code: def sense_ttf(self, target):
          
          log.debug("polling for NFC-F technology")
  
          if target.brty not in ("212F", "424F"):
              message = "unsupported bitrate {0}".format(target.brty)
              raise nfc.clf.UnsupportedTargetError(message)
  
          self.chipset.in_set_rf(target.brty)
          self.chipset.in_set_protocol(self.chipset.in_set_protocol_defaults)
          self.chipset.in_set_protocol(initial_guard_time=24)
  
          sensf_req = (target.sensf_req if target.sensf_req else
                       bytearray.fromhex("00FFFF0100"))
  
          log.debug("send SENSF_REQ " + hexlify(sensf_req))
          try:
              frame = chr(len(sensf_req)+1) + sensf_req
              frame = self.chipset.in_comm_rf(frame, 10)
          except CommunicationError as error:
              if error != "RECEIVE_TIMEOUT_ERROR":
                  log.debug(error)
              return None
  
          if len(frame) >= 18 and frame[0] == len(frame) and frame[1] == 1:
              log.debug("rcvd SENSF_RES " + hexlify(frame[1:]))
              return nfc.clf.RemoteTarget(target.brty, sensf_res=frame[1:])
docs: Sense for a Type F Target is supported for 212 and 424 kbps.