contrinex rfid technology · 2010-02-11 · rfid 1 operating principle 1.1 read/write module and...

CONTRINEX AG Industrial Electronicsroute André Piller 50 CH-1762 Givisiez SwitzerlandTel: +41 26 460 46 46 Fax +41 26 460 46 40 Internet: www.contrinex.com

061004J.-D. Chatelain

CONTRINEXRFID TECHNOLOGY

TABLE OF CONTENTs

RFID1 OPERATING PRINCIPLE ��11.1 Read/write module and transponder .............................................11.2 Operating principle ........................................................................11.3 CONTRINEX transponders ...........................................................21.4 CONTRINEX read/write modules..................................................21.5 Transponder’s integrated circuit ....................................................3

2 CODEs ��42.1 Decimal code ................................................................................42.2 Binary code ...................................................................................42.3 Hexadecimal code.........................................................................42.4 Counting ........................................................................................52.5 ASCII code ....................................................................................52.6 Comments .....................................................................................6

3 CONTRINEX TRANsPONDER MEMORY ��73.1 General information.......................................................................73.2 Word protection .............................................................................73.3 Memory zone protection by password ..........................................83.4 Structureoftheconfigurationword ...............................................8

4 POssIBLE OPERATIONs WITH CONTRINEX RFID TECHNOLOGY ��9

4.1 Reading .........................................................................................94.2 Writing ...........................................................................................94.3 Comparison ...................................................................................94.4 Addition .........................................................................................9

5 RFID sYsTEM ��105.1 Introduction .................................................................................105.2 Cyclic and autonomous operation of the system ........................105.3 Status of the read/write module and the interface device ........... 115.4 Acyclic commands by means of the interface device ................. 11

6 INTRINsIC PROPERTIEs OF RFID ��126.1 Identificationwithoutcontact .......................................................126.2 Identificationwithoutvisibility ......................................................126.3 Readflexibility .............................................................................12

6.4 Dynamicidentification .................................................................126.5 Counterfeits .................................................................................126.6 Errors of manipulation .................................................................126.7 Information durability ...................................................................12

7 sPECIFIC ADVANTAGEs OF CONTRINEX TECHNOLOGY ��13

7.1 Metal ...........................................................................................137.2 Operation in hostile environments ..............................................137.3 Resistance to mechanical shocks ...............................................137.4 Shearing resistance ....................................................................137.5 The limitations of all-metal components ......................................147.6 Protection of the transponder memory ........................................14

8 TRACEABILITY �� 158.1 Transponder memory and database ...........................................158.2 Traceability ..................................................................................15

9 PROGRAMMING AN INsTALLATION BY MEANs OF TRANsPONDERs �� 17

9.1 The transponder as an information vehicle ................................179.2 Entering a command onto the transponder .................................179.3 Reading the command ................................................................189.4 Installation programming by the command memorized in the tran-

sponder .......................................................................................189.5 Further procedure .......................................................................19

RFID1 OPERATING PRINCIPLE1.1 Read/write module and transponder

Seen from the outside, an RFID system comprises a read/write module (RWM) and a transponder (or tag).

page 1

read/write module

transponder

Worthy of note is the fact that CONTRINEX has developed all-metal RFID systems.Internally,anRFIDsystemcanberepresentedasshowninthefigurebelow:

electronic circuit integrated circuit

antenna antenna

1.2 Operating principleThemagneticfieldgeneratedbytheRWMcoiliscapturedbythetransponder,providing

thelatter’sintegratedcircuitwithsufficientenergytomakeitfunction.Datacanthusbeex-changed between the RWM and the transponder.

It should be borne in mind that the transponder is a passive device, i.e. it has no internal energy source of its own (no battery).

electroniccircuit

integrated circuit

antenna

antenna

energydata

transponder

read/write module

RS485point-to-point

Contrarytoothertransponders,whichtransmittheiridentificationnumberassoonastheyareintheRWM’smagneticfield,CONTRINEXtranspondersonlyreplywhensolicited.TheCONTRINEXread/writemoduleinvitestranspondersthatarewithinitsfieldtotransmittheiridentificationnumbersatregularintervals.

1.3 CONTRINEX transponders

synthetic transponders

smooth metal transponders

Threaded metal transponders

1.4 CONTRINEX read/write modulesRead/write modules with synthetic head

All-metal read/write modules

Hand-held read/write device

1.5 Transponder’s integrated circuitThe transponder’s integrated circuit manages

communications with the read/write moduleprocessing of data received or transmittedown power supply.

The integrated memory contains all the transponder’s usable information.

−−−

2 CODEs2.1 Decimal code

This is the most commonly used code. It consists of 10 characters called Arabic numerals.

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Anumbersuchas8604signifies:8604 = 8 * 103 + 6 * 102 + 0 * 101 + 4 * 100

Decimalcodingisaconsequenceofthefactthatmankindusesitstenfingersforcount-ing.

