We have posted the source code for the zigbee modules which are beginning to appear in various Temco projects. The code is hosted on the open source repository github.com: Temco Controls · GitHub which allows community development and source control.
For now the zigbee modules are available in the Tstat6 zone controller and T3-NC gateway, we’ll be adding to the list in the coming months. The Tstat6 and NC working together give you access to a zigbee network over bacnet, and because the NC and the zigbee modules are both open source there is a lot of room for adding your own protocols and customizing. You can also purchase the zigbee modules as a component for adding to your own projects, we use the Texas Instruments CC2530F256 chip in tandem with a CC2591 amplifier for 22 dmb output power with typical outdoor range of 200 meters / 50 meters indoors depending on the antennae used and building materials.
Here’s a preview of a pre-production unit with the RF shield off. Production units have the RF shield and gold plated pads. And tidier soldering of course. I’ll update the images with production units soon. 
This is interesting - we make a competing solution. Still, any mesh solution can be helpful. There is a LOT of well deserved fear of RF/radio/wireless in the field. ZigBee has suffered the same problem as early LONworks, where it is too easy to make a closed system you claim is open. Most Zigbee suppliers use proprietary joins, which eliminates any notion of being open. I’ve also used a few Zigbee products which lack robustness, meaning you can get it installed, but if there is any interruption of the system, some human needs to show up and press buttons to recover the system.
Its been a while since I posted in this topic but our efforts with wireless have been moving along. There’s now a ‘wire replacement’ series of products which can transparently route modbus RS485 traffic over wireless using a zigbee mesh. Feel free to send on any comments and suggestions. Wireless has been gaining traction in the building automation world and with these devices, wherever there’s 24VAC power you can add points.
https://www.temcocontrols.com/product/wireless-modbus-usb-converter/
