Rfid Core Technology

RFID CORE TECHNOLOGY

In the simplest terms, RFID is a technology that utilizes radio waves for communication between a transmitter and a receiver. In the case of RFID for business, the receiver is a reader/antenna and the transmitter is a tag. The tag is encoded with a unique identification number. This number is transmitted to the reader anytime the tag is queried. The unique ID number can then be referenced in a database for additional information regarding the tagged item.

Any RFID system is made of two main components: hardware, software/database. The hardware consists of tags, reader and antennas. The software consists of middleware and a database table containing a list of all encoded tags and at least one initial cross reference for the tag.

There are a wide number of tags on the market. Depending on the tag, the operating frequency range will be at 125 khz, 13.56 mhz, 915 mhz, 2.45 ghz or 5.8 ghz. A tag is

designed to work in only one frequency range. Tags are available in a wide range of styles and shapes. Tags also have limited read ranges. Tag type, style and frequency is dictated by structure of the item to be tagged, general environmental conditions in which the tag must operate, and the range at which the tag must be read. Tags can be divided into two main groups: active and passive. While the definition for each group continues to evolve, there is an easy definition which helps to separate the two groups. Active tags have a built-in power source (i.e. Battery) and will broadcast their signal to readers. Passive tags do not have a built in power source. Instead passive tags wait for a reader's signal to reach them and provide power to the tag. The passive tag will then utilize the signal from the reader for power and broadcast its unique ID back to the reader on the reader's signal. Currently tags in the 915mhz range are being used for many supply chain applications. These tags have a 64 or 96 bit memory capacity and are governed under a set of standards knows as Electronic Product Code (EPC). 915Mzh tags which comply with this standard are known as EPC tags.

A reader is a box which can have from 1 to 8 antennas attached to it. Each antenna can be turned on or off to control read rates and read areas. Currently most readers and antennas are designed for a specific frequency range, however this limitation is changing.

The reader contains firmware (controlling software built into the reader) which allows for a certain amount of control regarding the data collected from and sent to tags. A reader can also allow for output to other notification devices such as light bars, light sensors and Programmable Logic Controllers (PLCs). Finally a reader usually will have a direct serial or Ethernet connection to a computer or computer network. The tag information will be transferred to the computer for analysis and to determine what actions should be taken based on pre-defined business rules.

Middleware is software that runs on a computer or server that is attached to the reader or to the network the reader is connected to. The purpose of middleware is to be the interface between the tag information and the backend database system. Middleware will draw tag information from the readers, process the tags against a set of pre-defined business rules and then perform data operations based on the results of the business rules.

It can be linked directly to an Enterprise Resource Planning (ERP) system or perform its actions in a stand alone mode. Output options from middleware can be as diverse as updating the ERP system, building and sending XML or text files, sending signals to turn on or off light bars or other mechanical devices.

The database table will contain tag ids which the system encodes or reads and at least one link to a ERP table if necessary. Each tag has a unique identifier and that ID is used as a primary key for the tag database table. This table can be part of an existing ERP backend or can exist in a stand alone database or as a free table. The primary function of the tag database table is to link the tag to other vital information associated to the tag.

Diagram A

In skid level tagging an EPC tag

...