RFID

NFC (Near Field Communication), RFID

It is all about NFC technology applications, RFID tags, ISO/IEC14443, ISO/IEC18092. Information about near field communication RFID technologies.

Edited by Lim Siong Boon, last dated 03-Mar-2012.

Topic Discussion Overview

RFID Introduction
RFID Tags
Tag Packaging
RFID Reader
NFC
Card Reader IC
Magnetic materials

1. RFID Introduction

Having the Right Mindset for RFID technology.

RFID is known as Radio Frequency IDentification. The technology is able to wireless-ly picking up information from a RFID tag which can be embedded onto most object. Fast and reliable. RFID has helped to rise up our productivity.

The process starts with the RFID reader transmitting power and command wireless-ly. The RFID tag intecept the energy to power up itself. It starts to decode the request commanded and transmit the result back to the RFID reader. All these happen instantly with microseconds.

Many of the old technologies (bar-code, magnetic stripe, smart card) can be replaced by RFID system, but rate of adoption rate is slow. Examples of applications that the RFID have completely taken over are, security door access system and transportation payment card. Comparing RFID over the old technologies, it is perceive to be more expensive. The technology do has its advantages and disadvantages, which is why not all applications use RFID.

People likes to compare RFID to a bar-code system which is a cheaper alternative. The fact is, RFID tag will never be as cheap as a printed bar-code. It is more complex than bar-code. No matter how big the production volume will be, it will not be cheaper than the bar-code. Using a RFID to perform barcode application is analogy to hiring an engineer to do simple office cleaning work. No company would be in the right set of mind to invest in a expnsive solution to replace what a cheaper solution would solved.

People also think of RFID technology as a solution. RFID unique and good, but it can only solve part of the problem that we are facing in our life. You can analogy it to a very good engineer that you have hired. He/she has all the skills and know-how to design a quality system that no one else can, but there are no proper tools and equipments provided. Only a broom and a dustpan is provided. The engineer will be as good as a cleaner. RFID is designed to solve certain problem very efficiently. By itself, it cannot do any much. It has to work hand in hand with another good technology.

RFID has its own unique properties that no other technology is able replace it completely. Applying RFID technology to its advantage, to the right application will be the key to success adoption. If you want RFID system to be successful, you cannot think using a bar-code brain.

This site is dedicated to understand more about the properties of RFID technology, hence allowing us to apply its unique leading edge where no other technologies can replace. The focus will be mainly in the RFID for ISO/IEC14443 (HF 13.56MHz RFID system) which has a near perfect characteristic for interaction between humans and object; and also information on ISO/IEC18092 (NFC protocol implementation) which is the new trend on applying RFID technology. With the growing number of NFC mobile phones being launch, we can clearly see that the industry is committed in making our life more productive.

Let us start by a simple overview of various technologies that is related to RFID. We can easily see the advantages/disadvantages that the RFID can have in the application of tagging and identification.

Comparison chart of tagging/identification technologies

Description				Form factor can be like like a thicker credit card
Technology name	LF RFID (LF Passive)	HF RFID (HF Passive)	UHF RFID (UHF Passive)	Active RFID Tag (UHF Active)	2D Barcode	Barcode	Smart Card	Magnetic Stripe	Light	Sound
small in size
conceal easily
contain more information
attach to odd shaped object
attach to object with metal surface or liquid content
store information
durable
passive (no need battery)
contactless
no need to be line of sight
retrieve data fast
secured communication
low cost
far reading distance
simple to manufacture
frequency	<135KHz	13.56MHz	868-950MHz	433-5.8GHz
read distance	low 0-15cm	low-medium 0-1.5m 0-15cm (NFC)	far up to 10m	very far more than 10m to km
data rate	4-8kbps	6.7-848kbps

Selecting guide your RFID technologies. Click here -> rfid-guide.pdf

2. RFID Tags


HF RFID tag 125KHz / 13.56MHz	UHF RFID tag 860 – 960 MHz / 2.4Ghz

Click to enlarge the picture.

Basic RFID Tag

RFID tag, is also known as RFID Transponders. The tag is make up of three basic components. An IC chip, an antenna or coil, and a substrate that holds the chip and antenna/coil together.

