Powering off one End Device causes TX Delay to others

I have one coordinator and two end devices (ED#1 and ED#2) set up on a zigbee network in API mode. The idea is to poll each of them every second with a Tx request frame that contains a brief message to be parsed by a micropro. I am unicasting to each one individually rather than multicasting, which causes too much delay. The problem is when I turn ED#1 off, the next frame that is sent to the remaining end device ED#2 gets delayed by about 7 seconds !! After that, frames to ED#2 get randomly delayed by approx 1.5 seconds.

The setup is as follows:

Coordinator
XBP24-ZB Firmware ver 2164 (Zigbee coordinator API)

ED#1
XBP24-B Firmware ver 2964 (Zigbee End Device API)
SH: 0013A200
SL: 404B7C80

ED#2
XBP24-B Firmware ver 2964 (Zigbee End Device API)
SH: 0013A200
SL: 4054F04F

I am using the X-CTU assemble packet window to enter the following two consecutive API Tx Request frames with 64 bit addresses. I set the 16 bit network address to 0xFFFE.

7E000F10010013A200404B7C80FFFE000005B0
7E000F10010013A2004054F04FFFFE00000564

I cant predict when a node will loose power of go out of range, thus causing the delays to other nodes. Is there a way to stop this delay?

Hi friend,

Try setting the 16-bit address of end devices modules within the data packets. I think there is a delay for that.