dephi实现RS232串口通信。本程序需要一根RS232串口线连接两个串口实现。本程序包括两个部分：发送端和接收端

				unit Sender;
				
				interface
				
				uses
				  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
				  Dialogs, StdCtrls, Buttons, OleCtrls, MSCommLib_TLB;
				
				type
				  TMainForm = class(TForm)
				    GroupBox1: TGroupBox;
				    SendedDatas: TMemo;
				    SendDatas: TBitBtn;
				    ClearDatas: TBitBtn;
				    GoodBye: TBitBtn;
				    MSComm: TMSComm;
				    procedure GoodByeClick(Sender: TObject);
				    procedure ClearDatasClick(Sender: TObject);
				    procedure FormCreate(Sender: TObject);
				    procedure SendDatasClick(Sender: TObject);
				  private
				    { Private declarations }
				  public
				    { Public declarations }
				  end;
				
				var
				  MainForm: TMainForm;
				
				implementation
				
				{$R *.dfm}
				
				procedure TMainForm.GoodByeClick(Sender: TObject);
				begin
				  With MSComm Do      //关闭串口
				    Begin
				      PortOpen:=False;
				      DTREnable:=False;
				      RTSEnable:=False;
				    End;
				  Close;
				end;
				
				procedure TMainForm.ClearDatasClick(Sender: TObject);
				begin
				  SendedDatas.Lines.Clear;  //清空Memo的内容
				end;
				
				procedure TMainForm.FormCreate(Sender: TObject);
				begin
				  With MSComm Do                 //设置MSComm的工作参数
				    Begin
				      CommPort:=1;
				      Settings:='9600,n,8,1';
				      OutBufferSize:=1024;
				      OutBufferCount:=0;
				      PortOpen:=True;
				    End;
				end;
				
				procedure TMainForm.SendDatasClick(Sender: TObject);
				begin
				  With MSComm Do             //允许MSComm工作
				    Begin
				      DTREnable:=True;
				      RTSEnable:=True;
				    End;
				  If Not (SendedDatas.Text='') Then       //若输入的数据不为空则发送
				    MSComm.Output:=SendedDatas.Text
				  Else
				    Begin
				      ShowMessage('请输入要发送的数据！');
				      SendedDatas.SetFocus;
				    End;
				end;
				
				end.