Identiv uTrust 3720F User manual

Reference Manual for
uTrust 3720F Contactless Reader
and
uTrust 3721F Contactless Reader w/Keyboard
Interface
For Part #: 905592-* and 905593-*
Document Version: 1.00, Last Revised On: 2020-04-10

Document Version 1.00 Last revised on Page 2 of 87
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Reference Manual for uTrust 3720F and uTrust 3721F Readers
Abstract
This document contains in-depth information about the hardware and software features of the uTrust
3720 F Contactless Reader and uTrust 3721 F Contactless Reader with keyboard interface.
Audience
This document is intended for system integrators and software developers.
Revision History
Rev. Date Description
1.00 2020-04-10 Initial version
Contact Information
For additional information, please visit http://www.identiv.com/

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Table of Contents
1. Legal information .......................................................................................................... 7
1.1. Disclaimers ..................................................................................................................... 7
1.2. FCC, ISED Statement ....................................................................................................... 7
1.3. Licenses........................................................................................................................... 8
1.4. Trademarks ..................................................................................................................... 8
2. Introduction to the manual ........................................................................................... 9
2.1. Objective of the manual ................................................................................... 9
2.2. Target audience ................................................................................................ 9
2.3. Product version corresponding to the manual ................................................... 9
2.4. Definition of various terms and acronyms .............................................................. 10
2.5. References ............................................................................................................. 11
2.6. Conventions for Bits and Bytes ............................................................................... 12
3. General information about uTrust 372x F .................................................................... 13
3.1. uTrust 372x F key benefits .............................................................................. 13
3.2. uTrust 372x F key features .............................................................................. 13
3.3. uTrust 372x F ordering information ........................................................................ 14
3.4. Available accessories ...................................................................................... 14
3.5. uTrust 372x F customization options ............................................................... 14
3.6. Contactless communication principles and uTrust 372x F usage
recommendations ........................................................................................................... 15
3.6.1. Power supply .................................................................................................. 15
3.6.2. Data exchange ................................................................................................ 15
3.6.3. Recommendations .......................................................................................... 16
3.7. Applications ................................................................................................... 16
3.7.1. General .......................................................................................................... 16
3.7.2. Applications provided by Identiv Inc. .............................................................. 17
4. uTrust 372x F characteristics ........................................................................................ 18
4.1. uTrust 372x F high level architecture ............................................................................ 18
4.1.1. Block diagram ................................................................................................................. 18
4.1.2. Software architecture .................................................................................................... 19
4.2. Quick reference data .................................................................................................... 20
4.2.1. uTrust 372x F Physical Charteristics ............................................................................... 20
4.2.2. LED behavior .................................................................................................................. 20
4.2.3. Other data ...................................................................................................................... 21
4.2.3.1. General .................................................................................................................................... 21
4.2.3.2. USB ........................................................................................................................................... 21
4.2.3.3. Contactless HF interface .......................................................................................................... 22
4.2.3.4. Contactless LF interface ........................................................................................................... 22
5. Software modules ....................................................................................................... 23
5.1. Installation ................................................................................................................. 23

