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{{#seo:|description=How does RFID work? Learn how frequency, protocol, and chipset impacts reader compatibility.}}
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|description=Learn more about Phidget RFID interfaces here.
== What is RFID? ==
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[[Category:IntroGuide]]
__TOC__
==RFID Basics==
===What is RFID?===
RFID stands for ''Radio Frequency Identification''. It is a technology that uses radio waves to identify objects at a distance.


RFID, short for Radio Frequency Identification, is a system for identifying the presence of objects by attaching small "tags" that contain a unique identifying code. The code can be read when the tag comes within range of an RFID reader.  
====How Does RFID Work?====
RFID systems consist of two main components: an RFID reader and an RFID tag.


[[Image:Rfid_animation.gif|link=|center]]


When an RFID tag is brought close to an RFID reader, the tag is energized and begins transmitting data. The RFID reader can then read this data and perform an action, such as unlocking a door or updating a database.


{{HoverImageNoLink|TagReadH.jpg|TagRead.gif|link=}}
====RFID Tags====
[[Image:RFIDTag_125.png|thumb|link=https://cdn.phidgets.com/docs/images/2/28/RFIDTag_125.png|A low-frequency RFID tag with the RFID chip and antenna exposed.]]
[[Image:RFID_Tags.png|thumb|link=https://cdn.phidgets.com/docs/images/2/22/RFID_Tags.png|Low-frequency [https://www.phidgets.com/?tier=2&catid=47&pcid=40 RFID tags] sold by Phidgets Inc.]]
RFID tags are small devices consisting of an antenna and an integrated circuit (microchip). They are typically passive, meaning they are unpowered and will only function when energized by an RFID reader.




RFID microchips contain a small amount of non-volatile memory. The tag manufacturer usually preprograms this memory with a unique code or ID. When the microchip is energized, it will broadcast this data using the antenna.


RFID technology is used in a wide array of applications, for example-
* Building security and access control
* Tracking library books
* Tracking farm animals or wildlife
* Interactive museum exhibits


===How Does RFID Work?===
RFID tags come in various shapes and sizes. You have likely encountered them in the form of access cards, key fobs, or wristbands.
The RFID tag contains a loop of copper wire (or a thin copper circuit trace) connected to a tiny chip. The RFID reader has a large antenna that emits an electromagnetic field that will induce current in the copper loop inside any nearby tags. When the tag is energized in this way, the chip is programmed to broadcast its data to the RFID reader.  


[[Image:RFID-diagram.jpg|link=|750px]]
=====Frequencies=====
RFID tags can be grouped according to their frequencies:
# '''Low-frequency tags (100-150kHz)'''—These tags have slower data rates, meaning they are typically less secure and better suited for simple applications such as door access or animal tagging. They may provide a longer read range and better performance near liquids and metals.
# '''High-frequency tags (13.56MHz)'''—These tags have faster data rates, allowing them to be used for secure applications like transmitting banking information.


Because of how inductive power works, the surface of the tag needs to be approximately parallel to the surface of the reader. If the tag is perpendicular to the reader (i.e. the edge of the card resting on the reader), the tag may not receive power at all.
Additionally, '''ultra-high frequency (UHF) tags''' exist, although they are less common.


The distance at which the tag can be read depends on the size of both antennas, and also on the reader's operating frequency. Phidgets RFID readers and tags operate in the LF (Low-Frequency) band, which results in read distances of 5 to 10 centimeters.  
====RFID Readers====
[[Image:125kHz_RFID_Reader.jpg|link=|thumb|link=https://cdn.phidgets.com/docs/images/b/bf/125kHz_RFID_Reader.jpg|A 125kHz RFID reader used for access control.]]
RFID readers are the active components of an RFID system. They are powered devices that energize any nearby tags. Some RFID readers can also write data to blank or rewriteable RFID tags.  


==How Can I Use RFID With Phidgets?==
An RFID reader must match the frequency of the tag it is trying to read. For example, if you are using a low-frequency RFID tag, you must use a low-frequency RFID reader.


