RFID Reader
RFID Reader
A RFID Reader converts RF signals into a data stream that can be read by RFID tags. It can be either fixed or mobile (such as in a car) and is usually powered by battery.
Using RSS information, each reader can estimate its location. This information can be combined to create a map of the environment.
Detection
When an RFID reader detects a tag, it sends a signal to the IC on the tag and receives RFID Tag a backscatter signal in return. The IC uses the received signal to translate the ID information into usable data. This data can then be communicated to the reader’s RF antenna and sent to the host computer for processing. RFID readers can take three forms: portal, handheld, and mounted. Portal readers are stationary and allow tags to pass through them; handheld readers can be moved around a workspace and communicate with tags from varying distances; and mounted readers are positioned on equipment, such as forklifts, and communicate with the tags in their fixed location.
RFID systems can detect tags without contact, in the dark, or through liquids. The technology also functions despite dust or dirt, and can be used in places with high temperatures. It can also be used to track individual products and prevent stockouts by sending alerts when certain items are low.
To function, an RFID tag must be able to harness the electromagnetic energy from the reader’s RF signal. A tag can use this energy either passively or actively. Active tags have an integrated battery to boost the signal and have a longer range than passive tags. A passive tag has no power source of its own, so when it is within range of an RF signal from the reader’s RF antenna, it generates a magnetic field that radiates away from the tag’s conductive surface. This magnetic field induces an electric current in the IC, which powers it up and causes it to begin transmitting its data.
Identification
An RFID reader uses an antenna to detect a return signal from compatible tags. The tag carries data that identifies the asset, including its protocol, managing organization, asset description and serial number. Once it senses a valid identification signal, the reader transmits that information to database software. This allows systems to monitor and track assets as they move throughout a facility or supply chain.
RF tag chips can hold up to several kilobytes of information. The information inside the RF tags can contribute to realization of productivity improvement, quality improvement and traceability by storing work instructions or inspection results with time stamps. These work instructions and inspection results can be used to automatically perform work or inspections without manual input.
The RFID tag receives electromagnetic energy from the reader via its own built-in antenna. This energy is converted into electricity by the chip, which turns on the IC inside. The IC then begins to broadcast its own ID signal. The reader’s antenna picks up the signal and sends it to the reader’s IC for demodulation and processing.
A common problem is “tag collision,” where multiple RFID readers simultaneously scan the same area and confuse each other with their signals. To avoid this, choose a reader that employs an anti-collision protocol to ensure that each tag is scanned one at a time.
Verification
The RFID technology has revolutionized many industries and is now in credit cards, bus passes and passports. It works by sending electromagnetic signals through an antenna to activate RFID Reader a chip inside the tagged item that contains information about it. The tag then transmits the backscatter signal to the reader, which receives the signal and sends it to a computer for processing. This data carries information about the object’s condition, including status (i.e., if it’s still alive or not).
Once a chip in the tagged item has received energy from the radio transmission, it can then modulate the signal with the desired information and transmit it back toward the antenna/reader. This data is captured by the RFID reader/antenna combination, which provides a list of read records that are stored in a database. A specialized system configured to translate the comma delimited scan data and compare it with a preloaded control file is able to verify if the RFID tagging and reading process is functioning properly.
This verification can be done in various ways depending on the specific RFID reading system. Usually the system uses a standard air interface, meaning that the readers and cards/tags must use the same air interface in order to communicate. It can also be performed by using a protocol that makes sure only one card/tag is read at a time (anti-collision). Other methods can include monitoring the RF signal strength and phase value, or by using a Doppler shift to determine which symbol cluster the tag belongs to.
Reporting
In order to properly read RFID tags, the system’s components must communicate. The reader sends a signal to the antenna, which then emits radio frequency waves. When these waves reach a tag, they activate it and return information to the antenna. This information is then received by the reader, which manipulates it into useful data.
Some readers are portable, while others are fixed. Both types of readers come in a variety of sizes and shapes, with different features and capabilities. Many of these features can influence an RFID reader’s performance, such as its reading range and environmental conditions.
RFID readers are used in a number of applications, including inventory tracking and verification. They can reduce management time and improve the accuracy of data collection. The technology also helps cut costs in manufacturing, distribution, and other supply chain processes.
For example, RFID in the retail industry allows retailers to track which items were chosen by customers, where they were tried on, and how many try-ons they underwent. This can help determine which styles were most popular and increase customer satisfaction.
Hospitals use RFID to track surgical items and ensure they are accounted for after surgery. They can also use it to prevent shoplifting by customers or employees, and as a self checkout process for shoppers. The technology is even used to monitor the progress of an Ironman race and verify a participant’s results.