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5.2. Utilities ........................................................................................................................ 23
5.3. Driver ........................................................................................................................... 23
5.3.1. uTrust 372x F listing ....................................................................................................... 23
uTrust 3720 F is listed by PC/SC applications as ............................................................................. 23
5.3.2. Supported operating systems ........................................................................................ 23
5.3.3. PC/SC 2.0 compliant ATR for contactless interface ........................................................ 24
5.3.3.1. ATR for contactless storage user tokens .................................................................................. 24
5.3.3.2. ATR for ISO/IEC 14443-4 user tokens ...................................................................................... 26
5.3.3.3. ATR for ISO/IEC 15693 tokens .................................................................................................. 27
5.3.3.4. ATR for LF tokens ..................................................................................................................... 28
5.4. Firmware ............................................................................................................................... 29
5.4.1. CCID transport protocol ................................................................................................. 29
5.4.2. HID transport protocol.......................................................................................................... 30
6. Commands description ................................................................................................ 31
6.1. Generic APDU ............................................................................................................... 31
6.1.1. Working with DESFire and MIFARE Plus tokens .......................................................................... 31
6.1.2. PAPDU_GET_UID......................................................................................................................... 31
6.1.3. PAPDU_ESCAPE_CMD ................................................................................................................. 32
6.2. Supported Pseudo APDU (Contactless Interface) .......................................................... 33
6.2.1. PAPDU_MIFARE_READ_BINARY ................................................................................................. 33
6.2.2. PAPDU_MIFARE_UPDATE_BINARY ............................................................................................. 34
6.2.3. PAPDU_MIFARE_LOAD_KEYS...................................................................................................... 35
6.2.4. PAPDU_MIFARE_AUTHENTICATE ............................................................................................... 35
6.2.5. PAPDU_MIFARE_READ_SECTOR ................................................................................................. 36
6.2.6. PAPDU_MIFARE_READ_SECTOR_EX ........................................................................................... 37
6.2.7. PAPDU_MIFARE_WRITE_SECTOR ............................................................................................... 37
6.2.8. PAPDU_MIFARE_VALUE_BLK_OLD ............................................................................................. 38
6.2.9. PAPDU_MIFARE_VALUE_BLK_NEW ............................................................................................ 39
6.2.10. PAPDU_TCL_PASS_THRU (T=CL Pass Thru) ............................................................................... 40
6.2.11. PAPDU_ISO14443_PART3_PASS_THRU (Mifare Pass Thru) ....................................................... 41
6.2.12. PAPDU_ISO14443_PART4_PART3_SWITCH (TCL – Mifare Switch) .......................................... 41
6.2.13. PAPDU_FELICA_REQC ............................................................................................................... 41
6.2.14. PAPDU_FELICA_REQ_SERVICE ................................................................................................... 42
6.2.15. PAPDU_FELICA_REQ_RESPONSE .............................................................................................. 42
6.2.16. PAPDU_FELICA_READ_BLK ....................................................................................................... 42
6.2.17. PAPDU_FELICA_WRITE_BLK ....................................................................................................... 43
6.2.18. PAPDU_FELICA_SYS_CODE ....................................................................................................... 43
6.2.19. PAPDU_NFC_TYPE1_TAG_RID ................................................................................................... 44
6.2.20. PAPDU_NFC_TYPE1_TAG_RALL ................................................................................................ 44
6.2.21. PAPDU_NFC_TYPE1_TAG_READ ................................................................................................ 44
6.2.22. PAPDU_NFC_TYPE1_TAG_WRITE_E ......................................................................................... 45
6.2.23. PAPDU_NFC_TYPE1_TAG_WRITE_NE ........................................................................................ 45
6.2.24. PAPDU_NFC_TYPE1_TAG_RSEG ............................................................................................... 46
6.2.25. PAPDU_NFC_TYPE1_TAG_READ8 .............................................................................................. 46
6.2.26. PAPDU_NFC_TYPE1_TAG_WRITE_E8 ....................................................................................... 47
6.2.27. PAPDU_NFC_TYPE1_TAG_WRITE_NE8 ...................................................................................... 47
6.3. Escape commands for the uTrust 372x F ....................................................................... 48
6.3.1. Sending Escape commands to uTrust 372x F .............................................................................. 48
6.3.2. Escape command codes .............................................................................................................. 49
6.3.3. Generic Commands Common to uTrust Contactless Interfaces ................................................. 49

