How do I execute a function only one time in Simulink?

I am using an interpreted MATLAB function in simulink, to do some calculations. It then passes the results out that can be used by the rest of the model. However, it is very computationally expensive and cannot be done at every single time step. I want to run the simulation for 600 seconds with a time step of 0.1 seconds, but I only want this interpreted MATLAB function block to run every 100 seconds. Does anyone know how to do this? One approach I have been thinking about is almost like an if-statement, where the function will execute when the system time mod 100 = 0 (guarantees it will happen every 100 seconds), but I do not know how to do this in simulink. Thank you for your help!

Answer 1

[Carter Nolan]

There are two ways to do that :

1 -

First : Use the command get_param('YourModel','SimulationTime')

To get the time of the simulation and then set your

if .... else .... end 

fonction. (Source)

2 -

The second Method is the same idea, but done purely by Simulink, where you use a Clock and Mod function with the sampling time you want to use : (Source)

Answer 2

[Jim Riggs]

This is what rate transition blocks were created for. You might want to try this approach.

Simply insert a rate transition block on the input signal to the block that you want to run at a lower rate, and set the rate inside the rate transition block. You will find this block on the signal attributes menue.

[sajid ali]

thanks it was helpful

Answer 3

[Sean de Wolski]

Perhaps:

https://www.mathworks.com/help/releases/R2017b/simulink/slref/functioncallsubsystem.html

[Robert Jack]

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