@Override
        protected Void call() throws InterruptedException, IOException {
            //connect
            while(!Thread.currentThread().isInterrupted()) {
                do {
                    try {
                        plcc.connect();
                        getInstance().updateCommunicationStatus("polaczono");
                        Thread.sleep(5000);
                    } catch(IOException ioe) {
                        //System.out.println("ponawiam");
                        getInstance().updateCommunicationStatus("ponawiam");
                    }
                } while (!plcc.isConnected() && !Thread.currentThread().isInterrupted());
                //send request
                while(plcc.isConnected() && !plcc.isClosed() && !Thread.currentThread().isInterrupted()) {
                    try {
                        plcc.sendPosRequest();
                    } catch (IOException ioe) {
                        //System.out.println("error readera - nie zdarza sie");
                        getInstance().updateCommunicationStatus("error readera");
                    } catch (HandshakeException he) {
                        //System.out.println("brak odpowiedzi");
                        plcc.close();
                        getInstance().updateCommunicationStatus("brak handshake'a");
                        Thread.sleep(5000);
                    }
                }
            }
            return null;
        }