The Pulse Width Modulator node converts an analog input into a pulse where the ON/OFF ratio depends on the modulated value of the Input connector.
The node computes the ratio of the Input value with the Input Min. property and the Input Max. property and applies it to the Period of the output pulse to determine the ON time.
The ratio is calculated at every expiration of the Period and thus it considers the actual value of the Input connector in that moment.

 Behaviour of PWM

Behaviour of PWM