The picture on the left shows two typical tag design. The one on the left is a coil design. It is mean for LF/HF RFID tag (low/high frequency) that operates in a low frequency range. The tag uses induction method as a means for power and communication. The UHF RFID tag (ultra high frequency) on the right uses a dipole antenna design. The tag uses RF transmission (radio frequency operating at a much higher frequency) method to obtain its power and achieve communication.

Higher frequency tag is able to transmit information faster, and need less energy to receive/transmit information compare to a tag that uses lower frequency; lower frequency takes more time. Antenna helps to transmit the signal can be smaller at higher frequency. With the signal transmitting out of the antenna, tag can be read at a further distance away.

At this stage in time, you may think that a UHF tag is better than a HF tag. You can be right and wrong. A tag that can be read at a far away distance can be good. The same property will not be good if you need to get hold of a specify tag but end up with all the rest of the tag nearby. There is little value in defining the good and bad. What is more important, is understanding the property of what it can or cannot do, and apply its properties to its advantage. This depends mainly on the application.

For the application of tagging an object, I have valued HF tags more than the other alternative technologies. Passive RFID tag using HF or NFC has a higher potential in solving problems relating to interraction betweeen living things and physical object. This which will be further presented as another topic in another site.

This is a finger that I have downloaded from the internet. Notice the black square dot on the middle of the finger. That is the RFID transponder IC chip which can be found on a RFID tag. You can hardly see it.

IC chip for RFID tag

The IC chip on the RFID tag is very very small; not much bigger than a gain of sand (see photo on the left). This makes the tag small enough for a lot of purpose. This IC contains memory which can store information. The cost of the chip is proportional to the memory size and functional it has. The IC chip needs power to operate. It will get its power from its antenna. The tag’s antenna will capture the energy transmitted by the RFID reader. The RFID reader will generate the RF energy from its own antenna when a read command is initiated.

There is a limit distance in which the antenna can effectively capture the RF energy for powering up the tag. This distance will depends on the transmitting power from the RFID reader, as well as the size of the tag’s coil. The bigger the coil on the tag, the further the distance. As a rule of thumb, a bigger tag is expected to achieve a further read distance than a smaller tag..

**pic of transmitting energy from induction stove, RFID reader. Coil with LED. big tag further distance. higher power further distance

When the tag received enough power to operate, the IC will immediately power up, and response to the command from the RFID reader. The tag will usually read the binary information contains in its memory and send them back to the reader. The basic form of read information will be the tag identification number. If the tag contains additional user data, the reader can issue command to read them all. All these process happens within micro seconds.

RFID tag is essentially similar to a memory card. Similar to the flash memory card that we have been using for our digital camera, the RFID tag is using wireless power/communication, and has much less memory. The memory available can be as little as a few bytes to store the tag ID, to about 8Kbyte to store other user’s data. Each alphabet letter takes about 1byte of space, so a 8Kbyte memory can store about 8000 characters. The higher memory capacity tag will usually cost a bit more.

The LF RFID tags that I have seen can only be read. HF tags can be read/write. It is also possible to protect the tag from data writing. Some IC chip is able to kill the tag, therefore prevent a read from the tag, rendering the tag useless.

Depending on the chip, tags can be pre-programmed during the manufacturing to contain the same or unique ID no. (identification number). An unique ID no. for each tags will enable the reader to differential the multiple tags read.

LF and HF tags uses induction method and has a short reading distance <10cm. UHF tags can go as far as 10m. The distance will varies with varies RFID reader’s transmitting power and antenna/coil size. A bigger size antenna will usually have a longer read distance.

	Ferrite raw material in powder form
	Ferrite bead commonly used for EMI on cable.
	Ferrite sheet is form like a rubber mat and can be cut and place behind the RFID tag to improve readibility.

Fig 1. Magnetic field pattern of a typical RFID operation.
Fig 2. Magnetic field interference when RFID tag is stick close to a metal surface.
Fig 3. Improve magnetic field operation with a ferrite sheet between the tag and metal surface.

