Hello,

I created an OPC class to acess OPC server which is used in another class. I don't use the main function and I would like to use a signal when there is an itemchanged event.

In attachments : OPC_Client.h (header file) and OPC_Client.cpp

Hello,

Thanks you for this example but I need an example in c++ as C# example :

// This example shows how subscribe to changes of multiple items and display the value of the item with each change.
2
3using JetBrains.Annotations;
4using OpcLabs.EasyOpc.DataAccess;
5using System;
6using System.Threading;
7
8namespace DocExamples
9{
10 namespace _EasyDAClient
11 {
12 partial class SubscribeMultipleItems
13 {
14 public static void Main()
15 {
16 using (var easyDAClient = new EasyDAClient())
17 {
18 easyDAClient.ItemChanged += easyDAClient_ItemChanged;
19
20 easyDAClient.SubscribeMultipleItems(
21 new[] {
22 new DAItemGroupArguments("", "OPCLabs.KitServer.2", "Simulation.Random", 1000, null),
23 new DAItemGroupArguments("", "OPCLabs.KitServer.2", "Trends.Ramp (1 min)", 1000, null),
24 new DAItemGroupArguments("", "OPCLabs.KitServer.2", "Trends.Sine (1 min)", 1000, null),
25 new DAItemGroupArguments("", "OPCLabs.KitServer.2", "Simulation.Register_I4", 1000, null)
26 });
27
28 Console.WriteLine("Processing item changed events for 1 minute...");
29 Thread.Sleep(60 * 1000);
30 }
31 }
32
33 // Item changed event handler
34 static void easyDAClient_ItemChanged([NotNull] object sender, [NotNull] EasyDAItemChangedEventArgs e)
35 {
36 Console.WriteLine("{0}: {1}", e.ItemDescriptor.ItemId, e.Vtq);
37 }
38 }
39 }
40}

I created an OPC client class which use subscribe and read item. I would like to read item when it changes. I don't understand your example and how to add it in my class.

Hello,

I need an example of using of itemChanged event for one item in Visual Studio c++ COM project.

Thanks you.

Hello,

I referred to erros generated by IntelliSense. This problem is resolved.
I have a lot of problems to program with QuickOPC-COM. Do you have an example to Instatiate the EasyOPC-DA client object in a file different of the declaration. And examples with ReadItems, subsribeitem using std::string and an example with itemchanged event.

Thanks you.

Hello,

I have used the second possibility with the "COM Visual C++ Example (VS 2008).
I copied these sentences and paste in my header file :

#import "libid:FAB7A1E3-3B79-4292-9C3A-DF39A6F65EC1" version(5.2) exclude("_IEasyDAClientEvents") // EasyOpcDALib
#import "libid:965A3842-AEEA-4DF9-9241-28B963F76E24" version(5.2) // OPCUserObjects

using namespace EasyOpcLib;
using namespace OPCUserObjects;

There are the same error in my project and in your project : "impossible to open the source file".

Are there files to add in my project ?