Traceback (most recent call last):
  File "/usr/bin/cameramonitor", line 88, in timeout_callback
    if self.state != self.camera_on():
  File "/usr/bin/cameramonitor", line 76, in camera_on
    text = os.popen3('fuser '+self.video_device, 'r')[1].read()
IOError: [Errno 4] Llamada de interrupción de sistema