Each access point (i.e. a door, a parking
gate) generally has a human interface device (keypad, card and card reader,
biometrics station, etc...). The function of the human interface device is to
receive and authenticate access requests (i.e. determine who is requesting access and
make sure they are who they claim to be).
Once the identity has been proclaimed valid by the human interface device, a Wiegand code
identifying the requestor is sent to an access controller.
The controller's function is to authorize or deny access to the requestor
(send a signal to lock or unlock the door, open or close the gate, etc...),
based on a permission database (i.e. does the requestor have the right to access the
area to which access is requested at this day and time). Many such controllers may also be
networked together, thereby forming an access control network. Many of these networks may
be connected to monitoring and control centrals which oversee the entire security system.
| Wiegand controllers |
Wiegand readers and keypads |