我正在从OPC UA Foundation GitHub页面试用SampleApplication NetCoreConsoleClientOPC-UA.net Standard一路上我遇到了几个问题。
我想使用该库来简单地读取服务器发送的数据（我正在使用Prosys OPC UA服务器），并将其写到控制台中。我一直在努力获取与服务器一起发送的实际数据变量。我设法连接到它并订阅，但是我无法使用onNotification方法获得所需的MonitoredItem值。
Console.WriteLine("6 - Add a list of items (server current time and status) to the subscription.");
exitCode = ExitCode.ErrorMonitoredItem;
var list = new List<MonitoredItem> {
new MonitoredItem(subscription.DefaultItem)
{
DisplayName = "ServerStatusCurrentTime", StartNodeId = "i="+Variables.Server_ServerStatus_CurrentTime.ToString()
}
};
list.ForEach(i => i.Notification += OnNotification);
subscription.AddItems(list);
这里示例将新的MonitoredItem添加到列表中。当我尝试添加自己的项目时，即使Server一直在发送更改的值，我也从未收到任何响应，因此它应该触发onNotification方法。
我从这部分获得所需值的DisplayName和StartNodeId：
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);
}
}
等等：
var list = new List<MonitoredItem> {
new MonitoredItem(subscription.DefaultItem)
{
DisplayName = "Simulation", StartNodeId = "ns=2;s=85\:Simulation"
} };
我从不返回任何值。我对OPC UA标准及其打包数据的方式感到困惑。
我遇到了非常相似的问题，因为许多在线OPC UA示例未提供具体解决方案。下面的解决方案使用OPCFOundation的库从标准OPC UA服务器读取。
[我在kepware ServerEX OPC UA服务器上尝试了以下解决方案，并且工作完全稳定，但我认为同样适用于Prosys或任何标准OPC UA服务器，但需要进行一些细微调整。
安装以下Nuget软件包：OPCFoundation.NetStandard.Opc.Ua
参考：答案是对多个答案和人们在stackoverflow上所做的一些出色工作的改编。
using System;
using System.Collections.Generic;
using System.Windows.Forms;
using Opc.Ua; // Install-Package OPCFoundation.NetStandard.Opc.Ua
using Opc.Ua.Client;
using Opc.Ua.Configuration;
using System.Threading;
namespace Test_OPC_UA
{
public partial class Form1 : Form
{
//creating a object that encapsulates the netire OPC UA Server related work
OPCUAClass myOPCUAServer;
//creating a dictionary of Tags that would be captured from the OPC UA Server
Dictionary<String, Form1.OPCUAClass.TagClass> TagList = new Dictionary<String, Form1.OPCUAClass.TagClass>();
public Form1()
{
InitializeComponent();
//Add tags to the Tag List, For each tag, you have to define the name of the tag and its address
//the address can typically be found by browsing the OPC UA Server's tree. In the example below
// The OPC Server had the following hierarchy: M0401 -> CPU945 -> IBatchOutput
//i used TBC0401 as a name of the tag, you can use any name
//add as many tags as you want to capture
TagList.Add("TBC0401", new Form1.OPCUAClass.TagClass("TBC0401", "M0401.CPU945.iBatchOutput"));
//to initialize the OPC UA Server, provide the IP Address, Port Number, the list of tags you want to capture
//in some OPC UA servers and kepware aswell the session can be closed by the OPC UA Server, so its better to
//allow the class to reinitiate session periodically, before renewing current sessions are closed
myOPCUAServer = new OPCUAClass("127.0.0.1", "49320", TagList, true, 1, "2");
//once the OPC Server has been initialized, you can easily read Tag values and even see when they were
// updated last time
//as an example i could read the TBC0401 tag by:
var tagCurrentValue = TagList["TBC0401"].CurrentValue;
var tagLastGoodValue = TagList["TBC0401"].LastGoodValue;
var lastTimeTagupdated = TagList["TBC0401"].LastUpdatedTime;
}
public class OPCUAClass
{
public string ServerAddress { get; set; }
public string ServerPortNumber { get; set; }
public bool SecurityEnabled { get; set; }
public string MyApplicationName { get; set; }
public Session OPCSession { get; set; }
public string OPCNameSpace { get; set; }
