# XBee Explicit Transmit Issue

**URL:** <https://forums.digi.com/t/xbee-explicit-transmit-issue/19727>\
**Category:** XBee & XBee Gateway\
**Tags:** transmit, api, xbee\
**Created:** [July 18, 2018, 12:15pm UTC](https://forums.digi.com/t/xbee-explicit-transmit-issue/19727 "2018-07-18T12:15:37Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![mPul](https://avatars.discourse-cdn.com/v4/letter/m/2acd7d/32.png) [@mPul](https://forums.digi.com/u/mPul)\
**Post date:** [July 18, 2018, 12:15pm UTC](https://forums.digi.com/t/xbee-explicit-transmit-issue/19727/1 "2018-07-18T12:15:37Z")

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Hi all,

I’m trying to send a unicast message (API frame type 0x11) from a co-coordinator to an end-node, addressing the end-node using its 64 and 16-bit network address.

The problem is that the message is not always transmitted successfully. Instead I’m receiving a 0x24 Address Not Found message.

What’s strange is that the 64 and 16-bit address of the end-node are written correctly and I’ve verified this by observing traffic on the PAN using the Texas Instruments SmartRF Packet Sniffer. Also, the end-node has been connected successfully to the PAN (in fact I receive data from it without any issues).

What could be the cause of this?

The packet I’m sending is this:  
7E0035110500177A010605BADE2BC501010001C0FB0A00F9F3E5D839920E1B9017A6D23DA3987153257D22949BC640E8FAC2EB64D8D97354A0

As can be seen from the above packet the end-node has IEEE address 00177A010605BADE and network address 2BC5.

I’m using an XBee S2C module with firmware version 0x40 0x5F.

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**Author:** ![lavarox](https://avatars.discourse-cdn.com/v4/letter/l/76d3ee/32.png) [@lavarox](https://forums.digi.com/u/lavarox)\
**Post date:** [March 13, 2019, 10:12am UTC](https://forums.digi.com/t/xbee-explicit-transmit-issue/19727/2 "2019-03-13T10:12:17Z")

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I am looking at the same problem as well. S2C model with latest firmware as of 8 March 2019.

It usually takes 2 retries that returns “Address not found” before it finally succeeds.

I have tried setting 16-bit address to FFFE and also to provide source routing before sending the message. Both doesn’t help.

We have already invested a lot in this and it seems like that more devices added to the network, the worse it gets! I thought more devices makes the network “stronger”?

Can someone kindly advise pls.