Stateflow event not making sense

I have the following stateflow model (simulation time from 0 to 10 seconds, the step from 0 to 1 occurs at 5 seconds):

My expectation is to have output==1 up to 5 seconds and output==2 thereafter, since the default state (state1) sets the output to 1 and the transition to state2 occurs at 5 seconds, which is when the step occurs. However, I get instead the following output:

This does not make sense. What am I doing wrong? Thanks for helping!

Answer 1

[Sebastian Castro]

If you drive a Chart block with an Event, it is executed as an event-driven chart. So, the chart doesn't wake up until t=5 which is when the first event happens. If a value is unassigned, it will take a default initial value of 0.

What you can do to start the system is go to "File > Model Properties > Chart Properties" and turn on the "Execute Chart at Initialization" option. This will make sure your chart initializes at state1 instead of waiting for the first event to occur.

- Sebastian