CustomObject)eventArgs.Arguments.State; // Display the data if (eventArgs.Succeeded) Console.WriteLine($"{stateAsObject.Name}: {eventArgs.Vtq}"); else Console.WriteLine($"{stateAsObject.Name} *** Failure: {eventArgs.ErrorMessageBrief}"); } } }
# This example shows how subscribe to changes of multiple items and display each change, identifying the different # subscriptions by an object. # 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 * from OpcLabs.EasyOpc.DataAccess.OperationModel import * class CustomObject(object): def __init__(self, name): self.name = name # Item changed event handler. def itemChanged(sender, eventArgs): # Obtain the custom object we have passed in. stateAsObject = eventArgs.Arguments.State if eventArgs.Succeeded: print(stateAsObject.name, ': ', eventArgs.Vtq, sep='') else: print(stateAsObject.name, ' *** Failure: ', eventArgs.ErrorMessageBrief, sep='') # Instantiate the client object. client = EasyDAClient() # Hook events. client.ItemChanged += itemChanged print('Subscribing item changes...') handleArray = IEasyDAClientExtension.SubscribeMultipleItems(client, [ DAItemGroupArguments('', 'OPCLabs.KitServer.2', 'Simulation.Random', 1000, CustomObject('First')), # a custom object that corresponds to the subscription DAItemGroupArguments('', 'OPCLabs.KitServer.2', 'Trends.Ramp (1 min)', 1000, CustomObject('Second')), # a custom object that corresponds to the subscription DAItemGroupArguments('', 'OPCLabs.KitServer.2', 'Trends.Sine (1 min)', 1000, CustomObject('Third')), # a custom object that corresponds to the subscription DAItemGroupArguments('', 'OPCLabs.KitServer.2', 'Simulation.Register_I4', 1000, CustomObject('Fourth')), # a custom object that corresponds to the subscription ]) for i in range(len(handleArray)): print('handleArray[', i, ']: ', handleArray[i], sep='') print('Processing item change notifications for 1 minute...') time.sleep(60) print('Unsubscribing all items...') client.UnsubscribeAllItems() client.ItemChanged -= itemChanged print('Finished.')
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