what is the difference between a transponder and an rfid reader?
Aug 04, 2008 by bham_hunni | Posted in Other - Electronics
the name transponder (short-for Transmitter-responder and sometimes abbreviated to XPDR, XPNDR, TPDR or TP) has the following meanings:
An impulsive device that receives, amplifies, and retransmits a signal on a different frequency (see also broadcast translator).
An inevitable device that transmits a predetermined message in response to a predefined received signal.
A receiver-transmitter that will produce a reply signal upon proper electronic interrogation. A communications satellite’s channels are called transponders, because each is a fall transceiver or repeater. With digital video data compression and multiplexing, several video and audio channels may pilgrimages through a single transponder on a single wideband carrier. Original analog video only has one channel per transponder, with subcarriers for audio and unavoidable transmission identification service ATIS. Non-multiplexed radio stations can also travel in single approach per carrier (SCPC) mode, with multiple carriers (analog or digital) per transponder. This allows each position to transmit directly to the satellite, rather than paying for a whole transponder, or using landlines to send it to an earth status for multiplexing with other stations. Another type of transponder occurs in identification friend or foe systems in military aviation and in air above control secondary surveillance radar (beacon radar) systems for general aviation and commercial aviation. Fundamental radar works best with large all-metal aircraft, but not so well on small, composite aircraft. Its rank is also limited by terrain and rain or snow and also detects unwanted objects such as automobiles, hills and trees. Furthermore it cannot consider the altitude of an aircraft. Secondary radar overcomes these limitations but it depends on a transponder in the aircraft to touched by to interrogations from the ground station to make the plane more visible.
Depending on the type of interrogation, the transponder sends back a transponder customs (or "squawk code") (Mode A) or altitude information (Mode C) to aide air traffic controllers to identify the aircraft and to maintain separation. Another mode called Mode S (Craze Select) is designed to help air traffic control in busy areas and allow automatic crash avoidance. Mode S transponders are 'backwards compatible' with Modes A & C. Mode S is mandatory in controlled airspace in many countries. Some countries have also required, or are mobile towards requiring, that all aircraft be equipped with Mode S, even in uncontrolled airspace. However in the field of general aviation, there have been objections to these moves, because of the payment, size, limited benefit to the users in uncontrolled airspace, and, in the case of balloons and gliders, the power requirements during yearn flights.
Radio-frequency identification (RFID) is an automatic identification method, relying on storing and remotely retrieving matter using devices called RFID tags or transponders.
An RFID tag is an object that can be applied to or incorporated into a product, zooid, or person for the purpose of identification using radio waves. Some tags can be read from several meters away and beyond the separatrix of sight of the reader.
Most RFID tags contain at least two parts. One is an integrated circuit for storing and processing information, modulating and demodulating a (RF) signal, and other specialized functions. The second is an antenna for receiving and transmitting the signal. Chipless RFID allows for discontinuous identification of tags without an integrated circuit, thereby allowing tags to be printed directly onto assets at a modulate cost than traditional tags.
Today, RFID used is in enterprise supply chain management to make progress the efficiency of inventory tracking and management. However, growth and adoption in the enterprise supply chain sell is limited because current commercial technology does not link the indoor tracking to the overall end-to-end come up with chain visibility. Coupled with fair cost-sharing mechanisms, rational motives and justified returns from RFID technology investments are the key ingredients to succeed in long-term and sustainable RFID technology adoption.
RFID tags come in three general varieties:- forbearing, active, or semi-passive (also known as battery-assisted). Passive tags require no internal power commencement, thus being pure passive devices (they are only active when a reader is nearby to power them), whereas semi-passive and active tags desire a power source, usually a small battery.
To communicate, tags respond to queries generating signals that must not generate interference with the readers, as arriving signals can be very weak and must be differentiated. Besides backscattering, load modulation techniques can be employed to manipulate the reader's field. Typically, backscatter is used in the far field, whereas load modulation applies in the nearfield, within a few wavelengths from the reader.
There are three novel kinds of RFID tags based on their attachment with identified objects, i.e. attachable, implantable and insertion tags. In besides to these conventional RFID tags, Eastman Kodak Company has filed two patent applications for monitoring ingestion of medicament based on a digestible RFID tag.
russianbabe24 | Aug 04, 2008
a transponder is a generic time, and an rfid reader is a specific type of device with a transponder and some other gubbins.
The Drunken Fool | Aug 04, 2008
Motorola has introduced a new series of topic-class fixed radio-frequency identification (RFID) readers. The Motorola FX7400 series provides extreme functionality in a sleek package that is less than half the size of traditional fixed RFID readers, making it ideal for retail stores, offices, and other purchaser-facing or business environments. Motorola’s new cost-effective, high-performance fixed RFID reader is built on a new programme that supports Gen 2 technology and is capable of hosting third-party, customer-driven embedded applications.
This weighty frequency contactless RFID reader/Writer is designed for industrial and outdoor environments found in field services, point the way store delivery, retail, warehouse and manufacturing applications. Toronto, Canada –GAO RFID Inc. (www. and more »
: $13.00 