Fig 4. Cross section of the magnetic field detected

RFID operation with metalic or liquid objects

RFID has difficulty operating near metalic, liquid object (water bottle/ human body). Induction field around the tags will be collapse by these object. A minimum gap away from such object is required for proper operation. Metal surface can block/reflect RF signal, causing distortion to the signal, making it difficult to read the tag. There are special anti-metal tags (RFID Metal Pad) that allows RFID to operate under such tough condition. These tags are padded with a sheet of ferrite material behind the tag. The sheet actually forms the gap between the tag and the metal surface, allowing the tag to be read through the RF. The ferrite is itself a RF friendly material which permits the RF & field to sustain. With this padding, the tag readability can be improve slightly.

Ferrite sheet is available from:

TDK, FLEXIELD material

MARUWA, FLEX-u sheet

Active RFID tag

Active RFID tag with sensor attached

Active RFID tag with built-in sensor

Active RFID tag (sef powered, usually a battery) operates like a typically electronic transceiver device. Reading distance is a lot further than a passive RFID tag (not self power). The operations is similar to a passive tag where the reader will be able to retrieve the tag information when it is near enough. Some call the tag a signal beacon, where the tag keeps sending signal out. The tag can be read at a much further distance. This is because it has its own power source and do not need to harvest from the reader.

There are active tags that have built in sensor. The temperature/humidity sensor for example, will be operated by the RFID tag and send back the temperature read back to the reader. The battery usually last quite sometime, but it will definately need replacement one day.

Buy your NFC Tag Now at the PIC-store

Three typical standard among RFID tags
– LF tag (Low Frequency 125KHz) ISO11784 / ISO11785
– HF or NFC tag (High Frequency 13.56MHz) ISO/IEC 14443
– UHF tag (Ultra High Frequency EPC Class 1 Gen2)

Tag’s IC chip	Standard	Frequency	Memory
EM4001		125KHz	64byte
EM4305	ISO11784/ ISO11785	125KHz	512byte
NXP Hitag 1		125KHz	2048bit
NXP Hitag 2	ISO11784/85	125KHz	256bit
NXP Hitag S	ISO11784/85	125KHz	256/2048bit
Atmel Temic T5567	ISO11784/85	125KHz	363bit
Atmel Temic T5557	ISO11784/85	125KHz	363bit

NXP Mifare Ultralight, MF0 IC U1X	ISO/IEC14443A NFC Forum Tag Type 2	13.56MHz	64byte 7 bytes tag ID 16pgx4b
NXP Mifare Ultralight C, MF0 IC U2X	ISO/IEC14443A, NFC Forum Tag Type 2	13.56MHz	192byte 7 bytes tag ID 48pgx4b
NXP Mifare Classic Mini, S20	ISO/IEC14443A	13.56MHz	320byte 4 bytes tag ID
NXP Mifare Classic 1k, MF1 S50	ISO/IEC14443A	13.56MHz	1Kbyte 4 bytes tag ID 16 sectors x64b
NXP Mifare Classic 4k, MF1 S70	ISO/IEC14443A	13.56MHz	4Kbyte 4 bytes tag ID 32 sectors x64b 8 sectors x256b
NXP Mifare Plus S 2K, MF1 SPLUS 60 (replace Mifare Classic series )	ISO/IEC14443A	13.56MHz	2Kbyte 7 bytes tag ID 32 sectors x64b
NXP Mifare Plus S 4K, MF1 SPLUS 80 (replace Mifare Classic series )	ISO/IEC14443A 7 bytes tag ID	13.56MHz	4Kbyte 7 bytes tag ID 32 sectors x64b 8 sectors x256b
NXP Mifare Plus X 2K, MF1 PLUS 60 (replace Mifare Classic series )	ISO14443	13.56MHz	4Kbyte 7 bytes tag ID 32 sectors x64b 8 sectors x256b
NXP Mifare Plus X 4K, MF1 PLUS 80 (replace Mifare Classic series )	ISO14443	13.56MHz	4Kbyte 7 bytes tag ID 32 sectors x64b 8 sectors x256b
NXP Mifare DESFire EV1, MF3 IC D21 MF3 IC D41 MF3 IC D81	ISO/IEC14443A NFC Forum Tag Type 4	13.56MHz	2/4/8Kbyte 7 bytes tag ID flexible file system
NXP SmartMX	ISO/IEC14443A NFC Forum Tag Type 4	13.56MHz
NXP MIFARE SAM AV2	ISO/IEC 14443A	13.56MHz
Innovision Topaz	ISO/IEC14443A NFC Forum Tag Type 1	13.56MHz	96byte
Sony FeliCa lite	ISO 18092	13.56MHz
Sony FeliCa	ISO 18092 NFC Forum Tag Type 3	13.56MHz	1/4/9Kbyte
TI TAG-IT lite		13.56MHz	256bit
TI TAG-IT	ISO 15693	13.56MHz	2048bit
NXP ICODE EPC	EPC	13.56MHz	136byte
NXP ICODE 1	ICODE 1	13.56MHz	512byte
NXP ICODE SLI-L	ISO15693/ ISO18000/ EPC	13.56MHz	512bit
NXP ICODE SLI	ISO15693/ ISO18000	13.56MHz	1024bit
NXP ICODE SLI-S	ISO15693/ ISO18000/ EPC	13.56MHz	2048bit
Legic MIM256		13.56MHz	256byte
Legic MIM1024		13.56MHz	1024byte
Legic ATC-MV	ISO15693	13.56MHz	128/256/1024byte
Legic ATC-MP	ISO/IEC14443A	13.56MHz	0.5/2/4Kbyte
INSIDE PicoPass 2KS	ISO14443B/ ISO15693	13.56MHz	2Kbyte

