User's Guide

CHAPTER 2 RFID OVERVIEW
may, in fact, function as a wireless computer, able to interact with other
tags and devices or link to the Internet.
Memory vs. Power. While tags with minimal memory capacity can easily
function on the tiny bit of energy provided by the RF signal alone, higher tag
memory and processing demands typically require the support of a battery or
other type of power source.
I
NPUT/OUTPUT AND ONBOARD PROCESSING (OPTIONAL)
Certain tags can be configured to perform onboard processing functions and
may be also have input/output (I/O) capabilities.
Inputs and Outputs. A tag may be connected to an input device, such as a
temperature sensor, a meter, or a tamper/tilt detector. Such tags can receive
data from the input device and then convey that data (either as a record of
changes over time or as the current value) to the reader upon request.
Outputs, on the other hand, allow a tag to activate an attached device such
as a LED or emit an audible tone (to signal its presence) or can enable or
disable connected devices. (For example, an attached tag could disable a
computer or other equipment if removed from authorized premises.)
Onboard Processing. Tags with onboard processing capabilities can
perform a variety of calculations or functions depending upon the tag’s
microprocessor and power source/consumption. Such tags might work in
concert with an input device, for example, recording the temperature
variations a perishable product has been exposed to over time, then
calculating a more realistic expiration date based on that history.
Host Computer and Input/Output Functions
In order to put the data acquired from a tag to practical use, the RFID system
needs either a host computer to process that data or some kind of output
function that responds to the tag data.
In many cases, both host computer and output functions are used in the
RFID system.
H
OST COMPUTER
Through a host computer, the RFID system can log and process tag
transactions for a variety of purposes. For example:
 In a warehouse, a tag read can be associated with a location and time
for the purposes of tracking objects and their movements.
 In an automated toll system, a tag read can trigger a debit from the tag
owner’s account.
 In an automated meter reading system, a tag read also includes gas or
water usage data that can be forwarded to a customer billing system.
O
UTPUT FUNCTIONS
The simplest RFID system may only react with specified outputs according to
a set of rules programmed into the reader’s microprocessor. For example:
NANOSCANNER READER USER GUIDE • DOC # 8101001-000A 13
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