Examples - OPC Data Access - Read an item synchronously

// This example shows how to read an item synchronously, and display its value, timestamp and quality.
//
// 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._EasyDAClient
{
    partial class ReadItem
    {
        public static void Synchronous()
        {
            // Instantiate the client object.
            var client = new EasyDAClient();

            // Specify that only synchronous method is allowed. By default, both synchronous and asynchronous methods are
            // allowed, and the component picks a suitable method automatically. Disallowing asynchronous method leaves
            // only the synchronous method available for selection.
            client.InstanceParameters.Mode.AllowAsynchronousMethod = false;

            DAVtq vtq;
            try
            {
                vtq = client.ReadItem("", "OPCLabs.KitServer.2", "Simulation.Random");
            }
            catch (OpcException opcException)
            {
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
                return;
            }

            Console.WriteLine("Vtq: {0}", vtq);
        }
    }
}

# This example shows how to read an item synchronously, and display its value, timestamp and quality.
#
# 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 *
from OpcLabs.EasyOpc.OperationModel import *


# Instantiate the client object.
client = EasyDAClient()

# Specify that only synchronous method is allowed. By default, both synchronous and asynchronous methods are
# allowed, and the component picks a suitable method automatically. Disallowing asynchronous method leaves
# only the synchronous method available for selection.
client.InstanceParameters.Mode.AllowAsynchronousMethod = False

# Perform the operation.
try:
    vtq = IEasyDAClientExtension.ReadItem(client, '', 'OPCLabs.KitServer.2', 'Simulation.Random')
except OpcException as opcException:
    print('*** Failure: ' + opcException.GetBaseException().Message, sep='')
    exit()

# Display results.
print('Vtq: ', vtq, sep='')

' This example shows how to read an item synchronously, and display its value, timestamp and quality.
'
' 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._EasyDAClient
    Partial Friend Class ReadItem
        Public Shared Sub Synchronous()
            ' Instantiate the client object.
            Dim client = New EasyDAClient()

            ' Specify that only synchronous method is allowed. By default, both synchronous and asynchronous methods are
            ' allowed, and the component picks a suitable method automatically. Disallowing asynchronous method leaves
            ' only the synchronous method available for selection.
            client.InstanceParameters.Mode.AllowAsynchronousMethod = False

            Dim vtq As DAVtq
            Try
                vtq = client.ReadItem("", "OPCLabs.KitServer.2", "Simulation.Random")
            Catch opcException As OpcException
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message)
                Exit Sub
            End Try

            Console.WriteLine("Vtq: {0}", vtq)
        End Sub
    End Class
End Namespace

Conceptual

Examples - OPC Unified Architecture

Examples - OPC DA Layered Extensions