sampleinterval.tex

\documentclass{standalone}
\usepackage{tikz,rxmarbles}
\usetikzlibrary[arrows,shapes,positioning,matrix]

\begin{document}
\begin{tikzpicture}

\matrix[row sep=0.5cm]
{
  \draw [time] (0,0) -- (7,0);
  \node[marble,circle,orange] (0x0) at (0.5,0) {};
  \node[marble,circle,yellow] (1x0) at (2,0) {};
  \node[marble,circle,green] (2x0) at (3,0) {};
  \node[complete] (3x0) at (5,0) {};
  \\
  
  \node[box,minimum width=7cm] (op) {SampleInterval ($\Delta t$)};
  \\
  
  \draw [time] (0,0) -- (7,0);
  \coordinate (Sx2) at (0.3,0);
  \node[marble,circle,orange] (0x2) at (1.8,0) {};
  \node[marble,circle,green] (1x2) at (3.3,0) {};
  \node[complete] (2x2) at (6.3,0) {};

  \draw[time interval] (0.3,0) to (1.8,0);
  \draw[time interval] (1.8,0) to (3.3,0);
  \draw[time interval] (3.3,0) to (4.8,0);
  \draw[time interval] (4.8,0) to (6.3,0);
  \\
};

\draw [fdash] (0x0) -- (0x0|-op.north);
\draw [fdash] (1x0) -- (1x0|-op.north);
\draw [fdash] (2x0) -- (2x0|-op.north);
\draw [fdash] (3x0) -- (3x0|-op.north);

\draw [subscribe] (Sx2|-op.south) -- (Sx2) node[above,sloped,pos=0.5] {\tiny{subscribe}};
\draw [rdash] (0x2) -- (0x2|-op.south);
\draw [rdash] (1x2) -- (1x2|-op.south);
\draw [rdash] (2x2) -- (2x2|-op.south);

\end{tikzpicture}
\end{document}