Plotting for every Iteration and refreshing the Previous plot in the Figure.

I have a continuous signal data coming from a Simulink Model,for infinite Time. I want to capture that data and plot the data for every Iteration. How do i plot the data in single figure for every iteration, refreshing the old plot? I mean, i want to plot a fresh figure for every iteration. The problem is, i do not know the number of iterations. Generally we use 'hold on' to plot in the same Figure. But i dont to plot previous data. I want to refresh the previous data with current data, but, i would like to use only one figure, as we use 'hold on'. I dont want multiple figures to pop up for every iteration. Kindly help me.