使用C#開發OPC UA伺服器

星墨發表於2024-06-19

OPC基金會提供了OPC UA .NET標準庫以及示例程式,但官方文件過於簡單,光看官方文件和示例程式很難弄懂OPC UA .NET標準庫怎麼用,花了不少時間摸索才略微弄懂如何使用,以下記錄如何從一個控制檯程式開發一個OPC UA伺服器。

安裝Nuget包

安裝OPCFoundation.NetStandard.Opc.Ua
image

主程式

修改Program.cs程式碼如下:

using Opc.Ua;
using Opc.Ua.Configuration;
using Opc.Ua.Server;

namespace SampleOpcUaServer
{
    internal class Program
    {
        static void Main(string[] args)
        {
            // 啟動OPC UA伺服器
            ApplicationInstance application = new ApplicationInstance();
            application.ConfigSectionName = "OpcUaServer";
            application.LoadApplicationConfiguration(false).Wait();
            application.CheckApplicationInstanceCertificate(false, 0).Wait();

            var server = new StandardServer();
            var nodeManagerFactory = new NodeManagerFactory();
            server.AddNodeManager(nodeManagerFactory);
            application.Start(server).Wait();

            // 模擬資料
            var nodeManager = nodeManagerFactory.NodeManager;
            var simulationTimer = new System.Timers.Timer(1000);
            var random = new Random();
            simulationTimer.Elapsed += (sender, EventArgs) =>
            {
                nodeManager?.UpdateValue("ns=2;s=Root_Test", random.NextInt64());
            };
            simulationTimer.Start();

            // 輸出OPC UA Endpoint
            Console.WriteLine("Endpoints:");
            foreach (var endpoint in server.GetEndpoints().DistinctBy(x => x.EndpointUrl))
            {
                Console.WriteLine(endpoint.EndpointUrl);
            }

            Console.WriteLine("按Enter新增新變數");
            Console.ReadLine();

            // 新增新變數
            nodeManager?.AddVariable("ns=2;s=Root", "Test2", (int)BuiltInType.Int16, ValueRanks.Scalar);
            Console.WriteLine("已新增變數");
            Console.ReadLine();
        }
    }
}

上述程式碼中:

  • ApplicationInstance是OPC UA標準庫中用於配置OPC UA Server和檢查證書的類。
  • application.ConfigSectionName指定了配置檔案的名稱,配置檔案是xml檔案,將會在程式資料夾查詢名為OpcUaServer.Config.xml的配置檔案。配置檔案內容見後文。
  • application.LoadApplicationConfiguration載入前面指定的配置檔案。如果不想使用配置檔案,也可透過程式碼給application.ApplicationConfiguration賦值。
  • StandardServerReverseConnectServer兩種作為OPC UA伺服器的類,ReverseConnectServer派生於StandardServer,這兩種類的區別未深入研究,用StandardServer可滿足基本的需求。
  • OPC UA的地址空間由節點組成,簡單理解節點就是提供給OPC UA客戶端訪問的變數和資料夾。透過server.AddNodeManager方法新增節點管理工廠類,NodeManagerFactory類定義見後文。
  • 呼叫application.Start(server)方法後,OPC UA Server就會開始執行,並不會阻塞程式碼,為了保持在控制檯程式中執行,所以使用Console.ReadLine()阻塞程式。
  • nodeManager?.UpdateValue是自定義的更新OPC UA地址空間中變數值的方法。
  • nodeManager?.AddVariable在此演示動態新增一個新的變數。

OPC UA配置檔案

新建OpcUaServer.Config.xml檔案。

image

在屬性中設為“始終賦值”。

image

內容如下:

<?xml version="1.0" encoding="utf-8"?>
<ApplicationConfiguration
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:ua="http://opcfoundation.org/UA/2008/02/Types.xsd"
  xmlns="http://opcfoundation.org/UA/SDK/Configuration.xsd"
>
	<ApplicationName>Sample OPC UA Server</ApplicationName>
	<ApplicationUri>urn:localhost:UA:OpcUaServer</ApplicationUri>
	<ProductUri>uri:opcfoundation.org:OpcUaServer</ProductUri>
	<ApplicationType>Server_0</ApplicationType>

