The sensor supported by Viva is supplied by Fibaro. It detects motion using a passive IR sensor and will be accurate in a 4 meters range.This device also measures ambient temperature and light intensity.
Installation of a sensor is done by selecting Devices from the menu in the Viva app, clicking Install new... and selecting the Sensor.
Once a device is installed, it can be deleted by selecting the correct sensor from the list under Devices, selecting Delete and following the instructions. 
To open the sensor, twist the back and front part. To reassemble, make sure that the 2 small grey dots on the back and front align.
The multi-sensor reports temperature under the following conditions:
- when temperature changes by 0.5°C
- every 60 minutes
If a devices is unresponsive, or the gateway is no longer available, the device can be factory reset using the following process:
  1. Open sensor
  2. Press and hold button (15-20 seconds)
  3. The light will start to change colour. Release button when light turns yellow
  4. Quickly press button once to confirm reset
  5. After a couple of seconds it will blink red to confirm reset