使用 OPC UA .NET 从 Kepserver 读取 "Channel1.Device1.Tag1" 值

Question

I am using NetCoreConsoleClient sample from here: https://github.com/OPCFoundation/UA-.NETStandardLibrary

我自定义了代码，能够浏览整个服务器并为服务器上的每个节点获取时间戳、描述、数据类型等值。

对于节点 "Channel1.Device1.Tag1"，我能够获取所有 properties/vlaues（如数据类型、地址、描述），但我没有得到属性的实际值"Tag1"

在 Kepserver 上，我注意到 "Channel1.Device.Tag1" 没有任何名为 "Value" 的属性保存实际标签值。

当我使用 KepServer 提供的 "Quick Client" 时出现

"Tag1" 值。

我需要使用我自己的客户端以某种方式取出 "tag" 值。

修改后的一段代码：

`Console.WriteLine("4 - Browse the OPC UA server namespace.");
        ReferenceDescriptionCollection references;
        Byte[] continuationPoint;

        references = session.FetchReferences(ObjectIds.ObjectsFolder);

        session.Browse(
            null,
            null,
           ObjectIds.ObjectsFolder,
            //ObjectIds.RootFolder,
            0u,
            BrowseDirection.Forward,
            ReferenceTypeIds.HierarchicalReferences,
            true,
            (uint)NodeClass.Variable | (uint)NodeClass.Object | (uint)NodeClass.Method,
            out continuationPoint,
            out references);

        Console.WriteLine(" DisplayName, BrowseName, NodeClass");
        foreach (var rd in references)
        {
            Console.WriteLine(" {0}, {1}, {2}", rd.DisplayName, rd.BrowseName, rd.NodeClass);
            ReferenceDescriptionCollection nextRefs;
            byte[] nextCp;
            session.Browse(
                null,
                null,
                ExpandedNodeId.ToNodeId(rd.NodeId, session.NamespaceUris),
                0u,
                BrowseDirection.Forward,
                ReferenceTypeIds.HierarchicalReferences,
                true,
                (uint)NodeClass.Variable | (uint)NodeClass.Object | (uint)NodeClass.Method,
                out nextCp,
                out nextRefs);
            foreach (var nextRd in nextRefs)
            {
                Console.WriteLine("   + {0}, {1}, {2}", nextRd.DisplayName, nextRd.BrowseName, nextRd.NodeClass);
                ReferenceDescriptionCollection nextRefs1;
                byte[] nextCp1;
                session.Browse(
                   null,
                   null,
                   ExpandedNodeId.ToNodeId(nextRd.NodeId, session.NamespaceUris),
                   0u,
                   BrowseDirection.Forward,
                   ReferenceTypeIds.HierarchicalReferences,
                   true,
                   (uint)NodeClass.Variable | (uint)NodeClass.Object | (uint)NodeClass.Method,
                   out nextCp1,
                   out nextRefs1);
                foreach (var nextRd1 in nextRefs1)
                {
                    Console.WriteLine("   + {0}, {1}, {2}", nextRd1.DisplayName, nextRd1.BrowseName, nextRd1.NodeClass);
                    ReferenceDescriptionCollection nextRefs2;
                    byte[] nextCp2;
                   var res =  session.Browse(
                        null, null,
                        ExpandedNodeId.ToNodeId(nextRd1.NodeId, session.NamespaceUris), 0u, BrowseDirection.Forward,
                        ReferenceTypeIds.HierarchicalReferences, true,
                        (uint)NodeClass.Variable | (uint)NodeClass.Object | (uint)NodeClass.Method, out nextCp2, out nextRefs2);
                    double maxAge = 0; //Pick 0 millisecond old value directly from device not from the cache.
                    DataValueCollection results;
                    DiagnosticInfoCollection diagInfos;
                    ReadValueIdCollection readValueIds;
                    foreach (var nextRd2 in nextRefs2)
                    {
                        try
                        {
                            if (!nextRd2.NodeId.IsNull)
                            {
                                var node = ExpandedNodeId.ToNodeId(nextRd2.NodeId, session.NamespaceUris);
                                if (node != null)
                                {
                                    DataValue dv = session.ReadValue(node);
                                    ReferenceDescriptionCollection nextRefs3;
                                    byte[] nextCp3;
                                    var res1 = session.Browse(null, null,
                                           ExpandedNodeId.ToNodeId(nextRd2.NodeId, session.NamespaceUris), 0u, BrowseDirection.Forward,
                                           ReferenceTypeIds.HierarchicalReferences, true,
                                           (uint)NodeClass.Variable | (uint)NodeClass.Object | (uint)NodeClass.Method, out nextCp3, out nextRefs3);
                                    foreach (var nextRd3 in nextRefs3)
                                    {
                                        if (!nextRd3.NodeId.IsNull)
                                        {
                                            var node1 = ExpandedNodeId.ToNodeId(nextRd3.NodeId, session.NamespaceUris);
                                            if (node1 != null)
                                            {
                                                DataValue dv2 = session.ReadValue(node1);
                                            }
                                        }
                                    }
                                }
                            }
                        }
                        catch (ServiceResultException srex)
                        {
                            //eat exception yum yum yum!
                        }
                        catch (Exception ex)
                        {

                            //eat exception yum yum yum!
                        }`

Answer 1

通过示例代码的点击和试用，我找到了答案。

给出值的神奇语句是：

数据值 dv1 = session.ReadValue("ns=2;s=Channel1.Device1.Tag1");

                foreach (var nextRd1 in nextRefs1)
                {
                    Console.WriteLine("   + {0}, {1}, {2}", nextRd1.DisplayName, nextRd1.BrowseName, nextRd1.NodeClass);
                    try
                    {
                        var _node = ExpandedNodeId.ToNodeId(nextRd1.NodeId, session.NamespaceUris);
                        DataValue dv2 = session.ReadValue(_node);
                    }

Answer 2

此示例使用： https://github.com/hylasoft-usa/h-opc#documentation

您可能只需要找出您需要检索的值的类型

public void ReadValueFromOPC(string host, string userName, string password)
    {
        var options = new UaClientOptions
        {
            UserIdentity = new Opc.Ua.UserIdentity(
                userName,
                password)
        };

        using (var client = new UaClient(new Uri("opc.tcp://" +
            host), options))
        {

            client.Connect();
            var node = client.FindNode("SomeTag.SomeChildTag");

            // Find out what the type is before you try to get the value
            Type type = client.GetDataType(node.Tag);
            // If you find out it's a UInt32 then you use it.
            var value = client.Read<UInt32>(node.Tag).Value;

        }
    }

使用 OPC UA .NET 从 Kepserver 读取 "Channel1.Device1.Tag1" 值

Using OPC UA .NET read "Channel1.Device1.Tag1" value from Kepserver

.net

c#

opc

kepserverex

opc-ua