I just got few used XBee PRO S1 boards, but I have problem with one of them.
When I plug in my XBee PRO S1 board in USB dongle Associate LED (Red) is not blinking as it is with rest of the boards. And in XCTU when I want to add a radio module when user interaction is required (pushing reset button) board does not respond.
Try the API section in the product manual. You can also use the XCTU v 6.x’s API function or the API frame maker located at http://www.digi.com/support/kbase/kbaseresultdetl?id=3215 with XCTU version 5.x’s Assemble packet function on the terminal tab.