Sense for a Type F Target is supported for 212 and 424 kbps.

def sense_ttf(self, target):
        """Sense for a Type F Target is supported for 212 and 424 kbps.

        """
        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:])