An embodiment of an access control system is disclosed herein that is easily customized by a user. A user defines cardholders, clearance levels, and logic scripts that dictate how the system will operate. User-entered changes propagate through the system automatically. The disclosed embodiment includes personality modules coupled to both field devices and a server. However, the personality modules operate autonomously from the server. Personality modules can also be added to the system dynamically and are auto-configuring. Display modules may also be included for locally and remotely programming, testing, managing, and operating personality modules and field devices. The system may include an intelligent display station that includes a reader and a display, displaying information in an interactive user interface in accordance with an individual's clearance level. Because the personality modules contain their own operating system, they can execute applications that allow direct interface to third-party systems.