	<SecurityConfiguration>

		<!-- Where the application instance certificate is stored (MachineDefault) -->
		<ApplicationCertificate>
			<StoreType>Directory</StoreType>
			<StorePath>%CommonApplicationData%\OPC Foundation\pki\own</StorePath>
			<SubjectName>CN=Sample Opc Ua Server, C=US, S=Arizona, O=SomeCompany, DC=localhost</SubjectName>
		</ApplicationCertificate>

		<!-- Where the issuer certificate are stored (certificate authorities) -->
		<TrustedIssuerCertificates>
			<StoreType>Directory</StoreType>
			<StorePath>%CommonApplicationData%\OPC Foundation\pki\issuer</StorePath>
		</TrustedIssuerCertificates>

		<!-- Where the trust list is stored -->
		<TrustedPeerCertificates>
			<StoreType>Directory</StoreType>
			<StorePath>%CommonApplicationData%\OPC Foundation\pki\trusted</StorePath>
		</TrustedPeerCertificates>

		<!-- The directory used to store invalid certficates for later review by the administrator. -->
		<RejectedCertificateStore>
			<StoreType>Directory</StoreType>
			<StorePath>%CommonApplicationData%\OPC Foundation\pki\rejected</StorePath>
		</RejectedCertificateStore>
	</SecurityConfiguration>

	<TransportConfigurations></TransportConfigurations>

	<TransportQuotas>
		<OperationTimeout>600000</OperationTimeout>
		<MaxStringLength>1048576</MaxStringLength>
		<MaxByteStringLength>1048576</MaxByteStringLength>
		<MaxArrayLength>65535</MaxArrayLength>
		<MaxMessageSize>4194304</MaxMessageSize>
		<MaxBufferSize>65535</MaxBufferSize>
		<ChannelLifetime>300000</ChannelLifetime>
		<SecurityTokenLifetime>3600000</SecurityTokenLifetime>
	</TransportQuotas>
	<ServerConfiguration>
		<BaseAddresses>
			<ua:String>https://localhost:62545/OpcUaServer/</ua:String>
			<ua:String>opc.tcp://localhost:62546/OpcUaServer</ua:String>
		</BaseAddresses>
		<SecurityPolicies>
			<ServerSecurityPolicy>
				<SecurityMode>SignAndEncrypt_3</SecurityMode>
				<SecurityPolicyUri>http://opcfoundation.org/UA/SecurityPolicy#Basic256Sha256</SecurityPolicyUri>
			</ServerSecurityPolicy>
			<ServerSecurityPolicy>
				<SecurityMode>None_1</SecurityMode>
				<SecurityPolicyUri>http://opcfoundation.org/UA/SecurityPolicy#None</SecurityPolicyUri>
			</ServerSecurityPolicy>
			<ServerSecurityPolicy>
				<SecurityMode>Sign_2</SecurityMode>
				<SecurityPolicyUri></SecurityPolicyUri>
			</ServerSecurityPolicy>
			<ServerSecurityPolicy>
				<SecurityMode>SignAndEncrypt_3</SecurityMode>
				<SecurityPolicyUri></SecurityPolicyUri>
			</ServerSecurityPolicy>
		</SecurityPolicies>
		<UserTokenPolicies>
			<ua:UserTokenPolicy>
				<ua:TokenType>Anonymous_0</ua:TokenType>
			</ua:UserTokenPolicy>
			<ua:UserTokenPolicy>
				<ua:TokenType>UserName_1</ua:TokenType>
			</ua:UserTokenPolicy>
			<ua:UserTokenPolicy>
				<ua:TokenType>Certificate_2</ua:TokenType>
			</ua:UserTokenPolicy>
			<!--
      <ua:UserTokenPolicy>
        <ua:TokenType>IssuedToken_3</ua:TokenType>
        <ua:IssuedTokenType>urn:oasis:names:tc:SAML:1.0:assertion:Assertion</ua:IssuedTokenType>
      </ua:UserTokenPolicy>
      -->
		</UserTokenPolicies>
		<DiagnosticsEnabled>false</DiagnosticsEnabled>
		<MaxSessionCount>100</MaxSessionCount>
		<MinSessionTimeout>10000</MinSessionTimeout>
		<MaxSessionTimeout>3600000</MaxSessionTimeout>
		<MaxBrowseContinuationPoints>10</MaxBrowseContinuationPoints>
		<MaxQueryContinuationPoints>10</MaxQueryContinuationPoints>
		<MaxHistoryContinuationPoints>100</MaxHistoryContinuationPoints>
		<MaxRequestAge>600000</MaxRequestAge>
		<MinPublishingInterval>100</MinPublishingInterval>
		<MaxPublishingInterval>3600000</MaxPublishingInterval>
		<PublishingResolution>50</PublishingResolution>
		<MaxSubscriptionLifetime>3600000</MaxSubscriptionLifetime>
		<MaxMessageQueueSize>10</MaxMessageQueueSize>
		<MaxNotificationQueueSize>100</MaxNotificationQueueSize>
		<MaxNotificationsPerPublish>1000</MaxNotificationsPerPublish>
		<MinMetadataSamplingInterval>1000</MinMetadataSamplingInterval>
		<AvailableSamplingRates>
			<SamplingRateGroup>
				<Start>5</Start>
				<Increment>5</Increment>
				<Count>20</Count>
			</SamplingRateGroup>
			<SamplingRateGroup>
				<Start>100</Start>
				<Increment>100</Increment>
				<Count>4</Count>
			</SamplingRateGroup>
			<SamplingRateGroup>
				<Start>500</Start>
				<Increment>250</Increment>
				<Count>2</Count>
			</SamplingRateGroup>
			<SamplingRateGroup>
				<Start>1000</Start>
				<Increment>500</Increment>
				<Count>20</Count>
			</SamplingRateGroup>
		</AvailableSamplingRates>
		<MaxRegistrationInterval>30000</MaxRegistrationInterval>
		<NodeManagerSaveFile>OpcUaServer.nodes.xml</NodeManagerSaveFile>
	</ServerConfiguration>

