rand returns me the same numbers on Simulink?

Hello,

I'm making a simulation of how much time is required for an Item to get through some Workstation, and I wanted to give some kind of randomness to worktime, I tried by using a Matlab action service time source, and having a minimum Worktime on which is added the max delay the station can have multiplied for a rand(1) function (as shown below).

However running the simulation multiple times I noticed the value of service time that is returned is always the same, what am I doing wrong? how should I solve it?

Thanks in advance

Answer 1

[Reeshabh Kumar Ranjan]

Hey Teng,

I think this might be the reason of repetition of numbers: https://in.mathworks.com/help/matlab/math/why-do-random-numbers-repeat-after-startup.html

See if it solves your problem.

[Teng Da Wen]

Ye it was it, I solved this by adding this line of code, Actually I had already tried with rng('Shuffle') but it didn't work, then I found out on simulink I need to declare the function as an exstrinsic one, thanks.

coder.extrinsic('rng');
rng('shuffle')