... ,the other pattern is passive infrared trigger work.Mode one with yellow LED:Ultrasound+Alarm+FlashingMode two ... infrared probe to the target, trigger the first mode work(ultrasonic+alarm+falishing), work continued 30 seconds ... enter into the state of choose working mode,then press the button A to choose the ... modes, need 10 seconds enter into the alert mode and the first three modes are all woking ...