Xbee S2C Modem Issues

[oldfortune_]

Heya,

I have been using a group of 10 Xbees for a swarm robotics project and a few of the Xbees have started playing up. The Xbees are setup in a star configuration, all chatting back and forth with a single coordinator. After a few days of successful operation/testing some 2 of the Xbee radios stopped streaming data. It is unclear at this stage whether this is a fault of our hardware design, or the Xbees themselves, hence why I am asking for some expert opinion.

The behaviour of the Xbees when they failed was as follows :

- after initial failure, the Xbee could no longer communicate to the coordinator
- the Xbee could still be discovered by the XCTU software and could be recovered
- after factory resetting the device and configuring it in the network, it is able to communicate with the coordinator
- this communication has a extremely limited throughput going from the end-device to the coordinator (0.01kbs)
- the communication however still performs reasonably from the coordinator to the end device (14.56kbs)

We are wondering if it is possible that our hardware has somehow damaged the UART or the radio module in the XBee, if so would there be a way of determining if this is the case ? Or has anyone seen this kind of behaviour before?

We are using the following Xbee units:
- Part : XB24CAPIT-001 (Rev D)
- Firmware : XBEE24C 802.15.4 TH 2003

Any input on this strange behaviour would be super helpful! I feel like I have already exhausted many of the standard debugging techniques for this kind of issue, so some fresh thoughts would be rad!

Best,
Sean.

[coromonadalix]

I you see them thru xctu, the uart should be good,  its been a while since ive played with them,

if i recall, i used them in a mesh network,  i had some problems with firmwares updates, had to put the "old" one ... in some of them,  but i think they weren't good, ditched them.

Maybe its only 2x of them who gets bad, if you exchange them,  how long does it work ?

Have you contacted their tech support ?

[oldfortune_]

Thanks for the response

I was thinking potentially it could just be an issue with two faulty units, but I think that it would be quite unlikely out of a group of 10 units. I've played around with a few different firmware options but that doesn't seem to help out the throughput issue. I was thinking it could also be a damaged modem, but the fact that the performance is only effected in one direction made that seem unlikely (I think they do some handshaking in the protocol?)

If I exchange the units the system will work fine, for now this has worked for a number of days. The system needs to be really reliable though, so I'd like to get to the bottom of what has happened to the two faulty units.

Yer I've got in touch with Digi, yet to get a constructive response.

Thanks again.