blank multiple screens

From my Host tab I would like to be able to choose the system I would lIke to blank the screen on. This would be multiple screens and woulfd have a custom messge. For example we use this for

Digital signage and Noaa sends us messages. When I receive the message I could choose the

systems I want the message to go to . Enter the data and it would blank the screen with that message. Then from the host tab could uncheck the systems and the blank screen could disappear.