Zigbee Associated Indicator glows continuously after waking up from sleep

Hello guys,
I am using “XB24-Z7WIT-004”(as end device) in my project. My requirement is, the Zigbee has to be in sleep mode for 15 minutes.Then it has to wake up from sleep.

     I have connected 9th pin(Sleep Control Line) of zigbee to an external microcontroller. I control Sleep/Wake-up using external microcontroller. And I have connected Zigbee's 15th pin(Associated Indicator) to an LED.

    While running the program on microcontroller, the Zigbee goes to sleep and wakes at 15th minute. 

    As per my knowledge "Associated Indicator" should blink, when Zigbee wakes-up from sleep. But in my case the LED doesn't blink, it glows continuously.

Can anybody explain me, why Associated Indicator LED glows continuously after waking up from sleep…?

The glowing usually means that the device is not associated to a parent. You are correct that the light should blink if it is associated to a network.

Check the sleep settings of the parent device and make sure that they are as long or longer than the 15 minutes sleep cycle of the end device. If a parent doesn’t receive any communication from a child device within a certain amount of time (determined by SP and SN) it will kick the child device from its network table.

DystopianFerret, Thank you very much for reply.
I haven’t checked SN & SP settings in parent device. I’ll check.