Editing Access control (section)

===Access control topology===
[[File:Access control door wiring.png|thumb|right|Typical access control door wiring]]
[[File:Intelligent access control door wiring.PNG|thumb|right|Access control door wiring when using intelligent readers]]

Access control decisions are made by comparing the credentials to an access control list. This look-up can be done by a host or server, by an access control panel, or by a reader. The development of access control systems has observed a steady push of the look-up out from a central host to the edge of the system, or the reader. The predominant topology circa 2009 is hub and spoke with a control panel as the hub, and the readers as the spokes. The look-up and control functions are by the control panel. The spokes communicate through a serial connection; usually RS-485. Some manufactures are pushing the decision making to the edge by placing a controller at the door. The controllers are [[Internet Protocol|IP]] enabled, and connect to a host and database using standard networks<ref>{{Cite news|url=https://www.axis.com/blog/secure-insights/opening-new-doors-with-ip-access-control/|title=Opening new doors with IP access control – Secure Insights|date=16 March 2018|work=Secure Insights|access-date=20 June 2018|language=en-US}}</ref>