public void playBack(){
		logger.info(commands.size());
		try {
		if (isPlaybacking) {
			for (String comm : commands) {
				
				int portNo = Integer.parseInt(comm.substring(1, 2));
				int p = Integer.parseInt(comm.substring(3, comm.length()-1));
				log(portNo, p);
				serialPort.writeBytes(comm.getBytes());	
				Thread.sleep(50);
			}
		}
		} catch (SerialPortException e) {
			logger.error(e);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}