Hi all,
i am going to use a custom accumulate function like that:

rule "CrowdInAreaEvent-event"
    no-loop
    when
        $RFIDReader : SensorFixed(type == Sensor.SENSOR_TYPE_RFID, $coverageArea : areaOfInterest )
        not CrowdInAreaEvent( sensor == $RFIDReader, this meets[ 5s ] $obs )
        $count : Integer( intValue > 10 )
            from accumulate( $obs : RFIDObservation( $tagid : tagid, sensor == $RFIDReader )
            over window:time( 60s ) from entry-point lowLevelSensorStream, countDistinct( $tagid ) );
    then
        insert( SituationManager.createCrowdInAreaEvent( "Crowd, number people: " + $count, Event.THREAT_LOW, $coverageArea, $RFIDReader, $count, 60, 10 ) );
end

I need to refer $obs object in order to compare timing of new observation with last event. Is it possible to do that?

Thanks a lot,
Matteo.