NModbus使用示例
一、什么是ModBus通讯协议
Modbus协议是应用于电子控制器上的一种通用语言，此协议支持传统的RS-232、RS-422、RS-485和以太网设备。
ModBus功能码
| 01 | READ COIL STATUS |
| 02 | READ INPUT STATUS |
| 03 | READ HOLDING REGISTER |
| 04 | READ INPUT REGISTER |
| 05 | WRITE SINGLE COIL |
| 06 | WRITE SINGLE REGISTER |
| 15 | WRITE MULTIPLE COIL |
| 16 | WRITE MULTIPLE REGISTER |
二、ModBus通讯协议的.Net实现
推荐一个github的开源实现类库：NModBus，github地址：https://github.com/NModbus/NModbus。针对TCP、UDP、RTU等的ModBus通讯方式都有实现。
读写方法：
| 方法名 | 作用 | 所需参数 | 返回值 | 对应功能码 |
| ReadCoils | 读取DO的状态 | 从站地址(8位)
byte slaveAddress 起始地址(16位)
ushort startAddress 读取数量(16位) ushort numberOfPoints | bool[] | 01 |
| ReadInputs | 读取DI的状态 | 从站地址(8位)
byte slaveAddress 起始地址(16位)
ushort startAddress 读取数量(16位) ushort numberOfPoints | bool[] | 02 |
| ReadHoldingRegisters | 读取AO的值 | 从站地址(8位)
byte slaveAddress 起始地址(16位) ushort startAddress 读取数量(16位) ushort numberOfPoints | ushort[] | 03 |
| ReadInputRegisters | 读取AI的值 | 从站地址(8 位)
byte slaveAddress 起始地址(16位)
ushort startAddress 读取数量(16位) ushort numberOfPoints | ushort[] | 04 |
| WriteSingleCoil | 写入值到DO | 从站地址(8位)
byte slaveAddress 线圈地址(16位) ushort coilAddress 写入值(布尔型) bool value | 无返回值 | 05 |
| WriteSingleRegister | 写入值到AO | 从站地址(8位)
byte slaveAddress 寄存器地址(16位) ushort registerAddress 写入值(16位) ushort value | 无返回值 | 06 |
| WriteMultipleCoils | 写多线圈寄存器 | 从站地址(8位)
byte slaveAddress 起始地址(16位) ushort startAddress 写入值(布尔型数组) bool[] data | 无返回值 | 15 |
| WriteMultipleRegisters | 写多个保持寄存器 | 从站地址(8位)
byte slaveAddress
起始地址(16位) ushort startAddress, 寄存器值(16位整型数组) ushort[] data | 无返回值 | 16 |
| ReadWriteMultipleRegisters | 读写多个保持寄存器 | 从站地址(8位)
byte slaveAddress 读起始地址(16位) ushort startReadAddress
读取数量(16位) ushort numberOfPointsToRead, 写入起始地址(16位) ushort startWriteAddress, 写入值(16位整型数组) ushort[] writeData | ushort[] | 23 |
每个方法都有各自的异步方法实现。
三、NModBus Master 示例
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private static void Main(string[] args) { try { ModbusSerialRtuMasterWriteRegisters(); ModbusTcpMasterReadInputs(); } catch (Exception e) { Console.WriteLine(e.Message); } Console.WriteLine("Press any key to continue..."); Console.ReadKey(); } /// <summary> /// Simple Modbus serial RTU master write holding registers example. /// </summary> public static void ModbusSerialRtuMasterWriteRegisters() { using (SerialPort port = new SerialPort("COM3")) { // configure serial port port.BaudRate = 9600; port.DataBits = 8; port.Parity = Parity.None; port.StopBits = StopBits.One; port.Open(); var factory = new ModbusFactory(); IModbusMaster master = factory.CreateRtuMaster(port); byte slaveId = 1; ushort startAddress = 100; ushort[] registers = new ushort[] { 1, 2, 3 }; // write three registers master.WriteMultipleRegisters(slaveId, startAddress, registers); } } /// <summary> /// Simple Modbus TCP master read inputs example. /// </summary> public static void ModbusTcpMasterReadInputs() { using (TcpClient client = new TcpClient("127.0.0.1", 502)) { var factory = new ModbusFactory(); IModbusMaster master = factory.CreateMaster(client); // read five input values ushort startAddress = 100; ushort numInputs = 5; bool[] inputs = master.ReadInputs(0, startAddress, numInputs); for (int i = 0; i < numInputs; i++) { Console.WriteLine($"Input {(startAddress + i)}={(inputs[i] ? 1 : 0)}"); } } // output: // Input 100=0 // Input 101=0 // Input 102=0 // Input 103=0 // Input 104=0 } |
example: https://github.com/NModbus/NModbus/tree/develop/Samples
原创文章，作者：奋斗，如若转载，请注明出处：https://blog.ytso.com/314947.html