unit1.~pas

串口通信,基于PCOMM控件,可将串口2、3脚相连测试。

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls, ExtCtrls;

type
  TForm1 = class(TForm)
    rdCOM: TRadioGroup;
    btnOpenPort: TButton;
    btnEnd: TButton;
    btnSend: TButton;
    btnReceive: TButton;
    mSend: TMemo;
    mReceive: TMemo;
    procedure btnOpenPortClick(Sender: TObject);
    procedure btnEndClick(Sender: TObject);
    procedure btnSendClick(Sender: TObject);
    procedure btnReceiveClick(Sender: TObject);
  private

  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  DTRMode,RTSMode,Port:Integer;
  Function PortSet():Boolean;
implementation
 uses PComm,MxTool,EXGLOBAL; //PCOmm引用声明放于此
{$R *.DFM}

//以下是打开通信端口的程序
procedure TForm1.btnOpenPortClick(Sender: TObject);
var
 Ret:Integer;
begin
 //打开通信端口
 Port := rdCom.ItemIndex+1;  //指定通信端口
 Ret := sio_Open(Port);
  If ret <> SIO_OK Then
   begin
     ShowMessage('打开通信端口错误');
     sio_close (Port);
     Exit;
   end;
   If Not PortSet() Then   //参数设置
   begin
     sio_close(Port);
     ShowMessage('通信端口参数设置发生错误');
     Exit;
   End;
    //降低DTR及RTS的电压
    ret := sio_DTR(Port, 0);
    ret := sio_RTS(Port, 0);
end;


//以下是结束按钮的动作
procedure TForm1.btnEndClick(Sender: TObject);
begin
   //关闭通信端口
   sio_Close(Port);
   //结束程序
   close;
end;

procedure TForm1.btnSendClick(Sender: TObject);
var
 TxtStr:String;
begin
    //输出字符串指定
    TxtStr := mSend.Text;
    //把Pascal字符串转成C字符串后送出
    sio_write(Port, PChar(TxtStr), Length(TxtStr))
end;

procedure TForm1.btnReceiveClick(Sender: TObject);
var
  rLen:LongInt;
  PBuf:PChar;
  Buf:String;
begin
  //给一个空间存数据，一定要有
  PBuf := PChar(StringOfChar(' ',1024));
  rlen := sio_read(Port,PBuf , 1024); //读取数据
  If rlen = 0 Then Exit; //若无数据则跳出
  Buf := StrPas(PBuf);
  Buf := Copy(Buf,1,rlen);
  //将数据显示在Memo中
  mReceive.Text := mReceive.Text + Buf;
  mReceive.SelStart := Length(mReceive.Text);
  mReceive.SelLength := 0;
end;

//以下是通信参数的函数实现
Function PortSet():Boolean;
var
   mode,Hw,Sw,ret:LongInt;
begin
//参数设置子程序
    mode := P_NONE Or BIT_8 Or STOP_1;
    Hw := 0 ;   //没有硬件流量控制
    Sw := 0 ;  //没有软件流量控制
    Result := False ;
    ret := sio_ioctl(Port, B38400, mode); //Setting
    If ret <> SIO_OK Then
     begin
        ShowMessage('设置时发生错误');
        Exit;
     end;
    ret := sio_flowctrl(Port, Hw or Sw); //Flow Control
    If ret <> SIO_OK Then
      begin
        ShowMessage('流量设置时发生错误');
        Exit;
      end;
    Result := True;
End;
end.