Modbus TCP学习笔记

1. 功能码列表：     

            0x01 读线圈状态（Read Coils）
            0x02 读离散输入状态（Read Discrete Inputs ）            
            0x03 读保持寄存器（Read Holding Registers ）                 
            0x04 读输入寄存器（Read Input Registers）            
            0x05 写单线圈（Write Single Coil ）            
            0x06 写单寄存器（Write Single Register）            
            0x07 读取异常状态（限串行线）（Read Exception Status (Serial Line only) ）        
            0x08 通信系统诊断（限串行线）（Diagnostics (Serial Line only) ）    
            0x09-0x0A无    
            0x0B 获取串行通信事件计数器（Get Comm Event Counter (Serial Line only) ）    
            0x0C 获取串行通信事件日志 （ Get Comm Event Log (Serial Line only) ）    
            0x0D-0x0E无    
            0x0F 写多个线圈（Write Multiple Coils）    
            0x10 写多个寄存器（Write Multiple registers）    
            0x11 报告服务器ID（仅串行线）（Report Server ID (Serial Line only) ）    
            0x12-0x13无    
            0x14 读文件记录（Read File Record ）    
            0x15 写文件记录（Write File Record）    
            0x16 带屏蔽字写入寄存器（Mask Write Register ）    
            0x17 读/写多个寄存器（Read/Write Multiple registers）    
            0x18 读取先进先出（FIFO）队列（Read FIFO Queue）    
            0x19-0x2A无        
            0x2B 封装接口传输（Encapsulated Interface Transport .）

2. 分主站，从站，主站是客户端，从站是服务端。启动时先启动从站（服务端），然后主站再连上从站，获取信息。

3. Device and Modbus 地址表（最大地址看设备）

4. 用C#做了一个小工具，用作Modbus TCP 学习的总结，链接见：https://download.csdn.net/download/garyaofq/88396590 

界面左侧启动从站（自动门），右侧启动主站（RDS控制系统），启动3秒后锁定地址和端口。在右侧界面可以读，写线圈和寄存器。同时实时显示地址0-9的值。 帮助和左侧窗口显示功能码说明。

C#代码,引用EasyModbus，下面是详细的代码：

/*
 * Created by SharpDevelop.
 * User: yaof
 * Date: 2023/10/3
 * Time: 19:19
 * 
 * To change this template use Tools | Options | Coding | Edit Standard Headers.
 */
using System;
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 EasyModbus;
 
namespace Modbus_Slave
{
	/// 
	/// Description of MainForm.
	/// 
	public partial class MainForm : Form
	{
		EasyModbus.ModbusServer modbusServer=null;
		System.Data.DataTable dt=new System.Data.DataTable ();
		System.Threading.Thread th;
		
		System.Threading.Thread thc;
		System.Threading.Thread thcc;
		EasyModbus.ModbusClient Master = null;
		
		public MainForm()
		{
			//
			// The InitializeComponent() call is required for Windows Forms designer support.
			//
			InitializeComponent();
			thcc=new System.Threading.Thread (new System.Threading.ThreadStart(counterclock));
			
			//创建一个服务，作为从站设备，等待主站查询或设置
			//从站可以不设置IP
			modbusServer = new ModbusServer();
			th=new System.Threading.Thread (new System.Threading.ThreadStart(monitor));
			
			System.Data.DataColumn dc=new System.Data.DataColumn ("address");
            dt.Columns.Add(dc);
            dc=new System.Data.DataColumn ("value");
            dt.Columns.Add(dc);
            for(var m=0;m<10;m++)
            {
	            System.Data.DataRow dr=dt.NewRow();
	            dr[0]=m.ToString();
	            dr[1]="0";
	            dt.Rows.Add(dr);
            }
 
            dataGridView1 .DataSource=dt;
            dataGridView1.Columns[0].Width=50;
            dataGridView1 .Columns[1].Width=50;
            dataGridView1 .ScrollBars=ScrollBars.None;
			//
			// TODO: Add constructor code after the InitializeComponent() call.
			//
			this.Master = new ModbusClient();
            this.slaveIP.Text = "127.0.0.1";
            this.slavePort.Text = "502";
            this.SlaveAddress.Text="1";
            var slaveid=int.Parse(this.SlaveAddress.Text);
            byte[] bytes = BitConverter.GetBytes(slaveid);//将int32转换为字节数组
            Master.UnitIdentifier =bytes[0];
            thc=new System.Threading.Thread (new System.Threading.ThreadStart(connectequipment));
			
