C#|C# 使用modbus 读取PLC 寄存器地址的方法 C#使用modbus读取PLC寄存器地址的

使用的组件Nmodbus
定义参数，全局变量：

//创建modbus实体对象private static ModbusFactory modbusFactory; private static IModbusMaster master; //写线圈或写寄存器数组bool[] coilsBuffer; ushort[] registerBuffer; //功能码string functionCode; //参数(分别为站号,起始地址,长度)byte slaveAddress; ushort startAddress; ushort numberOfPoints; //ip 地址与端口号string IPAddress = string.Empty; int VisitPort = 502;

初始化参数，创建连接：

private void Connection(object sender, EventArgs e){try{//PLC连接配置信息，PLC ip地址IPAddress =127.0.0.1; //端口，modbus 默认502，根据实际情况填写VisitPort =502; //初始化modbusmastermodbusFactory = new ModbusFactory(); //在本地测试所以使用回环地址,modbus协议规定端口号 502master = modbusFactory.CreateMaster(new TcpClient(IPAddress, VisitPort)); //设置读取超时时间master.Transport.ReadTimeout = 10000; master.Transport.Retries = 2000; }catch (Exception ex){MessageBox.Show(ex.Message); }}

初始化读写参数

/// /// 初始化读参数/// private void SetReadParameters(int slaveAddress=1,int startAddress=200,int numberOfPoints=1){//DeviceIDslaveAddress = byte.Parse(slaveAddress); //起始地址，startAddress = ushort.Parse(startAddress); //数据长度numberOfPoints = ushort.Parse(numberOfPoints); }

运行读取方法

private async void ExecuteFunction(){try{//Moddbus共有这些功能码//01 Read Coils//02 Read DisCrete Inputs//03 Read Holding Registers//04 Read Input Registers//05 Write Single Coil//06 Write Single Registers//0F Write Multiple Coils//10 Write Multiple RegistersfunctionCode="01 Read Coils"；//根据实际点号类型选择读写功能码//重新实例化是为了 modbus slave更换连接时不报错 //master = modbusFactory.CreateMaster(new TcpClient(IPAddress, VisitPort)); if (functionCode != null){switch (functionCode){case "01 Read Coils"://读取单个线圈SetReadParameters(); coilsBuffer = master.ReadCoils(slaveAddress, startAddress, numberOfPoints); for (int i = 0; i < coilsBuffer.Length; i++){SetMsg(coilsBuffer[i] + " "); }SetMsg("\r\n"); break; case "02 Read DisCrete Inputs"://读取输入线圈/离散量线圈SetReadParameters(); coilsBuffer = master.ReadInputs(slaveAddress, startAddress, numberOfPoints); for (int i = 0; i < coilsBuffer.Length; i++){SetMsg(coilsBuffer[i] + " "); }SetMsg("\r\n"); break; case "03 Read Holding Registers"://读取保持寄存器SetReadParameters(); registerBuffer = master.ReadHoldingRegisters(slaveAddress, startAddress, numberOfPoints); for (int i = 0; i < registerBuffer.Length; i++){SetMsg(registerBuffer[i] + " "); }SetMsg("\r\n"); break; case "04 Read Input Registers"://读取输入寄存器SetReadParameters(); registerBuffer = master.ReadInputRegisters(slaveAddress, startAddress, numberOfPoints); for (int i = 0; i < registerBuffer.Length; i++){SetMsg(registerBuffer[i] + " "); }SetMsg("\r\n"); break; case "05 Write Single Coil"://写单个线圈SetWriteParametes(); await master.WriteSingleCoilAsync(slaveAddress, startAddress, coilsBuffer[0]); break; case "06 Write Single Registers"://写单个输入线圈/离散量线圈SetWriteParametes(); await master.WriteSingleRegisterAsync(slaveAddress, startAddress, registerBuffer[0]); break; case "0F Write Multiple Coils"://写一组线圈SetWriteParametes(); await master.WriteMultipleCoilsAsync(slaveAddress, startAddress, coilsBuffer); break; case "10 Write Multiple Registers"://写一组保持寄存器SetWriteParametes(); await master.WriteMultipleRegistersAsync(slaveAddress, startAddress, registerBuffer); break; default:break; }}else{MessageBox.Show("请选择功能码!"); }master.Dispose(); }catch (Exception ex){MessageBox.Show(ex.Message); }}

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