The HW416B has two orange trimmer potentiometers (variable resistors). Most datasheets label them simply as "Time" and "Sensitivity." That is not enough. Here is the better explanation.
The output signal of the HW416B is a digital signal that goes high (1) when a person is detected and low (0) when no person is detected. The output signal can be connected directly to a microcontroller or other digital circuit. hw416b pir sensor datasheet better