Use Smartthings to send a #tagged SMS to IFTTT. Upon receipt, IFTTT runs a Nexia automation.
You must configure SMS in IFTTT. Then set up a rule in Smartthings to text your IFTTT number with a specific #hashtag.
For example, text IFTTT when a temperature sensor exceeds and falls below a certain temperature to adjust your thermostat setpoint in Nexia.