QuickOPC User's Guide and Reference
IEasyUAFileTransfer Interface
Members  Example 



OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA.FileTransfer Namespace : IEasyUAFileTransfer Interface
Provides access to OPC UA information model for file transfer.
Syntax
'Declaration
 
<ComVisibleAttribute(False)>
<ExceptionContractVerificationAttribute(True)>
Public Interface IEasyUAFileTransfer 
'Usage
 
Dim instance As IEasyUAFileTransfer
[ComVisible(false)]
[ExceptionContractVerification(true)]
public interface IEasyUAFileTransfer 
[ComVisible(false)]
[ExceptionContractVerification(true)]
public interface class IEasyUAFileTransfer 
Remarks

The "file transfer" in the name corresponds to how the related OPC UA specification part is titled. In reality, the functionality covers more than just file transfer - it represents a file system in OPC UA, and provides file access and manipulation operations.

The related part of OPC UA specification is: .

See OPC UA File Transfer Concepts for basic information about what is OPC UA File Transfer and how it works.

Example

.NET

// Shows how to read the full contents of an OPC UA file at once, using the file transfer client.
// Note: Consider using a higher-level abstraction, OPC UA file provider, instead.

using System;
using System.IO;
using System.Text;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.FileTransfer;
using OpcLabs.EasyOpc.UA.IO.Extensions;

namespace UADocExamples.FileTransfer._EasyUAFileTransferClient
{
    class ReadAllBytes
    {
        public static void Main1()
        {
            // Unified Automation .NET based demo server (UaNETServer/UaServerNET.exe)
            UAEndpointDescriptor endpointDescriptor = "opc.tcp://localhost:48030";

            // A node that represents an instance of OPC UA FileType object.
            UANodeDescriptor fileNodeDescriptor = "nsu=http://www.unifiedautomation.com/DemoServer/ ;s=Demo.Files.TextFile";
            
            // Instantiate the file transfer client object
            var fileTransferClient = new EasyUAFileTransferClient();

            // Read in all contents from a specified file node.
            byte[] bytes;
            try
            {
                Console.WriteLine("Reading the whole file...");
                bytes = fileTransferClient.ReadAllBytes(endpointDescriptor, fileNodeDescriptor);
            }
            // Beware that ReadAllFileBytes throws IOException and not UAException.
            catch (IOException ioException)
            {
                Console.WriteLine("*** Failure: {0}", ioException.GetBaseException().Message);
                return;
            }

            // Display result
            Console.WriteLine();
            // We know that the file contains text, so we convert the received data to a string. If the file contents was
            // binary, you would process the data according to their format.
            string text = Encoding.UTF8.GetString(bytes);
            Console.WriteLine("File content:");
            Console.WriteLine(text);

            Console.WriteLine();
            Console.WriteLine("Finished...");
        }
    }
}
# Shows how to read the full contents of an OPC UA file at once, using the file transfer client.
# Note: Consider using a higher-level abstraction, OPC UA file provider, instead.

# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc

# Import .NET namespaces.
from System.Text import *
from OpcLabs.EasyOpc.UA import *
from OpcLabs.EasyOpc.UA.FileTransfer import *
from OpcLabs.EasyOpc.UA.IO.Extensions import *
from OpcLabs.EasyOpc.UA.Navigation import *


# Unified Automation .NET based demo server (UaNETServer/UaServerNET.exe).
endpointDescriptor = UAEndpointDescriptor('opc.tcp://localhost:48030')

# A node that represents an instance of OPC UA FileType object.
fileNodeDescriptor = UANodeDescriptor('nsu=http://www.unifiedautomation.com/DemoServer/ ;s=Demo.Files.TextFile')

# Instantiate the file transfer client object.
fileTransferClient = EasyUAFileTransferClient()

# Read in all contents from a specified file node.
try:
    print('Reading the whole file...')
    bytes = IEasyUAFileTransferExtension2.ReadAllBytes(fileTransferClient,
                                                       endpointDescriptor,
                                                       UANamedNodeDescriptor(fileNodeDescriptor))

# Beware that ReadAllFileBytes throws IOException and not UAException.
except IOException as ioException:
    print('*** Failure: ' + ioException.GetBaseException().Message)
    exit()

# Display result.
print()
# We know that the file contains text, so we convert the received data to a string. If the file contents was
# binary, you would process the data according to their format.
text = Encoding.UTF8.GetString(bytes)
print('File content:')
print(text)

print()
print('Finished.')
' Shows how to read the full contents of an OPC UA file at once, using the file transfer client.
' Note: Consider using a higher-level abstraction, OPC UA file provider, instead.

Imports System.IO
Imports System.Text
Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.FileTransfer
Imports OpcLabs.EasyOpc.UA.IO.Extensions

Namespace FileTransfer._EasyUAFileTransferClient

    Friend Class ReadAllBytes

        Public Shared Sub Main1()

            ' Unified Automation .NET based demo server (UaNETServer/UaServerNET.exe)
            Dim endpointDescriptor As UAEndpointDescriptor = "opc.tcp://localhost:48030"

            ' A node that represents an instance of OPC UA FileType object.
            Dim fileNodeDescriptor As UANodeDescriptor = "nsu=http://www.unifiedautomation.com/DemoServer/ ;s=Demo.Files.TextFile"

            ' Instantiate the file transfer client object
            Dim fileTransferClient = New EasyUAFileTransferClient

            ' Read in all contents from a specified file node.
            Dim bytes As Byte()
            Try
                Console.WriteLine("Reading the whole file...")
                bytes = fileTransferClient.ReadAllBytes(endpointDescriptor, fileNodeDescriptor)

                ' Beware that ReadAllFileBytes throws IOException And Not UAException.
            Catch ioException As IOException
                Console.WriteLine("*** Failure: {0}", ioException.GetBaseException.Message)
                Exit Sub
            End Try

            ' Display result
            Console.WriteLine()
            ' We know that the file contains text, so we convert the received data to a string. If the file contents was
            ' binary, you would process the data according to their format.
            Dim text As String = Encoding.UTF8.GetString(bytes)
            Console.WriteLine("File content:")
            Console.WriteLine(text)

            Console.WriteLine()
            Console.WriteLine("Finished...")
        End Sub
    End Class
End Namespace
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