CC2538: Event trigger (CC2538 Zstack3.0.1 Coordinator side) about lost End Device

Hi,

I have CC2538 (Coordinator, Zstack 3.0.1) join network with some CC2530 End devices. (1 Coordinator join with several End devices)

My Situation

Actually, in CC2538, I created an array which store all of the joined End device 16-bit short address, 64 bit address and my self defined "Device ID".  When zigbee network is established, ALL the end device address information can be stored. this is OK. But when one of the end device is lost, I expected Coordinator can deleted the lost end device address information. But I found that no event triggered in Coordinator side for lost end device!!

Question

When the Zigbee network formed, CC2538 Coordinator and CC2530 End device will jump into ZDO_STATE_CHANGE. But when one of the end device loss connection, the CC2538 Coordinator will not jump into ZDO_STATE_CHANGE. So, is there any other event triggered in  Zstack3.0.1 (Coordinator side) for lost End device?  If no,  is there any method /or api function call which can handle this kind of situation? Please advise.

Thank you very much

Bruce Lam