用c#编写pc机与plc的串口通信(高分请教)

Question

用c#编写pc机与plc的串口通信,需要用到什么技术,需要看哪些方面的书.望高手请教!!!

Answer 1

/******************************************************************
 * Copyright(c)  : Tangxu
 * Description   : 
 * CreateDate    : 2006-9-01 04:53:08
 * Creater       : Tang.xu
 * LastChangeDate: 
 * LastChanger   : 
 * Version Info  : 1.0.0
 * ******************************************************************/
using System;
using System.IO.Ports;
using System.Threading;
using System.Text;namespace Tangxu.Common
{
    public class ReadCom
    {
        public ReadCom() { }        public ReadCom(string sCom,int nBaud) 
        {
            _sComPort = sCom;
            _nBaud = nBaud;
        }        private string _sComPort;
        private int _nBaud;
        private SerialPort _Sp;
        #region Open com port        public bool InitCom()//初始化建串口类实例
        {
            try
            {
                _Sp = new SerialPort(_sComPort, _nBaud, Parity.None, 8);
                _Sp.ReceivedBytesThreshold = 10;
                _Sp.Handshake = Handshake.RequestToSend;
                _Sp.Parity = Parity.None;
                _Sp.ReadTimeout = 600;
                _Sp.WriteTimeout = 600;
                if (!_Sp.IsOpen)
                {
                    _Sp.Open();                  
                }
                return true;
            }
            catch
            {
                throw new Exception("Serial Port Can't Open!");
            }
        }
        #endregion        #region FreeDrv
        /// <summary>
        /// free opw
        /// </summary>
        public void FreeDrv()
        {
            if (_Sp != null)
            {
                _Sp.Dispose();
                _Sp.Close();
            }
        }
        #endregion        #region Write command to OPW
        /// <summary>
        /// 发操作命令给OPW设备
        /// 并返回状态
        /// </summary>
        /// <param name="sCommand"></param>
        /// <returns></returns>
        public string WriteCommand(string sCommand)
        {
            StringBuilder sb = new StringBuilder();
            _Sp.Write(sCommand+"\r");
            Thread.Sleep(500);
            bool bRead = true;
            while (bRead)
            {
                byte[] buffer = new byte[_Sp.BytesToRead];
                _Sp.Read(buffer, 0, buffer.Length);
                sb.Append(System.Text.Encoding.ASCII.GetString(buffer));
                if (buffer.Length <= 0)
                {
                    bRead = false;
                }
                Thread.Sleep(300);
            }
            return sb.ToString();
        }
        #endregion        #region Get All COM Port
        public string[] GetAllComPort()
        {
            string[] sAllPort = null;
            try
            {
                sAllPort = SerialPort.GetPortNames();
            }
            catch (Exception ex)
            {
                throw new Exception("获取计算机COM口列表失败!\r\n错误信息:" + ex.Message);
            }
            return sAllPort;
        }
        #endregion    }}

Answer 2

不同的PLC是有协议的，不只是简单的串口通信。此外还要看结构设计了。
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