Modbus协议时应用于电子控制器上的一种通用语言。通过此协议,控制器相互之间、控制器经由网络/串口和其它设备之间可以进行通信。它已经成为了一种工业标准。有了这个通信协议,不同的厂商生成的控制设备就可以连城工业网络,进行集中监控。
本文实现需要借用一个开源的NModbus库来完成,通过在菜单栏,工具-----NuGet包管理器-----管理解决方案的NuGet程序包,安装NModbus的开源库。
本次实例的基本框架和实现效果如下所示:
可自动识别当前设备的可用串口。
Modbus RTU通信的具体的实现如下:
using System; using System.Collections; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows.Forms; using Modbus.Device; using System.Net.Sockets; using System.Threading; using System.IO.Ports; using System.Drawing.Text; using System.Windows.Forms.VisualStyles; using System.Timers; using System.CodeDom.Compiler; namespace ModbusRtuMaster { public partial class Form1 : Form { #region 参数配置 private static IModbusMaster master; private static SerialPort port; //写线圈或写寄存器数组 private bool[] coilsBuffer; private ushort[] registerBuffer; //功能码 private string functionCode; //功能码序号 private int functionOder; //参数(分别为从站地址,起始地址,长度) private byte slaveAddress; private ushort startAddress; private ushort numberOfPoints; //串口参数 private string portName; private int baudRate; private Parity parity; private int dataBits; private StopBits stopBits; //自动测试标志位 private bool AutoFlag = false; //获取当前时间 private System.DateTime Current_time; //定时器初始化 private System.Timers.Timer t = new System.Timers.Timer(1000); private const int WM_DEVICE_CHANGE = 0x219; //设备改变 private const int DBT_DEVICEARRIVAL = 0x8000; //设备插入 private const int DBT_DEVICE_REMOVE_COMPLETE = 0x8004; //设备移除 #endregion public Form1() { InitializeComponent(); GetSerialLstTb1(); } private void Form1_Load(object sender, EventArgs e) { //界面初始化 cmb_portname.SelectedIndex = 0; cmb_baud.SelectedIndex = 5; cmb_parity.SelectedIndex = 2; cmb_databBits.SelectedIndex = 1; cmb_stopBits.SelectedIndex = 0; } #region 定时器 //定时器初始化,失能状态 private void init_Timer() { t.Elapsed += new System.Timers.ElapsedEventHandler(Execute); t.AutoReset = true;//设置false定时器执行一次,设置true定时器一直执行 t.Enabled = false;//定时器使能true,失能false //t.Start(); } private void Execute(object source,System.Timers.ElapsedEventArgs e) { //停止定时器后再打开定时器,避免重复打开 t.Stop(); //ExecuteFunctionandroid();可添加执行操作 t.Start(); } #endregion #region 串口配置 /// <summary> /// 串口参数获取 /// </summary> /// <returns></返回串口配置参数> private SerialPort InitSerialPortParameter() { if (cmb_portname.SelectedIndex < 0 || cmb_baud.SelectedIndex < 0 || cmb_parity.SelectedIndex < 0 || cmb_databBits.SelectedIndex < 0 || cmb_stopBits.SelectedIndex < 0) { MessageBox.Show("请选择串口参数"); return null; } else { portName = cmb_portname.SelectedItem.ToString(); baudRate = int.Parse(cmb_baud.SelectedItem.ToString()); switch (cmb_parity.SelectedItem.ToString()) { case "奇": parity = Parity.Odd; break; case "偶": parity = Parity.Even; break; case "无": parity = Parity.None; break; default: break; } dataBits = int.Parse(cmb_databBits.SelectedItem.ToString()); switch (cmb_stopBits.SelectedItem.ToString()) { case "1": stopBits = StopBits.One; break; case "2": stopBits = StopBits.Two; break; default: break; } port = new SerialPort(portName, baudRate, parity, dataBits, stopBits); return port; } } #endregion #region 串口收/发 private async void ExecuteFunction() { Current_time = System.DateTime.Now; try { if (port.IsOpen == false) { port.Open(); } if (functionCode != null) { switch (functionCode) { case "01 Read Coils"://读取单个线圈 SetReadParameters(); try { coilsBuffer = master.ReadCoils(slaveAddress, startAddress, numberOfPoints); } catch(Exception) { MessageBox.Show("参数配置错误"); //MessageBox.Show(e.Message); AutoFlag = false; break; } SetMsg("[" + Current_time.ToString("yyyy-MM-dd HH:mm:ss" + "]" + " ")); 