QuickOPC User's Guide and Reference
Examples - Live Mapping - Various data kinds with OPC DA type-less mapping

The example below shows how to make various kinds of mappings:

// This example for OPC DA type-less mapping shows how to define mappings of various kinds, and perform subscribe and 
// unsubscribe operations.

using System;
using System.Threading;
using OpcLabs.BaseLib.ComponentModel.Linking;
using OpcLabs.EasyOpc.DataAccess;
using OpcLabs.EasyOpc.DataAccess.Generic;
using OpcLabs.EasyOpc.DataAccess.LiveMapping;

namespace DocExamples.DataAccess._DAClientMapper
{
    partial class DefineMapping
    {
        class MyClassMappingKinds
        {
            public Double CurrentValue
            {
                set
                {
                    // Display the incoming value
                    Console.WriteLine("Value: {0}", value);
                }
            }

            public DAVtq<Double> CurrentVtq
            {
                set
                {
                    // Display the incoming Vtq
                    Console.WriteLine("Vtq: {0}", value);
                }
            }

            public Exception CurrentException
            {
                set
                {
                    // Display the incoming exception
                    Console.WriteLine("Exception: {0}", value);
                }
            }

            public DAVtqResult<Double> CurrentResult
            {
                set
                {
                    // Display the incoming result
                    Console.WriteLine("Result: {0}", value);
                }
            }
        }

        public static void MappingKinds()
        {
            // Instantiate the client mapper object.
            var mapper = new DAClientMapper();

            var target = new MyClassMappingKinds();

            // Define several type-less mappings for the same source, with different mapping kinds.

            Type targetType = target.GetType();
            var source = new DAClientItemSource("OPCLabs.KitServer.2", "Demo.Ramp", 1000, DADataSource.Cache);

            mapper.DefineMapping(
                 source,
                 new DAClientItemMapping(typeof(Double)),
                 new ObjectMemberLinkingTarget(targetType, target, "CurrentValue"));

            mapper.DefineMapping(
                 source,
                 new DAClientItemMapping(typeof(Double), DAItemMappingKind.Vtq),
                 new ObjectMemberLinkingTarget(targetType, target, "CurrentVtq"));

            mapper.DefineMapping(
                 source,
                 new DAClientItemMapping(typeof(Double), DAItemMappingKind.Exception),
                 new ObjectMemberLinkingTarget(targetType, target, "CurrentException"));

            mapper.DefineMapping(
                 source,
                 new DAClientItemMapping(typeof(Double), DAItemMappingKind.Result),
                 new ObjectMemberLinkingTarget(targetType, target, "CurrentResult"));

            // Perform a subscribe operation.
            mapper.Subscribe(true);

            Thread.Sleep(30 * 1000);

            // Perform an unsubscribe operation.
            mapper.Subscribe(false);
        }
    }
}

' This example for OPC DA type-less mapping shows how to define mappings of various kinds, and perform subscribe and 
' unsubscribe operations.

Imports OpcLabs.BaseLib.ComponentModel.Linking
Imports OpcLabs.EasyOpc.DataAccess
Imports OpcLabs.EasyOpc.DataAccess.Generic
Imports OpcLabs.EasyOpc.DataAccess.LiveMapping

Namespace _DAClientMapper
    Partial Friend Class DefineMapping
        Class MyClassMappingKinds
            Public WriteOnly Property CurrentValue As Double
                Set(value As Double)
                    ' Display the incoming value
                    Console.WriteLine("Value: {0}", value)
                End Set
            End Property

            Public WriteOnly Property CurrentVtq As DAVtq(Of Double)
                Set(value As DAVtq(Of Double))
                    ' Display the incoming Vtq
                    Console.WriteLine("Vtq: {0}", value)
                End Set
            End Property

            Public WriteOnly Property CurrentException As Exception
                Set(value As Exception)
                    ' Display the incoming exception
                    Console.WriteLine("Exception: {0}", value)
                End Set
            End Property

            Public WriteOnly Property CurrentResult As DAVtqResult(Of Double)
                Set(value As DAVtqResult(Of Double))
                    ' Display the incoming result
                    Console.WriteLine("Result: {0}", value)
                End Set
            End Property
        End Class

        Public Shared Sub MappingKinds()
            Dim mapper = New DAClientMapper()
            Dim target = New MyClassMappingKinds()

            ' Define several type-less mappings for the same source, with different mapping kinds.

            Dim targetType = target.GetType()
            Dim source = New DAClientItemSource("OPCLabs.KitServer.2", "Demo.Ramp", 1000, DADataSource.Cache)

            mapper.DefineMapping(
                 source,
                 New DAClientItemMapping(GetType(Double)),
                 New ObjectMemberLinkingTarget(targetType, target, "CurrentValue"))

            mapper.DefineMapping(
                 source,
                 New DAClientItemMapping(GetType(Double), DAItemMappingKind.Vtq),
                 New ObjectMemberLinkingTarget(targetType, target, "CurrentVtq"))

            mapper.DefineMapping(
                 source,
                 New DAClientItemMapping(GetType(Double), DAItemMappingKind.Exception),
                 New ObjectMemberLinkingTarget(targetType, target, "CurrentException"))

            mapper.DefineMapping(
                 source,
                 New DAClientItemMapping(GetType(Double), DAItemMappingKind.Result),
                 New ObjectMemberLinkingTarget(targetType, target, "CurrentResult"))

            ' Perform a subscribe operation.
            mapper.Subscribe(True)

            Threading.Thread.Sleep(30 * 1000)

            ' Perform an unsubscribe operation.
            mapper.Subscribe(False)
        End Sub
    End Class
End Namespace

 

See Also

Conceptual