SATO CL408E Guía Del Usuario
Version 0.8
21/10/2004
Page 10 of 44
1. A programmable RFID tag for storing data;
2. An antenna to facilitate the reading and writing of data into the tag;
3. A reader that encodes/decodes the data in the tag's integrated circuitry
2. An antenna to facilitate the reading and writing of data into the tag;
3. A reader that encodes/decodes the data in the tag's integrated circuitry
The programmable RFID tag is an integrated circuit (IC) embedded in a thin film medium.
Information stored in the tag is transmitted via radio frequencies to an RF
Information stored in the tag is transmitted via radio frequencies to an RF
Figure: Construction of a RFID tag
(Thermal Transfer Paper can also be PET substrate)
(Thermal Transfer Paper can also be PET substrate)
reader. The performance characteristics of the RFID tag will then be determined by factors
such as the type of IC used, the read/write capability, the radio frequency and the read
range.
Q: What are the differences between passive and active tags?
RFID tags are categorized as either passive or active (also semi-passive).
Passive tags do not have an independent power supply, and must absorb their power from
the host reader. There exist passive RFID tags with the capability to store a few kilobytes
of data.
Active tags come with their own battery power source to start up the tag operation. As a
result of the built-in battery, active tags can operate over a longer range but have a shorter
service life and are more costly. What makes the active tags attractive is the extended
reading distance, which can be up to many miles—allowing communications with even
orbiting satellites. For a lower cost of implementation, passive tags are a more attractive
solution.
Q: What are the characteristics of RFID tags in terms of data storage capabilities?
The information that can be stored inside an RFID tag is defined by its read/write
characteristics. For a read-only tag, the information to be stored within it must be recorded
during the manufacturing process and cannot be erased. Typically, the information stored
is a unique “serial number” to allow one tag to be distinguished from another. Read-only
tags are therefore useful for identifying an object, much like the “license plate” of a car. For
a read/write tag, data can be written to and erased from the IC on demand. Depending on
the application, a rewriteable tag can be updated hundreds of times, and its reusability can
help to reduce the number of tags that need to be purchased.
Q: What does an RFID reader do?