Building a simple RFID system with Phidgets is easy. Here's everything you'll need:
==Phidget RFID Systems==
===RFID Interfaces===
For new systems, the [https://www.phidgets.com/?prodid=1282 PhidgetRFID Read-Write (1024_1)] is recommended.
[[Image:1024_1.jpg|link=|center|500px]]


[[Image:RFID-functional.jpg|link=|300px]]
* A [{{SERVER}}/?tier=1&catid=81&pcid=72 RFID reader], like the 1024 - PhidgetRFID Read/Write
* Some [{{SERVER}}/?tier=1&catid=47&pcid=40 RFID tags]
* A mini-USB cable


Next, go to the '''User Guide''' tab on the product page for your Phidget RFID reader. This will walk you through the installation of the Phidget libraries on your computer, and show you how to use the Phidget Control Panel to test out your Phidgets.
{| style="width: 85%;
 
|-
== Which RFID Tags Can I Use? ==
| Operating Frequency|| 125 kHz
 
RFID is a very broad technology, with many different variants and options. All of the tags sold by Phidgets Inc. are compatible with our readers, but you may find you need tags that come in a different shape or form factor than what we offer. In order to check if an RFID tag can be used with a Phidgets RFID board, you should ensure that the '''Frequency''', '''Protocol''' and '''Chipset''' are all compatible.
 
===Antenna Frequency===
 
The antenna on our RFID boards operates within '''125-150 kHz''', also called "Low Frequency".
 
 
{|
! Band || Frequency || Compatible with Phidgets
|-
|-
| LF (Low Frequency)|| 125-150kHz || ✔️
| Controlled By || USB or VINT
|-
|-
| HF (High Frequency) || 13.56MHz || ❌
| Functionality|| Reading and writing low-frequency RFID tags
|-
|-
| UHF (Ultra-High Frequency) || 300MHz - 3GHz || ❌
|}
|}


===Tag Protocol===
====Supported Protocols====
For '''read-only''' tags, the data on the tag must be encoded according to one of these standardized protocols:
There are many low-frequency RFID protocols, each dictating how to communicate with specific chipsets. The PhidgetRFID Read Write (1024_1) supports the following low-frequency RFID protocols:
 
 
{|
{|
! Protocol || Encoding || Tag String || Compatible with Phidgets
! Protocol || Tag String  
|-
|-
| EM4100 / EM4102|| Manchester || 10-digit hexadecimal (0-9, A-F) || ✔️
| [[#EM4100|EM4100]] || 10-digit hexadecimal (40-bit)  
|-
|-
| ISO11785 FDX-B || BiPhase || 15-digit numeric || ✔️
| [[#ISO11785 FDX-B|ISO11785 FDX-B]] || 15-digit numeric
|-
|-
| PhidgetTag (ASCII) || BiPhase || 24-character plain text || ✔️
| [[#H10301 (HID 26-bit/Wiegand)|H10301 (HID 26-bit/Wiegand)]] || 8-digit numeric
|-
| [[#HID Generic|HID Generic]] || 11-digit hexadecimal (44-bit)
|-
| [[#PhidgetTag (ASCII)|PhidgetTag (ASCII)]] || 24-character plain text
|}
|}


=====EM4100=====
[[Image:1024_em4100_example.png|link=https://cdn.phidgets.com/docs/images/3/31/1024_em4100_example.png|thumb|Reading a EM4100 RFID tag with a Phidget RFID interface.]]
EM4100 is a commonly used low-frequency RFID protocol, originally introduced via the EM4100 chipset.


For '''writable''' tags, the protocol is unimportant because they usually come blank, and if they are pre-written in an unsupported format, you can just rewrite them.  
EM4100 compatible tags feature 64 bits of read-only memory, though only 40 bits are available for encoded data. Phidget RFID interfaces represent this protocol as a 10-digit hexadecimal string (e.g. 0087f3bc91).


===Tag Chipset===
=====ISO11785 FDX-B=====
Each RFID tag contains a tiny microchip that determines how it communicates and what kind of special features it supports.  
ISO11785, in connection with ISO11784, defines low-frequency RFID tags used for animal identification. If you have a cat or dog, they likely have one of these tags implanted. FDX-B refers to the way that the ISO11785 data is encoded on the RFID tag and is the industry-standard encoding scheme.


