modbus_gw is a USB Stick I have created in order to interface wireless 433MHz sensors with Modbus.
It support Oregon Scientific an WT480 temperature sensors. It also has the capability to notify Nexa RF receivers like Nexa switch and Nexa doorbell in order to turn on/off lights or ring the doorbell with different sounds based on events.

The module has primarily been tested with Tridium Niagara. But since it’s based on Modbus RTU, it should work with all systems supporting Modbus.

Contact me if you are interested in adding this kind of sensors to your Niagara installation.