Vishi,
One of the new features in CVI 7 in plot legends in graphs. You may want to use a graph and make it behave like a chart. Basically when you get a new data point you add it to your chart buffer and redraw the data by deleting the old plot and replotting it.
The other option is to use a waveform graph that you make transparent except the legend and you plot some dummy data to it to generate the labels and use them for the chart.
Your third option here is you use a small graph that just plots a line of the color you want it and you can use this grapg label to indicate the plot name.
Take a look at this UIR file for some ideas.
Hope that helps.
Regards,
Juan Carlos
N.I.