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6.3.3.1. READER_GET_IFDTYPE ............................................................................................................. 49
6.3.3.2. READER_LED_CONTROL ............................................................................................................ 50
6.3.3.3. READER_GET_INFO_EXTENDED ................................................................................................ 51
6.3.3.4. READER_LED_CONTROL_BY_FW .............................................................................................. 52
6.3.3.5. READER_GENERIC_ESCAPE ....................................................................................................... 52
6.3.4. Specific for Contactless Interface................................................................................................ 53
6.3.4.1. CNTLESS_GET_CARD_INFO ...................................................................................................... 53
6.3.4.2. CNTLESS_GET_ATS_ATQB ......................................................................................................... 54
6.3.4.3. READER_CNTLESS_GET_TYPE .................................................................................................. 55
6.3.4.4. READER_CNTLESS_SET_TYPE .................................................................................................... 55
6.3.4.5. CNTLESS_CONTROL_PPS ........................................................................................................... 56
6.3.4.6. CNTLESS_RF_SWITCH............................................................................................................... 57
6.3.4.7. CNTLESS_CONTROL_848 .......................................................................................................... 57
6.3.4.8. CNTLESS_GET_BAUDRATE ....................................................................................................... 58
6.3.4.9. CNTLESS_CONTROL_RETRIES ................................................................................................... 59
6.3.4.10. CNTLESS_CONTROL_POLLING ................................................................................................ 59
6.3.4.11. CNTLESS_FORCE_BAUDRATE .................................................................................................. 60
6.3.4.12. CNTLESS_GET_CARD_DETAILS ............................................................................................... 61
6.3.4.13. CNTLESS_IS_COLLISION_DETECTED ........................................................................................ 62
6.3.4.14. CNTLESS_FELICA_PASS_THRU ............................................................................................... 63
6.3.5. Specific for Keyboard Interface ................................................................................................... 64
6.3.5.1. READER_CONTROL_KEYBOARD_SLOT ..................................................................................... 64
6.3.6. my-d Move Specific Commands .................................................................................................. 65
6.3.6.1. Access ...................................................................................................................................... 65
6.3.6.2. Set Password ............................................................................................................................ 65
6.3.6.3. Compatibility Write .................................................................................................................. 65
6.3.6.4. Write 2 Blocks (8 bytes) ........................................................................................................... 66
6.3.6.5. Write 1 Block (4 bytes) ............................................................................................................. 66
6.3.6.6. Read 4 Blocks (16 bytes) .......................................................................................................... 66
6.3.6.7. Read 2 Blocks (8 bytes) ............................................................................................................ 67
6.3.6.8. Decrement ............................................................................................................................... 67
6.3.7. ISO15693 Specific Commands ..................................................................................................... 68
6.3.7.1. Read Single Block ..................................................................................................................... 68
6.3.7.1. Write Single Block .................................................................................................................... 68
6.3.7.3. Lock Block ................................................................................................................................ 69
6.3.7.4. Read Multiple Blocks ............................................................................................................... 69
6.3.7.5. Write Multiple Blocks .............................................................................................................. 70
6.3.7.6. Write AFI .................................................................................................................................. 70
6.3.7.7. Lock AFI .................................................................................................................................... 71
6.3.7.8. Write DSFID .............................................................................................................................. 71
6.3.7.9. Lock DSFID................................................................................................................................ 71
6.3.7.10. Get System Info ...................................................................................................................... 72
6.3.7.11. Read Multiple Block Security Status ...................................................................................... 73
6.3.7.12. Traverse ................................................................................................................................. 74
6.4. Reader Key Management ........................................................................................................ 76
6.4.1. Reader Authenticate ................................................................................................................... 76
6.4.2. Reader Load Keys ........................................................................................................................ 76
6.4.2.1. Load Reader Authentication PIN into Reader .......................................................................... 77
6.4.2.2. Load MIFARE Authentication Keys into Reader ....................................................................... 77
6.4.2.3. Load DESFire Authentication Keys into Reader ....................................................................... 78
6.4.2.4. Load MIFARE Plus Authentication Keys into Reader ............................................................... 80

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6.4.2.5. Load MIFARE ULC Authentication Keys into Reader ................................................................ 81
7. Annexes ...................................................................................................................... 82
7.1. Annex A – Status words table ....................................................................................... 82
7.2. Annex B – Sample code using escape commands ......................................................... 83
7.3. Annex C – Mechanical drawings ................................................................................... 86
7.3.1. Reader (without stand) .................................................................................................. 86
7.3.2. Reader with Stand ......................................................................................................... 87