For '''read-only''' tags, the chipset is unimportant as long as the tag data is encoded in one of the supported protocols listed in the section above this one.
These tags consist of 64 bits of non-volatile memory. There is a 10-bit ISO 3166 country code and a 38-bit unique ID. Phidget RFID interfaces represents this protocol as a 15-digit decimal with the 3-digit country code leading the 12-digit unique ID. For example, ''124000000000123'' would represent a Canadian country code and an unique ID of 123. Please note that the 12-digit unique ID cannot exceed the 38-bit maximum integer value of 274,877,906,943.


=====HID 26-bit (H10301)=====
[[Image:1024_HID26_example.png|link=https://cdn.phidgets.com/docs/images/e/e7/1024_HID26_example.png|thumb|Reading a HID 26-bit RFID tag with a Phidget RFID Read-Write (1024_1).]]
''Note: This protocol is only supported on the PhidgetRFID Read-Write (1024_1) with firmware version 310 or higher''


To use '''writable''' tags with Phidgets, the chipset must be '''T5577'''. Our RFID boards are only designed to write to tags with this specific chipset.  
The HID 26-bit format, often referred to as ''H10301'' or ''Wiegand'', is an open format that is commonly used for access control systems. Phidget RFID interfaces represents this protocol as an eight-digit number with a three-digit facility code and a five-digit card number. The card number is often printed on the card, while the facility code is not.


The facility code is 8-bits, and can support numbers up to 255, and the card number is 16 bits, and supports values up to 65535.


{|
=====HID Generic=====
! Chipset || Writable using Phidgets
''Note: This protocol is only supported on the PhidgetRFID Read-Write (1024_1) with firmware version 310 or higher''
|-
 
| T5577 || ✔️
HID Global Corporation provides several cards that use proprietary protocols. The raw data from these cards can be read and written, but not intelligently interpreted using a Phidget RFID interface. When a HID tag does not match the 26-bit format, your Phidget RFID interface will read the tag as a ''HID Generic Tag'' and will present the 44 raw bits of tag data as an 11-digit hexadecimal string.
|-
 
| EM4305 ||
This means the 1024_1 can read and copy such tags, but cannot provide any insight on the protocol that would allow you to write new valid tags of the same kind.
|}
 
=====PhidgetTAG=====
[[Image:1024_PhidgetTag_example.png|thumb|link=https://cdn.phidgets.com/docs/images/5/5b/1024_PhidgetTag_example.png|Reading a PhidgetTAG RFID tag with a Phidget RFID Read-Write (1024_1).]]
The PhidgetTAG protocol is unique to Phidget RFID interfaces. It is useful for users that want plain-text alphanumeric tag strings.
 
This protocol allows storing an ASCII string, of up to 24 characters (e.g. ''I am a Phidgets Tag''). 7-bit ASCII is supported, including all standard text and control codes. If you have questions about a particular protocol, please [https://www.phidgets.com/?view=contact contact us] for more information.
 
====Supported Chipsets====
[[Image:RFID_Tag_Example_TK4100.png|thumb|link=https://cdn.phidgets.com/docs/images/f/f5/RFID_Tag_Example_TK4100.png|A product listing for read-only RFID tags where the TK4100 chipset is featured prominently. This chipset is a clone of the EM4100 chipset, and therefore uses the EM4100 protocol.]]
[[Image:RFID_Tag_Example.png|thumb|link=https://cdn.phidgets.com/docs/images/6/65/RFID_Tag_Example.png|A listing for writable RFID tags where the T5577 chipset is featured prominently.]]
When shopping for RFID tags online, you will often see the chipset advertised (e.g. ''Writeable T5577 RFID Tag''). The term ''chipset'' is used loosely, but generally refers to the microchip present in the RFID tag.
 
 
When purchasing '''read-only''' RFID tags, you typically do not need to consider the chipset of the RFID tag you are purchasing. Instead, you should simply confirm the protocol is supported by your RFID reader.




When shopping for tags online, be aware that some products may list multiple chipsets (e.g. both T5577 and EM4305) in the product title, probably to maximize search results. In these cases, it's best to check the datasheet to confirm which chipset is actually present inside the tag.
When purchasing '''writable''' RFID tags, you should confirm the chipset is supported by your RFID interface. The 1024_1 currently supports writing to T5577 and EM4305 tags.


