\documentclass{article}
\usepackage{tikz}
\usepackage{pgfplotstable}
\usepackage{pgfplots}
\begin{document}

\begin{tikzpicture}
\begin{axis}[
 xlabel=  Power Cap Values (W),
 ylabel = Average Idle Time (secs),
 ymax=12, ymin=0, xmax=60, xmin=23,
 x tick label style={black},
 grid=both
 ]
\addplot table [x=POWER, y= WOLB_AV_IDLE]{data.dat};
\addlegendentry {Without LB}
\end{axis}
\end{tikzpicture}

 
\end{document}