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1. Legal information
1.1. Disclaimers
The content published in this document is believed to be accurate. However, Identiv does not provide
any representation or warranty regarding the accuracy or completeness of its content, or regarding
the consequences of your use of the information contained herein.
Identiv reserves the right to change the content of this document without prior notice. The content
of this document supersedes the content of any previous versions of the same document. This
document may contain application descriptions and/or source code examples, which are for
illustrative purposes only. Identiv gives no representation or warranty that such descriptions or
examples are suitable for the application that you may want to use them for.
Should you notice any problems with this document, please provide your feedback to
[email protected].
1.2. FCC, ISED Statement
The device contains license-exempt transmitter(s)/receiver(s) that comply with Innovation, Science and
Economic Development Canada’s license-exempt RSS(s). Operation is subject to the following two
conditions:
(1) This device may not cause harmful interference, and
(2) This device must accept any interference received, including interference that may cause
undesired operation
This equipment has been tested and found to comply with the limits for a Class B digital device,
pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection
against harmful interference in a residential installation. This equipment generates uses and can
radiate radio frequency energy and, if not installed and used in accordance with the instructions, may
cause harmful interference to radio communications.
However, there is no guarantee that interference will not occur in a particular installation. If this
equipment does cause harmful interference to radio or television reception, which can be determined
by turning the equipment off and on, the user is encouraged to try to correct the interference by one
or more of the following measures:
• Reorient or relocate the receiving antenna.
• Increase the separation between the equipment and receiver.
• Connect the equipment into an outlet on a circuit different from that to which the receiver is
connected.
• Consult the dealer or an experienced radio/TV technician for help.
Information to user: Changes or modifications not expressly approved by Identiv could void the user's
authority to operate the equipment.

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1.3. Licenses
If the document contains source code examples, they are provided for illustrative purposes only and
subject to the following restrictions:
●
You MAY at your own risk use or modify the source code provided in the document in
applications you may develop. You MAY distribute those applications ONLY in form of
compiled applications.
●
You MAY NOT copy or distribute parts of or the entire source code without prior written
consent from Identiv Inc.
●
You MAY NOT combine or distribute the source code provided with Open Source Software
or with software developed using Open Source Software in a manner that subjects the
source code or any portion thereof to any license obligations of such Open Source Software.
If the document contains technical drawings related to Identiv Inc. products, they are
provided for documentation purposes only. Identiv Inc. does not grant you any license to its
designs.
1.4. Trademarks
MIFARE
TM
, DESFire
TM
are registered trademarks of NXP Semiconductors B.V.
FeliCa
TM
is a registered trademark of Sony Corporation.
Windows
TM
is a trademark of Microsoft Corporation.
Chrome OS
TM
is a trademark of Google
my-d
TM
is a trademark of Infineon Technology
CryptoRF
TM
is a registered trademark of Microchip Technology

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2. Introduction to the manual
2.1. Objective of the manual
This manual provides an overview of the hardware and software features of the uTrust 372x F
contactless smart card readers (uTrust 3720 F and uTrust 3721 F).
This manual describes in detail interfaces and supported commands available for developers using
uTrust 372x F in their applications.
2.2. Target audience
This document describes the technical implementation of uTrust 372x F.
The manual targets software developers. It assumes knowledge about ISO 7816, 13.56 MHz contactless
technologies like ISO/IEC 14443, ISO/IEC 15693 and commonly used engineering terms.
Should you have questions, you may send them to [email protected].
2.3. Product version corresponding to the manual
Product Component Version
Hardware 0.1
Firmware 1.00 and above

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2.4. Definition of various terms and acronyms
Term or Acronym Expansion
APDU
Application Protocol Data Unit
ATR Answer to Reset, defined in ISO7816
ATS Answer to select, defined in ISO/IEC 14443
Byte Group of 8 bits
CCID Chip Card Interface Device
CID Card Identifier
DFU Device Firmware Upgrade
DR Divider receive: used to determine the baud rate between the reader
to the card
DS Divider send: used to determine the baud rate between the card to
the reader
LED Light emitting diode
LF Low frequency (125 KHz)
MIFARE The ISO14443 Type A with extensions for security (NXP)
NA Not applicable
NAD Node Address
Nibble Group of 4 bits. 1 digit of the hexadecimal representation of a byte.
Example: 0xA3 is represented in binary as (10100011)b. The least
significant nibble is 0x3 or (0011)b and the most significant nibble is
0xA or (1010)b
PCD Proximity Coupling Device
PC/SC Personal Computer/Smart Card: software interface to communicate
between a PC and a smart card
PICC Proximity Integrated Chip Card
PID Product ID
Proximity Distance coverage till ~10 cm.
PUPI Pseudo unique PICC identifier
RF Radio Frequency
RFU Reserved for future use
USB Universal Serial Bus
VCD Vicinity Coupling Device
VICC Vicinity Integrated Circuit Card
VID
Vendor ID
(xyz)b Binary notation of a number x, y, z ∈{0,1}.
0xYY The byte value YY is represented in hexadecimal

