# XBEE PRO S2 and S2B and XB24-ZB Function Set with 21A7 Firmware

**URL:** <https://forums.digi.com/t/xbee-pro-s2-and-s2b-and-xb24-zb-function-set-with-21a7-firmware/936>\
**Category:** XBee - Zigbee\
**Created:** [August 21, 2012, 5:03am UTC](https://forums.digi.com/t/xbee-pro-s2-and-s2b-and-xb24-zb-function-set-with-21a7-firmware/936 "2012-08-21T05:03:51Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![lrivera3\_at\_gmu.edu](https://avatars.discourse-cdn.com/v4/letter/l/22d042/32.png) [@lrivera3\_at\_gmu.edu](https://forums.digi.com/u/lrivera3_at_gmu.edu)\
**Post date:** [August 21, 2012, 5:03am UTC](https://forums.digi.com/t/xbee-pro-s2-and-s2b-and-xb24-zb-function-set-with-21a7-firmware/936/1 "2012-08-21T05:03:51Z")

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Greetings,

I have 2 Xbee Pro S2 and 2 Xbee Pro S2B.

My issue is communicating with these devices using the End Device Function set.

When I program any of them with the Coordinator or Router Function Set I am able to communicate with them both via the XBEE-API or the X-CTU with no issues. However when I attempt using the End Device Function set with any of them communication with the device becomes intermittent, even with X-CTU.

Has anyone come across this issue?

Thank you,

~Luis

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**Author:** ![lrivera3\_at\_gmu.edu](https://avatars.discourse-cdn.com/v4/letter/l/22d042/32.png) [@lrivera3\_at\_gmu.edu](https://forums.digi.com/u/lrivera3_at_gmu.edu)\
**Post date:** [August 21, 2012, 5:13am UTC](https://forums.digi.com/t/xbee-pro-s2-and-s2b-and-xb24-zb-function-set-with-21a7-firmware/936/2 "2012-08-21T05:13:56Z")

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Correction to previous posting - its the XBP24-ZB Function Set/Firmware not XB24-ZB.

Thanks again.

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**Author:** ![kavya](https://avatars.discourse-cdn.com/v4/letter/k/e480ec/32.png) [@kavya](https://forums.digi.com/u/kavya)\
**Post date:** [September 25, 2012, 1:33pm UTC](https://forums.digi.com/t/xbee-pro-s2-and-s2b-and-xb24-zb-function-set-with-21a7-firmware/936/3 "2012-09-25T13:33:31Z")

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Hi,

If you are able to read the parameters of the end device through X-CTU, then it may be the problem with the sleeping parameters of the end device i think.

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**Author:** ![lynnl](https://avatars.discourse-cdn.com/v4/letter/l/22d042/32.png) [@lynnl](https://forums.digi.com/u/lynnl)\
**Post date:** [September 26, 2012, 3:31pm UTC](https://forums.digi.com/t/xbee-pro-s2-and-s2b-and-xb24-zb-function-set-with-21a7-firmware/936/4 "2012-09-26T15:31:01Z")

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You probably are not setting the ‘sleep’ parameters in the parents correctly. Yes, that seems odd, but you do need to set SN/SP in the Coordinator and Router correctly or your end-device appears to never talk because verytime it wakes, it has no ‘parent’.

Make sure you understand this information:  
[http://www.digi.com/wiki/developer/index.php/XBee\_Sleeping\_Problems](http://www.digi.com/wiki/developer/index.php/XBee_Sleeping_Problems)