code: def _connect(self, id_mask):
          
          # Get all devices attached as USB serial
          all_devices = glob.glob('/dev/ttyUSB*')
  
          # Identify which of the devices are LoadStar Serial Sensors
          sensors = []
          for device in all_devices:
              try:
                  ser = serial.Serial(port=device,
                                      timeout=0.5,
                                      exclusive=True)
                  ser.write('ID\r')
                  ser.flush()
                  time.sleep(0.05)
                  resp = ser.read(13)
                  ser.close()
  
                  if len(resp) >= 10 and resp[:len(id_mask)] == id_mask:
                      sensors.append((device, resp.rstrip('\r\n')))
              except:
                  continue
          sensors = sorted(sensors, key=lambda x : x[1])
  
          # Connect to each of the serial devices
          serials = []
          for device, key in sensors:
              ser = serial.Serial(port=device, timeout=0.5)
              serials.append(ser)
              rospy.loginfo('Connected to load cell {} at {}'.format(key, device))
          return serials
docs: Connects to all of the load cells serially.