def get_firmware_version(self):
        """
        :return: the firmware version
        """
        cmd_response = self.__send_command(const.CMD_GET_VERSION,b'', 1024)
        if cmd_response.get('status'):
            firmware_version = self.__data.split(b'\x00')[0]
            return firmware_version.decode()
        else:
            raise ZKErrorResponse("Can't read frimware version")
:return: the firmware version