// This example shows how data from parent node can be used in the read event handler.
// You can use any OPC UA client, including our Connectivity Explorer and OpcCmd utility, to connect to the server.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client, server and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-OPCStudio-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 OpcLabs.BaseLib.NodeSpace;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.NodeSpace;
using OpcLabs.EasyOpc.UA.OperationModel;
namespace UAServerDocExamples._UAServerNode
{
class ParentNode
{
public static void Main1()
{
// Instantiate the server object.
// By default, the server will run on endpoint URL "opc.tcp://localhost:48040/".
var server = new EasyUAServer();
// Create multiple folder nodes, each with a data variable in it. Distinguish the folders by their state, however
// the data variables are constructed the same, and use the same read event handler.
UAFolder myFolder1 = UAFolder.CreateIn(server.Objects, "MyFolder1").SetState(1);
UADataVariable.CreateIn(myFolder1, "MyDataVariable").Read += MyDataVariableOnRead;
UAFolder myFolder2 = UAFolder.CreateIn(server.Objects, "MyFolder2").SetState(2);
UADataVariable.CreateIn(myFolder2, "MyDataVariable").Read += MyDataVariableOnRead;
UAFolder myFolder3 = UAFolder.CreateIn(server.Objects, "MyFolder3").SetState(3);
UADataVariable.CreateIn(myFolder3, "MyDataVariable").Read += MyDataVariableOnRead;
UAFolder myFolder4 = UAFolder.CreateIn(server.Objects, "MyFolder4").SetState(4);
UADataVariable.CreateIn(myFolder4, "MyDataVariable").Read += MyDataVariableOnRead;
UAFolder myFolder5 = UAFolder.CreateIn(server.Objects, "MyFolder5").SetState(5);
UADataVariable.CreateIn(myFolder5, "MyDataVariable").Read += MyDataVariableOnRead;
// Start the server.
Console.WriteLine("The server is starting...");
server.Start();
Console.WriteLine("The server is started.");
Console.WriteLine();
// Let the user decide when to stop.
Console.WriteLine("Press Enter to stop the server...");
Console.ReadLine();
// Stop the server.
Console.WriteLine("The server is stopping...");
server.Stop();
Console.WriteLine("The server is stopped.");
}
/// <summary>
/// Event handler for the read event on the data variable.
/// </summary>
/// <param name="sender">The data variable object that sends the event.</param>
/// <param name="e">Data for the variable read event.</param>
static private void MyDataVariableOnRead(object sender, UADataVariableReadEventArgs e)
{
// Obtain the parent folder of the data variable that is being read.
UAServerNode parentNode = e.DataVariable.ParentNode;
// Obtain the state associated with the folder, where the data variable is located.
// Use it as the offset for the random value, so that each data variable generates values in a unique range.
int offset = (int)parentNode.State*100;
// Generate a random value, indicate that the read has been handled, and return the generated value.
e.HandleAndReturn(Random.Next(offset, offset + 100));
}
static private readonly Random Random = new Random();
}
}
' This example shows how data from parent node can be used in the read event handler.
' You can use any OPC UA client, including our Connectivity Explorer and OpcCmd utility, to connect to the server.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-VBNET .
' 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 System
Imports OpcLabs.BaseLib.NodeSpace
Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.NodeSpace
Imports OpcLabs.EasyOpc.UA.OperationModel
Namespace _UAServerNode
Partial Friend Class ParentNode
Shared Sub Main1()
' Instantiate the server object.
' By default, the server will run on endpoint URL "opc.tcp://localhost:48040/".
Dim server = New EasyUAServer()
' Create multiple folder nodes, each with a data variable in it. Distinguish the folders by their state, however
' the data variables are constructed the same, and use the same read event handler.
Dim myFolder1 As UAFolder = UAFolder.CreateIn(server.Objects, "MyFolder1").SetState(1)
AddHandler UADataVariable.CreateIn(myFolder1, "MyDataVariable").Read, AddressOf MyDataVariableOnRead
Dim myFolder2 As UAFolder = UAFolder.CreateIn(server.Objects, "MyFolder2").SetState(2)
AddHandler UADataVariable.CreateIn(myFolder2, "MyDataVariable").Read, AddressOf MyDataVariableOnRead
Dim myFolder3 As UAFolder = UAFolder.CreateIn(server.Objects, "MyFolder3").SetState(3)
AddHandler UADataVariable.CreateIn(myFolder3, "MyDataVariable").Read, AddressOf MyDataVariableOnRead
Dim myFolder4 As UAFolder = UAFolder.CreateIn(server.Objects, "MyFolder4").SetState(4)
AddHandler UADataVariable.CreateIn(myFolder4, "MyDataVariable").Read, AddressOf MyDataVariableOnRead
Dim myFolder5 As UAFolder = UAFolder.CreateIn(server.Objects, "MyFolder5").SetState(5)
AddHandler UADataVariable.CreateIn(myFolder5, "MyDataVariable").Read, AddressOf MyDataVariableOnRead
' Start the server.
Console.WriteLine("The server is starting...")
server.Start()
Console.WriteLine("The server is started.")
Console.WriteLine()
' Let the user decide when to stop.
Console.WriteLine("Press Enter to stop the server...")
Console.ReadLine()
' Stop the server.
Console.WriteLine("The server is stopping...")
server.Stop()
Console.WriteLine("The server is stopped.")
End Sub
''' <summary>
''' Event handler for the read event on the data variable.
''' </summary>
''' <param name="sender">The data variable object that sends the event.</param>
''' <param name="e">Data for the variable read event.</param>
Private Shared Sub MyDataVariableOnRead(ByVal sender As Object, ByVal e As UADataVariableReadEventArgs)
' Obtain the parent folder of the data variable that is being read.
Dim parentNode As UAServerNode = e.DataVariable.ParentNode
' Obtain the state associated with the folder, where the data variable is located.
' Use it as the offset for the random value, so that each data variable generates values in a unique range.
Dim offset As Integer = CInt(parentNode.State * 100)
' Generate a random value, indicate that the read has been handled, and return the generated value.
e.HandleAndReturn(Random.Next(offset, offset + 100))
End Sub
Private Shared ReadOnly Random As Random = New Random()
End Class
End Namespace