procedure TForm1.Button1Click(Sender: TObject);
begin
  Label1.Caption:= '';    //  ST
  Label2.Caption:= '';
  Label3.Caption:= '';    //  vaha
  Label4.Caption:= '';    //
  LazSerial1.WriteData(#$52#$0d#$0a);

  while (stavvazeni = 'ST') do
   begin
     Application.ProcessMessages;
     sleep(100);
     LazSerial1.WriteData(#$52#$0d#$0a);
 end;

  sleep(500);
  Memo1.Lines.AddText('stav vazeni ' + stavvazeni);
  Label5.Caption:= stavvazeni;
  Label6.Caption:= vaha;
end;

procedure TForm1.LazSerial1RxData(Sender: TObject);
var
    sl: TStringList;
begin
data := '';
sleep(50);
data := lazserial1.ReadData;
sl := TStringList.Create;
sl.Delimiter := ',';
sl.DelimitedText := data;
stavvazeni := Trim (sl[0]);
vaha := Trim (sl[2]);
Label1.Caption:= stavvazeni ;
Label2.Caption:= Trim (sl[1]);
Label3.Caption:= Trim (sl[2]);
Label4.Caption:= Trim (sl[3]);
sl.Free;
end;