Hello @qianchihuang
Just to confirm, you are trying to use JN-AN-1243 with End Device functionality, is this correct?
According to JN-AN-1243 Zigbee 3 Base Device App Note document (inside JN-AN-1243 folder > Doc), Section 4.4 End Device Functionality, the End Device should be a sleepy, 'Rx Off when idle' device) by default. As a Sleepy End Device, the End Device will most likely be asleep and should wake up periodically to poll for incoming messages.
When the system is idle or if there is no activity in progress, main_task should suspend CPU operation with PWR_EnterLowPower().
For more information on Timers Management and Low-Power Library, you can consult to the Connectivity Framework Reference Manual inside JN5189 SDK docs folder > docs > wireless > Common.
Regards,
Eduardo.