public Dictionary<string, TagClass> TagList { get; set; }
public bool SessionRenewalRequired { get; set; }
public double SessionRenewalPeriodMins { get; set; }
public DateTime LastTimeSessionRenewed { get; set; }
public DateTime LastTimeOPCServerFoundAlive { get; set; }
public bool ClassDisposing { get; set; }
public bool InitialisationCompleted { get; set; }
private Thread RenewerTHread { get; set; }
public OPCUAClass(string serverAddres, string serverport, Dictionary<string, TagClass> taglist, bool sessionrenewalRequired, double sessionRenewalMinutes, string nameSpace)
{
ServerAddress = serverAddres;
ServerPortNumber = serverport;
MyApplicationName = "MyApplication";
TagList = taglist;
SessionRenewalRequired = sessionrenewalRequired;
SessionRenewalPeriodMins = sessionRenewalMinutes;
OPCNameSpace = nameSpace;
LastTimeOPCServerFoundAlive = DateTime.Now;
InitializeOPCUAClient();
if (SessionRenewalRequired)
{
LastTimeSessionRenewed = DateTime.Now;
RenewerTHread = new Thread(renewSessionThread);
RenewerTHread.Start();
}
}
//class destructor
~OPCUAClass()
{
ClassDisposing = true;
try
{
OPCSession.Close();
OPCSession.Dispose();
OPCSession = null;
RenewerTHread.Abort();
}
catch { }
}
private void renewSessionThread()
{
while (!ClassDisposing)
{
if ((DateTime.Now - LastTimeSessionRenewed).TotalMinutes > SessionRenewalPeriodMins
|| (DateTime.Now - LastTimeOPCServerFoundAlive).TotalSeconds > 60)
{
Console.WriteLine("Renewing Session");
try
{
OPCSession.Close();
OPCSession.Dispose();
}
catch { }
InitializeOPCUAClient();
LastTimeSessionRenewed = DateTime.Now;
}
Thread.Sleep(2000);
}
}
public void InitializeOPCUAClient()
{
//Console.WriteLine("Step 1 - Create application configuration and certificate.");
var config = new ApplicationConfiguration()
{
ApplicationName = MyApplicationName,
ApplicationUri = Utils.Format(@"urn:{0}:" + MyApplicationName + "", ServerAddress),
ApplicationType = ApplicationType.Client,
SecurityConfiguration = new SecurityConfiguration
{
ApplicationCertificate = new CertificateIdentifier { StoreType = @"Directory", StorePath = @"%CommonApplicationData%\OPC Foundation\CertificateStores\MachineDefault", SubjectName = Utils.Format(@"CN={0}, DC={1}", MyApplicationName, ServerAddress) },
TrustedIssuerCertificates = new CertificateTrustList { StoreType = @"Directory", StorePath = @"%CommonApplicationData%\OPC Foundation\CertificateStores\UA Certificate Authorities" },
TrustedPeerCertificates = new CertificateTrustList { StoreType = @"Directory", StorePath = @"%CommonApplicationData%\OPC Foundation\CertificateStores\UA Applications" },
RejectedCertificateStore = new CertificateTrustList { StoreType = @"Directory", StorePath = @"%CommonApplicationData%\OPC Foundation\CertificateStores\RejectedCertificates" },
AutoAcceptUntrustedCertificates = true,
AddAppCertToTrustedStore = true
},
TransportConfigurations = new TransportConfigurationCollection(),
TransportQuotas = new TransportQuotas { OperationTimeout = 15000 },
ClientConfiguration = new ClientConfiguration { DefaultSessionTimeout = 60000 },
TraceConfiguration = new TraceConfiguration()
};
config.Validate(ApplicationType.Client).GetAwaiter().GetResult();
if (config.SecurityConfiguration.AutoAcceptUntrustedCertificates)
{
config.CertificateValidator.CertificateValidation += (s, e) => { e.Accept = (e.Error.StatusCode == StatusCodes.BadCertificateUntrusted); };
}
