How can I start a timer when the value of a signal becomes zero?

I want to start a counter when the value of a signal becomes zero.

After that, when the time in the timer becomes 2 sec, I need to change a flag status.

I need help in doing these in simulink.

Thanks,

Answer 1

[Guy Rouleau]

Use Stateflow... it allows you to express this type of procedural logic in a very intuitive way.

If you need to use Simulink only, then a combination of basic math (Sum, Switch, Delay, etc) will do it.