// This example shows how to create a data variable of OPC data type ByteString and implement its reading using a function.
// 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.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.NodeSpace;
namespace UAServerDocExamples._UADataVariable
{
partial class ReadValueFunction
{
public static void ByteString()
{
// Instantiate the server object.
// By default, the server will run on endpoint URL "opc.tcp://localhost:48040/".
var server = new EasyUAServer();
// Create a data variable, defining its read values by a function.
// The type of the data variable (ByteString, in this case) is inferred from the type returned by the function.
// An array of .NET Byte is used to represent the ByteString.
var random = new Random();
server.Add(new UADataVariable("ReadThisVariable").ReadValueFunction(() =>
{
var buffer = new byte[20];
random.NextBytes(buffer);
return buffer;
}));
// 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.");
}
}
}
' This example shows how to create a data variable of OPC data type ByteString and implement its reading using a function.
' 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.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.NodeSpace
Namespace _UADataVariable
Partial Friend Class ReadValueFunction
Shared Sub ByteString()
' Instantiate the server object.
' By default, the server will run on endpoint URL "opc.tcp://localhost:48040/".
Dim server = New EasyUAServer()
' Create a data variable, defining its read values by a function.
' The type of the data variable (ByteString, in this case) is inferred from the type returned by the function.
' An array of .NET Byte is used to represent the ByteString.
Dim random = New Random()
server.Add(New UADataVariable("ReadThisVariable").ReadValueFunction(Function()
Dim buffer = New Byte(19) {}
random.NextBytes(buffer)
Return buffer
End Function
))
' 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
End Class
End Namespace
