Examples - OPC XML-DA - Get a value of single property

// This example shows how to get a value of a single OPC XML-DA property.
//
// Note that some properties may not have a useful value initially (e.g. until the item is activated in a group), which also the
// case with Timestamp property as implemented by the demo server. This behavior is server-dependent, and normal. You can run 
// IEasyDAClient.ReadItemValue.Main.vbs shortly before this example, in order to obtain better property values. Your code may 
// also subscribe to the item in order to assure that it remains active.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

using System;
using OpcLabs.EasyOpc.DataAccess;
using OpcLabs.EasyOpc.OperationModel;

namespace DocExamples.DataAccess.Xml
{
    partial class GetPropertyValue
    {
        public static void Main1Xml()
        {
            // Instantiate the client object.
            var client = new EasyDAClient();

            object value;
            try
            {
                value = client.GetPropertyValue("http://opcxml.demo-this.com/XmlDaSampleServer/Service.asmx", "Dynamic/Analog Types/Int",
                    DAPropertyDescriptor.Timestamp);
            }
            catch (OpcException opcException)
            {
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
                return;
            }

            Console.WriteLine(value);
        }
    }
}

# This example shows how to get a value of a single OPC XML-DA property.
#
# 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 import *
from OpcLabs.EasyOpc.DataAccess import *

# Instantiate the client object.
client = EasyDAClient()

# Perform the operation
try:
    value = IEasyDAClientExtension.GetPropertyValue(client, ServerDescriptor('http://opcxml.demo-this.com/XmlDaSampleServer/Service.asmx'), DANodeDescriptor('Dynamic/Analog Types/Int'), 
                                                    DAPropertyDescriptor(DAPropertyId(DAPropertyDescriptor.Timestamp)))
except OpcException as opcException:
    print('*** Failure: ' + opcException.GetBaseException().Message, sep='')
    exit()

# Display results
print('value: ', value, sep='')

' This example shows how to get a value of a single OPC XML-DA property.
'
' Note that some properties may not have a useful value initially (e.g. until the item is activated in a group), which also the
' case with Timestamp property as implemented by the demo server. This behavior is server-dependent, and normal. You can run 
' IEasyDAClient.ReadItemValue.Main.vbs shortly before this example, in order to obtain better property values. Your code may 
' also subscribe to the item in order to assure that it remains active.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

Imports OpcLabs.EasyOpc.DataAccess
Imports OpcLabs.EasyOpc.OperationModel

Namespace DataAccess.Xml
    Partial Friend Class GetPropertyValue
        Public Shared Sub Main1Xml()
            Dim client = New EasyDAClient()

            Dim value As Object
            Try
                value = client.GetPropertyValue("http://opcxml.demo-this.com/XmlDaSampleServer/Service.asmx", "Dynamic/Analog Types/Int", DAPropertyDescriptor.Timestamp)
            Catch opcException As OpcException
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message)
                Exit Sub
            End Try

            Console.WriteLine(value)
        End Sub
    End Class
End Namespace

QuickOPC supports OPC XML-DA also on Linux and macOS.

Examples - OPC Data Access

Examples - OPC Data Access - Get a value of single property

Conceptual

Getting OPC Classic Property Values