What is RFID ?
RFID stands for Radio Frequency Identification.
RFID is one member in the family of Automatic Identification and Data Capture
( AIDC ) technologies and is a fast and reliable means of identifying objects.
There are two main components:
The Interrogator (RFID Reader) which transmits and receives the signal
and
the Transponder (tag) that is attached to the object.
An RFID tag is composed of a miniscule microchip and antenna. RFID tags
can be passive or active and come in a wide variety of sizes, shapes, and
forms.
Communication between the RFID Reader and tags occurs wirelessly and
therefore does not require a line of sight between the devices. An RFID
Reader
can read through most anything with the exception of conductive materials
like
water and metal, but with modifications and positioning, even these can
be
overcome. The RFID Reader emits a low-power radio wave field which is used
to power up the tag so as to pass on any information that is contained
on the chip.
In addition, readers can be fitted with an additional interface that converts
the
radio waves returned from the tag into a form that can then be passed on
to
another system, like a computer or any programmable logic controller.
Passive tags are generally smaller, lighter and less expensive than those
that
are active and can be applied to objects in harsh environments, are maintenance
free and will last for years. These transponders are only activated when
within
the response range of an RFID Reader. Active tags differ in that they incorporate
their own power source, where as the tag is a transmitter rather than a
reflector
of radio frequency signals which enables a broader range of functionality
like
programmable and read/write capabilities.
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