Ionics makes a plug variant called Stratus which is available with Zwave and ZigBee radio options.
Here's a simple procedure to tell if the ZigBee radio is installed and working, no software needed:
1. Define the plug port /dev/ttyUSB0 to be 19200/8/N/1 as follows:
debian:~# stty -F /dev/ttyUSB0 -raw ispeed 19200 ospeed 19200
2. Redirect output from the ZigBee module to the console terminal as follows:
debian:~# cat < /dev/ttyUSB0 &
3. Now send the "AT" commands as follows:
debian:~# echo "ATZ" > /dev/ttyUSB0
debian:~# echo "ATI" > /dev/ttyUSB0
The Stratus plug uses an ETRX2 ZigBee module from Telegesis, based on an EM250 chip from Ember.
The module interprets “AT” modem style commands documented here: http://www.telegesis.com/downloads/general/TG-ETRXn-R303-Commands.pdf