The problem here is that you cannot specify X values with the BarSeries (this is a limitation of the product). You will need to use a ShapeSeries instead.
After 24 hours, do you want to start adding data to a new series? Or is it suppose to continue after? Or you want it to erase the last 24 hours and replace it with new data?
Charles Bérubé-Rémillard
Technical Support
Xceed Software Inc.