	<TraceConfiguration>
		<OutputFilePath>Logs\SampleOpcUaServer.log</OutputFilePath>
		<DeleteOnLoad>true</DeleteOnLoad>
		<!-- Show Only Errors -->
		<!-- <TraceMasks>1</TraceMasks> -->
		<!-- Show Only Security and Errors -->
		<!-- <TraceMasks>513</TraceMasks> -->
		<!-- Show Only Security, Errors and Trace -->
		<TraceMasks>515</TraceMasks>
		<!-- Show Only Security, COM Calls, Errors and Trace -->
		<!-- <TraceMasks>771</TraceMasks> -->
		<!-- Show Only Security, Service Calls, Errors and Trace -->
		<!-- <TraceMasks>523</TraceMasks> -->
		<!-- Show Only Security, ServiceResultExceptions, Errors and Trace -->
		<!-- <TraceMasks>519</TraceMasks> -->
	</TraceConfiguration>

</ApplicationConfiguration>

需要關注的內容有:

  • ApplicationName:在透過OPC UA工具連線此伺服器時,顯示的伺服器名稱就是該值。

  • ApplicationType:應用型別,可用的值有:

    • Server_0:伺服器
    • Client_1:客戶端
    • ClientAndServer_2:客戶機和伺服器
    • DisconveryServer_3:發現伺服器。發現伺服器用於註冊OPC UA伺服器,然後提供OPC UA客戶端搜尋到伺服器。
  • SecurityConfiguration:該節點中指定了OPC UA的證書儲存路徑,一般保持預設,不需修改。

