When notifications from the Sensor Activities screen are enabled for a given sensor, every activity detected by that device will appear in the Activities log.

Door and window sensors are typically triggered a few times each day, but motion sensors may detect hundreds of events as people move around the premises, creating so many notifications that system performance is degraded.

To reduce undesirable activity tracking from motion sensors, they cannot be turned on with a single actionlike other sensors, not even with the "Turn all on" switch at the top of the page:

However, sensor activity logging can be enabled for motion sensors by creating a SENSOR OPEN notification.  

Here's how:

Go to the Notifications List page and select Add Notification.
  • On the New Notification screen, select Security. (The Security category includes, among other things, arming/disarming and door/window sensors, as well as motion sensors.)
  • Under Security Notification, select Sensor Open/Close (the system categorizes motion detection as something you might want to know about, the same as a door or window opening or closing).     
  • Under New Notification, give the notification an appropriate name, such as "Suspicious movement" or "Kids coming in after curfew".
    • Then, select the device that generates the notification, in this case a motion sensor
  • Under Notification Schedules, set the time(s) of day when you want to be notified about activity detected by motion sensors.
    • In addition to pre-set options such as times when the system is armed (or not armed) you can create a new schedule.  (If you do, don't forget to name it at the top of the screen).
  • Under Send Notification To, choose who receives the notification(s) you've created. 
 These steps will create an email notification and will also enable Sensor Activity for the desired motion sensors.