XBee Synchronization sleep

when my XBEE S1 module(router)(Cyclic Sleep Mode (SM=8)) connenct directly to PC or powered by battery without connent anything, i changed my coordinator sleep time ,the router will Synchronized with coordinator.
When i connect the router to a MCU,nothing else changed,if the sleep time set the same as coordinator ,coordinator and my board communicate very well. But when i changed my coordinator sleep time ,my router can not follow the coordinator .It’s still wake up depends on the original sleep time. I am realy puzzled,i need your help,thans.

Is this DigiMesh?

You probably need to look at SO (sleep options) to make sure your coordinator is acting as ‘sleep coordinator’.

For example, I run my DigiMesh with my coordinator set to SM=7, SO=0x05, and the remote ‘sleeper’ has SM=8 and SO=0x02 (default). You should be able to set the coordinator to SM=0x08 as well, I just don’t use DM that way.

Anyway, the SO=0x05 is what informs the coordinator to ‘share’ it’s sleep settings.

Thank you for your help,lynnl.
i have already resolve this problem,as you said,i changed SM register to 7,make the xbee module support sleep mode.
your advice S0=0x05 is very useful for me ,thank you very much!