Screen changing/cycling software

We have a plasma screen at work which displays our outstanding helpdesk calls per team etc and we want it to to be able to alternate the display between that display and another showing other stats. The pc that the plasma screen runs from is an xp box. Is there any software we can load that will display the first screen for 30 secs then switch to the second for 30 secs etc and then back to the first screen so that the screen isn’t burned by having the one image on it.