scan Joiner

        Args:
            xEUI: Joiner's EUI-64
            strPSKd: Joiner's PSKd for commissioning

        Returns:
            True: successful to add Joiner's steering data
            False: fail to add Joiner's steering data

def scanJoiner(self, xEUI='*', strPSKd='threadjpaketest'):
        """scan Joiner

        Args:
            xEUI: Joiner's EUI-64
            strPSKd: Joiner's PSKd for commissioning

        Returns:
            True: successful to add Joiner's steering data
            False: fail to add Joiner's steering data
        """
        print '%s call scanJoiner' % self.port

        # long timeout value to avoid automatic joiner removal (in seconds)
        timeout = 500

        if not isinstance(xEUI, str):
            eui64 = self.__convertLongToString(xEUI)

            # prepend 0 at the beginning
            if len(eui64) < 16:
                eui64 = eui64.zfill(16)
                print eui64
        else:
            eui64 = xEUI

        cmd = 'commissioner joiner add %s %s %s' % (eui64, strPSKd, str(timeout))
        print cmd
        if self.__sendCommand(cmd)[0] == 'Done':
            if self.logThreadStatus == self.logStatus['stop']:
                self.logThread = ThreadRunner.run(target=self.__readCommissioningLogs, args=(120,))
            return True
        else:
            return False