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2.5. References
Document
reference in the
manual Description of the referenced document Document Issuer
ISO/IEC 7816-3
Identification cards
—
Integrated circuit cards
—
Part
3:Cards with contacts — Electrical interface and
transmission protocols
ISO / IEC
ISO/IEC 7816-4 Identification cards - Integrated circuit(s)
cards with contacts
Part 4: Interindustry commands for interchange ISO/IEC
7816-4: 1995 (E)
ISO / IEC
ISO/IEC 14443-3 Identification cards — Contactless integrated circuit(s)
cards — Proximity cards —Part 3:Initialization and
anticollision
ISO / IEC
ISO/IEC 14443-4
Identification cards
—
Contactless integrated circuit(s)
cards — Proximity cards
Part 4: Transmission protocol ISO/IEC 14443-
4:2001(E)
ISO / IEC
ISO/IEC 15693-3 Identification cards – Contactless integrated circuit(s)
cards – Vicinity cards – Part 3: Anticollision and
transmission protocol
ISO / IEC
ATMEL-5276 Atmel CrytoRF Specification (AT88SCxxxxCRF) Rev 5276G,
01/2014
Microchip
Technology
NXP-163735 MF 1PLUSx0y1 Mainstream contactless smart card IC for
fast and easy solution development Rev 3.5
NXP
Semiconductors
B.V.
PC/SC Interoperability Specification for ICCs and Personal
Computer Systems v2.01
PC/SC Workgroup
PCSC3
Interoperability Specification for ICCs and
Personal Computer Systems
Part 3. Requirements for PC-Connected
Interface Devices
PC/SC Workgroup
PCSC3-AMD1
Interoperability Specification for ICCs and
Personal Computer Systems
Part 3. Requirements for PC-Connected
Interface Devices– Amendment 1
PC/SC Workgroup
PCSC3-SUP
Interoperability Specification for ICCs and
Personal Computer Systems
Part 3. Supplemental Document
PC/SC Workgroup

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Document
reference in the
manual Description of the referenced document Document Issuer
PCSC3-SUP2
Interoperability Specification for ICCs and
Personal Computer Systems
Part 3. Supplemental Document for
Contactless ICCs
PC/SC Workgroup
CCID
Specification for Integrated Circuit(s) Cards Interface
Devices 1.1
USB
-
IF
USB Universal Serial Bus Specification 2.0 USB-IF
2.6. Conventions for Bits and Bytes
Bits are represented by lower case ‘b’ where followed by a numbering digit.
Bytes are represented by upper case ‘B’ where followed by a numbering digit.
Example:
163 decimal number is represented
●
in hexadecimal as 0xA3
●
in binary as (10100011)b
The least significant nibble of 0xA3 is
● 0x3 in hexadecimal
●
(0011)b in binary
The most significant nibble of =xA3 is
●
0xA in hexadecimal
●
(1010)b in binary

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3. General information about uTrust 372x F
3.1. uTrust 372x F key benefits
With its combination of a modern slim design and its state of the art feature set, uTrust 3720 F is the
perfect desktop reader choice for environments where HF/LF contactless card support is required
while uTrust 3721 F perfectly fits environments where access to HF/LF contactless cards with data read
as keyboard input is required.
As for all Identiv Inc. products, uTrust 372x F is designed to offer best in class interoperability.
3.2. uTrust 372x F key features
●
13.56MHz contactless reader:
o ISO14443 Type A & B
o ISO15693 (NFC Forum Tag Type 5)
o MIFARE
TM
o FELICA
TM
o Topaz (NFC Forum Tag Type 1)
o Type B Innovatron protocol support (Calypso)
o my-d move
o CryptoRF
●
125KHz contactless reader with support for popular formats
●
PC/SC v2.0 compliant
●
Secure in-field SmartOS
TM
firmware upgrade
●
Unique reader serial number which enables that uTrust 372x F can be plugged into any USB
slot on a PC without having to re-install the driver. Additionally, the application S/W running
on the host can check for exact readers
●
Communication speed up to 848 Kbps for ISO14443 (when PICCC also supports it)
●
Wall mount option on reader
●
Optional stand and card holder available as accessory

