# PIR/Ultrasonic Sensors used in an Occupancy Sensor

**URL:** <https://community.homey.app/t/pir-ultrasonic-sensors-used-in-an-occupancy-sensor/25454>\
**Category:** Questions & Help\
**Tags:** zigbee\
**Created:** [February 3, 2020, 10:39pm UTC](https://community.homey.app/t/pir-ultrasonic-sensors-used-in-an-occupancy-sensor/25454 "2020-02-03T22:39:41Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Jon\_C](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/jon_c/32/21369_2.png) [@Jon\_C](https://community.homey.app/u/Jon_C)\
**Post date:** [February 3, 2020, 10:39pm UTC](https://community.homey.app/t/pir-ultrasonic-sensors-used-in-an-occupancy-sensor/25454/1 "2020-02-03T22:39:41Z")

</div>

I am confused about why the Occupancy Sensor Cluster (ClusterID 0x0406) lists PIR/Ultrasonic sensors as its optional OccupancySensorType attribute (AttributeID 0x0001)?

My understanding is that an Occupancy Sensor is suppose to sense if a room is occupied (ie - would detect a motionless human). A PIR/Ultrasonic sensor can only detects motion and therefore cannot detect the motionless human in the room. Therefore, I feel like a PIR/Ultrasonic sensor would be better fitted to be for the IAS Zone Cluster (ClusterID 0x0500) Motion Sensor.

---

<div class="post-metadata">

**Author:** ![robertklep](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/robertklep/32/160628_2.png) [@robertklep](https://community.homey.app/u/robertklep)\
**Post date:** [February 4, 2020, 5:50am UTC](https://community.homey.app/t/pir-ultrasonic-sensors-used-in-an-occupancy-sensor/25454/2 "2020-02-04T05:50:58Z")

</div>

What sort of answer do you expect? I don’t think anyone here was directly involved in the Zigbee cluster specification, so the only thing we can do is speculate.

> [@](#):
>
> Therefore, I feel like a PIR/Ultrasonic sensor would be better fitted to be for the IAS Zone Cluster (ClusterID 0x0500) Motion Sensor.

Aqara motion sensors use both clusters.