The EV3 Ultrasonic Sensor has an “Advanced mode" which measures either in centimeters or in inches. When exactly do you use this mode? Why doesn’t the sensor send just a single ultrasonic signal?
From the official LEGO education site:
Measure – Advanced - Centimeters
The Measure – Advanced – Centimeters mode is similar to the Measure – Distance Centimeters mode, except that you can choose whether the sensor sends a single ultrasonic signal or continuous signals with the Measuring Mode input. The distance in centimeters is output in the Distance in Centimeters."
I can only guess to the reason why LEGO implemented this “Measuring Mode” option in a separate Advanced mode, but most likely it is to hide the subtle difference, which might be difficult to understand at first, from beginner users. The default measuring mode is the easiest to understand.