NXP UCODE HSL	ISO18000-6B	2.4 GHz	2048 bit
NXP UCODE EPC Gen2	EPC Class 1 Gen2	860 – 960 MHz	512 bit
NXP UCODE G2XL	EPC Class 1 Gen2	860 – 960 MHz	368 bit
NXP UCODE G2XM	EPC Class 1 Gen2	860 – 960 MHz	880 bit
Alien Higgs 2		860 – 960 MHz
Alien Higgs 3		860 – 960 MHz

Innovision Jewel
ISSI4442
ISSI4428
ISSIM1
Infineon SLE5542
Infineon SLE4428
Infineon SLE4442
Infineon SLE5528
Infineon SLE6636
Atmel 24C16/24
Atmel 24C64/128
Atmel 24C512/1024
Atmel AT88SC0204C
Atmel AT88SC0404C
Atmel AT88SC1616C
Atmel AT88SC3216C
Atmel AT88SC0808C
Atmel AT88SC1608

Java
JCOP

Good RFID tag reference information, http://www.gorferay.com

RFID tag IC chip and standard

When dealing with RFID tags or reader, we will often come across various ISO standards. These ISO defines a common standard for the hardware or software to interact with one another.

The LF RFID (125Khz), ISO11784/ISO11785 is a common standard.

For UHF RFID, it is EPC Gen2 or EPCglobal UHF Class 1 Generation 2

For HF there are standard ISO15693, ISO14443 and ISO18092 (NFC). For NFC, we will focus on ISO14443 and ISO18092.

Some notes regarding NFC standards or ISO18092 (from website http://users.skynet.be/marc.sel/index-MTC.html)

In transport applications, cards suffer from daily use, for which reason contactless cards are preferred. Contact cards are more prone to hardware wear-out, hence contactless cards are better suited in the transport sector. This led to the creation of the RFID standard, ISO 14443, composed of 4 parts. It operates in the non-licensed 13.56 Mhz band. As there were two main “competitors”, there are two substandards:

ISO 14443 type A (origine: NXP)
ISO 14443 type B (origine: RATP)

Later under impetus from Sony, the NFC standard was established as ISO 18092. It’s a backward compatible extension to RFID, mainly aiming at use in mobile phones. It’s was actually proposed as ISO 14443 type C by Sony, based on FeliCa. It’s used e.g. in the Hong Kong Octopus and Singapore EZ-link systems. It did not make it to the 14443 standard, but came back as NFC.

Article for ISO/IEC 14443

Mifare Tag ID issues (tag ID unqiue?)

Mifare name comes from the “MIkron FARE Collection System”. Mikron was aquired by Philips (NXP) in 1998. Given the Mifare Classic tag ID of 4 bytes, will the tag ID run out of unique ID?

