Why does the PWM Generator (DC-DC) block not work for negative time?

I've attached a simple Simulink model that runs from -0.1 seconds to 0.1 seconds. The PWM Generator (DC-DC) block doesn't seem to work for negative time. (It outputs a constant 1 until time reaches 0.) Is this expected? If so, why? Should I generally avoid running simulations with negative time?

Answer 1

[Sabin]

The block you are using is not suitable for negative simulation time. For simulation involving both negative and positive simulation time the following options will be more suitable:

PWM Generator in Simscape Electrical - https://www.mathworks.com/help/sps/ref/pwmgenerator.html

PWM block in Simulink - https://www.mathworks.com/help/simulink/slref/pwm.html