  • ServerConfiguration.BaseAddresses:該節點指定OPC UA伺服器的url地址。

  • ServerConfiguration.SecurityPolicies:該節點配置允許的伺服器安全策略,配置通訊是否要簽名和加密。

  • ServerConfiguration.UserTokenPolicies:該節點配置允許的使用者Token策略,例如是否允許匿名訪問。

  • AvailableSamplingRates:配置支援的變數取樣率。

  • TraceConfiguration:配置OPC UA伺服器的日誌記錄,設定日誌記錄路徑,配置的路徑是在系統臨時資料夾下的路徑,日誌檔案的完整路徑是在%TEMP%\Logs\SampleOpcUaServer.log

NodeManagerFactory

新建NodeManagerFactory類,OPC UA server將呼叫該類的Create方法建立INodeManager實現類,而INodeManager實現類用於管理OPC UA地址空間。內容如下:

using Opc.Ua;
using Opc.Ua.Server;

namespace SampleOpcUaServer
{
    internal class NodeManagerFactory : INodeManagerFactory
    {
        public NodeManager? NodeManager { get; private set; }
        public StringCollection NamespacesUris => new StringCollection() { "http://opcfoundation.org/OpcUaServer" };

        public INodeManager Create(IServerInternal server, ApplicationConfiguration configuration)
        {
            if (NodeManager != null)
                return NodeManager;

            NodeManager = new NodeManager(server, configuration, NamespacesUris.ToArray());
            return NodeManager;
        }
    }
}
  • 實現INodeManagerFactory介面,需實現NamespacesUris屬性和Create方法。
  • NodeManager類是自定義的類,定義見後文。
  • 為了獲取Create方法返回的NodeManager類,定義了NodeManager屬性。

NodeManager

新建NodeManager類:

using Opc.Ua;
using Opc.Ua.Server;

namespace SampleOpcUaServer
{
    internal class NodeManager : CustomNodeManager2
    {
        public NodeManager(IServerInternal server, params string[] namespaceUris)
            : base(server, namespaceUris)
        {
        }

        public NodeManager(IServerInternal server, ApplicationConfiguration configuration, params string[] namespaceUris)
            : base(server, configuration, namespaceUris)
        {
        }

        protected override NodeStateCollection LoadPredefinedNodes(ISystemContext context)
        {
            FolderState root = CreateFolder(null, "Root");
            root.AddReference(ReferenceTypes.Organizes, true, ObjectIds.ObjectsFolder); // 將節點新增到伺服器根節點
            root.EventNotifier = EventNotifiers.SubscribeToEvents;
            AddRootNotifier(root);

            CreateVariable(root, "Test", BuiltInType.Int64, ValueRanks.Scalar);

            return new NodeStateCollection(new List<NodeState> { root });
        }

        protected virtual FolderState CreateFolder(NodeState? parent, string name)
        {
            string path = parent?.NodeId.Identifier is string id ? id + "_" + name : name;

            FolderState folder = new FolderState(parent);
            folder.SymbolicName = name;
            folder.ReferenceTypeId = ReferenceTypes.Organizes;
            folder.TypeDefinitionId = ObjectTypeIds.FolderType;
            folder.NodeId = new NodeId(path, NamespaceIndex);
            folder.BrowseName = new QualifiedName(path, NamespaceIndex);
            folder.DisplayName = new LocalizedText("en", name);
            folder.WriteMask = AttributeWriteMask.None;
            folder.UserWriteMask = AttributeWriteMask.None;
            folder.EventNotifier = EventNotifiers.None;

            if (parent != null)
            {
                parent.AddChild(folder);
            }

            return folder;
        }

        protected virtual BaseDataVariableState CreateVariable(NodeState? parent, string name, BuiltInType dataType, int valueRank)
        {
            return CreateVariable(parent, name, (uint)dataType, valueRank);
        }

        protected virtual BaseDataVariableState CreateVariable(NodeState? parent, string name, NodeId dataType, int valueRank)
        {
            string path = parent?.NodeId.Identifier is string id ? id + "_" + name : name;

