Sure it's possible. I once did a creep-application that ran for months. If you do long-term logging/graphing it is very important to save the data to file. How? After receiving the new data-points add the new (preferably ASCII-coded values) to the file. Why? An ordinary PC will not run continously for this time. After reboot, the application will need to continue as if nothing happened. And the goals of most data-acquisitioning is data for analysing/reporting purposes, not just a graph. If you tell us more about the instrument/interface/signal you can get a more specific answer.