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(); try { coilsBuffer = master.ReadInputs(slaveAddress, startAddress, numberOfPoints); } catch(Exception) { MessageBox.Show("参数配置错误"); AutoFlag = false; break; } javascript SetMsg("[" + Current_time.ToString("yyyy-MM-dd HH:mm:ssjs" + "]" + " ")); 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(); try { registerBuffer = master.ReadHoldingRegisters(slaveAddress, startAddress, numberOfPoints); } catch (Exception) { MessageBox.Show("参数配置错误"); AutoFlag = false; break; } SetMsg("[" + Current_time.ToString("yyyy-MM-dd HH:mm:ss" + "]" + " ")); 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(); try { registerBuffer = master.ReadInputRegisters(slaveAddress, startAddress, numberOfPoints); } catch (Exception) { MessageBox.Show("参数配置错误"); AutoFlag = false; break; } SetMsg("[" + Current_time.ToString("yyyy-MM-dd HH:mm:ss" + "]" + " ")); 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!"); } port.Close(); } catch (Exception ex) { port.Close(); MessageBox.Show(ex.Message); } } #endregion /// <summary> /// 设置读参数 /// </summary> private void SetReadParameters() { if (txt_startAddr1.Text == "" || txt_slave1.Text == "" || txt_length.Text == "") { MessageBox.Show("请填写读参数!"); } else { slaveAddress = byte.Parse(txt_slave1.Text); startAddress = ushort.Parse(txt_startAddr1.Text); numberOfPoints = ushort.Parse(txt_length.Text); } } /// <summary> /// 设置写参数 /// </summary> private void SetWriteParametes() { if (txt_startAddr2.Text == "" || txt_slave2.Text == "" || txt_data.Text == "") { MessageBox.Showandroid("请填写写参数!"); } else { slaveAddress = byte.Parse(txt_slave2.Text); startAddress = ushort.Parse(txt_startAddr2.Text); //判断是否写线圈 if (functionOder == 4 || functionOder == 6) { string[] strarr = txt_data.Text.Split(' '); coilsBuffer = new bool[strarr.Length]; //转化为bool数组 for (int i = 0; i < strarr.Length; i++) { // strarr[i] == "0" ? coilsBuffer[i] = false : coilsBuffer[i] = true; if (strarr[i] == "0") { coilsBuffer[i] = false; } else { coilsBuffer[i] = true; } } } else { //转化ushort数组 string[] strarr = txt_data.Text.Split(' '); registerBuffer = new ushort[strarr.Length]; for (int i = 0; i < strarr.Length; i++) { registerBuffer[i] = ushort.Parse(strarr[i]); } } } } /// <summary> /// 创建委托,打印日志 /// </summary> /// <param name="msg"></param> public void SetMsg(string msg) { richTextBox1.Invoke(new Action(() => { richTextBox1.AppendText(msg); })); } /// <summary> /// 清空日志 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void button2_Click(object sender, EventArgs e) { richTextBox1.Clear(); } /// <summary> /// 单击button1事件,串口完成一次读/写操作 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void button1_Click(object sender, EventArgs e) { //AutoFlag = false; //button_AutomaticTest.Enabled = true; try { //初始化串口参数 InitSerialPortParameter(); master = ModbusSerialMaster.CreateRtu(port); ExecuteFunction(); } catch (Exception) { MessageBox.Show("初始化异常"); } } /// <summary> /// 自动测试初始化 /// </summary> private void AutomaticTest() { AutoFlag = true; button1.Enabled = false; InitSerialPortParameter(); master = ModbusSerialMaster.CreateRtu(port); Task.Factory.StartNew(() => { //初始化串口参数 while (AutoFlag) { try { ExecuteFunction(); } catch (Exception) { MessageBox.Show("初始化异常"); } Thread.Sleep(500); } }); } /// <summary> /// 读取数据时,失能写数据;写数据时,失能读数据 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void comboBox1_SelectedIndexChanged(object sender, EventArgs e) { if (comboBox1.SelectedIndex >= 4) { groupBox2.Enabled = true; groupBox1.Enabled = false; } else { groupBox1.Enabled = true; groupBox2.Enabled = false; } //委托事件,在主线程中创建的控件,在子线程中读取设置控件的属性会出现异常,使用Invoke方法可以解决 comboBox1.Invoke(new Action(() => { functionCode = comboBox1.SelectedItem.ToString(); functionOder = comboBox1.SelectedIndex; })); } /// <summary> /// 将打印日志显示到最新接收到的符号位置 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void richTextBox1_TextChanged(object sender, EventArgs e) { this.richTextBox1.SelectionStart = int.MaxValue; this.richTextBox1.ScrollToCaret(); } /// <summary> /// 自动化测试 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void button_AutomaticTest_Click(object sender, EventArgs e) { AutoFlag = false; button_AutomaticTest.Enabled = false; //自动收发按钮失能,避免从复开启线程 if (AutoFlag == false) { AutomaticTest(); } } /// <summary> /// 串口关闭,停止读/写 /// js</summary> /// <param name="sender"></param> /// <param name="e"></param> private void button_ClosePort_Click(object sender, EventArgs e) { AutoFlag = false; button1.Enabled = true; button_AutomaticTest.Enabled = true; t.Enabled = false;//失能定时器 if (port.IsOpen) { port.Close(); } } #region 串口下拉列表刷新 /// <summary> /// 刷新下拉列表显示 /// </summary> private void GetSerialLstTb1() { //清除cmb_portname显示 cmb_portname.SelectedIndex = -1; cmb_portname.Items.Clear(); //获取串口列表 string[] serialLst = SerialPort.GetPortNames(); if (serialLst.Length > 0) { //取串口进行排序 Array.Sort(serialLst); //将串口列表输出到cmb_portname cmb_portname.Items.AddRange(serialLst); cmb_portname.SelectedIndex = 0; } } /// <summary> /// 消息处理 /// </summary> /// <param name="m"></param> protected override void WndProc(ref Message m) { switch (m.Msg) //判断消息类型 { case WM_DEVICE_CHANGE: //设备改变消息 { GetSerialLstTb1(); //设备改变时重新花去串口列表 } break; } base.WndProc(ref m); } #endregion private void label11_Click(object sender, EventArgs e) { } private void txt_slave1_TextChanged(object sender, EventArgs e) { } private void label7_Click(object sender, EventArgs e) { } private void txt_startAddr1_TextChanged(object sender, EventArgs e) { } private void label8_Click(object sender, EventArgs e) { } private void txt_length_TextChanged(object sender, EventArgs e) { } } }
在线程中对控件的属性进行操作可能会出现代码异常,可以使用Invoke委托方法完成相应的操作:
public void SetMsg(string msg) { richTextBox1.Invoke(new Action(() => { richTextBox1.AppendText(msg); })); }
在进行自动读/写操作时,为避免多次点击按键控件,多次重复建立新线程;在进入自动读写线程中时,将对应的按键控件失能,等待停止读写操作时再使能:
private void AutomaticTest() { AutoFlag = true; button1.Enabled = false; InitSerialPortParameter(); master = ModbusSerialMaster.CreateRtu(port); Task.Factory.StartNew(() => { //初始化串口参数 while (AutoFlag) { try { ExecuteFunction(); } catch (Exception) { MessageBox.Show("初始化异常"); } Thread.Sleep(500); } }); }
自动获取当前设备的可用串口实现如下:
#region 串口下拉列表刷新 /// <summary> /// 刷新下拉列表显示 /// </summary> private void GetSerialLstTb1() { //清除cmb_portname显示 cmb_portname.SelectedIndex = -1; cmb_portname.Items.Clear(); //获取串口列表 string[] serialLst = SerialPort.GetPortNames(); if (serialLst.Length > 0) { //取串口进行排序 Array.Sort(serialLst); //将串口列表输出到cmb_portname cmb_portname.Items.AddRange(serialLst); cmb_portname.SelectedIndex = 0; } } /// <summary> /// 消息处理 /// </summary> /// <param name="m"></param> protected override void WndProc(ref Message m) { switch (m.Msg) //判断消息类型 { case WM_DEVICE_CHANGE: //设备改变消息 { GetSerialLstTb1(); //设备改变时重新花去串口列表 } break; } base.WndProc(ref m); } #endregion
对本次实例进行测试需要使用到串口模拟软件,串口模拟器可以到网上下载
Modbus从站需要完成一下两步操作:
一、菜单栏Connection-----Connect
二、菜单栏Setup-----Slave Definition
最后需要运行自己创建的Modbus RTU Master上位机,完成相应的配置:
实现的最终效果:
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