C#串口通讯控制4路继电上位机

界面如下

源码如下

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;

//引入空间
using System.Windows.Forms;
using System.IO.Ports;
using System.Threading;

namespace 继电器上位机开发
{
    public partial class frmrelay : Form
    {
        public frmrelay()
        {
            InitializeComponent();
        }

        private void frmrelay_Load(object sender, EventArgs e)
        {
            btn1open.Enabled = false;
            btn1close.Enabled = false;
            btn2close.Enabled = false;
            btn2open.Enabled = false;
            btn3close.Enabled = false;
            btn3open.Enabled = false;
            btn4close.Enabled = false;
            btn4open.Enabled = false;
            string[] PortNames = SerialPort.GetPortNames();    //获取本机串口名称，存入PortNames数组中

            for (int i = 0; i < PortNames.Count(); i++)

            {

                comboBox1.Items.Add(PortNames[i]);   //将数组内容加载到comboBox控件中

            }
        }
        public byte[] CmdopenA = { 0x01, 0x05, 0x00, 0x00, 0xFF, 0x00, 0x8C, 0x3A };//1开
        public byte[] CmdcloseA = { 0x01, 0x05, 0x00, 0x00, 0x00, 0x00, 0xCD, 0xCA };//1关

        public byte[] CmdopenB = { 0x01, 0x05, 0x00, 0x01, 0xFF, 0x00, 0xDD, 0xFA };//2开
        public byte[] CmdcloseB = { 0x01, 0x05, 0x00, 0x01, 0x00, 0x00, 0x9C, 0x0A };//2关

        public byte[] CmdopenC = { 0x01, 0x05, 0x00, 0x02, 0xFF, 0x00, 0x2D, 0xFA };//3开
        public byte[] CmdcloseC = { 0x01, 0x05, 0x00, 0x02, 0x00, 0x00, 0x6C, 0x0A };//3关

        public byte[] CmdopenD = { 0x01, 0x05, 0x00, 0x03, 0xFF, 0x00, 0x7C, 0x3A };//4开
        public byte[] CmdcloseD = { 0x01, 0x05, 0x00, 0x03, 0x00, 0x00, 0x3D, 0xCA };//4关

        public byte[] CmdDatacloseAll = { 0x01, 0x0F, 0x00, 0x00, 0x00, 0x08, 0x01, 0x00, 0xFE, 0x95 };//全关
        public byte[] CmdDataopenAll = { 0x01, 0x0F, 0x00, 0x00, 0x00, 0x08, 0x01, 0xFF, 0xBE, 0xD5 };//全开

        private void btn1open_Click(object sender, EventArgs e)
        {
            sp1.Write(CmdopenA, 0, 8);
            Thread.Sleep(100);

        }

        private void btnportopen_Click(object sender, EventArgs e)
        {
            if (btnportopen.Text == "打开串口")
            {
                try
                {
                    if (!sp1.IsOpen)
                    {
                        // 串口参数设置
                        //串口号
                        sp1.PortName = comboBox1.SelectedItem.ToString();
                        //串口设置
                        sp1.BaudRate = 9600;//波特率
                        sp1.DataBits = 8;//数据位
                        sp1.StopBits = StopBits.One;
                        sp1.Parity = Parity.None;
                        sp1.Open();
                        btnportopen.Text = "关闭串口";
                        btn1open.Enabled = true;
                        btn1close.Enabled =true;
                        btn2close.Enabled =true;
                        btn2open.Enabled = true;
                        btn3close.Enabled =true;
                        btn3open.Enabled = true;
                        btn4close.Enabled =true;
                        btn4open.Enabled = true;
                    }
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }
            }
            else
            {
                try
                {
                    sp1.Close();
                    btnportopen.Text = "打开串口";
                    btn1open.Enabled = false;
                    btn1close.Enabled = false;
                    btn2close.Enabled = false;
                    btn2open.Enabled = false;
                    btn3close.Enabled = false;
                    btn3open.Enabled = false;
                    btn4close.Enabled = false;
                    btn4open.Enabled = false;
                }
                catch (Exception Err)
                {

                    MessageBox.Show(Err.Message);
                }
            }
           
        }

        private void btn1close_Click(object sender, EventArgs e)
        {
            sp1.Write(CmdcloseA, 0, 8);
            Thread.Sleep(100);
        }

        private void btn2open_Click(object sender, EventArgs e)
        {
            sp1.Write(CmdopenB, 0, 8);
            Thread.Sleep(100);
        }

        private void btn2close_Click(object sender, EventArgs e)
        {
            sp1.Write(CmdcloseB, 0, 8);
            Thread.Sleep(100);
        }

        private void btn3open_Click(object sender, EventArgs e)
        {
            sp1.Write(CmdopenC, 0, 8);
            Thread.Sleep(100);
        }

        private void btn3close_Click(object sender, EventArgs e)
        {
            sp1.Write(CmdcloseC, 0, 8);
            Thread.Sleep(100);
        }

        private void btn4open_Click(object sender, EventArgs e)
        {
            sp1.Write(CmdopenD, 0, 8);
            Thread.Sleep(100);
        }

        private void btn4close_Click(object sender, EventArgs e)
        {
            sp1.Write(CmdcloseD, 0, 8);
            Thread.Sleep(100);
        }
    } }

通讯协议是modbus RTU