var application = new ApplicationInstance
{
ApplicationName = MyApplicationName,
ApplicationType = ApplicationType.Client,
ApplicationConfiguration = config
};
application.CheckApplicationInstanceCertificate(false, 2048).GetAwaiter().GetResult();
//string serverAddress = Dns.GetHostName();
string serverAddress = ServerAddress; ;
var selectedEndpoint = CoreClientUtils.SelectEndpoint("opc.tcp://" + serverAddress + ":" + ServerPortNumber + "", useSecurity: SecurityEnabled, operationTimeout: 15000);
// Console.WriteLine($"Step 2 - Create a session with your server: {selectedEndpoint.EndpointUrl} ");
OPCSession = Session.Create(config, new ConfiguredEndpoint(null, selectedEndpoint, EndpointConfiguration.Create(config)), false, "", 60000, null, null).GetAwaiter().GetResult();
{
//Console.WriteLine("Step 4 - Create a subscription. Set a faster publishing interval if you wish.");
var subscription = new Subscription(OPCSession.DefaultSubscription) { PublishingInterval = 1000 };
//Console.WriteLine("Step 5 - Add a list of items you wish to monitor to the subscription.");
var list = new List<MonitoredItem> { };
//list.Add(new MonitoredItem(subscription.DefaultItem) { DisplayName = "M0404.CPU945.iBatchOutput", StartNodeId = "ns=2;s=M0404.CPU945.iBatchOutput" });
list.Add(new MonitoredItem(subscription.DefaultItem) { DisplayName = "ServerStatusCurrentTime", StartNodeId = "i=2258" });
foreach (KeyValuePair<string, TagClass> td in TagList)
{
list.Add(new MonitoredItem(subscription.DefaultItem) { DisplayName = td.Value.DisplayName, StartNodeId = "ns=" + OPCNameSpace + ";s=" + td.Value.NodeID + "" });
}
list.ForEach(i => i.Notification += OnTagValueChange);
subscription.AddItems(list);
//Console.WriteLine("Step 6 - Add the subscription to the session.");
OPCSession.AddSubscription(subscription);
subscription.Create();
}
}
public class TagClass
{
public TagClass(string displayName, string nodeID)
{
DisplayName = displayName;
NodeID = nodeID;
}
public DateTime LastUpdatedTime { get; set; }
public DateTime LastSourceTimeStamp { get; set; }
public string StatusCode { get; set; }
public string LastGoodValue { get; set; }
public string CurrentValue { get; set; }
public string NodeID { get; set; }
public string DisplayName { get; set; }
}
public void OnTagValueChange(MonitoredItem item, MonitoredItemNotificationEventArgs e)
{
foreach (var value in item.DequeueValues())
{
if (item.DisplayName == "ServerStatusCurrentTime")
{
LastTimeOPCServerFoundAlive = value.SourceTimestamp.ToLocalTime();
}
else
{
if (value.Value != null)
Console.WriteLine("{0}: {1}, {2}, {3}", item.DisplayName, value.Value.ToString(), value.SourceTimestamp.ToLocalTime(), value.StatusCode);
else
Console.WriteLine("{0}: {1}, {2}, {3}", item.DisplayName, "Null Value", value.SourceTimestamp, value.StatusCode);
if (TagList.ContainsKey(item.DisplayName))
{
if (value.Value != null)
{
TagList[item.DisplayName].LastGoodValue = value.Value.ToString();
TagList[item.DisplayName].CurrentValue = value.Value.ToString();
TagList[item.DisplayName].LastUpdatedTime = DateTime.Now;
TagList[item.DisplayName].LastSourceTimeStamp = value.SourceTimestamp.ToLocalTime();
TagList[item.DisplayName].StatusCode = value.StatusCode.ToString();
}
else
{
TagList[item.DisplayName].StatusCode = value.StatusCode.ToString();
TagList[item.DisplayName].CurrentValue = null;
}
}
}
}
InitialisationCompleted = true;
}
}
}
}