			string bodystr="
Device and Modbus address ranges
";
			bodystr+="";
			bodystr+="
";
			bodystr+="
";
			bodystr+="
";
			bodystr+="
";
			bodystr+="
Device address
Modbus address
Description
Function
R/W
Comments
1...10000
address-1
Coils(outputs)
01
Read/Write
05 and 15
10001...20000
address-10001
Discrete Inputs
02
Read
40001...50000
address-40001
Holding Registers
03
Read/Write
06,16,22 and 23
30001...40000
address-30001
Input Registers
04
Read
";
			webBrowser1.DocumentText=bodystr;
			button3.BackColor =Color.Red;
			button5.BackColor =Color.Red;
			button6.BackColor =Color.Red;
			button3.Enabled =true;
			button5.Enabled =true;
			button6.Enabled =true;
		}
	
		private bool UpdateCoil(int modbusaddress,int mvalue)
		{
			var slaveid=int.Parse(this.SlaveAddress.Text);
            byte[] bytes = BitConverter.GetBytes(slaveid);//将int32转换为字节数组
            modbusServer.UnitIdentifier=bytes[0];
			try
            {
				Master.WriteSingleCoil(modbusaddress, mvalue==1?true:false);
            }
            catch
            {
                return false;
            }
            return true;
		}
		
		private void UpdateRegister(int modbusaddress,int mvalue)
		{
			var slaveid=int.Parse(this.SlaveAddress.Text);
            byte[] bytes = BitConverter.GetBytes(slaveid);//将int32转换为字节数组
            modbusServer.UnitIdentifier=bytes[0];
			Master.WriteSingleRegister(modbusaddress,mvalue);
		}
		
		public void counterclock()
		{
			for(var m=3;m>=0;m--)
			{
				if(counter.InvokeRequired)
				{
					counter.Invoke(new Action(()=>{
					     counter.Text=m.ToString();                     	
					                          }));
				}else
				{
					counter.Text=m.ToString();
				}
				System.Threading .SpinWait.SpinUntil(() => false, 1000);
				//System.Threading .Thread.Sleep(1000);
			}
		}
		
		public void connectequipment()
		{
			//延时9秒启动服务，在此期间可以设置端口
			System.Threading .Thread.Sleep(3000);
			var SlaveIP="";
			var SlavePort="";
			
			if(slaveIP.InvokeRequired)
			{
				slaveIP.Invoke(new Action(()=>{
				    SlaveIP =slaveIP.Text; 
					slaveIP.Enabled=false;				    
				                             }));
			}else
			{
				SlaveIP =slaveIP.Text;
				slaveIP.Enabled=false;
			}
			if(slavePort.InvokeRequired)
			{
				slavePort.Invoke(new Action(()=>{
				    SlavePort =slavePort.Text; 
				    slavePort.Enabled=false;
				                             }));
			}else
			{
				SlavePort =slavePort.Text;
				slavePort.Enabled=false;
			}
			Master.Connect(this.slaveIP.Text, int.Parse(this.slavePort.Text));
		}
		public void monitor()
		{
			//延时9秒启动服务，在此期间可以设置端口
			System.Threading .Thread.Sleep(3000);
			if(serverPort.InvokeRequired)
			{
				serverPort.Invoke(new Action(()=>{
				    serverPort.Enabled =false;
            		modbusServer.Port=int.Parse(this.serverPort.Text);                       	
				                             }));
			}else
			{
				serverPort.Enabled =false;
            	modbusServer.Port=int.Parse(this.serverPort.Text);
			}
			
			modbusServer.Listen();
			while(true)
			{
				//主站监控
				if(Master.Connected)
				{
					bool[] coilvalue=Master.ReadCoils(0,10);
					for(var m=0;m<10;m++)
					{
						System.Data.DataRow dr=dt.Rows[m];
						dr[0]=m;
						dr[1]=coilvalue[(m)% 10000]==true?1:0;
					}
					
				}
				System.Threading .Thread.Sleep(500);
			}
		}
 
		void Button2Click(object sender, EventArgs e)
		{
			if(comboBox1.SelectedItem.ToString()=="05")
			{
				UpdateCoil(int.Parse(address.Text),int.Parse(value.Text));
			}else if(comboBox1.SelectedItem.ToString()=="06")
			{
				UpdateRegister(40000+int.Parse(address.Text),int.Parse(value.Text));
			}
		}
 
