Simulink Linear Analysis Pole/Zero Plots

Attached is the Simulink file I'm having problems with. I have this system controlled by a PID controller which gives me the desired response on 'Scope1'. Now I want to do some plots using "Analysis -> Control Design -> Linear Analysis...".

Here I get my bode and step responses plot, but when I go to the "I/O Pole/Zero Map" all the poles and zeros are on the right side (real positive values) which means the system is unstable and it seems to be contradictory from the step and bode plot that shows an stable system. Am I missing or misinterpreting anything? Here are the bode and step plots I get:

And this is the I/O Pole/Zero Map:

Answer 1

[Sebastian Castro]

Based on the staircase step response, looks like your system is discrete.

This means that stability is inside the unit circle (circle of radius 1), which it is :)

- Sebastian

[Andres]

Hooo ok, so in discrete systems everything inside the circle is stable? Do you have any resource where I can read about this? Thank you Sebastian :)

[Sebastian Castro]

You can start with good old Wikipedia:

https://en.wikipedia.org/wiki/BIBO_stability#Frequency-domain_condition_for_linear_time-invariant_systems

https://en.wikipedia.org/wiki/Pole%E2%80%93zero_plot#Region_of_convergence_2

https://en.wikipedia.org/wiki/Z-transform#Region_of_convergence

- Sebastian