Tikz beginner, where to find manual

Question

I have looked at the LaTex code, form this post: Block Diagrams using Tikz
My question is, where can I get description of: input, sum, block,...I want to use multiplication, but I can't find anywhere the documentation of those elments.

EDIT: I got the answer where those blocks come from, now I would like to ask if there are some kind of premade block that can I import, it is really difficult for me to draw in LaTex and I don't feel capable to make my own blocks.

\tikzset{
block/.style = {draw, fill=white, rectangle, minimum height=3em, minimum width=3em},
tmp/.style  = {coordinate}, 
sum/.style= {draw, fill=white, circle, node distance=1cm},
input/.style = {coordinate},
output/.style= {coordinate},
pinstyle/.style = {pin edge={to-,thin,black}
}
}

    \begin{tikzpicture}[auto, node distance=2cm,>=latex']
        \node [input, name=rinput] (rinput) {};
        \node [sum, right of=rinput] (sum1) {};
        \node [block, right of=sum1] (controller) {$k_{p\beta}$};
        \node [block, above of=controller,node distance=1.3cm] (up){$\frac{k_{i\beta}}{s}$};
        \node [block, below of=controller,node distance=1.3cm] (rate) {$sk_{d\beta}$};
        \node [sum, right of=controller,node distance=2cm] (sum2) {};
        \node [block, above = 2cm of sum2](extra){$\frac{1}{\alpha_{\beta2}}$};  %
        \node [block, right of=sum2,node distance=2cm] (system) 
    {$\frac{a_{\beta 2}}{s+a_{\beta 1}}$};
        \node [output, right of=system, node distance=2cm] (output) {};
        \node [tmp, below of=controller] (tmp1){$H(s)$};
        \draw [->] (rinput) -- node{$R(s)$} (sum1);
        \draw [->] (sum1) --node[name=z,anchor=north]{$E(s)$} (controller);
        \draw [->] (controller) -- (sum2);
        \draw [->] (sum2) -- node{$U(s)$} (system);
        \draw [->] (system) -- node [name=y] {$Y(s)$}(output);
        \draw [->] (z) |- (rate);
        \draw [->] (rate) -| (sum2);
        \draw [->] (z) |- (up);
        \draw [->] (up) -| (sum2);
        \draw [->] (y) |- (tmp1)-| node[pos=0.99] {$-$} (sum1);
        \draw [->] (extra)--(sum2);
        \draw [->] ($(0,1.5cm)+(extra)$)node[above]{$d_{\beta 2}$} -- (extra);
        \end{tikzpicture}

Answer 1

If I correctly understand your question,. you actually are not interested for PI controller scheme but how to design some elements ... I will try to answer in two steps:

• modernize your MWE with syntax which is preferable now (if you will carefully compare both solution, you will easy find differences)

• suggest how to design some "building blocks" for drawing control schemes

First revision of your MWE:

 \documentclass[border=3mm,
                tikz]{standalone}
\usetikzlibrary{arrows, 
                calc,
                quotes,
                positioning,
                babel} % <--- added for
    \tikzset{
       block/.style = {rectangle, draw, %fill=white, 
                       minimum size=3em},
         tmp/.style = {coordinate},
         sum/.style = {circle, draw, minimum size=1ex, inner sep=1pt,
                       node contents={} },
         dot/.style = {sum, fill=black, minimum size=2pt,
                       node contents={} },
       input/.style = {coordinate},
      output/.style = {coordinate},
    pinstyle/.style = {pin edge={to-,thin,black}}
            }

    \begin{document}
        \begin{tikzpicture}[auto, 
    node distance = 3mm and 13mm,
                > = latex']
    \coordinate (input) at (0,0);
    \node (sum1)   [sum, right=of input];
    \node (input') [dot, right=of sum1];
    \node (cntrl)  [block, right=of input'] {$k_{p\beta}$};
    \node (up)   [block, above=of cntrl]    {$\frac{k_{i\beta}}{s}$};
    \node (rate) [block, below=of cntrl]    {$sk_{d\beta}$};
    \node (sum2) [sum, right=of cntrl];
    \node (extra)[block, 
                  above=of up.north -| sum2]     {$\frac{1}{\alpha_{\beta2}}$};  %
    \node (extra') [above=of extra]              {$d_{\beta 2}$};
    \node (system) [block, right=of sum2]        {$\frac{a_{\beta 2}}{s+a_{\beta 1}}$};
    \coordinate[right=of system] (output);
    \node [tmp, below=of cntrl] (tmp1)      {$H(s)$};
    %
    \draw[->]   (input)     to ["$R(s)$"]   (sum1) 
                (sum1)      edge["$E(s)$"]  (input')
                (input')    edge            (cntrl)
                (cntrl)     edge       (sum2)
                (sum2)      edge["$U(s)$"]  (system)
                (system)    edge["$Y(s)$"]  (output)
                (extra')    edge            (extra);
    \draw[->]   (input') |- (up);
    \draw[->]   (input') |- (rate);
    \draw[->]   (up)     -| (sum2);
    \draw[->]   (rate)   -| (sum2);
    \draw       (extra)  -- (extra |- up);
    \draw[->]   ($(system.east)!0.5!(output)$) node[dot] -- + (0,-22mm)   -| (sum1);
         \end{tikzpicture}
    \end{document}

Already here you can observe, how are designed sum and dot. Symbol for summation as well for multiplication are not standardized (actualy, they are, but rare used ...). So you need first to decide how you like to have they looks out. Below are examples of those symbols which are quite common in signal processing and in control too.

\documentclass[border=1mm,
               tikz,{standalone}
\usetikzlibrary{arrows,
                calc,
                quotes,
                positioning,
                babel}

    \begin{document}
\begin{tikzpicture}[
shorten <>/.style = {shorten >=#1, shorten <=#1},
mlt-s/.style={fill=#1,   % <-- symb. for multiplication, square
    rectangle, draw, minimum size=6mm,
    path picture={\draw[very thick,shorten <>=1.5mm]
    (path picture bounding box.north west)edge(path picture bounding box.south east)
    (path picture bounding box.south west) -- (path picture bounding box.north east);
                },% end of node contents
            node contents={}},
mlt-c/.style={fill=#1,    % <-- symb. for multiplication, circle
    circle, draw, minimum size=6mm,
    path picture={\draw[very thick,shorten <>=2mm]
    (path picture bounding box.north west)edge(path picture bounding box.south east)
    (path picture bounding box.south west) -- (path picture bounding box.north east);
                },% end of node contents
            node contents={}},
sum/.style={fill=#1,    % <-- symb. for summation
    circle, draw, minimum size=6mm,
    path picture={\draw[very thick,shorten <>=1mm]
    (path picture bounding box.north)edge(path picture bounding box.south)
    (path picture bounding box.west)  -- (path picture bounding box.east);
                },% end of node contents
            node contents={}},
                    ]
\node (a) [sum=gray!10];
\node (b) [mlt-s=gray!10,right=of a];
\node (c) [mlt-c=gray!20,right=of b];
\draw (a) -- (b);
\end{tikzpicture}
    \end{document}

Use of those symbols is demonstrated in example image. Note: since this symbols haven't any text, they are designed so, that empty text is part of node definition, consequently no empty curly braces is needed. This require, that node names should be before node definition (see code above).

Edit: Use of TikZ library quotes is sensitive on used babel packages. For some languages (Slovene is one of them) change catcode for quotes. To eliminate this problem is designed library babel. So, for documents in language other than English, it is sensible precaution to add it as it is now done in the both above codes.