Estimating process noise using System Identification Toolbox

Dear community,

I am unable to understand how the System Identification Toolbox is simulating process. I have created a dummy simulation -- see attached file -- where i simulate a SISO system actuated only though the Gaussian noise.

I am unable to understand what kind of noise simulation the toolbox is using -- i would assume some kind of wiener process, but the internal state tend towards 0. Additionally, I cannot get the correct K value when i change the step time of the simulation to another value than 1.

NB: I have been able to get the desired behaviour using SDE simulation (Stochastic simulation)

[soeren graabaek]

I have not yet found the solution, but i have found this example that helped me progress [1].

[1]: https://se.mathworks.com/help/ident/ug/identifying-state-space-models-with-independent-process-and-measurement-noise.html