2.2 Binary codeThe binary code comprises only two characters:

Anumbersuchas1101signifies:1101 = 1 * 23 + 1 * 22 + 0 * 21 + 1 * 20 = 13 (dec)Binary code is used in all digital electronic systems, since these systems combine switches

(transistors) that are either closed (0) or open (1).

2.3 Hexadecimal codeIn information technology, binary numbers are assembled into groups (words) of eight bits,

called bytes,

which results in 28 = 256 different possibilities. In order to represent a byte as a number, 256 different characters would be needed… unthinkable! On the other hand, by splitting a byte into two words of four bits, 24 = 16 different characters are required and the byte can be coded using 2 characters. The 16 characters used by the hexadecimal code are as follows:

Acombinationsuchas1D3Asignifies:1D3A = 1(dec=1) * 163 + D(dec=13) * 162 + 3(dec=3) * 161 + A(dec=10) * 160 = 7482 dec

2.4 Counting

decimal binary hexadecimal

weight

2.5 ASCII codeThe ASCII (American Standard for Information Interchange) code is used for coding alpha-

numeric characters. All the alphanumeric characters can be coded using two hexadecimal digits, i.e. 8 bits.

Thus, “K” is coded 4B in hexadecimal or 0100 1011 in binary, and “v” is coded 76 in hexa-decimal, or 0111 0110 in binary.

2.6 CommentsWhen programmed in ASCII, CONTRINEX read/write modules return:

“ * “ for codes 00 to 1F“ . “ for code 20 (space)“ ? “ for codes above 7E.

It should be noted here that only two ASCII characters per word can be written in the memory of a CONTRINEX transponder.

−−−

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3 CONTRINEX TRANsPONDER MEMORY3.1 General information

The memory of a CONTRINEX transponder is made up of 128 words, each of 18 bits, i.e. a total of 2304 bits.

Each word is located by an address from 000 to 127.The last twobitsofaword(LSB:LeastSignificantBits)arededicated to itsprotection,

leaving 16 usable bits per word.Thefirstthreewords(addresses000to002)areprogrammedinthefactory(laserROM)

andcontainthetransponder’suniqueandunalterableidentificationnumber.The following three words (addresses 003 to 005) are reserved for CONTRINEX.Thewordataddress126permitsconfigurationoftheprotectionimposedbythepassword,

which is found at address 127.The user therefore has access to 120 words of 16 bits for stocking information.

Laser ROM000001002003004005

126127

Freely usable memory:

120 words, 16 bits each

128 words

password

writ

e pr

otec

tion

read

pro

tect

ion

16 bits 2 bits

2 words

120 words

3 words

3 words

18 bits

configurationword

3.2 Word protectionEach word can be individually protected in both reading and writing mode by protection

bits. Once word protection has been activated, it is irreversible.

2 bits16 bits

0 00 11 01 1

write protectionread protection

non-protected wordread-protected wordwrite-protected word

read and write-protected word

16 bits 2 bits

3.3 Memory zone protection by passwordAddress127containsthepassword.Thezoneprotectedbythepasswordisdefinedby

theconfigurationwordataddress126.Itshouldbenotedthat,incontrasttowordprotection,protection by password is reversible.

3.4 StructureoftheconfigurationwordThe bits representing the number of attempts remaining and the alarm bit are managed

internally and consequently cannot be programmed.Starting from the maximum number of attempts for the password, the number of tries

remaining is reduced after each invalid attempt. When the number of attempts remaining reacheszero,thealarmbitisactivatedandtheprotectedpartofthetransponderisdefini-tively and irreversibly blocked.Theidentificationnumberofthetransponder(laserROM)is,however,readableatalltimes

bymeansofaspecificinstruction.

12614 12 10 9 8 7 6 5 4 3 2 1 015 13 11

...

prot

ecte

d zo

ne

read

abilit

y of

the

prot

ecte

d zo

neau

to-s

elec

tion

stat

us o

f the

atte

mpt

cou

nter

max

imum

num

ber o

f atte

mpt

s

unus

ed

alar

m b

it

num

ber o

f atte

mpt

s re

mai

ning

no protection25 % protection starting from address 12750 % protection starting from address 12775 % protection starting from address 127100 % protection starting from address 127

write protectionread and write protection

attempt counter deactivatedattempt counter activated

alarm bit deactivatedalarm bit activated

maximum number of attempts: from 0 to 7

configurationword

16 bits

126127

2 bits

passwordconfigurationword

16 bits 2 bits

4 POssIBLE OPERATIONs WITH CONTRINEX RFID TECH-NOLOGY

4.1 ReadingWhen reading, the address from which reading starts and the number of words to be read

mustbespecified.If a read-protected word is found in the selected zone, it will appear as “FFFF”. On the

other hand, it is possible to read a word that is write protected.Specificreadinstructionsareusedinordertoreadtheidentificationnumberofthetran-

sponder and the words reserved for CONTRINEX.

