Deconz Binding: Xiaomi Motion Sensor


I successfully connected a Xiaomi Motion Sensor to my openhab setup, but still have one question:

I implemented the sensor manually to my items file like this:

Switch	Alarm_PIR1	"Alarm1 [%s]"	<motion>	(FF_Wg)		{ channel="deconz:presencesensor:homeserver:PIR1:presence" } 

I also added a update item:

ateTime Alarm_PIR1_Update "letzte Bewegung: [%1$td.%1$tm.%1$ty %1$tH:%1$tM]" <clock> (FF_Wg) { channel="deconz:presencesensor:homeserver:PIR1:last_updated"}

Unfortunately the first item always show “ON” and is not turning OFF, but I see the sensor is working correctly because hte Update stamp is updating when movement is detected.

So any idea what I have done wrong with my first item?

Thanks in advance

edit: I realised it indeed turns from ON to OFF, but it take 90 seconds to do so. Is there a way to reduce the interval?