== Can I Use Multiple Readers? ==


If you try to use multiple RFID readers close to one another (in hopes of increasing your area of tag detection), you'll find that neither reader will be able to read the tag. This is because the antennas of the two readers interfere with one another, causing the tag to receive inconsistent power. The possible solutions are:
If you have questions about a particular chipset, please [https://www.phidgets.com/?view=contact contact us] for more information.


* Move the readers further apart, until tag reading is consistent
===RFID Tags===
* Use the antenna enable/disable function in our API to cycle through each reader (see [{{SERVER}}/?view=articles&article=MultipleRfidReadersCloseRange this article] for details)
Phidgets Inc. stocks a wide variety of read-only and writable low-frequency [https://www.phidgets.com/?tier=1&catid=47&pcid=40 RFID tags]. All tags sold are compatible with Phidget RFID interfaces.
* Use metallic barriers to shield the readers from one another (not recommended, difficult to do properly)


== Quick Links ==
===Advanced Topics===
====Using Multiple RFID Interfaces====
Please review [https://www.phidgets.com/?view=articles&article=MultipleRfidReadersCloseRange this article].


* [{{SERVER}}/?prodid=1023 Phidgets RFID Readers]
====Reading Multiple Tags Simultaneously====
* [{{SERVER}}/?view=comparetable&rel=RFIDTag Phidgets RFID Tags]
Phidget RFID interfaces do not support any anti-collision protocols. This means you will not be able to read more than one tag at a time.

Latest revision as of 21:13, 5 November 2024

RFID Basics

What is RFID?

RFID stands for Radio Frequency Identification. It is a technology that uses radio waves to identify objects at a distance.

How Does RFID Work?

RFID systems consist of two main components: an RFID reader and an RFID tag.

Rfid animation.gif

When an RFID tag is brought close to an RFID reader, the tag is energized and begins transmitting data. The RFID reader can then read this data and perform an action, such as unlocking a door or updating a database.

RFID Tags

A low-frequency RFID tag with the RFID chip and antenna exposed.
Low-frequency RFID tags sold by Phidgets Inc.

RFID tags are small devices consisting of an antenna and an integrated circuit (microchip). They are typically passive, meaning they are unpowered and will only function when energized by an RFID reader.


RFID microchips contain a small amount of non-volatile memory. The tag manufacturer usually preprograms this memory with a unique code or ID. When the microchip is energized, it will broadcast this data using the antenna.


RFID tags come in various shapes and sizes. You have likely encountered them in the form of access cards, key fobs, or wristbands.

Frequencies

RFID tags can be grouped according to their frequencies:

  1. Low-frequency tags (100-150kHz)—These tags have slower data rates, meaning they are typically less secure and better suited for simple applications such as door access or animal tagging. They may provide a longer read range and better performance near liquids and metals.
  2. High-frequency tags (13.56MHz)—These tags have faster data rates, allowing them to be used for secure applications like transmitting banking information.

Additionally, ultra-high frequency (UHF) tags exist, although they are less common.

RFID Readers

A 125kHz RFID reader used for access control.

RFID readers are the active components of an RFID system. They are powered devices that energize any nearby tags. Some RFID readers can also write data to blank or rewriteable RFID tags.

An RFID reader must match the frequency of the tag it is trying to read. For example, if you are using a low-frequency RFID tag, you must use a low-frequency RFID reader.

Phidget RFID Systems

RFID Interfaces

For new systems, the PhidgetRFID Read-Write (1024_1) is recommended.

1024 1.jpg


Operating Frequency 125 kHz
Controlled By USB or VINT
Functionality Reading and writing low-frequency RFID tags

Supported Protocols

There are many low-frequency RFID protocols, each dictating how to communicate with specific chipsets. The PhidgetRFID Read Write (1024_1) supports the following low-frequency RFID protocols:

Protocol Tag String
EM4100 10-digit hexadecimal (40-bit)
ISO11785 FDX-B 15-digit numeric
H10301 (HID 26-bit/Wiegand) 8-digit numeric
HID Generic 11-digit hexadecimal (44-bit)
PhidgetTag (ASCII) 24-character plain text
EM4100
Reading a EM4100 RFID tag with a Phidget RFID interface.

