1.按照上一篇日志“ OPC客户端设计 ”的方法安装动态链接库及相关的注册工作。
2.包含头文件：
opcda.h
opc_ae.h
WTclientAPI.h
3.添加库文件：
WTclient.lib (要被加入解决方案)
WTclient.dll
4.初始化方法：
WTclientCoInit();
CoUninitialize();
5.查询所有的OPC server：
1 //得到OPC server个数 2 int serverNumber = NumberOfOPCServers(TRUE, ""); 3 4 //得到所有OPC server的名字 5 char buf[100]; 6 CString serverName; 7 for(int i=0; i < serverNumber; i++) 8 { 9 GetOPCServerName (i, buf, 100); 10 serverName = buf; 11 MessageBox(0, serverName, 0); 12 }
6.建立OPC连接：
ConnectionHandle = ConnectOPC ("", serverName, FALSE);
7.断开OPC连接：
DisconnectOPC(ConnectionHandle);
ConnectionHandle = INVALID_HANDLE_VALUE;
8.添加组：
1 CString groupName = "groupName"; 2 DWORD Rate = 100; 3 float DeadBand = 100; 4 HANDLE hGroup = AddOPCGroup (ConnectionHandle, groupName, &Rate, &DeadBand); 5 6 if (hGroup == INVALID_HANDLE_VALUE) 7 { 8 MessageBox("Error in adding group.", "警告", 0); 9 return; 10 }
9.删除组：
void RemoveOPCGroup (HANDLE hConnect, HANDLE hGroup);
10.添加项目：
CString itemName = "itemName";
HANDLE itemHandle = AddOPCItem(ConnectionHandle, hGroup, itemName);
11.移除项目：
void RemoveOPCItem (HANDLE hConnect, HANDLE hGroup, HANDLE hItem);
12.读取项目：
//读取项目
VARIANT *pVar = new VARIANT;
FILETIME *pTimeStamp = new FILETIME;
DWORD *pQuality = new DWORD;
ReadOPCItem (ConnectionHandle, hGroup, itemHandle, pVar, pTimeStamp, pQuality);
13.写入项目
VARIANT newVar;
newVar.dblVal = 3.141592;
WriteOPCItem (ConnectionHandle, hGroup, itemHandle, &newVar, 1);
我的完整示例：
1 //初始化 2 WTclientCoInit(); 3 4 //得到OPC server个数 5 int serverNumber = NumberOfOPCServers(TRUE, ""); 6 7 //得到所有OPC server的名字 8 char buf[100]; 9 CString serverName; 10 vector<CString> serverNames; 11 12 for(int i=0; i < serverNumber; i++) 13 { 14 GetOPCServerName (i, buf, 100); 15 serverName = buf; 16 serverNames.push_back(serverName); 17 } 18 19 if(serverNumber == 0) 20 { 21 MessageBox("没有可用的OPC服务器", "警告", 0); 22 return ; 23 } 24 25 //建立OPC连接 26 ConnectionHandle = ConnectOPC ("", serverNames[0], TRUE); 27 28 if (ConnectionHandle == INVALID_HANDLE_VALUE) 29 { 30 MessageBox("Error in connecting.", "警告", 0); 31 return; 32 } 33 34 //得到项目个数 35 int itemNum = NumberOfOPCItems(ConnectionHandle); 36 37 //得到所有项目名称 38 char itemBuf[128]; 39 CString iName; 40 vector<CString> itemNames; 41 for(int index = 0; index < itemNum; index++) 42 { 43 if(GetOPCItemName (ConnectionHandle, index, itemBuf, 128)) 44 { 45 iName = itemBuf; 46 itemNames.push_back(iName); 47 } 48 else 49 { 50 MessageBox("读取item名失败", "警告", 0); 51 return ; 52 } 53 54 } 55 56 //得到所有项目属性 57 for(vector<CString>::iterator iter = itemNames.begin(); iter != itemNames.end(); ++iter) 58 { 59 //得到当前项目的属性个数 60 int propNum = NumberOfItemProperties(ConnectionHandle, *iter); 61 62 for(int i = 0; i < propNum; i++) 63 { 64 //得到属性特征 65 DWORD propertyID = 0; 66 VARTYPE vt; 67 BYTE describtion[1024]; 68 GetItemPropertyDescription (ConnectionHandle, i, &propertyID, &vt, describtion, 1024); 69 70 //读取当前属性值 71 VARIANT value; 72 ReadPropertyValue (ConnectionHandle, *iter, propertyID, &value); 73 } 74 } 75 76 //添加组 77 CString groupName = "groupName"; 78 DWORD Rate = 1; 79 float DeadBand = 1; 80 HANDLE hGroup = AddOPCGroup (ConnectionHandle, groupName, &Rate, &DeadBand); 81 82 if (hGroup == INVALID_HANDLE_VALUE) 83 { 84 MessageBox("Error in adding group.", "警告", 0); 85 return; 86 } 87 88 //添加项目 89 CString itemName = "Bucket Brigade.Boolean"; 90 HANDLE itemHandle = AddOPCItem(ConnectionHandle, hGroup, itemName); 91 92 if (itemHandle == INVALID_HANDLE_VALUE) 93 { 94 MessageBox("该项不存在.", "警告", 0); 95 return; 96 } 97 98 //得到项目类型 99 VARTYPE type; 100 DWORD AccessRights; 101 GetOPCItemType(ConnectionHandle, hGroup, "Bucket Brigade.Boolean", &type, &AccessRights); 102 103 104 105 //读取项目 106 VARIANT *pVar = new VARIANT; 107 FILETIME *pTimeStamp = new FILETIME; 108 DWORD *pQuality = new DWORD; 109 if( !ReadOPCItem (ConnectionHandle, hGroup, itemHandle, pVar, pTimeStamp, pQuality)) 110 { 111 MessageBox("读取失败.", "警告", 0); 112 return ; 113 } 114 115 116 //写入项目 117 VARIANT newVar; 118 newVar.vt = 4; 119 newVar.fltVal = 3.14; 120 if(!WriteOPCItem (ConnectionHandle, hGroup, itemHandle, &newVar, 1)) 121 { 122 MessageBox("写入失败.", "警告", 0); 123 return ; 124 } 125 126 127 //读取项目 128 ReadOPCItem (ConnectionHandle, hGroup, itemHandle, pVar, pTimeStamp, pQuality);