RFID tag/transponder IC manufacturer

	NXP Semiconductors, Mifare RFID transponder IC manufacturer
	Alien Technology, has many UHF tags
	ST microelectronic
	EM Microelectronic
	Texas Instruments
	Legic
	Inside Contactless
	Atmel
	Siemens (infineon)
	Innovation Research & Technology
	ISSI

3. Tag Packaging

Common RFID tag packaging

**Packaging (find chinese terms)
– inlay (wet/dry)

Reference:
http://www.skyrfid.com/RFID_Tag_Inlays.php

Inlay (dry)

Dry inlay is the fundenmental building block for RFID tag. They are usually be further packaged into RFID tag products. The term “dry” means that it does not have adhesive on it’s tag surface. The inlay can comes in roll or sheet form.

RFID in roll form

RFID in sheet form

Common size:
35x35mm
43x26mm
50x30mm
85.5x54mm

Inlay layer and thickness
	Layer: IC:75um-150um Al(TOP)30um PET:38um AL(Bottom):10um

Layer within a RFID card
	Different layer of a package RFID card. The RFID inlay is sandwiched between the PVC (Polyvinyl chloride) and next with printed PET/PVC (polyethylene terephthalate) finishing.

Inlay (wet)

Wet inlay means that the inlay has adhesive on one of its side. The tag will be attached to a pressure sensitive liner base.

– sticker label

IDCard/Badge

These are hard PVC card about 1mm thickness. The card printing can be customised. There is also a special printer that prints on these plain tags.

– PVC/Plastic card
– glossy, matt paper

RFID Cards and tags printer

Zebra

Intermec

ezlink using CEPAS card

FlashPay using CEPAS card

Visa Paywave

www.octopus.com.hk

Payment Card (Singapore)

Ezlink, based on the Sony FeliCa smartcard technology

Flash Pay

payWave

CEPAS = ISO/IEC 14443-4 + ISO/IEC 7816-4: 2005

– Singapore Standard, specification for contactless e-purse application

Octopus card, based on the Sony FeliCa smartcard technology

base on MIFARE DESFire EV1 card

Label Stickers

Key Chain, Key Fob

Waterproof Rubber Bracelet, Wrist band

Patient Tag

Lugagge Tag

Button Tag, Washing Tag

Disc or Ring Tag, Laundry Tag, Pucks

Casino Game Token

Fragile Tag, Security Tag

Anti-Metal Tag

Hard Tag

Pill

CD label

UHF tags

RFID Tag manufacturer

	HID
	Intermec
	Avery Dennison
	Alien Technology, has many UHF tags

4. RFID Reader

RFID reader is getting more and more common. Nowsaday Windows & mobile phone OS has built in driver treating RFID reader as a standard device.

Common RFID interface
RS232
RS485
Wiegand
USB
Ethernet

USB RFID reader kit

OEM board

Door Access Security

Mobile phone NFC / RFID reader

Payment station

UHF RFID reader and Antenna

RFID Reader manufacturer

	HID
	Intermec
	Alien Technology, has many UHF tags
	Motorola

5. NFC

NFC (Near Field Communication)

NFC phone to phone,

Phone to RFID tag

NFC currently use for Payment, transportation payment.

Instantly access to webpage,

Instant bluetooth/WiFi connectivity.

Reference:

– NFC Tags A technical introduction, applications and products, R_10014

– Understanding the Requirements of ISO IEC 14443

– MIFARE Ultralight as Type 2 Tag, AN1303

– NFC Type MIFARE Classic Tag Operation, AN1304

– MIFARE Classic as NFC Type MIFARE Classic Tag, AN1305

– MIFARE Type Identification Procedure, AN10833

6. Card Reader IC

13.56MHz RFID card reader IC

Reader IC	Manufacturer	Standards & Protocol	Interface
CL RC663	NXP	NFC Tag Type Reader ISO14443A ISO14443B ISO15693 MIFARE Classic support ICODE 1 protocol HF EPC protocol ISO 18092 (NFC)	SPI 2x IC RS232
CL RC632	NXP	NFC Tag Type Reader ISO14443A ISO14443B ISO15693 MIFARE Classic support ICODE 1 protocol HF EPC protocol	SPI 8-bit parallel
MF RC531	NXP	NFC Tag Type Reader ISO14443A ISO14443B MIFARE Classic support	SPI 8-bit parallel
MF RC523	NXP	NFC Tag Type Reader ISO14443A ISO14443B MIFARE Classic support	SPI IC RS232
MF RC500 MF RC530	NXP	NFC Tag Type Reader ISO14443A MIFARE Classic support	8-bit parallel
MF RC522	NXP	NFC Tag Type Reader ISO14443A MIFARE Classic support	SPI IC RS232
CR95HF	ST microelectronics		SPI UART
TRF7970A	Texas Instruments
TRH033M-S	3ALogics

Getting to understand RFID was quite a confussing experience, with so many technical jargon. This was the reason why this website is setup; to sort out all the technical stuff into bits and pieces.