EM4100 is a commonly used low-frequency RFID protocol, originally introduced via the EM4100 chipset.

EM4100 compatible tags feature 64 bits of read-only memory, though only 40 bits are available for encoded data. Phidget RFID interfaces represent this protocol as a 10-digit hexadecimal string (e.g. 0087f3bc91).

ISO11785 FDX-B

ISO11785, in connection with ISO11784, defines low-frequency RFID tags used for animal identification. If you have a cat or dog, they likely have one of these tags implanted. FDX-B refers to the way that the ISO11785 data is encoded on the RFID tag and is the industry-standard encoding scheme.

These tags consist of 64 bits of non-volatile memory. There is a 10-bit ISO 3166 country code and a 38-bit unique ID. Phidget RFID interfaces represents this protocol as a 15-digit decimal with the 3-digit country code leading the 12-digit unique ID. For example, 124000000000123 would represent a Canadian country code and an unique ID of 123. Please note that the 12-digit unique ID cannot exceed the 38-bit maximum integer value of 274,877,906,943.

HID 26-bit (H10301)
Reading a HID 26-bit RFID tag with a Phidget RFID Read-Write (1024_1).

Note: This protocol is only supported on the PhidgetRFID Read-Write (1024_1) with firmware version 310 or higher

The HID 26-bit format, often referred to as H10301 or Wiegand, is an open format that is commonly used for access control systems. Phidget RFID interfaces represents this protocol as an eight-digit number with a three-digit facility code and a five-digit card number. The card number is often printed on the card, while the facility code is not.

The facility code is 8-bits, and can support numbers up to 255, and the card number is 16 bits, and supports values up to 65535.

HID Generic

Note: This protocol is only supported on the PhidgetRFID Read-Write (1024_1) with firmware version 310 or higher

HID Global Corporation provides several cards that use proprietary protocols. The raw data from these cards can be read and written, but not intelligently interpreted using a Phidget RFID interface. When a HID tag does not match the 26-bit format, your Phidget RFID interface will read the tag as a HID Generic Tag and will present the 44 raw bits of tag data as an 11-digit hexadecimal string.

This means the 1024_1 can read and copy such tags, but cannot provide any insight on the protocol that would allow you to write new valid tags of the same kind.

PhidgetTAG
Reading a PhidgetTAG RFID tag with a Phidget RFID Read-Write (1024_1).

The PhidgetTAG protocol is unique to Phidget RFID interfaces. It is useful for users that want plain-text alphanumeric tag strings.

This protocol allows storing an ASCII string, of up to 24 characters (e.g. I am a Phidgets Tag). 7-bit ASCII is supported, including all standard text and control codes. If you have questions about a particular protocol, please contact us for more information.

Supported Chipsets

A product listing for read-only RFID tags where the TK4100 chipset is featured prominently. This chipset is a clone of the EM4100 chipset, and therefore uses the EM4100 protocol.
A listing for writable RFID tags where the T5577 chipset is featured prominently.

When shopping for RFID tags online, you will often see the chipset advertised (e.g. Writeable T5577 RFID Tag). The term chipset is used loosely, but generally refers to the microchip present in the RFID tag.


When purchasing read-only RFID tags, you typically do not need to consider the chipset of the RFID tag you are purchasing. Instead, you should simply confirm the protocol is supported by your RFID reader.


When purchasing writable RFID tags, you should confirm the chipset is supported by your RFID interface. The 1024_1 currently supports writing to T5577 and EM4305 tags.


If you have questions about a particular chipset, please contact us for more information.

RFID Tags

Phidgets Inc. stocks a wide variety of read-only and writable low-frequency RFID tags. All tags sold are compatible with Phidget RFID interfaces.

Advanced Topics

Using Multiple RFID Interfaces

Please review this article.

Reading Multiple Tags Simultaneously

Phidget RFID interfaces do not support any anti-collision protocols. This means you will not be able to read more than one tag at a time.