How is Vacancy sensing mode achieved using a Motion sensor?

1. Go to the 'Groups' tab 
2. Go to the settings of the Group to which the Sensor has been associated and where the Vacancy sensing mode is to be configured
3. Go to Group Automation Settings -> Motion sensor settings -> select the required time period
   
4. Disable the option 'When someone arrives' 
5. Configure the required details for the option 'When everybody leaves'
   

Please go to the following link for more details: 

https://knowledgebase.lumoscontrols.com/knowledge/how-to-configure-a-group-for-occupancy-based-lighting-using-mobile-app-1 

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