The example below shows how to write data into a section of an OPC UA file, using the file provider model.
// Shows how to write data into a section of an OPC UA file, using the file provider model. // // Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html . // OPC client and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-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 System.IO; using System.Text; using OpcLabs.BaseLib.Extensions.FileProviders; using OpcLabs.EasyOpc.UA; using OpcLabs.EasyOpc.UA.FileTransfer; namespace UADocExamples.FileProviders._WritableFileInfo { class Write { 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(); Console.WriteLine("Getting writable file info..."); IWritableFileInfo writableFileInfo = fileTransferClient.GetWritableFileInfo(endpointDescriptor, fileNodeDescriptor); // From this point onwards, the code is independent of the concrete realization of the file provider, and would // be identical e.g. for files in the physical file system, if the corresponding file provider was used. // Open the file, write a section of it, and close it. try { Console.WriteLine("Opening file..."); using (Stream stream = writableFileInfo.CreateWriteStream(FileMode.Open, FileAccess.ReadWrite)) { Console.WriteLine("Writing file section..."); byte[] data = Encoding.UTF8.GetBytes("TEXT FROM FILE TRANSFER CLIENT EXAMPLE. Demonstrates writing a section of a file. <<<"); stream.Write(data, 0, data.Length); Console.WriteLine("Closing file..."); // Disposing of the stream closes the file. } } // Methods in the file provider model throw IOException and other exceptions, but not UAException. catch (Exception exception) { Console.WriteLine($"*** Failure: {exception.GetBaseException().Message}"); return; } Console.WriteLine(); Console.WriteLine("Finished..."); } } }
' Shows how to write data into a section of an OPC UA file, using the file provider model. ' ' 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.IO Imports System.Text Imports OpcLabs.BaseLib.Extensions.FileProviders Imports OpcLabs.EasyOpc.UA Imports OpcLabs.EasyOpc.UA.FileTransfer Namespace FileProviders._WritableFileInfo Friend Class Write 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 Console.WriteLine("Getting writable file info...") Dim writableFileInfo As IWritableFileInfo = fileTransferClient.GetWritableFileInfo(endpointDescriptor, fileNodeDescriptor) ' From this point onwards, the code is independent of the concrete realization of the file provider, and would ' be identical e.g. for files in the physical file system, if the corresponding file provider was used. ' Open the file, write a section of it, and close it. Try Console.WriteLine("Opening file...") Using stream As Stream = writableFileInfo.CreateWriteStream(FileMode.Open, FileAccess.ReadWrite) Console.WriteLine("Writing file section...") Dim data As Byte() = Encoding.UTF8.GetBytes("TEXT FROM FILE TRANSFER CLIENT EXAMPLE. Demonstrates writing a section of a file. <<<") stream.Write(data, 0, data.Length) Console.WriteLine("Closing file...") ' Disposing of the stream closes the file. End Using ' Methods in the file provider model throw IOException and other exceptions, but not UAException. Catch exception As Exception Console.WriteLine("*** Failure: {0}", exception.GetBaseException.Message) Exit Sub End Try Console.WriteLine() Console.WriteLine("Finished...") End Sub End Class End Namespace
# Shows how to write data into a section of an OPC UA file, using the file provider model. # # Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html . # OPC client and subscriber examples in Python on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-Python . # 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. # The QuickOPC package is needed. Install it using "pip install opclabs_quickopc". import opclabs_quickopc # Import .NET namespaces. from System import * from System.IO import * from System.Text import * from OpcLabs.BaseLib.Extensions.FileProviders import * from OpcLabs.EasyOpc.UA import * from OpcLabs.EasyOpc.UA.FileTransfer 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 OPC UA file system (a root directory). fileNodeDescriptor = UANodeDescriptor('nsu=http://www.unifiedautomation.com/DemoServer/ ;s=Demo.Files.TextFile') # Instantiate the file transfer client object. fileTransferClient = EasyUAFileTransferClient() print('Getting writable file info...') writableFileInfo = IEasyUAFileTransferExtension.GetWritableFileInfo(fileTransferClient, endpointDescriptor, UANamedNodeDescriptor(fileNodeDescriptor)) # From this point onwards, the code is independent of the concrete realization of the file provider, and would # be identical e.g. for files in the physical file system, if the corresponding file provider was used. # Open the file, write a section of it, and close it. stream = None try: print('Opening file...') stream = writableFileInfo.CreateWriteStream(FileMode.Open, FileAccess.ReadWrite) print('Writing file section...') data = Encoding.UTF8.GetBytes('TEXT FROM FILE TRANSFER CLIENT EXAMPLE. Demonstrates writing a section of a file. ' '<<<') stream.Write(data, 0, data.Length) print('Closing file...') # Disposing of the stream (in the 'finally' block) closes the file. # Methods in the file provider model throw IOException and other exceptions, but not UAException. except Exception as exception: print('*** Failure: ' + exception.GetBaseException().Message) exit() finally: stream and stream.Dispose() print() print('Finished.')
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