Monday, June 20, 2011

RFID Tags: General Information

By Owen Jones


All RFID tags are used to hold and ultimately send data. They can best be thought of as the replacement for the bar code. However, they have significant advantages over bar codes. For example: RFID tags can hold much more data than bar codes; they can be read from further away and they can in point of fact send information, not only store data.

There are three kinds of RFID tags: passive, active and hybrid. Passive RFID tags are the least expensive, because they are less complex. They have to be asked to disclose their information by taking power from an RFID reader. When the reader's radio waves hit them, they echo back their information. This is the sort of tag used in goods in a retail outlet or on crates in a warehouse.

On the other hand, active RFID tags have a battery, a transmitter and an antenna so that they are always transmitting. These devices are clearly a lot more expensive and so are used only on more costly items such as a container, a battle tank, an aircraft, on criminals ankle bands or on an animal of an endangered species.

The hybrid RFID tag is capable of transmitting, but it needs to be told to transmit; it has to be turned on by a signal. This signal could be a satellite passing over head. These hybrid RFID tags are also costly, but the battery lasts longer because they are not 'always on'. These tags have the same applications as the active tags, but are appropriate for use where it is not critical to know where something is every minute of the day: for instance cattle in a field or goats on a mountain.

Passive tags can be attached permanently by sewing them into linings or placing them under skin because they do not have their own electricity source and do not wear out. This is a cause of concern to some people who worry about an invasion of their privacy or the erosion of their human rights.

Active and hybrid tags are most often clearly visible so that the batteries can be changed as and when necessary. If this is going to be not likely to take place, as in the case of wild animals, the tag can have a biodegradable fastener which will break sometime after the expected expiry of the battery.

Some uses for RFID tags are on season tickets so that the holder can pass through the style more quickly than a customer paying by cash. It has uses in security; most of the ID badges you see pinned to jackets have RFID built into them so that security guards do not have to stop and question everybody.

They can be put into trucks that regularly cross borders so that they do not need to stop for identification. They can be placed in windscreens so that as you pass through a motorway toll station, either your credit card is billed or the charge is added to your company's monthly statement.

Hospitals utilize them on patients so that they do not misplace anyone or misidentify them. RFID tags are useful in our daily lives but people are concerned about criminals being able to read all this information too easily as well.




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