冠冕堂皇

摘要： 4.4.8.4 IOPCBrowseServerAddressSpace:: GetItemIDHRESULT GetItemID( [in] LPCWSTR szItemDataID, [out, string] LPWSTR * szItemID );DescriptionProvides a way to assemble a ‘fully qualified’ ITEM ID in a hierarchical space. This is required since the browsing functions return only the components or token 阅读全文

摘要： from：http://www.51plc.com/thread-10584-1-2.html表1 ModBus功能码功能码名称作用01读取线圈状态取得一组逻辑线圈的当前状态（ON/OFF)02读取输入状态取得一组开关输入的当前状态（ON/OFF)03读取保持寄存器在一个或多个保持寄存器中取得当前的二进制值04读取输入寄存器在一个或多个输入寄存器中取得当前的二进制值05强置单线圈强置一个逻辑线圈的通断状态06预置单寄存器把具体二进值装入一个保持寄存器07读取异常状态取得8个内部线圈的通断状态，这8个线圈的地址由控制器决定，用户逻辑可以将这些线圈定义，以说明从机状态，短报文适宜于迅速读取状态08 阅读全文

摘要： The ItemID is the fully qualified definition of a data item in the server, commonly referred to as the WHAT. No other information is required to identify the data item for the client to be able to read/write values.The Item definition (ItemID) used in the OPCITEMDEF(定义见最下) and elsewhere is a nul-ter 阅读全文

摘要： 通讯参数串口类型RS485波特率（Baud Rate）9600数据位（Data Bits）8停止位（Stop Bits）1校验方式（Parity）无校验通讯协议Modbus RTUModbus ID0x01-0xff从机数据寄存器地址序号描述数据类型寄存器地址单位量程计算1温度十六进制0000℃0~2402压力十六进制0001KPa0~70003工况流量十六进制0002m3//h根据口径4标况流量十六进制0003Nm3/h根据口径5标况累积流量十六进制0004Nm3备注： 1）流量计的参数采用IEEE-754浮点数标准 2）工况流量和标况流量是根据所用流量计口径而定。例如标准DN50，其工况流 阅读全文

摘要： OPC specifications always contain two sets of interfaces; Custom Interfaces and Automation Interfaces. It has been found that it is not possible to define a single (dual-automation) interface which is both highly efficient and provides the look-and-feel of typical automation servers, like Excel. In 阅读全文

摘要： FROM:http://en.wikipedia.org/wiki/Computer-supported_telecommunications_applicationsComputer-supported telecommunications applications (CSTA)is anabstractionlayer fortelecommunicationsapplications. It is independent of underlyingprotocols. It has a telephone device model that enablesCTIapplications 阅读全文

摘要： FROM :http://en.wikipedia.org/wiki/Computer_telephony_integrationComputer telephony integration, also called computer–telephone integration orCTI, is a common name for any technology that allows interactions on atelephoneand acomputerto be integrated or coordinated. The term is predominantly used to 阅读全文

摘要： FROM:http://en.wikipedia.org/wiki/CT_ConnectCT Connectis a software product that allows computer applications to monitor and control telephone calls. This monitoring and control is calledcomputer-telephone integration, or CTI. CT Connect implements CTI by providingserversoftware that supports the CT 阅读全文

摘要： 以下的代码演示了如何使用LINQ to XML来快速创建一个xml：隐藏行号 复制代码 ？ 创建 XMLpublic static void CreateDocument(){ string path = @"d:\website"; XDocument xdoc = new XDocument(new XDeclaration("1.0", "utf-8", "yes"), new XElement("Root", "root")); xdoc.Save(path);}运行 阅读全文

摘要： SQL Server .NET Data Provider 连接字符串包含一个由一些属性名/值对组成的集合。每一个属性/值对都由分号隔开。PropertyName1=Value1;PropertyName2=Value2;PropertyName3=Value3;.....同样，连接字符串必须包含SQL Server实例名称:Data Source=ServerName;使用本地的SQL Server(localhost)，如果想要使用远程服务器运行，应该在示例对象中把正确的服务器赋给Data Source 属性。此外，还必须指定所支持的两种身份验证方法(即Windows身份验证和SQL Se 阅读全文