Examples - OPC XML-DA - Read multiple item values

// This example shows how to read values of 4 items at once, and display them.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

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

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

            ValueResult[] valueResults = client.ReadMultipleItemValues("http://opcxml.demo-this.com/XmlDaSampleServer/Service.asmx",
                new DAItemDescriptor[]
                {
                    "Dynamic/Analog Types/Double", "Dynamic/Analog Types/Double[]", "Dynamic/Analog Types/Int", "Static/Analog Types/Int"
                });

            for (int i = 0; i < valueResults.Length; i++)
            {
                ValueResult valueResult = valueResults[i];
                Debug.Assert(!(valueResult is null));

                if (valueResult.Succeeded)
                    Console.WriteLine($"valueResults[{i}].Value: {valueResult.Value}");
                else
                    Console.WriteLine($"valueResults[{i}] *** Failure: {valueResult.ErrorMessageBrief}");
            }
        }


        // Example output:
        //
        //valueResults[0].Value: 50
        //valueResults[1].Value: System.Double[]
        //valueResults[2].Value: 100
        //valueResults[3].Value: 12345
    }
}

# This example shows how to read values of 4 items at once, and display them.
#
# 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.DataAccess.OperationModel import *
from OpcLabs.EasyOpc.OperationModel import *


# Instantiate the client object.
client = EasyDAClient()

valueResults = IEasyDAClientExtension.ReadMultipleItemValues(client,
    ServerDescriptor('http://opcxml.demo-this.com/XmlDaSampleServer/Service.asmx'),
    [
        DAItemDescriptor('Dynamic/Analog Types/Double'),
        DAItemDescriptor('Dynamic/Analog Types/Double[]'),
        DAItemDescriptor('Dynamic/Analog Types/Int'),
        DAItemDescriptor('Static/Analog Types/Int')
    ])

for i, valueResult in enumerate(valueResults):
    assert valueResult is not None
    if valueResult.Succeeded:
        print('valueResults[', i, '].Value: ', valueResult.Value, sep='')
    else:
        print('valueResults[', i, '] *** Failure: ', valueResult.ErrorMessageBrief, sep='')


# Example output:
#
#valueResults[0].Value: 0.00125125888851588
#valueResults[1].Value: System.Double[]
#valueResults[2].Value: -0.993968485238202
#valueResults[3].Value: 0

' This example shows how to read values of 4 items at once, and display them.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

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

Namespace DataAccess.Xml
    Partial Friend Class ReadMultipleItemValues
        Public Shared Sub Main1Xml()
            ' Instantiate the client object.
            Dim client = New EasyDAClient()

            Dim valueResults() As ValueResult = client.ReadMultipleItemValues("http://opcxml.demo-this.com/XmlDaSampleServer/Service.asmx",
                New DAItemDescriptor() {"Dynamic/Analog Types/Double", "Dynamic/Analog Types/Double[]", "Dynamic/Analog Types/Int", "Static/Analog Types/Int"})

            For i = 0 To valueResults.Length - 1
                Dim valueResult As ValueResult = valueResults(i)
                Debug.Assert(valueResult IsNot Nothing)

                If valueResult.Succeeded Then
                    Console.WriteLine($"valueResults[{i}].Value: {valueResult.Value}")
                Else
                    Console.WriteLine($"valueResults[{i}] *** Failure: {valueResult.ErrorMessageBrief}")
                End If
            Next i
        End Sub

        ' Example output:
        '
        'valueResults[0].Value: 50
        'valueResults[1].Value System.Double[]
        'valueResults[2].Value: 100
        'valueResults[3].Value: 12345

    End Class
End Namespace

OPC Data Client supports OPC XML-DA also on Linux and macOS.

Examples - OPC Data Access

Conceptual

Examples - OPC Unified Architecture