RFID technology, and applications in logistics

RFID what it is?

It is a unique and automatic identification technology, based on electro-magnetic waves that propagate in the air and allow the remote identification of living beings and objects, both moving and static. The real meaning of the letters “RFID” corresponds to the English acronym for Radio Frequency IDentification.

In practice, it is used to identify any product, giving it a unique identity on an electronic level. In this way, RFID acts as a bridge between the physical world and the digital world, giving a unique identity to any object or living being that enables the interconnection between objects, people and various services: in practice Internet of Things (IoT)

TAG: What is it. - RFID labels.

An RFID tag is a simple self-identification tag that has a microchip and antenna.
This electronic label (TAG) has the function of storing and transmitting data without the need for physical contact.
It also allows you to unambiguously follow every single product, since the RFID TAG is unique and unrepeatable.

RFID technology in logistics

Basic components of an RFID tag are:

Microchip
- This component contains the label-specific data.
- It can store information such as unique codes, product handling, production data, storage point.
Antenna
- The antenna wirelessly transmits data contained in the microchip.
- It allows two-way communication, when activated by a radio frequency signal emitted by an RFID reader.
Support
- Normally it is a label made of adhesive paper, or plastic.

Types of TAGs:

Passive TAGS

They have no energy of their own
Short reading distance
Inability to integrate auxiliary
sensors

LOW COST TAG

Semi-passive TAGS

They are helped to “awaken” thanks to their own
energy
Long reading distance
Can integrate auxiliary sensors

MEDIUM COST

Active TAGS

They have their own energy
Long reading distance
Can integrate auxiliary
sensors

HIGH COST

Is RFID the same as NFC?

The answer is NO!

NFC is a subset of RFID technology. In fact, it is limited compared to RFID.
NFC works at a distance of up to 10 cm.
Above this distance the NFC is unable to communicate with the reader.
NFC allows two-way communication between the reader and the NFC TAG.

Here are the key differences between RFID tags and NFC.

Charecteristics	Tag RFID	Tag NFC
Reading distance	Reading distance is from 20cm to over 10 meters	Max reading distance 10 cm
Device support	Needs an RFID reader to read an RFID tag	Can be read by smartphones and other NFC-enabled devices
Communication	Send One-Way Information	Two-way communication: can send and share information
Velocity	Multiple tags can be read at the same time NFC	Only one tag can be read at a time
Data Store	Carry ID information only	Can store and transmit multiple types of data
Cost	More expensive given its longer read range NFC	Cheaper given shorter read range

Here are the different fundamental characteristics between RFID and barcode

Charecteristics	RFID	Barcode
Effectiveness	Multiple RFID tags are read simultaneously (up to 200/sec) and no line of sight is required for reading	One code is read at a time and a line of sight is required between the code and the scanner to read
Resistance	Tags can be very durable. It is not susceptible to agents that prevent it from being read.	Labels are easily damaged. Dirt and other agents can prevent them from being read
Capacity	They are equipped with internal memory and can be associated with a large amount of data.	A very limited amount of data can be assigned to it.
Flexibility	The data on the tags can be both read and written. The tags are reusable and allow dynamic access to information.	The information is static. Not modifiable.
Other advantages of RFID over barcode:	Compared to barcodes and other identification technologies, radio frequency technology offers several advantages: Reading does not require direct contact Reading does not require optical line of sight and therefore there is no need for orientation towards the scanner. Tags can Be read at the same time Work in dirty or contaminated environments and also withstand very difficult conditions (environmental agents, thermal, chemical, mechanical stresses). They are therefore more durable. RFID tags contain more data than the barcode and can be rewritten and updated with new information. RFID tags also operate immersed in a fluid, inside the object you want to identify or inside a container. The RFID tag contains a unique and unique serial number that identifies every single product manufactured in the world, while the barcode identifies only the batch of a product, but not the individual item. RFID tags are more expensive compared to barcodes, but the cost/benefit ratio is generally advantageous.

How Passive RFID Works

Identification is done using an antenna to read a chip (called tag, or transponder) that has been applied to the object (or person or vehicle) to be identified. The tag contains a certain amount of information about the object on which it is applied (such as the code, the date of manufacture, the manufacturer), which can be static, or change over time.

The tag does not need power sources (electricity) to work: when it is “illuminated” by the magnetic field of the antenna to which it is exposed, the tag is in fact able to accumulate the little energy it needs to transmit, to short distance, the information it contains. This type of tag is called “passive.”

When it enters the field of action of a reader (from a few centimeters to a few meters) the tag is “woken up” by the ELECTROMAGNETIC FIELD generated by the reader and responds by “reflecting”, modulated, the signal.

The modulated response signal is then received by the reader which decodes it. This type of tag, called passive, is the most popular on the market thanks above all to the price that makes it usable in many applications.

ACTIVE RFID
How it works technically

The Telepass is an example of an active RFID transponder application

If, on the other hand, it is necessary to transmit over a long distance, a higher power is required and the tag must be powered by an electricity source, such as a battery.

In the latter case, the tag is called “active”.

There are many sectors in which RFID technology can be applied.

Tags are spreading a lot in the sectors of industrial production, logistics and clothing, but also in healthcare, public administrations, access control, etc.

What are the frequencies used in RFID?

RFID systems use various frequencies, which can be classified as:

– low frequencies (LF, between 125 and 134 kHz)
– high frequencies (HF, around 13 MHz)
– very high frequencies (UHF, between 860 and 960 MHz)
– microwave (over 2.45 GHz)

In general, as the frequency increases, the reading distance and the amount of information that can be transferred in a unit of time increase, the ability to withstand operating conditions and costs decrease. Low-frequency (LF) tags use little power, are capable of passing through non-metallic materials and liquids, but the signal for reading does not exceed 30-40 centimeters.

High-frequency (HF) tags work best with metal objects and can cover a distance of about one meter.

Ultra-high frequencies (UHF) offer wider read ranges and allow data to be transferred quickly, but do not pass through materials easily.

Solutions with 2.45 GHz tags are used in telepasses and similar.