tikz: automatic anchor point

Question

Can you see label "prodotti"?

\documentclass{article}
\usepackage{float}
\usepackage[dvipsnames]{xcolor}
\usepackage{tikz}
\usetikzlibrary{positioning}
\begin{document}
\begin{figure}[H]
\centering
\begin{tikzpicture}
 
% Sum shape
\node[] (enter) at (0,0){alimentazione};
 
\node [draw,
    fill=SeaGreen!50,
    minimum width=3cm,
    minimum height=1.6cm,
    rounded corners=0.5mm,
    right=1cm of enter,
]  (system) {unità di separazione};

\draw[-stealth] (enter.east) -- ++(1,0);
\node[above=1em of system.east] (a) {};
\draw[-stealth] (a.center) -- ++(1,0) node (b) {};
\node[below=1em of system.east] (c) {};
\draw[-stealth] (c.center) -- ++(1,0) node (d) {};
\node[below=2em of system.south] (separator_agent) {agente separante};
\draw[-stealth] (separator_agent.north) -- (system.south) {};
\node[] (e) at (b.east) {prodotti}; % <--- this
\end{tikzpicture}
\end{figure}
\end{document}

Is there a way to anchor the label directly to the end of the arrow, without having to "manually" calculate the position via xshift?

Answer 1

You need to specify the anchor of the node.

\documentclass{article}
\usepackage{float}
\usepackage[dvipsnames]{xcolor}
\usepackage{tikz}
\usetikzlibrary{positioning}
\begin{document}
  \begin{figure}[H]
    \centering
    \begin{tikzpicture}
    
    % Sum shape
    \node (enter) at (0,0) {alimentazione};
    
    \node [draw,
      fill=SeaGreen!50,
      minimum width=3cm,
      minimum height=1.6cm,
      rounded corners=0.5mm,
      right=1cm of enter,
    ]  (system) {unità di separazione};
    
    \draw[-stealth] (enter.east) -- ++(1,0);
    \node[above=1em of system.east] (a) {};
    \draw[-stealth] (a.center) -- ++(1,0) node (b) {};
    \node[below=1em of system.east] (c) {};
    \draw[-stealth] (c.center) -- ++(1,0) node (d) {};
    \node[below=2em of system.south] (separator_agent) {agente separante};
    \draw[-stealth] (separator_agent.north) -- (system.south) {};
    \node[anchor=west] (e) at (b.east) {prodotti}; % <--- this
    \end{tikzpicture}
  \end{figure}
\end{document}

As pointed out by @SebGlav, you can code right instead of anchor=west in the node's optional argument.