Classroom Doors

I had this idea back in 2010 that classrooms should have monitors embedded in them with IP addresses that could be accessed from any administration computer for classroom announcements, such as canceled class, or professor caught in traffic.  A simple phone call to the administrative assistant and your message could be posted on the monitor on your classroom door!

These are just card readers........ but it's on the right track..... If a refrigerator can get on the Internet, a classroom door should be able to also.  And they have video doorbells now too.
IP Door Access Control Systems are easy to install and provide excellent flexibility, yet many people who are used to the older type systems have concerns about using them.  This article tries to take the mystery out of network attached door access control systems, and describes how very easy they are to install and use.  You will find that all the signals that were used before are encoded on the standard Ethernet network.
From:  http://portal.isonas.com/news-education/how-to-install-an-ip-door-access-control/