real time

Hello, I would like to draw a graph of multiple serie with y and y2. This I can do it. Now my problem is that I want to display data in real time but in a chart in which the size of axis doesnt change. a small drawing worths better than long explanation. so the graph should start like this...

I am developing a real time application that should run at real time when it is taking the information from the hardware installed on the PC. It is direct readings of the machine. at the same time, I need to use the database to store these data, this means that I need to get the program to a...