set the xBee-s2 to Zigbee router sensor and then can't connect to it with X-CTU

I set the xBee-s2 to Zigbee router sensor and then I can;t communicate with it. I have tried to reset and recovery it, but it doesn’t work.

Take help of this KB article:
http://www.digi.com/support/kbase/kbaseresultdetl?id=3402

you will need a interface board with hardware flow control lines present (eg. Digi XBIB board). If not, then first optimize USB settings of system before attempting recovery:
http://www.digi.com/support/kbase/kbaseresultdetl?id=3418

The reason for this is that the firmware version you selected disables the UART on the radio. You must use the recovery function or an OTA update to change the code after this occurs.