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<metadesc>RFID tags store data and are used to identify people, animals, or objects. RFID readers and tags are available at Phidgets.com.</metadesc>
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[[Category: Primer]]
|description=Learn more about Phidget RFID interfaces here.
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[[Category:IntroGuide]]
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==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.


==Introduction==
====How Does RFID Work?====
[[Image:1024.jpg|400px|link=|right]]
RFID systems consist of two main components: an RFID reader and an RFID tag.
RFID (radio frequency identification) systems use data strings stored inside RFID tags (or transponders) to uniquely identify people or objects when they are scanned by an RFID reader.  These types of systems are found in many applications such as passport protection, animal identification, inventory control systems, and secure access control systems.
<br clear=all>


==Principles of operation==
[[Image:Rfid_animation.gif|link=|center]]
RFID works on the same principle as a transformer.  When the reader is powered up, it gives power to a large coil.  The coil creates an external magnetic field which can then be paired with a coil inside a nearby tag.  This delivers a small amount of power wirelessly to the tag.  With that power, the tag is able to access a small internal memory bank and transmit a key string back to the reader via modulation on the wireless signal.


==RFID Protocols==
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.
In order for an RFID reader like the [{{SERVER}}/products.php?product_id=1024 1024 - PhidgetRFID Read/Write] to communicate with an RFID tag, they must share a common protocol.  This protocol acts as a set of rules for the way data is transmitted wirelessly between the reader and tag. It's common for people to assume that an RFID tag and reader need only share the same operating frequency to be compatible, but they also need to use the same communication protocol. Check the user guide for your device to determine which protocols it supports.


Common RFID protocols:
====RFID Tags====
*EM4100 Series
[[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.]]
*ISO11784/ISO11785 (FDX-B)
[[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.]]
*ISO18000-2
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.
*ISO10536
*ISO14443
*ISO18000-3
*ISO18000-6
*EPC class 0
*EPC class 1
*EPC GEN II
*ISO18000-4
*Intellitag
*μ-chip


==Communication and Effectiveness==
RFID tags come in two main varieties: passive and active.  Active tags have their own power supply which they use to power an antenna to broadcast data.  Passive tags derive the power they require to operate directly from the RF output of the RFID reader, and no other power supply is necessary.  This makes passive tags cheaper to produce and much more suitable for common applications whereas active tags are used in situations where very large read distance is desirable(train cars for example are one of the few places active tags are used).


Because passive tags require a strong RF field to operate, their effective range is limited to an area in close proximity to the RFID reader.  In the case of the PhidgetRFID, tags brought within approximately 3-4” of the reader can be read. The distance over which the RFID tag is usable is affected by such things as the tag shape and size, materials being used in the area near the reader, and the orientation of the reader and tag in respect to each other and in their operating environment.  The smaller a tag, the closer it must be to the reader to operate. A reader's range cannot be increased with any sort of simple modification.
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.


Some varieties of tags support writing. These tags can have any protocol or data written to them.
[[Image:tags.jpg|400px|link=|center]]


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


Multiple RFID readers within 1 to 2 meters will interfere with each other.  This can be overcome in software by enabling the antennae of individual RFID readers in sequence. Starting with all readers disabled, enable the antenna of the first RFID reader. Wait for 100ms or more to detect any tags. Disable the antenna of the first reader and enable the antenna of the second, and perform another wait cycle and repeat. This can cause some issues if the tag is expected to only be present for a short period of time since a particular reader may be inactive at that moment. For more details on this method, have a look at {{ARTICLE|MultipleRfidReadersCloseRange|this article}}.  
=====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.


The other way to attack this problem is to shield the readers from one another.  This is more difficult than it appears on the face of it however.  In general this will involve placing metallic barriers between the readers of indeterminate size.  The shielding required will vary from set up to set up but sufficed to say, air on the side of more shielding than less shielding in all situations and it may end up that shielding just isn't not drastic enough to work for your system in which case you will have to revert to plan A which is the polling method.
Additionally, '''ultra-high frequency (UHF) tags''' exist, although they are less common.


==Multiple Tags==
====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.


While some RFID readers offer the capability to read multiple tags at once, the majority do not.  In order to read a tag, any other tags must first be removed from the reader's field of effect.
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.


==RFID Tags==
==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]]


RFID tags come in a variety of shapes and sizes to suit various applications.  All RFID tags '''of the same type''' sold by Phidgets are guaranteed to be uniquely identifiable, and are available as:


*30mm Disc Tags
{| style="width: 85%;
*Credit Card Sized Tags
|-
*Key Fob Tags (attach easily to key rings)
| Operating Frequency|| 125 kHz
*Wrist Strap Tags
|-
*'Nail' Tags (Could be hammered into a crate)
| Controlled By || USB or VINT
*Threaded Cylindrical Tags
|-
*Bird Leg Ring Tag
| 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|EM4100]] || 10-digit hexadecimal (40-bit)
|-
| [[#ISO11785 FDX-B|ISO11785 FDX-B]] || 15-digit numeric
|-
| [[#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.
 
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)=====
[[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''
 
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=====
[[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 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 [https://www.phidgets.com/?view=contact contact us] for more information.
 
===RFID Tags===
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.
 
===Advanced Topics===
====Using Multiple RFID Interfaces====
Please review [https://www.phidgets.com/?view=articles&article=MultipleRfidReadersCloseRange 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.

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.

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