xbee freezes sometimes

I have an application where I use 2 Xbee modules( coord and end).
The coord is connected with a PC to receive data and store it.
The end device is build in a small tool which is plugged in to the OBD of a car. A µc reads out data over CANBUS and sends it to the end device which then transmit it to the coord/pc.Afterwards the tools is disconnected (all power gone) and the reconnected to the next car.
It works fine most of the time but sometimes the coord seems to hang up. It will receive nothing any more. A reset ATFR doesn’t help always after some resets or taking power away from the Coord helps and everything runs again.
Any Ideas how to solve the problem. (i use unicast)


What version of firmware are you running?

I use 1220 for the end devices and 1020 as coordinator

Have you tried updating to ZNet 2.5 rev. 1x47 firmware?

Or better yet, try updating to ZB firmware 2x41: