Raised when data cannot be converted from
Read, for
Write, or in data subscription's
OpcLabs.BaseLib.ISink<T>.OnNext.
Event Data
The event handler receives an argument of type UADataVariableConversionErrorEventArgs containing data related to this event. The following UADataVariableConversionErrorEventArgs properties provide information specific to this event.
Example
// This example shows how to handle conversion errors on the server level.
// 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;
using OpcLabs.EasyOpc.UA.OperationModel;
namespace UAServerDocExamples._EasyUAServer
{
class ConversionError
{
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();
// Define a data variable of type Byte.
UADataVariable dataVariable = UADataVariable.CreateIn(server.Objects, "MyDataVariable").ValueType<byte>();
// Add a Read handler that returns random values between 0 and 511. Those greater than 255 will cause conversion
// errors.
var random = new Random();
dataVariable.Read += (sender, args) => args.HandleAndReturn(random.Next(0, 512));
// Hook events to the server.
// Note that the conversion error event can also be handled on the data variable or folder level, if that's what
// you requirements call for.
server.ConversionError += ServerOnConversionError;
// 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.");
}
// Event handler for the ConversionError event. It simply prints out the event.
static private void ServerOnConversionError(object sender, UADataVariableConversionErrorEventArgs e)
{
Console.WriteLine();
Console.WriteLine($"*** {e}");
// Following are some useful properties in the event notification:
// e.DataVariable
// e.Action
// e.ServiceResult
switch (e.Action)
{
case UADataVariableConversionAction.Read:
Console.WriteLine("The conversion error occurred during a Read operation.");
break;
case UADataVariableConversionAction.Write:
Console.WriteLine("The conversion error occurred during a Write operation.");
break;
case UADataVariableConversionAction.Update:
Console.WriteLine("The conversion error occurred during an Update operation.");
break;
}
Console.WriteLine($"It occured on the data variable: {e.DataVariable}.");
Console.WriteLine($"The service result was: {e.ServiceResult.Message}");
}
}
}
Requirements
Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2016, Windows Server 2022; .NET: Linux, macOS, Microsoft Windows
See Also