The "Site Inactivity Timeout" controls the amount of time a sensor or gateway can be inactive (as in not heard from by our system) before its status changes from "A" for active to "I" for inactive. The "Site Inactivity Timeout" value is set on the site detail page and can be changed by clicking on "Job Sites" then "edit" to reach the site detail page for the site in question. The timeout is in minutes and a value of 0 disables the inactivity timeout feature. Note you will receive an alert email every time a sensor or gateway changes from active to inactive so use this feature only if you need it. The default value is 0 meaning that the inactivity timeout is disabled by default.