		void MainFormFormClosing(object sender, FormClosingEventArgs e)
		{
        	th.Abort();
        	Master.Disconnect();
		}
		void HelpToolStripMenuItemClick(object sender, EventArgs e)
		{
			string funstr="Function 01 (01hex) Read Coils\r\n";
			funstr+="Function 02(02hex) Read Discrete Inputs\r\n";
			funstr+="Function 03 (03hex) Read Holding Registers\r\n";
			funstr+="Function 04 (04hex) Read Input Registers\r\n";
			funstr+="Function 05 (05hex) Write Single Coil\r\n";
			funstr+="Function 06 (06hex) Write Single Register\r\n";
			funstr+="Function 15 (0Fhex) Write Multiple Coils\r\n";
			funstr+="Function 16 (10hex) Write Multiple Registers\r\n";
			MessageBox.Show(funstr);
		}
		void Button1Click(object sender, EventArgs e)
		{
			var slaveid=int.Parse(this.SlaveAddress.Text);
            byte[] bytes = BitConverter.GetBytes(slaveid);//将int32转换为字节数组
            modbusServer.UnitIdentifier=bytes[0];
			try
            {
				if(comboBox2.SelectedItem.ToString()=="01")
				{
					bool[] coilstatus=Master.ReadCoils(int.Parse(saddress.Text),1);
					svalue.Text=coilstatus[0]==true?"1":"0";
				}else if(comboBox2.SelectedItem.ToString()=="02")
				{
					bool[] coilstatus=Master.ReadDiscreteInputs(10000+int.Parse(saddress.Text),1);
					svalue.Text=coilstatus[0]==true?"1":"0";
				}else if(comboBox2.SelectedItem.ToString()=="03")
				{
					int[] coilstatus=Master.ReadHoldingRegisters(40000+int.Parse(saddress.Text),1);
					svalue.Text=coilstatus[0].ToString();
				}else if(comboBox2.SelectedItem.ToString()=="04")
				{
					int[] coilstatus=Master.ReadInputRegisters(30000+int.Parse(saddress.Text),1);
					svalue.Text=coilstatus[0].ToString();
				}
            }
            catch
            {
                
            }
		}
		void Button3Click(object sender, EventArgs e)
		{
			thcc.Start();
			th.Start();
			thc.Start();
			button3.BackColor =Color.Green;
			button5.BackColor =Color.Gray;
			button6.BackColor =Color.Gray;
			button5.Enabled =false;
			button6.Enabled =false;
		}
		void Button4Click(object sender, EventArgs e)
		{
			if(comboBox1.SelectedItem.ToString()=="05")
			{
				UpdateCoil(int.Parse(address.Text),1);
			}else if(comboBox1.SelectedItem.ToString()=="06")
			{
				UpdateRegister(40000+int.Parse(address.Text),1);
			}
		}
		void Button5Click(object sender, EventArgs e)
		{
			//仅启动从站
			thcc.Start();
			th.Start();
			button5.BackColor =Color.Green;
			button3.Enabled =false;
			button3.BackColor =Color.Gray;
		}
		void Button6Click(object sender, EventArgs e)
		{
			//仅启动主站
			thc.Start();
			button6.BackColor =Color.Green;
		}
		/**************************************************************************************
		 * 	0x01 读线圈状态（Read Coils）
			0x02 读离散输入状态（Read Discrete Inputs ）			
			0x03 读保持寄存器（Read Holding Registers ）     			
			0x04 读输入寄存器（Read Input Registers）			
			0x05 写单线圈（Write Single Coil ）			
			0x06 写单寄存器（Write Single Register）			
			0x07 读取异常状态（限串行线）（Read Exception Status (Serial Line only) ）		
			0x08 通信系统诊断（限串行线）（Diagnostics (Serial Line only) ）	
			0x09-0x0A无	
			0x0B 获取串行通信事件计数器（Get Comm Event Counter (Serial Line only) ）	
			0x0C 获取串行通信事件日志 （ Get Comm Event Log (Serial Line only) ）	
			0x0D-0x0E无	
			0x0F 写多个线圈（Write Multiple Coils）	
			0x10 写多个寄存器（Write Multiple registers）	
			0x11 报告服务器ID（仅串行线）（Report Server ID (Serial Line only) ）	
			0x12-0x13无	
			0x14 读文件记录（Read File Record ）	
			0x15 写文件记录（Write File Record）	
			0x16 带屏蔽字写入寄存器（Mask Write Register ）	
			0x17 读/写多个寄存器（Read/Write Multiple registers）	
			0x18 读取先进先出（FIFO）队列（Read FIFO Queue）	
			0x19-0x2A无		
			0x2B 封装接口传输（Encapsulated Interface Transport .）
		 ********************************************************************************/
	}
	
}