A Web Enabled Distributed Door Entry System

This integrated security system that monitors and controls the access to a particular room/area was created as a demonstration of a typical distributed, web-enabled industrial application. It utilizes a bar code scanner, a data terminal, a PC at the door and another as a database and web server, a set of motion sensors, a PC camera and an electric door strike. These components communicate in a variety of ways including dedicated wires, RS-232, and TCP/IP networking. All authorized users are registered in a database. They can access the room by scanning their University identity card on the bar-code scanner. When a scan is made, the barcode is passed to the data terminal using a hardwired connection. The data terminal decodes the barcode and sends the information to the PC using RS-232. The PC queries the database using TCP/IP to determine if the door should be opened. If the user is in the database with the appropriate permissions, the PC instructs the data terminal to unlock the door. In this case, the scanner sets an output pin high to activate the door strike and unlock the door for four seconds. When a motion sensor trips, an interrupt occurs in the data terminal’s program. The data terminal checks the other sensor to see if it’s also tripped. If both are tripped, it sends a message to the PC via RS232 to trigger a video capture. The database keeps record of all the authorizations, entries and the movies. The web front to the system creates a web page on demand giving information on recent entries. This page also contains click-able links for viewing movies associated with a particular entry.