Wintermute User Guide

trigger_add: <zone>.<variable> | <level> | rise/fall/both | reset/<reset level> :: <command>

This sets a trigger on a variable

zone is the zone containing the variable
variable is the variable to have the trigger added to
level is the value at which the trigger will fire
rise/fall/both determines at which edge the trigger will fire¹⁾
reset/{reset level} is an optional field that determines what happens after the trigger has fired - if it's absent, the trigger will be removed after firing once; the flag “reset” will cause trigger to go on firing every time the condition is met; placing a value in this field will require the variable to reach this value to re-arm the trigger²⁾
command is the command to be executed when the trigger is fired

¹⁾

i.e. if it's set to fall, it will only fire if the variable's value falls past the trigger value

²⁾

this is to provide the option of hysteresis in a the trigger mechanism and prevent over-firing in a noisy system.