The access control is via a card, a matching
card reader and a control panel interfaced to the server. We use proximity cards
with unique identification numbers integrated into it. Card reader reads data
and sends it to control section, which is a micro controller. The controller
checks the validity of data with server, which has a database. The server is pre-loaded
with the data about the card-holder for a given number.
The control section checks whether the
person is allowed to enter a particular door or not. If the authentication is
successful, then the person is allowed access to the particular entrance.
The permission in a given entrance can
also be as per the person’s designation. The access control is employed at this
point when a person of a particular designation is not supposed to be allowed
in a given entrance.
CIRCUIT DIAGRAM
Radio frequency (RF) refers to
electromagnetic waves that have a wavelength suited for use in radio
communication. Radio waves are classified by their frequencies, which are
expressed in kilohertz, megahertz, or gigahertz. Radio frequencies range from
very low frequency (VLF), which has a range of 10 to 30 kHz, to extremely high
frequency, which has a range of 30 to 300 GHz.
RF-ID is a flexible technology that is
convenient, easy to use, and well suited for automatic operation. It combines
advantages not available with other identification technologies. RF-ID can be
supplied as read-only or read / write, does not require contact or
line-of-sight to operate, can function under a variety of environmental
conditions, and provides a high level of data integrity. In addition, because
the technology is difficult to counterfeit, RF-ID provides a high level of
security.
RF-ID is similar in concept to bar
coding. Bar code systems use a reader and coded labels that are attached to an
item, whereas RF-ID uses a reader and special RF-ID devices that are attached to
an item. Bar code uses optical signals to transfer information from the label
to the reader; RF-ID uses RF signals to transfer information from the RF-ID
device to the reader.
Radio waves transfer data between an
item to which an RF-ID device is attached and an RF-ID reader. The device can
contain data about the item, such as what the item is, what time the device traveled through a certain zone, perhaps even a parameter such as temperature. RF-ID devices, such as a tag or label, can be attached to virtually anything –
from a vehicle to a pallet of merchandise.
RF-ID technology uses frequencies
within the range of 50 kHz to 2.5 GHz. An RF-ID system typically includes the
following components:
• An RF-ID device (transponder or
tag) that contains data about an item
• An antenna used to transmit the RF
signals between the reader and the RF-ID device
• An RF transceiver that generates the
RF signals
• A reader that receives RF
transmissions from an RF-ID device and passes the data to a host system for
processing
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