DAVIS WeatherLink for Alarm Output Add. User Manual
Page 13
13
“Greater Than or =” or “Less Than or =” difference. Make sure the equa-
tion you create results in the check that you want. Some examples are
provided below:
1. A user wants to activate a fan to bring in cooler outside air to passively
cool their house. This affect only works if the temperature outside is 5°F
lower than the inside temperatures. Additionally, you don't want to cool
your house if the inside temperature is 70°F or lower. This can be
expressed as:
“IF Inside Temperature Minus Outside Temperature IS Greater Than or =
5.0°F. AND Inside Temperature IS Greater Than or = 70°F; DONE.”
2. A user wants to activate the sprinkler system when the Daily ET exceeds
the Daily Rainfall by 0.05":
“IF Daily ET Minus Daily Rain IS Greater Than or = 0.05; DONE”.
3. A user wants to activate environmental controls whenever the tempera-
ture outside differs from the inside temperature by 20°F or more.
Whether it is hotter or colder outside does not matter, but if the inside
temperature is between 68°F and 72°F, there is no need to alter the inside
temperature:
“IF Outside Temperature Minus Inside Temperature IS Greater Than or =
20.0°F OR Inside Temperature Minus Outside Temperature IS Greater
Than or = 20.0°F AND Inside Temperature is NOT Between 68°F &
72°F; DONE”.