set thread device mode:

        Args:
           mode: thread device mode. 15=rsdn, 13=rsn, 4=s
           r: rx-on-when-idle
           s: secure IEEE 802.15.4 data request
           d: full thread device
           n: full network data

        Returns:
           True: successful to set the device mode
           False: fail to set the device mode

def __setDeviceMode(self, mode):
        """set thread device mode:

        Args:
           mode: thread device mode. 15=rsdn, 13=rsn, 4=s
           r: rx-on-when-idle
           s: secure IEEE 802.15.4 data request
           d: full thread device
           n: full network data

        Returns:
           True: successful to set the device mode
           False: fail to set the device mode
        """
        print 'call __setDeviceMode'

        try:
            cmd = WPANCTL_CMD + 'setprop Thread:DeviceMode %d' % mode
            return self.__sendCommand(cmd)[0] != 'Fail'
        except Exception, e:
            ModuleHelper.WriteIntoDebugLogger('setDeviceMode() Error: ' + str(e))