Card Reader is another interest topic to looking. A card reader helps to read out the information in a tag. An RFID reader is not a different device to understand, but not the card reader.

What is the difference between an RFID reader and a card reader? The RFID reader reads RFID tag. There are many variety of RFID standards in the industry. This means that there are also many type of RFID reader to read each type of card. (The type of cards was already presented above).

The variety of reader is going to make things complicated for developer who are developing application. This call for an universal solution known as ISO 7816. This is a standard defined for interfacing application with all smart card devices.

From what I read in the internet, this standard goes way back to the smart card technology. The smart card unlike RFID card is using wired communication to read the information on the card. You can identify it by the contact pins as shown in the following pic.

It is possible that a card has both the smart card as well as RFID card.

With the introduction of new form of card like RFID, the ISO 7816 evolve over time. ISO 7816 defines a standard interface for the card reader. The communication standard to a card reader device becomes a standard.

Article for ISO 7816 (specification for interfacing with card reader)

– AN4029, The DS8007 and Smart Card Interface Fundamentals

PCSC Personal Computer Smart Card is a standard framework for Smart Card access on Windows Platforms. This will make the job easier for application developers to interface to a card reader. To the developer, all card reader seems to work the same way.

The window operating system will automatically detects.

Interoperability Specification for ICCs and Personal Computer Systems

– PCSC_Part1, Introduction and Architecture Overview.pdf.pdf
– PCSC_Part2, Interface Requirements for Compatible IC Cards and
Readers.pdf
– PCSC_Part3, Requirements for PC-Connected Interface Devices.pdf
– PCSC_Part4, IFD Design Considerations and Reference Design
Information.pdf
– PCSC_Part5, ICC Resource Manager Definition.pdf
– PCSC_Part6, ICC Service Provider Interface Definition.pdf
– PCSC_Part7, Application Domain and Developer Design
Considerations.pdf
– PCSC_Part8, Recommendations for ICC Security and Privacy
Devices.pdf

My card reader

ACR122 NFC card reader from ACS.

Documentation
– PPE_ACR122, presentation.pdf
– API_ACR122U, Application Programming Interface.pdf
– TSP_ACR122U_v2.5, Technical Specification.pdf

Win7 64bits driver
– DIG_ACR122, Driver Installation Guide.pdf
– ACR122U_MSI_Winx64_1120_P

This is the first NFC card reader that I have brought. I have purchased this reader without any development kit, and was struck wondering how I can read a RFID tag without any software.

After understand about ISO 7816 and PCSC, I managed to find a number of free software that can communication with this NFC card reader. They are designed to work with PCSC compliants card reader.

– SCardToolSet, Smart Card ToolSet PRO v3.4
– sq2075-ba, SpringCard PCSC Diag
– online PCSC card reader program

The software are able to detect my card reader immediately. When my RFID tagis placed on the reader, the software detects it and display the tag information.

The very first unqiue string that was captured when I read the RFID tag is this string call ATR (Answer To Reset). It is a very weird name, because I was thinking that this should be the unqiue ID of the RFID tag. No it is not. This ATR string (as defined in ISO 7816) is telling us how we can communicate with the current tag found on the card reader.

This is the ATR string that I read when the tag (picture on the left) is on the reader

ATR = 3B 8F 80 01 80 4F 0C A0 00 00 03 06 03 00 03 00 00 00 00 68

So what does this hexidecimal string of number means?

