# Unexpected response from ATND in network

**URL:** <https://forums.digi.com/t/unexpected-response-from-atnd-in-network/647>\
**Category:** XBee - Zigbee\
**Created:** [February 15, 2011, 1:43am UTC](https://forums.digi.com/t/unexpected-response-from-atnd-in-network/647 "2011-02-15T01:43:26Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![microguy](https://avatars.discourse-cdn.com/v4/letter/m/977dab/32.png) [@microguy](https://forums.digi.com/u/microguy)\
**Post date:** [February 15, 2011, 1:43am UTC](https://forums.digi.com/t/unexpected-response-from-atnd-in-network/647/1 "2011-02-15T01:43:26Z")

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I have two End devices properly associated with one Coordinator (XB24, firmware 10E6) and have used an ATND command as well as an API ND packet to get information from End devices. They respond properly, except the response to the ATND and API command packet both show the MY-16-Bit Source Address as FFFE for each of the End devices. I cannot find this response documented. What does it mean? The End devices retain the original programmed MY address information 0x01AB, and 0x89FA, when examined separately:

AT response:

+++OK  
ATND  
FFFE  
13A200  
4049E0EC  
2F  
XMTR

FFFE  
13A200  
4049E1E6  
25  
END

Thanks for help. --Jon

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<div class="post-metadata">

**Author:** ![microguy](https://avatars.discourse-cdn.com/v4/letter/m/977dab/32.png) [@microguy](https://forums.digi.com/u/microguy)\
**Post date:** [February 15, 2011, 4:32pm UTC](https://forums.digi.com/t/unexpected-response-from-atnd-in-network/647/2 "2011-02-15T16:32:53Z")

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OK, found the answer in Digi’s documentation, but in the Addressing section of the XBee/XBee-Pro manual. Attention Digi: Please also include this information in the “Association” section under “End Device Start-Up,” heading 3, “Association to a Valid Coordinator.” People shouldn’t have to spend time searching for this type of information in unlikely places:

When an End Device associates to a Coordinator, its MY parameter is set to 0xFFFE to enable 64-bit addressing. The 64-bit address of the module is stored as SH and SL parameters. To send a packet to a specific module, the Destination Address (DL + DH) on the sender must match the  
Source Address (SL + SH) of the desired receiver.