C# OPC使用
OPC客户端操作主要有4个步骤:
1.连接OPC服务器
2.创建组和项
3.读写数据
4.断开服务器连接
全部代码:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
using System; using System.Collections.Generic; using System.Net; using System.Threading; using OPCAutomation; namespace ConsoleOPC { public class OPCClient { private OPCServer KepServer; private OPCGroups KepGroups; public OPCGroup KepGroup; private OPCItems KepItems; private OPCItem KepItem; int itmHandleClient = 0; int itmHandleServer = 0; public object readValue; public List<string> serverNames = new List<string>(); public List<string> Tags = new List<string>(); /// <summary> /// 枚举本地OPC SERVER /// </summary> public void GetOPCServers() { IPHostEntry IPHost = Dns.GetHostEntry(Environment.MachineName); Console.WriteLine("MAC Address:"); foreach (IPAddress ip in IPHost.AddressList) { Console.WriteLine(ip.ToString()); } Console.WriteLine("Please Enter IPHOST"); string strHostIP = "localhost";//Console.ReadLine(); IPHostEntry ipHostEntry = Dns.GetHostEntry(strHostIP); try { KepServer = new OPCServer(); object serverList = KepServer.GetOPCServers(ipHostEntry.HostName.ToString()); int i = 0; foreach (string serverName in (Array)serverList) { Console.WriteLine(i.ToString() + "." + serverName); serverNames.Add(serverName); } } catch (Exception ex) { Console.WriteLine("Connect Error:" + ex.Message); } } /// <summary> /// 连接OPC SERVER /// </summary> /// <param name="serverName">OPC SERVER名字</param> public void ConnectServer(string serverName) { try { KepServer.Connect(serverName, ""); CreateGroup(""); CreateItems(); } catch (Exception ex) { Console.WriteLine("Connect Error:" + ex.Message); } } /// <summary> /// 创建组,组名无所谓 /// </summary> private void CreateGroup(string groupName) { try { KepGroups = KepServer.OPCGroups; KepGroup = KepGroups.Add(groupName); KepServer.OPCGroups.DefaultGroupIsActive = true; KepServer.OPCGroups.DefaultGroupDeadband = 0; KepGroup.UpdateRate = 250; KepGroup.IsActive = true; KepGroup.IsSubscribed = true; } catch (Exception ex) { Console.WriteLine("Create group error:" + ex.Message); } } private void CreateItems() { KepItems = KepGroup.OPCItems; KepGroup.DataChange += new DIOPCGroupEvent_DataChangeEventHandler(KepGroup_DataChange); } private void KepGroup_DataChange(int TransactionID, int NumItems, ref Array ClientHandles, ref Array ItemValues, ref Array Qualities, ref Array TimeStamps) { for (int i = 1; i <= NumItems; i++) { readValue = ItemValues.GetValue(i).ToString(); } } private void GetTagValue(string tagName) { try { readValue = ""; if (itmHandleClient != 0) { Array Errors; OPCItem bItem = KepItems.GetOPCItem(itmHandleServer); //注:OPC中以1为数组的基数 int[] temp = new int[2] { 0, bItem.ServerHandle }; Array serverHandle = (Array)temp; //移除上一次选择的项 KepItems.Remove(KepItems.Count, ref serverHandle, out Errors); } itmHandleClient = 12345; KepItem = KepItems.AddItem(tagName, itmHandleClient); itmHandleServer = KepItem.ServerHandle; } catch (Exception err) { //没有任何权限的项,都是OPC服务器保留的系统项,此处可不做处理。 itmHandleClient = 0; Console.WriteLine("Read value error:" + err.Message); } } public void WriteValue(string tagName, object _value) { GetTagValue(tagName); OPCItem bItem = KepItems.GetOPCItem(itmHandleServer); int[] temp = new int[2] { 0, bItem.ServerHandle }; Array serverHandles = (Array)temp; object[] valueTemp = new object[2] { "", _value }; Array values = (Array)valueTemp; Array Errors; int cancelID; KepGroup.AsyncWrite(1, ref serverHandles, ref values, out Errors, 2009, out cancelID); //KepItem.Write(txtWriteTagValue.Text);//这句也可以写入,但并不触发写入事件 GC.Collect(); } public object ReadValue(string tagName) { GetTagValue(tagName); Thread.Sleep(500); try { return KepItem.Value; } catch { return null; } } public void ReadValue(string tagName,bool wtf) { GetTagValue(tagName); OPCItem bItem = KepItems.GetOPCItem(itmHandleServer); int[] temp = new int[2] { 0, bItem.ServerHandle }; Array serverHandles = (Array)temp; Array Errors; int cancel; KepGroup.AsyncRead(1, ref serverHandles, out Errors, 2009, out cancel); GC.Collect(); } } }
步骤:
1.使用GetOPCServers方法,将本地所有OPC Server上所有OPC服务器服务枚举并写入serverNames变量中
2.使用ConnectServer方法,连接服务器。此方法自动创建OPC Group,创建方法中的groupname任意写
3.使用ReadValue及WriteValue方法读写数据。
PS:
1.OPCItems是一个列表,每次将旧数据移除,插入新数据,即列表中永远只有一个元素;
2.读的时候有可能旧数据移除,新数据未写入,报对象为null的错误,sleep一下即可
第二条不一定对,使用模拟器的时候也有此问题,连PLC时无此问题