Card Access Systems typically consist of four components. Depending on the size and purpose of the system, there may be many additional types of devices however the four basic elements are:
3. Access Control Panels
4. Host PC
Proximity Cards carry a set of binary numbers (ones and zeros) that are used to identify the cardholder. The data on the card is a string of binary numbers of some fixed configuration and length. The card itself has no awareness of the makeup of its format, nor is it aware of any access privileges for the cardholder. That information exists only at the controller, and possibly the host (if present).
Standard readers simply convert the binary card data to Wiegand (or other) Protocol and send it to the controller. The reader itself has no awareness of the makeup of the card data format, nor is it aware of any access privileges for the cardholder. That information exists only at the controller.
Access Control Panel (Controller)
When the controller receives the data from the reader, its software begins the process of deciding whether or not to grant access. This is usually done in several stages.
• Does the Card Bit Format Match? If the Bit Format is not recognized, access will be DENIED (i.e. If your designated bit format in the software is 26bit, but you are trying to utilize a 34bit card, access will be DENIED). Only when you allow for the 34bit format in your system, will the controller grant access. Most systems have "Multiple Bit Technology", meaning they can run more than one bit format at a time. It is quite possible that you could run 26, 34, 37 and more bit formats - all at the same time.
• Does the Facility Code Match? If the Facility Codes doesn't match, access will be DENIED. (i.e. If your designated facility code in the software is "35", but you are trying to utilize a facility code of "45", access will be DENIED). Only when you allow for the correct facility code in your system, will the controller grant access. Most systems have the ability to run multiple facility codes at the same time.
• Is the Card Number allowed? If the Card Number is not allowed, access will be DENIED. Be sure that you have enrolled the card number in the system before trying to gain access at a reader access point.
You must understand your controller’s capabilities to fully debug any apparent problem with card and reader performance.
Operator Interface (Host Software)
Every integrated access control system has some form of terminal or PC program for operators to use. This is where an operator or administrator can:
• Add and delete cardholders
• Assign, modify or delete access privileges
• Assign, modify or delete bit formats & facility codes
• Create and modify time schedules, holiday lists, etc.
• Configure system hardware for doors, alarm points, etc.
• Monitor system events in real time
• Generate historical reports on all types of system activity
*Information credited to HID Corporation. Click here for the complete, uncondensed version.