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3.3. uTrust 372x F ordering information
Item Part number
uTrust 3720 F HF+LF 905592 PC/SC compatible reader that
supports HF and LF
uTrust 3720 F HF 905592-1 PC/SC compatible reader that
supports HF only
uTrust 3720 F LF 905592-2 PC/SC compatible reader that
supports LF only
uTrust 3721 F HF+LF 905593
PC/SC compatible reader with
keyboard interface that supports
HF and LF
uTrust 3721 F HF 905593-1
PC/SC compatible reader with
keyboard interface that supports
HF only
uTrust 3721 F LF 905593-2
PC/SC compatible reader with
keyboard interface that supports
LF only
3.4. Available accessories
The reader has an optional stand accessory that allows the reader to be placed on level surface at 40°
angle. A card holder clip accessory is available to hold the card in place. Either the stand or card holder
clip accessory, or both accessories can be pre-assembled if needed.
3.5. uTrust 372x F customization options
Upon request, Identiv Inc. can consider customizing:
●
The color of the casing
●
The logo
●
The product label
●
The USB strings
Terms and conditions apply, please contact your local Identiv representative or send an email to
[email protected].

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3.6. Contactless communication principles and uTrust 372x F usage
recommendations
uTrust 372x F is a dual interface reader capable of reading contactless user tokens. The following
paragraph focuses on a few specifics of contactless communication to outline usage recommendations
in order to ensure best user experience.
uTrust 372x F is a contactless reader
1
designed to communicate with user credentials.
User credentials
2
are made of a contactless integrated circuit chip connected to an antenna
User credentials can take several form factors:
●
Credit card sized smart card
●
Key fob
●
USB token
●
NFC mobile phone etc…
Communication between uTrust 372x F and user credentials uses magnetic field inductive coupling.
The magnetic field generated by uTrust 372x F has a carrier frequency of 13.56MHz for HF and 125KHz
for LF.
3.6.1. Power supply
When the user credential is put in the magnetic field of the reader, its antenna couples with the reader
and an induction current appears in the antenna thus providing power to the integrated circuit. The
generated current is proportional to the magnetic flux going through the antenna of the user
credential.
3.6.2. Data exchange
The carrier frequency of the magnetic field is used as a fundamental clock signal for the communication
between the reader and the credential. It is also used as a fundamental clock input for the integrated
circuit microprocessor to function.
To send data to the user credential the reader modulates the amplitude of the field. There are several
amplitude modulation and data encoding rules defined in ISO/IEC 14443 and ISO/IEC 15693. The
reader should refer to the standard for further details.
To answer the reader, the integrated circuit card of the user credential modulates its way of loading
(impedance) the field generated by the reader. Here also further details can be found in ISO/IEC 14443
and ISO/IEC 15693.
1
In the ISO/IEC 14443 standard, the reader is called the proximity coupling device (PCD); in the ISO/IEC 15693 standard, the reader is
called the vicinity coupling device (VCD)
2
In the ISO/IEC 14443 standard, the user credential is called proximity integrated chip card (PICC); in the ISO/IEC 15693 standard, the
reader is called vicinity integrated chip card (VICC)

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3.6.3. Recommendations
The communication between the reader and the user credential is sensitive to the presence of material
or objects interfering with the magnetic field generated by the reader.
The presence of conductive materials like metal in the vicinity of the reader and the user credential
can significantly degrade the communication and even make it impossible. The magnetic field of the
reader generates Eddy or Foucault’s currents in the conductive materials; the field is literally absorbed
by that kind of material.
• It is recommended for proper communication to avoid placing uTrust 372x F in close proximity
of conductive materials.
The presence of multiple user credentials in the field also interferes with the communication. When
several user credentials are in the field of the reader, load of the field increases which implies that less
energy is available for each of them and that the system is detuned. For this reason, Identiv has
implemented in its driver only one slot.
• It is recommended to present only one user credential at a time in front of uTrust 372x F.
The communication between the reader and the credential is sensitive to the geometry of the system
{reader, credential}. Parameters like the geometry and especially the relative size of the reader’s and
credential’s antennas directly influence the inductive coupling and therefore the communication.
uTrust 372x F was designed and optimized to function with user credentials of various technologies
and sizes.
• It may happen, that uTrust 372x F is not capable of communicating with extremely large or
extremely small credentials.
• In order to optimize the coupling between the reader and the credential, it is recommended
to put both antennas as parallel as possible to each other
• In order to optimize transaction speed between the reader and the card it is recommended to
place the credential as close as possible to the reader. This will increase the amount of energy
supplied to the user credential which will then be able to use its microprocessor at higher
speeds
3.7. Applications
3.7.1. General
uTrust 372x F is a transparent reader designed to interface a personal computer host supporting PC/SC
interface with 13.56MHz user tokens like public transport cards, contactless banking cards, electronic
identification documents – e.g. e-passports, e-ID cards, driving licenses etc. and smartcards like CAC
and PKI cards and health insurance cards.
User credentials can have several form factors like credit cards, key fobs, NFC mobile phones or USB
dongles like our uTrust Token products.

