count the duration for which variable value is zero in simulink

t=(1:1:24); I=[0 0 0 1 1 1 2 2 2 5 5 5 10 10 10 15 15 15 5 5 5 0 0 0];

If these are the inputs in Simulink using a lookup

How can I determine the period for which the variabe (I) has the value of 0

Any help on this will be appreciated

Thanks.

regards Manish

[K E]

Do you need the duration that I=0 during the simulation, or after it has finished?

[Manish]

During the Simulation.

Answer 1

[C.J. Harris]

I'd take the input and convert it into a logical signal (1's and 0's), inverse this signal using a NOT block. Convert this back to a number (again, 1's and 0's) and feed it through an integrator block. The integrator output will then increase by a factor of 1 each second the input is non-zero. This output will then equal the amount of time your signal was zero.

[Manish]

This logic gives me the total number of instances when the value is zero. What I need is, the count should start when the variable Value is zero and reset the count when the variable value becomes nozero. Which means I need to determine the period for which the value is continuously zero.

Thanks would appreciate your inputs.

[C.J. Harris]

In this case add a reset condition to the integrator. Reset the integrator whenever it receives a non-zero value.

[Manish]

Thanks C.J.Harris it was really helpful. Just one last question will this logic be applicable if I want to check it for a variable value like 1 or 2 instead of zero?

[C.J. Harris]

Yes, you would need a slight modification though. Instead of converting the signal straight to a logical you would have to compare it against a constant.