// This example shows how to obtain "data nodes" under the "Objects" node, recursively.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
using System;
using System.Diagnostics;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.AddressSpace;
using OpcLabs.EasyOpc.UA.AddressSpace.Standard;
using OpcLabs.EasyOpc.UA.OperationModel;
namespace UADocExamples._EasyUAClient
{
partial class BrowseDataNodes
{
public static void Recursive()
{
UAEndpointDescriptor endpointDescriptor =
"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer";
// or "http://opcua.demo-this.com:51211/UA/SampleServer" (currently not supported)
// or "https://opcua.demo-this.com:51212/UA/SampleServer/"
// Instantiate the client object
var client = new EasyUAClient();
try
{
BrowseFromNode(client, endpointDescriptor, UAObjectIds.ObjectsFolder, level:0);
}
catch (UAException uaException)
{
Console.WriteLine($"*** Failure: {uaException.GetBaseException().Message}");
}
}
private static void BrowseFromNode(
EasyUAClient client,
UAEndpointDescriptor endpointDescriptor,
UANodeDescriptor parentNodeDescriptor,
int level)
{
Debug.Assert(!(client is null));
Debug.Assert(!(endpointDescriptor is null));
Debug.Assert(!(parentNodeDescriptor is null));
// Obtain all node elements under parentNodeDescriptor
UANodeElementCollection nodeElementCollection =
client.BrowseDataNodes(endpointDescriptor, parentNodeDescriptor);
// Remark: BrowseDataNodes(...) may throw UAException; we handle it in the calling method.
foreach (UANodeElement nodeElement in nodeElementCollection)
{
Debug.Assert(!(nodeElement is null));
Console.Write(new string(' ', level*2)); // indent
Console.WriteLine(nodeElement);
// Browse recursively into the node.
// The UANodeElement has an implicit conversion to UANodeDescriptor.
BrowseFromNode(client, endpointDescriptor, nodeElement, level + 1);
// Note that the number of nodes you obtain through recursive browsing may be very large, or even infinite.
// Production code should contain appropriate safeguards for these cases.
}
}
// Example output:
//
//ServerStatus -> nsu=http://opcfoundation.org/UA/ ;i=2256 (Variable)
// StartTime -> nsu=http://opcfoundation.org/UA/ ;i=2257 (Variable)
// CurrentTime -> nsu=http://opcfoundation.org/UA/ ;i=2258 (Variable)
// State -> nsu=http://opcfoundation.org/UA/ ;i=2259 (Variable)
// BuildInfo -> nsu=http://opcfoundation.org/UA/ ;i=2260 (Variable)
// ProductUri -> nsu=http://opcfoundation.org/UA/ ;i=2262 (Variable)
// ManufacturerName -> nsu=http://opcfoundation.org/UA/ ;i=2263 (Variable)
// ProductName -> nsu=http://opcfoundation.org/UA/ ;i=2261 (Variable)
// SoftwareVersion -> nsu=http://opcfoundation.org/UA/ ;i=2264 (Variable)
// BuildNumber -> nsu=http://opcfoundation.org/UA/ ;i=2265 (Variable)
// BuildDate -> nsu=http://opcfoundation.org/UA/ ;i=2266 (Variable)
// SecondsTillShutdown -> nsu=http://opcfoundation.org/UA/ ;i=2992 (Variable)
// ShutdownReason -> nsu=http://opcfoundation.org/UA/ ;i=2993 (Variable)
//ServerCapabilities -> nsu=http://opcfoundation.org/UA/ ;i=2268 (Object)
// OperationLimits -> nsu=http://opcfoundation.org/UA/ ;i=11704 (Object)
// MaxNodesPerRead -> nsu=http://opcfoundation.org/UA/ ;i=11705 (Variable)
// MaxNodesPerHistoryReadData -> nsu=http://opcfoundation.org/UA/ ;i=12165 (Variable)
// MaxNodesPerHistoryReadEvents -> nsu=http://opcfoundation.org/UA/ ;i=12166 (Variable)
// MaxNodesPerWrite -> nsu=http://opcfoundation.org/UA/ ;i=11707 (Variable)
// MaxNodesPerHistoryUpdateData -> nsu=http://opcfoundation.org/UA/ ;i=12167 (Variable)
//...
