如何浏览到数组节点 OPC UA (OPC foundation .NET)

Question

我做了一个测试程序（修改了this代码）从我的opc ua服务器（siemens s7-1200）浏览到节点：

using (var session = Session.Create(config, new ConfiguredEndpoint(null, selectedEndpoint, EndpointConfiguration.Create(config)), false, "", 60000, null, null).GetAwaiter().GetResult())
        {
            Console.WriteLine("Step 3 - Browse the server namespace.");
            ReferenceDescriptionCollection refs;
            byte[] bts;
            session.Browse(null, null, ObjectIds.ObjectsFolder, 0u, BrowseDirection.Forward, ReferenceTypeIds.HierarchicalReferences, true, (uint)NodeClass.Variable | (uint)NodeClass.Object | (uint)NodeClass.Method, out bts, out refs);
            Console.WriteLine("DisplayName: BrowseName, NodeClass");
            foreach (var rd in refs.Where(r => r.DisplayName == "ServerInterfaces"))
            {
                Console.WriteLine("{0}: {1}, {2}", rd.DisplayName, rd.BrowseName, rd.NodeClass);
                ReferenceDescriptionCollection refs2;
                byte[] bts2;
                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 bts2, out refs2);
                foreach (var nextRd in refs2)
                {
                    ReferenceDescriptionCollection refs3;
                    byte[] bts3;
                    Console.WriteLine("NameSpace+ {0}: {1}, {2}", nextRd.DisplayName, nextRd.BrowseName, nextRd.NodeClass);
                    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 bts3, out refs3);
                    foreach (var nextRd2 in refs3.Where(n => n.DisplayName != "Icon"))
                    {

                        NodeId nodeId = new NodeId(nextRd2.NodeId.ToString());
                        var value = session.ReadValue(nodeId);
                        Console.WriteLine("Node+ {0}: {1}, {2}, NodeId = {3}, Value = {4}", nextRd2.DisplayName, nextRd2.BrowseName, nextRd2.NodeClass, nextRd2.NodeId, value);
                    }
                }
            }

我面临的问题是数组。我的 OPC ua 服务器中有一组 INT。目前这是控制台显示的内容：

ServerInterfaces: 3:ServerInterfaces, Object
NameSpace+ Server interface_1: 4:Server interface_1, Object
Node+ read: 4:read, Variable, NodeId = ns=4;i=2, Value = (null)
Node+ IntValue1: 4:IntValue1, Variable, NodeId = ns=4;i=7, Value = 100

这是我的预期输出：

ServerInterfaces: 3:ServerInterfaces, Object
NameSpace+ Server interface_1: 4:Server interface_1, Object
Node+ read: 4:read, Variable, NodeId = ns=4;i=2, Value = (null)
Node+ read: 4:read[0], Variable, NodeId = ns=4;i=3, Value = 1
Node+ read: 4:read[1], Variable, NodeId = ns=4;i=4, Value = 1
Node+ read: 4:read[2], Variable, NodeId = ns=4;i=5, Value = 1
Node+ read: 4:read[3], Variable, NodeId = ns=4;i=6, Value = 1
Node+ IntValue1: 4:IntValue1, Variable, NodeId = ns=4;i=7, Value = 100

如何更改此代码（或新代码）以获得预期的输出？

我做了另一个程序来获取每个节点。奇怪的是我可以从一些自动生成的内容中得到一个数组：

ServerProfileArray: System.String[]
                    [0] Variable = http://opcfoundation.org/UA-Profile/Server/StandardUA
                    [1] Variable = http://opcfoundation.org/UA-Profile/Server/Methods
                    [2] Variable = http://opcfoundation.org/UA-Profile/Server/StandardEventSubscription
                    [3] Variable = http://opcfoundation.org/UA-Profile/Server/DataAccess

但是当我进行“阅读”时，它仍然不显示数组项：

read
                read:

TIA 门户：

Answer 1

我想通了，所以更好的答案仍然值得赞赏（：

Using：

var references = session.FetchReferences(nodeId);

您可以从一个节点获取所有引用。您还将获得更多您可能不需要的信息，但您可以稍后将其过滤掉。

foreach (var ref3 in refs3.Where(n => n.DisplayName != "Icon"))
                    {

                        NodeId nodeId = new NodeId(ref3.NodeId.ToString());
                        var value = session.ReadValue(nodeId);
                        Console.WriteLine("----------------------");
                        Console.WriteLine("Node+ {0}: {1}, {2}, NodeId = {3}, Value = {4}", ref3.DisplayName, ref3.BrowseName, ref3.NodeClass, ref3.NodeId, value);
                        var references = session.FetchReferences(nodeId);
                        if (references != null)
                        {
                            Console.WriteLine("array");
                            foreach (var reference in references.Where(r => r.NodeClass.ToString() == "Variable"))
                            {
                                Console.WriteLine(reference.BrowseName + " NodeId: " + reference.NodeId.ToString());
                            }
                        }
                        Console.WriteLine("----------------------");
                    }

输出：

Node+ read: 4:read, Variable, NodeId = ns=4;i=2, Value = (null)
array
4:[0] NodeId: ns=4;i=3
4:[1] NodeId: ns=4;i=4
4:[2] NodeId: ns=4;i=5
4:[3] NodeId: ns=4;i=6