Plotting vertical line on real-time data plot

[GroverGun]

Good afternoon,

In the attached VI I am collecting real time data from an RS32 device and displays them on a waveform chart. This chart displays 400 data points at one time. I would like to plot a vertical line at a pre-determined distance from the LEFT edge of the plot. So if 250 (or any number between 0 and 400) is the desired location for the vertical line, I need it to stay at 250 data points from the LEFT side. I am sure there are many ways to do this, but I can not get one to work. The last method I tried (which is still represented in this VI) is the XScale MarkerValues. 

Thank you in advance for your help. 

-Grover

[jcarmody]

You could change your waveform chart to a graph and use a cursor.  You'd need to collect the data points in an array, too.

  

[GroverGun]

How would I setup the various parameters in the CrsrList constant? (i.e. xF2FF08) Also, would this be something that the user would need to "click" into place each time? Or would it display once the VI is running?