}
}
# This example shows how to obtain "data nodes" under the "Objects" node, recursively.
#
# 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 .
# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc
# Import .NET namespaces.
from OpcLabs.EasyOpc.UA import *
from OpcLabs.EasyOpc.UA.AddressSpace import *
from OpcLabs.EasyOpc.UA.AddressSpace.Standard import *
from OpcLabs.EasyOpc.UA.OperationModel import *
def browseFromNode(client, endpointDescriptor, parentNodeDescriptor, level):
assert client is not None
assert endpointDescriptor is not None
assert parentNodeDescriptor is not None
# Obtain all node elements under parentNodeDescriptor
nodeElementCollection = IEasyUAClientExtension.BrowseDataNodes(client, endpointDescriptor, parentNodeDescriptor)
# Remark: BrowseDataNodes(...) may throw UAException; we handle it in the calling method.
#
for nodeElement in nodeElementCollection:
assert nodeElement is not None
print(' '*(level*2), end='') # indent
print(nodeElement)
# Browse recursively into the node.
# The UANodeElement has an implicit conversion to UANodeDescriptor.
browseFromNode(client, endpointDescriptor, nodeElement.ToUANodeDescriptor(), level + 1)
# Note that the number of nodes you obtain through recursive browsing may be very large, or even infinite.
# Production code should contain appropriate safeguards for these cases.
endpointDescriptor = UAEndpointDescriptor('opc.tcp://opcua.demo-this.com:51210/UA/SampleServer')
# or 'http://opcua.demo-this.com:51211/UA/SampleServer' (currently not supported)
# or 'https://opcua.demo-this.com:51212/UA/SampleServer/'
# Instantiate the client object.
client = EasyUAClient()
try:
browseFromNode(client, endpointDescriptor, UANodeDescriptor(UAObjectIds.ObjectsFolder), 0)
except UAException as uaException:
print('*** Failure: ' + uaException.GetBaseException().Message)
exit()
print()
print('Finished.')
' This example shows how to obtain "data nodes" under the "Objects" node, recursively.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.AddressSpace
Imports OpcLabs.EasyOpc.UA.AddressSpace.Standard
Imports OpcLabs.EasyOpc.UA.OperationModel
Namespace _EasyUAClient
Partial Friend Class BrowseDataNodes
Public Shared Sub Recursive()
' Define which server we will work with.
Dim endpointDescriptor As UAEndpointDescriptor =
"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
' or "http://opcua.demo-this.com:51211/UA/SampleServer" (currently not supported)
' or "https://opcua.demo-this.com:51212/UA/SampleServer/"
' Instantiate the client object
Dim client = New EasyUAClient()
Try
BrowseFromNode(client, endpointDescriptor, UAObjectIds.ObjectsFolder, level:=0)
Catch uaException As UAException
Console.WriteLine($"*** Failure: {uaException.GetBaseException().Message}")
Exit Sub
End Try
End Sub
Private Shared Sub BrowseFromNode(client As EasyUAClient, endPointDescriptor As UAEndpointDescriptor, parentNodeDescriptor As UANodeDescriptor, level As Integer)
Debug.Assert(client IsNot Nothing)
Debug.Assert(endPointDescriptor IsNot Nothing)
Debug.Assert(parentNodeDescriptor IsNot Nothing)
' Obtain all node elements under parentNodeDescriptor
Dim nodeElementCollection As UANodeElementCollection =
client.BrowseDataNodes(endPointDescriptor, parentNodeDescriptor)
' Remark: BrowseDataNodes(...) may throw UAException; we handle it in the calling method.
For Each nodeElement As UANodeElement In nodeElementCollection
Debug.Assert(nodeElement IsNot Nothing)
Console.Write(New String(" "c, level * 2))
Console.WriteLine(nodeElement)
' Browse recursively into the node.
' The UANodeElement has an implicit conversion to UANodeDescriptor.
BrowseFromNode(client, endPointDescriptor, nodeElement, level + 1)
' Note that the number of nodes you obtain through recursive browsing may be very large, or even infinite.
' Production code should contain appropriate safeguards for these cases.
Next nodeElement
End Sub
End Class
End Namespace