4.2 WritingWhen writing, the address from which the data is to be written as well as the data to be

writtenarespecified.Itisthisdatathatdeterminestheextentofthezoneconcerned.An error will be returned if an attempt is made to write in a write-protected zone. On the

other hand, it is possible to modify a word that is read protected.Specificwriteinstructionsareusedtowritethepassandconfigurationwords,aswellasfor

introducing the data in the part reserved for CONTRINEX.The data written overwrites any existing data.

4.3 ComparisonWhen data is read protected, it is still possible to compare it with the data introduced by

means of a comparison operation. To do this, the start address of the data to be compared withthedataintroducedisspecified.Theresultgivestheanswer“Identical”or“Different”.

4.4 AdditionIt is possible to add data to the contents of an address. This operation could be of inter-

est, for example, if one wants to know how many times the transponder has been read or modified.

5 RFID sYsTEM5.1 Introduction

The read/write module (RWM) is a mono-operational device that does not support inter-ruptions during an operation.Acontrolconsole,connectedtoafieldbus,isintendedtocontrolseveralRWMs.InordertoprovideabufferbetweentheRWMsandthefieldbus,aninterfacedeviceis

used.

transponder

read/write module RWM1 RWM2 RWM3

control console

interface device

power supply

fieldbus

5.2 Cyclic and autonomous operation of the system

interrogation of RWM3 by interface device



transponder detection attempt by RWM3



time

RWM3

RWM2

RWM1

interface device

Eachread/writemoduleperiodicallyattemptstoreadtheidentificationnumberofatran-sponderlikelytobewithinitsfield.

The interface device sequentially interrogates each of the read/write modules connected to it.

5.3 Status of the read/write module and the interface device

time

interface device

RWM1 status

RWM1

interface device status

transponder physically present

transponder detection attempt

transponder detected by RWM1


RWM1 status recognized by interface device

transponder absent

absence of transponder detected by RWM1

RWM1 memorizes the number of the last transponder detected

RWM1 status recognized by interface device and re-initialization of RWM1

transponder present

Ifatransponderispresent,theread/writemodulemodifiesitsstatusduringatransponderdetection attempt, and the interface device takes this status into account when it interrogates the read/write module.

5.4 Acyclic commands by means of the interface devicetransponder present

interface device

RWM1 status

RWM1

interface device statuscommunication inter-

face device - bustransponder physically

presenttransponder detection

attempttransponder detected by

RWM1interrogation of RWM1 by

interface deviceRWM1 status recognized

by interface devicetransmission of a command

for RWM1 to interface devicereceptionconfirmedby

interface devicetransmission of command

to RWM1receptionconfirmedby

RWM1connexion interface device

- RWM1 occupiedexecution of command by

RWM1RWM1 occupied

interface device available for other commands

RWM1 has executed command

at the end of the calculated period, the interface device

interrogates RWM1RWM1 sends its data to

interface device

command of result to the interface device

interface device sends data to bus

Only the interface - bus communication is visible to the user.

time

6 INTRINsIC PROPERTIEs OF RFID6.1 Identificationwithoutcontact

With RFID systems, the transfer of information is effected by means of electromagnetic waves. No contact is necessary in order to identify an object, which can, therefore, be identi-fiedremotely.

6.2 IdentificationwithoutvisibilityAn RFID transponder can be read even if it is masked. A particular feature of the CON-

TRINEX transponders is that they can even be read when behind metallic masks.Thisincludespollutionoccurringinadifficultenvironment.I should further be pointed out that a symmetric RFID transponder can be read from either

side.

6.3 ReadflexibilityIt is possible to very precisely select the information that one wants to read in the memory

ofthetransponder.Inpractice,duringareadoperation,theusercandefinethenumberofwords he wants to read starting from the address of his choice.

6.4 DynamicidentificationIn transponders of the read/write (R/W) type as proposed by CONTRINEX, information can

not only be read but also written. It is therefore possible to add to or modify the information in a transponder.Itshouldbepointedoutthattherearealsotranspondersthathaveonlyanidentification

number and onto which it is impossible to write. These are called read-only (RO) transpon-ders.

6.5 CounterfeitsIn contrast to printed labels, on which information is visible and hence reproducible, in a

transponder, the information is stored in the memory of an integrated circuit. As a result, it is verydifficultandveryexpensivetoreproducesuchascircuit.

6.6 Errors of manipulationIdentificationbyRFIDisparticularlysuitedtoautomation.Consequently,informationcan

be introduced and readings made without human intervention. Data capture errors are thus eliminated.

6.7 Information durabilityEntering information onto a transponder guarantees the durability of the information. Even

in the case of a breakdown of the IT network that pilots the RFID system, the information contained in the transponder is not affected.

