unit2.pas

siemens PLC Prodave 通讯测试

unit Unit2;

interface

uses
  Windows,Controls, Classes,Unit1 ,SysUtils;

type
  mmcread = class(TThread)
  private
    { Private declarations }
    procedure  updatemm ;
  protected
    procedure Execute; override;




  end;

implementation

{ Important: Methods and properties of objects in visual components can only be
  used in a method called using Synchronize, for example,

      Synchronize(UpdateCaption);

  and UpdateCaption could look like,

    procedure mmcread.UpdateCaption;
    begin
      Form1.Caption := 'Updated in a thread';
    end; }

{ mmcread }
var
sss:string;





procedure mmcread.Execute;
var
  I: Integer;

j:integer;

  hdiskhand2:THandle;
  hfilehand:THandle;
  errorcount:integer;//出现错误重试次数；连续三次则不读取跳过
  pbuff:pchar;
  
 // sss:string;
begin
  { Place thread code here }   
        QSectorCount := 1; //读写扇区数
        QSectorStart := 0; //起始扇区数
     //   pbuff := allocmem(QSectorCount * QBytesPerSector); //  必须是新申请的内存或全局变量，不能是局部变量
        Hdiskhand2 := CreateFile(Qdiskname,
                              GENERIC_ALL,
                              FILE_SHARE_READ ,
                              nil,
                              OPEN_EXISTING,
                              0,
                              0      );
         if (Hdiskhand2 = INVALID_HANDLE_VALUE) then
        begin
         sss:= '创建设备错误:'+SysErrorMessage(GetLastError);
         Synchronize(updatemm);
         exit;
        end;
       sss:= '创建设备成功:'+SysErrorMessage(GetLastError);


        Synchronize(updatemm);
        hfilehand := FileOpen(filename1, fmOpenwrite);
        FileSeek(hfilehand,0,0);

        QSectorCount := sectonum; //读写扇区数
        QSectorStart := 0; //起始扇区数
         pbuff := allocmem(QSectorCount * QBytesPerSector);

           

 for I := 0  to ((sector_file_end-sector_file_start+1)div sectonum)   do    // 读取指定扇区
 begin

        QSectorCount := sectonum; //读写扇区数
        QSectorStart := I*sectonum +sector_file_start; //起始扇区数

          for j := 0 to QSectorCount * QBytesPerSector-1 do    // Iterate
          begin
             pbuff[j]:=char(0);
          end;    // for


        if ((sector_file_end-sector_file_start+1) div sectonum )=i then
           begin
             if   ((sector_file_end-sector_file_start+1) mod sectonum)=0  then
             break;
              QSectorCount := ((sector_file_end-sector_file_start+1) mod sectonum) ;
           end;
        if ((sector_file_end-sector_file_start+1) div sectonum )>i then
            QSectorCount := sectonum  ;
          //  pbuff := allocmem(QSectorCount * QBytesPerSector);
          if ( FileSeek(Hdiskhand2,  QSectorStart *  QBytesPerSector, 0)=-1)
            then
            begin
             sss:='文件指针定位错误'+SysErrorMessage(GetLastError); //起始扇区
             Synchronize(updatemm);
             exit;
            end else           //inttostr( QSectorStart )                                     QSectorCount
            begin          
             sss:='起始扇区号:'+Format('%-.8d  %-.8x', [QSectorStart,QSectorStart]) +'  扇区数:'+Format('%-8d', [QSectorCount])+'定位'+SysErrorMessage(GetLastError);
            end;
          if FileRead(Hdiskhand2,  pbuff[0], QSectorCount * QBytesPerSector) <>  QSectorCount * QBytesPerSector then//读扇区
              begin
              sss:= '文件读取错误 非整扇区'+SysErrorMessage(GetLastError);
              Synchronize(updatemm);
              raise  Exception.Create('Read  Error!');
              exit;
              end else
              begin
               sss:= sss +'  读取'+ SysErrorMessage(GetLastError);
               Synchronize(updatemm);
              end;


     //  写入文件
       if ( FileSeek(hfilehand,  QSectorStart *  QBytesPerSector, 0)=-1)
            then
            begin
             sss:='文件指针定位错误'+SysErrorMessage(GetLastError); //起始扇区
             Synchronize(updatemm);
             exit;
            end else           //inttostr( QSectorStart )                                     QSectorCount
            begin
             sss:='起始扇区号:'+Format('%-.8d  %-.8x', [QSectorStart,QSectorStart]) +'  扇区数:'+Format('%-8d', [QSectorCount])+'定位'+SysErrorMessage(GetLastError);
            end;


      if Filewrite(hfilehand,  pbuff[0], QSectorCount * QBytesPerSector) <>  QSectorCount * QBytesPerSector then//读扇区
              begin
              sss:= '文件写入错误 非整扇区'+SysErrorMessage(GetLastError);
              Synchronize(updatemm);
              raise  Exception.Create('Read  Error!');
              exit;
              end else
              begin
               sss:=sss+ '  写入文件'+ SysErrorMessage(GetLastError);
               Synchronize(updatemm);
              end;




 end;   //end for

     //输出状态信息
     //保存数据
    Closehandle(Hdiskhand2);
    FreeMem(pbuff); //     使用完后需要释放内存
    FileClose(hfilehand);

  
end;




procedure mmcread.updatemm;
begin
form1.Memo2.Lines.Add(sss) ;
end;

end.