I'd like to draw this very simple diagram below. No need those rounded corners on the feedback line.
I tried to follow other guides, but I don't know how to draw the feedback line nor how to distribute the inputs vertically on the left side of the rectangle.
Below is my try:
\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{shapes,arrows,positioning}
\begin{document}
\tikzstyle{block} = [draw, rectangle, minimum height=3em, minimum width=3em]
\tikzstyle{virtual} = [coordinate]
\begin{tikzpicture}[auto, node distance=2cm]
% Place nodes
\node [virtual] (input) {};
\node [block, right of=input] (model) {Model};
\node [virtual, right of=model] (output) {};
\node [virtual, below of=model] (feedback) {};
% Connect nodes
\draw [->] (input) -- node {$u$} (model);
\draw [->] (model) -- node [name=y] {$y$}(output);
\draw [->] (y) |- (feedback);
\end{tikzpicture}
\end{document}
Rendering as follows:
Could you please guide me here? Thanks