The Honeywell outdoor temperature sensor used with the Honeywell VisionPRO touch screen thermostat has a part number of C7089U1006. Sometimes we get calls asking if you can install one sensor to multiple thermostats. You can only have one sensor wired to one thermostat.
You can not have one sensor wired to more than one stat, and you can not have more multiple sensors hooked up to just one stat.
It is always a one to one ratio!
The C7089U Outdoor Sensor has a negative temperature coefficient (NTC) meaning that resistance decreases as the temperature increases. Being a resistance sensor limits the applications to a one to one ratio of sensors to stats when measuring outside air temperature.