            BaseDataVariableState variable = new BaseDataVariableState(parent);
            variable.SymbolicName = name;
            variable.ReferenceTypeId = ReferenceTypes.Organizes;
            variable.TypeDefinitionId = VariableTypeIds.BaseDataVariableType;
            variable.NodeId = new NodeId(path, NamespaceIndex);
            variable.BrowseName = new QualifiedName(path, NamespaceIndex);
            variable.DisplayName = new LocalizedText("en", name);
            variable.WriteMask = AttributeWriteMask.None;
            variable.UserWriteMask = AttributeWriteMask.None;
            variable.DataType = dataType;
            variable.ValueRank = valueRank;
            variable.AccessLevel = AccessLevels.CurrentReadOrWrite;
            variable.UserAccessLevel = AccessLevels.CurrentReadOrWrite;
            variable.Historizing = false;
            variable.Value = Opc.Ua.TypeInfo.GetDefaultValue(dataType, valueRank, Server.TypeTree);
            variable.StatusCode = StatusCodes.Good;
            variable.Timestamp = DateTime.UtcNow;

            if (valueRank == ValueRanks.OneDimension)
            {
                variable.ArrayDimensions = new ReadOnlyList<uint>(new List<uint> { 0 });
            }
            else if (valueRank == ValueRanks.TwoDimensions)
            {
                variable.ArrayDimensions = new ReadOnlyList<uint>(new List<uint> { 0, 0 });
            }

            if (parent != null)
            {
                parent.AddChild(variable);
            }

            return variable;
        }

        public void UpdateValue(NodeId nodeId, object value)
        {
            var variable = (BaseDataVariableState)FindPredefinedNode(nodeId, typeof(BaseDataVariableState));
            if (variable != null)
            {
                variable.Value = value;
                variable.Timestamp = DateTime.UtcNow;
                variable.ClearChangeMasks(SystemContext, false);
            }
        }

		public void AddFolder(NodeId parentId, string name)
		{
		    var node = Find(parentId);
		    if (node != null)
		    {
		        CreateFolder(node, name);
		        AddPredefinedNode(SystemContext, node);
		    }
		}

		public void AddVariable(NodeId parentId, string name, BuiltInType dataType, int valueRank)
		{
		    AddVariable(parentId, name, (uint)dataType, valueRank);
		}

		public void AddVariable(NodeId parentId, string name, NodeId dataType, int valueRank)
		{
		    var node = Find(parentId);
		    if (node != null)
		    {
		        CreateVariable(node, name, dataType, valueRank);
		        AddPredefinedNode(SystemContext, node);
		    }
		}
    }
}

上述程式碼中:

  • 需繼承CustomNodeManager2,這是OPC UA標準庫中提供的類。
  • 重寫LoadPredefinedNodes方法,在該方法中配置預定義節點。其中建立了一個Root資料夾,Root資料夾中新增了Test變數。
  • root.AddReference(ReferenceTypes.Organizes, true, ObjectIds.ObjectsFolder)該語句將節點新增到OPC UA伺服器根節點,如果不使用該語句,可在Server節點下看到新增的節點。
  • CreateFolder是定義的方法,用於簡化建立資料夾節點。
  • CreateVariable是自定義的方法,用於簡化建立變數節點。
  • UpdateValue是用於更新變數節點值的方法。其中修改值後,需呼叫ClearChangeMasks方法,才能通知客戶端更新值。
  • AddFolder用於啟動伺服器後新增新的資料夾。
  • AddVariable用於啟動伺服器後新增新的變數。

測試伺服器

比較好用的測試工具有:

  • UaExpert:Unified Automation公司提供的測試工具,需安裝,能用於連線OPC UA。

  • OpcExpert:opcti公司提供的免費測試工具,綠色版,能連線OPC和OPC UA。

以下用OpcExpert測試。

瀏覽本地計算機可發現OPC UA伺服器,可看到新增的Root節點和Test變數,Test變數的值會每秒更新。

image

原始碼地址:https://github.com/Yada-Yang/SampleOpcUaServer

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