Byte	Name	Comments
0x3B	TS	Direction convention
0x8F	T0
0x80	TD1	Higher nibble 8 means: no TA2, TB2, TC2, only TD2 is following. Lower nibble 0 means T=0
0x01	TD2	Higher nibble 8 means: no TA3, TB3, TC3, only TD3 is following. Lower nibble 1 means T=1
0x80	T1	Category indicator byte, 80 means A status indicator may be present in an optional COMPACT-TLV data object.
0x4F	Tk	Application identifier Presence Indicator
0x0C	Length	Length = 12 data byte (from next byte to check sum byte)
0xA0 0x00 0x00 0x03 0x06	RID	PC/SC Workgroup
0x03	Standard	ISO14443A, part 3
0x00 0x03	Card Name	Mifare Ultralight 00 01 Mifare 1K 00 02 Mifare 4K 00 03 Mifare Ultralight 00 26 Mifare Mini F0 04 Topaz and Jewel F0 11 Felica 212K F0 12 Felica 424K FF [SAK] undefined
0x00 0x00 0x00 0x00	RFU	RFU # 00 00 00 00
68	TCK	Check Sum. Ex-OR of all the bytes T0 to Tk

With this ATR string provided by my card reader, I will know more about the RFID tag that I am actually dealing with. The RFID tag that I have place is using the Mifare Ultralight tag’s IC chip. ISO14443A is use for communication between the reader and the tag. The rest of the information seems not so useful to me.

To communicate with the card reader we will have to send a string of bytes to the card reader. The data format to communicate with the reader is known as APDU (Application Protocol Data Unit).

I have refered to the API (Application Programming Interface) datasheet provided by the card reader manufacturer. The first command to try is the command “Get Data”. The command will fetch the unique ID of the tag.

data send -> FF CA 00 00 04
where CA is the <Get Data> command.

The following response bytes are received.

data received <- 04 06 CD E2 90 00
where “90 00” is the response code (The operation completed sucessfully)
” 04 06 CD E2″ is the unique tag ID.

Next I tried to get the card reader firmware version.

data send -> FF 00 48 00 00
data received <- 41 43 52 31 32 32 55 32 31 30

The data received is “ACR122U210” in ascii format

Reading Mifare Ultralight tag 1, tag ID

Another Mifare Ultralight tag1 was read for its ATR and tag ID

ATR = 3B 8F 80 01 80 4F 0C A0 00 00 03 06 03 00 03 00 00 00 00 68
APDU send -> FF CA 00 00 04 (read tag ID)
APDU received <- 04 AA 2C 79 90 00

Reading Mifare Ultralight tag 2, tag ID

Another Mifare Ultralight tag2 was read for its ATR and tag ID

ATR = 3B 8F 80 01 80 4F 0C A0 00 00 03 06 03 00 03 00 00 00 00 68
APDU send -> FF CA 00 00 04 (read tag ID)
APDU received <- 04 2D 44 79 90 00

Reading Singapore Ezlink card (CEPAS card)

Next I tried another RFID tag. Our Singapore Ezlink card, which stores transportation logs in CEPAS format.

ATR = 3B 8C 80 01 50 72 23 AA 5E 1C 2D 94 11 F7 71 85 4F

When the tag is removed and placed on the reader again, the ATR string changes. This is unlike the previous tag where the ATR will remains the same for the same tag.

ATR = 3B 8C 80 01 50 21 0A 96 CF 1C 2D 94 11 F7 71 85 98
ATR = 3B 8C 80 01 50 B5 AE 55 A7 1C 2D 94 11 F7 71 85 03
ATR = 3B 8C 80 01 50 6D 83 67 F0 1C 2D 94 11 F7 71 85 93

The ATR tells us that it uses the application identifier 0x50. I don’t know what it means.

Next I proceed to send read tag ID command.

ATR = 3B 8C 80 01 50 5D 83 48 22 1C 2D 94 11 F7 71 85 5E
APDU send -> FF CA 00 00 04 (read tag ID)
APDU received <- 5D 83 48 22 90 00

ATR = 3B 8C 80 01 50 FE 15 0F A4 1C 2D 94 11 F7 71 85 AA
APDU send -> FF CA 00 00 04 (read tag ID)
APDU received <- FE 15 0F A4 90 00

The tag ID changes with the ATR string. A closer look review that the tag ID is the same data as the substring in the ATR.

Reading DESFire EV1 2K tag

A DESFire EV1 card ATR string is unexpectedly short.

ATR = 3B 81 80 01 80 80

The ATR string remains the same when the tag is

APDU send -> 90 0A 00 00 01 00 00
APDU received <- 84 D9 62 65 A2 3C A7 C8 91 AF