Questions about the sleep mode of the Xbee 900 pro


I am using X-CTU to set the Xbee 900 pro to cyclic sleep mode. From the datasheet the SM command has 0-8 options, where the option 8 is synchronous cyclic sleep mode. But the X-CTU only supports 0-4 options. How can I set option 8?

Another issue is: when I set option 4 which is asynchronous cyclic sleep mode and write the changes, the module seems working at cyclic sleep mode because the red led periodically on and off. but I cannot access the module through the COM. When I click the button Test/Query under PC Settings Tab, the X-CTU always gives error message “Unable to communicat with the modem”.

Could you tell me how I recover the COM? Thanks.



I find a way to recover the COM:

Just after reset, I send “+++”, and “SM0”. And there commands change the XBee to non-sleep mode. Then I can use COM again.

I think the reason is that the wakeup time is too short to respond the AT command.