Your Outdoor Motion Sensor has two modes, and the LED indicator will behave differently depending on what mode the device is in.
There's Test Mode, which can be initiated by turning the timer and lux knobs all the way to the left. This is the mode you want to be in when the sensor isn't mounted and the tamper switch isn't being pressed. While in Test Mode, the LED indicator will flash every time motion is detected. This mode is great for checking that the installation location is within range of your Z-Wave hub, and changing the device's positioning for optimal motion detection. During Test Mode the sensor will report motion and trigger associated Z-Wave lights any time movement is detected. To exit this mode, just adjust knobs back to their regular positions.
Then there's Normal Mode, which can be activated by pressing the tamper switch for at least 10 seconds. The device should be in Normal Mode once it's mounted and the timer and lux knobs are configured to your liking. To save battery, the LED indicator will not flash when motion is detected while in Normal Mode. However, the device will still send motion alerts and trigger any associated lights according to the timer and lux knob settings you have place. If the device is in Normal Mode and you see the LED indicator flash, this means the device's battery is low and should be changed out.
Let us know if you have any questions about this functionality! We'll be happy to help.