7 sPECIFIC ADVANTAGEs OF CONTRINEX TECHNOLOGY7.1 Metal

The use of all-metal RFID components (read/write modules and transponders) distinguish-es CONTRINEX technology from that of its competitors.

7.2 Operation in hostile environmentsWhilst conventional RFID components all at least in part consist of plastic (head of read/

write modules and transponders), CONTRINEX all-metal RFID components are of stainless steel. They are thus suited for use in hostile environments (cleaning, chemical products, water, frost).

7.3 Resistance to mechanical shocksAll-metal RFID components resist mechanical shocks better than plastic ones.

7.4 Shearing resistanceThreaded CONTRINEX all-metal transponders can easily be embedded in the object to be

tagged. Consequently, the transponder does not protrude beyond the surface of the object and is thus protected from shearing.

7.5 The limitations of all-metal componentsThemetalpartiallyabsorbsthemagneticfieldemittedbytheread/writemodule.Thisre-

sults in a shorter read/write distance than that achieved with a conventional transponder and read/write module.

conventional RFID system

Afurtherconsequenceofmagneticfieldabsorptionbythemetalisthatthelateraloperat-ing range is reduced.

conventional RFID system

7.6 Protection of the transponder memoryThere are two kinds of protection that can be applied to the memory:

Irreversible word protection using protection bitsReversible zone protection using a password

−−

CONTRINEX commercializes RFID components made entirely of stainless steel, allowing it to attack markets that could previously not use this technology. Without doubt, metallic technology is a lot more resistant than conventional technology.

page 15

8 TRACEABILITY8.1 Transponder memory and database

Although it would be possible to write information onto transponders in clear (ASCII), it is normally coded. As previously mentioned, in a memory word, only two ASCII characters can be written, which corresponds to a total of 240 keystrokes (including spaces). To illustrate this, the following text could be written onto a CONTRINEX transponder.

It can be seen that the transponder memory would quickly be full. However, if the informa-tion is coded, one memory word allows 65,536 possible references.

The different types of data are referenced by numbers. In a database, these numbers represent the access key to the complete data relating to the object.

8.2 TraceabilityDuring its passage through a production line, a product is subject to transformations. A

transpondercanfulfiltheroleofaprogresssheetandrecordtheproduct’shistory.Thead-vantages of using RFID are, on the one hand, that the recording operations can be carried out automatically and, on the other, that the loss of information, or its deterioration during the process, is avoided.

This procedure also presents an obvious advantage in clean rooms (dust-free), where special, expensive papers that cannot be reused, have to be used. A transponder, by nature, can be reused.

01015

01015

01015Lafabrique SARue du Stand 18

1024 EcublensTél. +41 21 690 40 40Fax +41 21 690 40 [email protected]

transponder

transponder memory

client datadatabase

65 536possible references

1word

Logistics Reception Assembly Test Dispatch

The data contained in the transponder’s memory is used for generating

delivery notesclient addressesinvoicesetc.

−−−−

Client numberOrder dateOrder year

Production order no.






Production order no.Object number 1

Reception yearReception date

Object number 2


Object number 3


Object number 4


Object number 1


Object number 2


Object number 3


Object number 4


Object number 1


Object number 2


Object number 3


Object number 4


Employee numberDispatch dateDispatch time




Article numberEmployee number

Dispatch dateDispatch time

Article number

Type of test

Employee numberTest result

Dispatch dateDispatch time

Transponder memory

9 PROGRAMMING AN INsTALLATION BY MEANs OF TRANsPONDERs

9.1 The transponder as an information vehicle In the following example, it can bee seen that, at the information level, the transponder

makes the link between two distinct production centers A and B.It is assumed that all the objects (cars) that pass along the production line are equipped

with a transponder.

9.2 Entering a command onto the transponderA command is introduced using a control console and is transmitted to the transponder via

an interface device and RWM1.

A Bcontrol console A

interface device

interface device

installation

RWM2RWM1

production line

control console B

RED

9.3 Reading the commandThe command recorded in the transponder is read by RWM2, and sent to the control con-

soleviainterfacedeviceandfieldbus.

9.4 Installation programming by the command memorized in the tran-sponder

The installation is programmed by the control console and does its work in accordance with the instructions memorized in the transponder.

A B

A Bcontrol console A

interface device

interface device

installation

RWM2RWM1

production line

control console B

control console A

interface device

interface device

installation

RWM2RWM1

production line

control console B

RED

BLuE RED

9.5 Further procedureEach object can individually be the carrier of a command that will program the installation

at an opportune moment.

A B

page 19

control console A

interface device

interface device

installation

RWM2RWM1

production line

control console B

BLuE

contrinex rfid technology · 2010-02-11 · rfid 1 operating principle 1.1 read/write module and...

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