大家好！串口问题！！！

Question

我用delphi编的串口通讯程序接收插在PCI插槽板上的数据出错。
我板上发送的数据是55H，而接收的是‘fffef8’而且每次接收的都不一样。请问是什么原因？
我用本机的com2口接收。
delphi程序如下：
unit Comm;interfaceuses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls, SPComm;type
  TFCOMM = class(TForm)
    Memo1: TMemo;
    Btn_send: TButton;
    Button1: TButton;
    Comm2: TComm;
    Memo2: TMemo;
    procedure FormShow(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure Btn_sendClick(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Comm2ReceiveData(Sender: TObject; Buffer: Pointer;
      BufferLength: Word);
  private
    { Private declarations }
  public
    { Public declarations }
  end;var
  FCOMM: TFCOMM;
  Viewstring:string;
  i:integer;
  rbuf,sbuf:array[1..5] of byte;   //定义发送和接收数组implementation{$R *.DFM}procedure TFCOMM.FormShow(Sender: TObject);
  begin
    //comm1.StartComm;     //打开串口
    comm2.StartComm;
  end;procedure TFCOMM.FormClose(Sender: TObject; var Action: TCloseAction);
  begin
  //  comm1.StopComm;     //关闭串口
    comm2.StopComm;
  end;procedure senddata;     //自定义的发送数据过程
  var
    i:integer;
    commflg:boolean;
  begin
    viewstring:='';
    commflg:=true;
    for i:=1 to length(sbuf) do
      begin
        if not fcomm.comm2.writecommdata(@sbuf[i],1) then
          begin
            commflg:=false;
            break;
          end;
        sleep(2);         //发送时字节间的延时
        viewstring:=viewstring+inttohex(sbuf[i],2)+'';
      end;
    viewstring:='发送:'+viewstring;
    fcomm.memo1.lines.add(viewstring);
    //fcomm.memo1.lines.add('');
    if not commflg then
      messagedlg('发送失败!',mterror,[mbyes],0); 
  end;
  
procedure TFCOMM.Btn_sendClick(Sender: TObject);
  begin
    sbuf[1]:=byte($55);
    sbuf[2]:=byte($00);
    sbuf[3]:=byte($00);
    sbuf[4]:=byte($00);
    sbuf[5]:=byte($55);
    senddata;{调用发送函数}
  end;procedure TFCOMM.Button1Click(Sender: TObject);
  begin
    close();
  end;procedure TFCOMM.Comm2ReceiveData(Sender: TObject; Buffer: Pointer;
  BufferLength: Word);         //COM2接收过程
  var
    i:integer;
  begin
    viewstring:='';
    move(buffer^,pchar(@rbuf)^,bufferlength);
    for i:=1 to BufferLength do
      begin
        viewstring:=viewstring+inttohex(rbuf[i],2)+'';
      end;
    viewstring:='接收:'+viewstring;
    memo2.lines.add(viewstring);
    //memo2.lines.add('');
  end;end.