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Question

procedure updateString(KanbanID,subid:integer;kbstr:string);
var
   commtimeouts:TCommTimeouts;
    dcb:         Tdcb;
    hcommfile: Thandle;
    temp:array[0..10] of byte;
    s,s_edit:string;
    dataptr,input:pchar;
    datasize,nsent,fdwEvtMask:dword;
    i,j,k:integer;
    port:integer;
    sendnum:integer;
begin  port:=2;
  case port of
  1:s:=’com1’;
  2:s:=’com2’;
  3:s:=’com3’;
  4:s:=’com4’;
  end;
  hCommFile := CreateFile
     ( PChar(s),GENERIC_READ+GENERIC_WRITE,
      0,nil,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,0);
  if(hCommFile = INVALID_HANDLE_VALUE)or
    (GetFileType( hCommFile )<>FILE_TYPE_CHAR)then exit;
  fillchar( dcb, sizeof(dcb), 0 );         //setup dcb struct
  dcb.DCBLength :=sizeof(dcb);
  dcb.Flags:=$00000003;
  dcb.BaudRate:=2400;
  dcb.bytesize:=8;
  dcb.Parity:=MARKPARITY;//2;
  dcb.StopBits:=ONESTOPBIT;//0;  commtimeouts.ReadIntervalTimeout         :=1;  //setup commtimeout
  commtimeouts.ReadTotalTimeoutMultiplier  :=1;
  commtimeouts.ReadTotalTimeoutConstant    :=1;
  commtimeouts.WriteTotalTimeoutMultiplier :=0;
  commtimeouts.WriteTotalTimeoutConstant   :=0;
  SetCommTimeouts(hCommFile,commtimeouts);
    fdwEvtMask:=EV_TXEMPTY;
  setcommmask(hcommfile,fdwEvtMask);
  SetCommState(hCommFile,dcb);
  s:=chr(subid)+chr(subid)+chr(subid);//setup kanban id and subid
  datasize:=length(s);      //write routine
  dataptr:=pchar(s);  while datasize > 0 do
  begin
    WriteFile(hcommfile,DataPtr^,DataSize,nsent,nil );
    DataSize := DataSize - abs(nsent);
  end;    dcb.Parity:=SPACEPARITY;//2;
     SetCommState(hCommFile,dcb);
////////////////send str
   if length(kbstr)>10 then
       kbstr := copy(kbstr,1,10);
   datasize:=length(kbstr);
          s_edit := kbstr;
       while datasize<10 do
           begin
               s_edit:=s_edit+chr($20);
               inc(datasize);
           end;
       s:=chr($ee)+chr($00)+chr($1)+chr($01)+chr(9)+s_edit;
       datasize:=length(s);      //write routine
       dataptr:=pchar(s);
       //  sleep(20);
       while datasize > 0 do
           begin
               WriteFile(hcommfile,DataPtr^,DataSize,nsent,nil );
               DataSize := DataSize - abs(nsent);
           end;  CloseHandle(hCommFile);
end;