C# MODBUS 通信
背景
电厂有多组监控设备，需要在指定的设备上显示某些数据（其他设备对接过来的）。通信协议是modbus主从结构。
源码：
http://download.csdn.net/download/wolf12/8931267
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO.Ports;
using System.Threading;
using System.Net.Sockets;
using System.Net;
namespace ModsDataCtl
{
public partial class Form1 : Form
{
System.IO.Ports.SerialPort com;
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
Microsoft.VisualBasic.Devices.Computer pc = new Microsoft.VisualBasic.Devices.Computer();
foreach (string s in pc.Ports.SerialPortNames)//遍历本机所有串口
{
this.comboBox1.Items.Add(s);
}
com = new System.IO.Ports.SerialPort();
}
private void button1_Click(object sender, EventArgs e)
{
try
{
com.PortName = comboBox1.Items[comboBox1.SelectedIndex].ToString();
com.BaudRate = 9600;//波特率
com.Parity = Parity.None;//无奇偶校验位
com.StopBits = StopBits.One;//两个停止位
// com.Handshake = Handshake.RequestToSendXOnXOff;//控制协议
com.ReadTimeout = 2000;
com.WriteTimeout = 2000;
//com.ReceivedBytesThreshold = 4;//设置 DataReceived 事件发生前内部输入缓冲区中的字节数
// com.NewLine = "/r/n";
com.RtsEnable = true;
com.Open(); //打开串口
MessageBox.Show("串口打开成功");
}
catch
{
MessageBox.Show("串口已打开!");
}
}
/// <summary>
/// 监听com端口接收的报文
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void serialPort1_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
try
{
StringBuilder strBuilder = new StringBuilder();
while (com.BytesToRead > 0)
{
char ch = (char)com.ReadByte();
strBuilder.Append(ch);
}
strBuilder = new StringBuilder();
}
catch (Exception ex)
{
Console.Write(ex.Message.ToString());
}
}
private void button2_Click(object sender, EventArgs e)
{
//发送指令
byte[] sendbyte = new byte[8] { 01, 03, 0x0F, 0xA0, 00, 24, 46, 0xE7 };
com.Write(sendbyte, 0, sendbyte.Length);
MessageBox.Show("成功");
}
Thread thread;
private void button3_Click(object sender, EventArgs e)
{
com.DataReceived += new SerialDataReceivedEventHandler(com_DataReceived);
MessageBox.Show("发送成功");
}
private void button4_Click(object sender, EventArgs e)
{
com.Close(); //关闭串口
}
/// <summary>
/// 测试
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void button5_Click(object sender, EventArgs e)
{
TcpClient tcp = new TcpClient();
UdpClient udp = new UdpClient();
udp.Connect("127.0.0.1", 7102);
// tcp.Connect("192.168.1.101", 7101);
// NetworkStream ns = ud
byte[] sendbyte = new byte[8] { 01, 03, 0x0F, 0xA0, 0x00, 0x24, 0x46, 0xE7 };
// byte[] sendbyte = new byte[8] { 01, 03, 10, 00, 00,02, 0xC0, 0xCB};
// 01 0F 00 01 00 04 01 00 03 56
// 01 06 00 01 00 17 98 04
//01 03 10 00 00 02 C0 CB
// ns.Write(sendbyte, 0, sendbyte.Length);
udp.Send(sendbyte, sendbyte.Length);
//System.Net.IPEndPoint ip = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 7101);
//var fff = udp.Receive(ref ip);
}
#region CRC
/// <summary>
/// 计算CRC-16
/// </summary>
/// <param name="data"></param>
/// <returns>高位在前</returns>
public byte[] CRC_16(string data)
{
if ((data.Length % 2) != 0) { throw new Exception("参数\"data\"长度不合法"); }
byte[] tmp = StrToByte(data);
/*
1、预置16位寄存器为十六进制FFFF（即全为1）。称此寄存器为CRC寄存器；
2、把第一个8位数据与16位CRC寄存器的低位相异或，把结果放于CRC寄存器；
3、把寄存器的内容右移一位(朝低位)，用0填补最高位，检查最低位；
4、如果最低位为0：重复第3步(再次移位); 如果最低位为1：CRC寄存器与多项式A001（1010 0000 0000 0001）进行异或；
5、重复步骤3和4，直到右移8次，这样整个8位数据全部进行了处理；
6、重复步骤2到步骤5，进行下一个8位数据的处理；
7、最后得到的CRC寄存器即为CRC码。
*/
UInt16 CRCREG = (UInt16)0xffff;
for (int i = 0; i < tmp.Length; i++)
{
CRCREG = (UInt16)(CRCREG ^ (UInt16)tmp[i]);//<< 8;
for (int j = 0; j < 8; j++)
{
UInt16 CRCtmp = (UInt16)(CRCREG & (UInt16)0x0001);
CRCREG = (UInt16)(CRCREG >> (UInt16)1);
if (CRCtmp == (UInt16)1)
{
CRCREG = (UInt16)(CRCREG ^ (UInt16)0xA001);
}
}
}
string strtmp = CRCREG.ToString("X4");
byte[] retunBtye = new byte[8];
tmp.CopyTo(retunBtye, 0);
retunBtye[6] = StrToByte(strtmp.Substring(2, 2))[0];
retunBtye[7] = StrToByte(strtmp.Substring(0, 2))[0];
return retunBtye;
}
public byte[] StrToByte(string data)
{
byte[] bt = new byte[data.Length / 2];
for (int i = 0; i < data.Length / 2; i++)
{
bt[i] = Convert.ToByte(data.Substring(i * 2, 2), 16);
}
return bt;
}
#endregion
private void timer1_Tick(object sender, EventArgs e)
{
//byte f = Convert.ToByte('\0');
//string dd = "wefef\0";
//byte[] fef = System.Text.Encoding.Default.GetBytes(dd);
// MessageBox.Show(com.BytesToRead.ToString());
//01 03 48 01 F4 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 E3 59
/*
16:05:16.859 回复(no=077): 01 03 48 01 F4 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 E3 59
16:05:16.859 收到(no=008): 01 03 0F A0 00 24 46 E7------CRC正确
*
* 16:07:09.406 收到(no=008): 01 03 0F A0 00 24 46 E7------CRC正确
*/
/*
从机
16:07:26.484 回复(no=077): 01 03 48 01 F4 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 E3 59
16:07:26.484 收到(no=008): 01 03 0F A0 00 24 46 E7------CRC正确
*/
}
void com_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
this.Invoke(new Action(() =>
{
byte[] buffer = new byte[com.BytesToRead];
com.Read(buffer, 0, com.BytesToRead);
string instr = "";
foreach (byte b in buffer)
{
instr += b.ToString("X2");
}
if (instr != "")
{
this.listBox1.Items.Add("收到:" + instr);
}
// byte[] sendbyte = new byte[] { 0x01, 0x03, 0x48, 0x01, 0xF4, 0x00, 0x00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 0xE3, 0x59 };
byte[] sendbyte = new byte[] { 01,03,02,01,0xF4,0xB8,0x53};
com.Write(sendbyte, 0, sendbyte.Length);
string wri = "";
foreach (byte b in sendbyte)
{
wri += b.ToString("X2");
}
if (wri != "")
{
this.listBox1.Items.Add("回复:" + wri);
}
}));
}
}
}