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uTrust 3720 F itself handles the communication protocol but not the application related to the token
or card. The application-specific logic has to be implemented by software developers on the host.
uTrust 3721 F handles the communication protocol related to the token or card and has some
capabilities to handle some application logic like authentication, reading a specific block, data
extraction, data formatting.
3.7.2. Applications provided by Identiv Inc.
Identiv Inc. does not provide payment or transport applications or PKI or CAC applications.
Identiv Inc. provides a few utilities for evaluation purposes that can function with uTrust 372x F. They
are covered in Section 5.2.

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4. uTrust 372x F characteristics
4.1. uTrust 372x F high level architecture
4.1.1. Block diagram
The link between uTrust 372x F and the host to which it is connected is the USB interface providing
both the power and the communication channel.
The device controller has several interfaces available. In the uTrust 372x F implementation three
peripherals are connected to the device controller:
●
LED for reader status indication
●
HF AFE to handle communication with HF cards; this peripheral is not present in LF only
variants
●
LF analog circuitry to handle communication with LF cards; this peripheral is not present in
HF only variants
The controller embeds flash memory that contains the firmware developed by Identiv to handle all the
RF communication protocols and the CCID communication protocol with the host. The flash can be
upgraded once the device is deployed in the field, hence enabling firmware upgrades to add and
potentially patch features.
The RF frontend or analog circuitry ensures the coding/decoding/framing modulation/demodulation
required for the RF communication. It is controlled by the device controller through registers.
The matching circuitry provides the transmission and receiver paths adaptation for the antenna to
function properly.

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4.1.2. Software architecture
Applications can interface with the driver directly through the PC/SC interface.
The uTrust 372x F leverages a PC/SC CCID driver that is freely available for all supported operating
systems (Windows, macOS X and Linux). With current Windows versions (starting with Windows Vista)
and macOS, this driver is already included in the basic installation.
With the diverse Linux derivatives, there may be distribution specific drivers that should get installed
using the install mechanism of the used distribution.
If there is none, the driver may always be downloaded from https://ccid.apdu.fr/.
Additionally, Identiv provides a proprietary driver for all the supported operating systems (except
Chrome OS where inbox driver is sufficient).

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4.2. Quick reference data
4.2.1. uTrust 372x F Physical Charteristics
Item
Characteristic
Value
uTrust 3720 F
uTrust 3721 F
Weight
905592 HF + LF
88 gms
905592-1 HF 85 gms
905592-2 LF 88 gms
905593 HF + LF 88 gms
905593-1 HF 85 gms
905593-2 LF 88 gms
External
dimensions 91 x 75 x 12 mm (3.583 x 2.953 x 0.472 in)
Cable length 1.5 meter long with USB type A plug
Default color White and grey
Drawing with dimensions of the uTrust 372x F can be found in annex.
4.2.2. LED behavior
uTrust 372x F is equipped with one bicolor LED. Its default behavior is described in the table below.
Note that when RED and GREEN are turned on in sync, the color would appear as AMBER.
Reader states GREEN RED
Just after plug-in (with drivers already
installed) ON OFF
Just after DFU operation ON OFF
Suspend / standby OFF OFF
Reader powered,
Contactless card IN field, but not
powered
ON ON
Contactless card powered /
communication
500ms ON
500ms OFF
500ms ON
500ms OFF
Reader / card errors OFF 100ms ON
100ms OFF