WO2008012856A2

WO2008012856A2 - Rfid network for tracking documents and goods

Info

Publication number: WO2008012856A2
Application number: PCT/IT2007/000522
Authority: WO
Inventors: Claudio De Rubeis; Carlo Di Pasquale
Original assignee: Entropia S.R. S.R.L.
Priority date: 2006-07-27
Filing date: 2007-07-24
Publication date: 2008-01-31
Also published as: WO2008012856A3; ITRM20060404A1

Abstract

Present invention relates to a RFID network for tracking documents and goods: - one or more tags (7), each one apt to contain information relevant to the good on which it is applied; - one or more RFID readers (L), each one suitable to detect information stored within said one or more tags (T); - one or more antennas (A) for each RFID reader (L), each of which is suitable to detect tags (T) present within its detection field, characterised in that said antennas (A) are suitable to be connected, in groups of antennas and with a bus architecture, to each one of said RFID readers (L), and in that a control module is provided for each group of antennas (A) and each RFID reader (L) relevant to the antenna (A), said control module being suitable to be connected to a host computer (P) and to receive instructions from said computer for enabling a single antenna (A) per time by activation of a relays circuit (R1 ) so that relevant RFID reader (L) is connected only to said enabled antenna (A) and detects information contained within tags (T) present within the detection field of the enabled antenna (A).

Description

RFID NETWORK FOR TRACKING DOCUMENTS AND

GOODS

Present invention relates to the store logistic sector and to the paper documents managing, and more particularly to means suitable to track position of goods within the store or of paper documents by tags applied on the same.

More specifically, the invention relates to the realisation of a network permitting to a user monitoring a huge amount of product with a remarkable saving of costs for realising the network, as well as for installing and managing the same.

According to the invention, it is provided the realisation of a network comprising a plurality of antenna groups connected by a bus architecture, being provided with an own RFID (Radio Frequency IDentification) reader, wherein a control module is associated to each

RFID reader suitable to enable a set antenna of the relevant group so as the latter is only connected with a set reader.

At present, traditional RFID networks used for tracking position of documents and goods comprise, in combination, at least a RFID multiplexer, at least a RFID reader and one or more antennas controlled by said reader. They are mainly conceived for large companies, since costs for buying a single RFID multiplexer, a single RFID reader, as well as, most times, a plurality of antennas, are too large for a user or medium/small company. Costs for installing the system and for managing the same must be added to the above costs.

It is evident that this makes the system not interesting for single users or small/medium companies, not being convenient for them this network and preferring still managing goods manually. It should suffice thinking, for example to Law Firms, personnel of which must quickly find a file without knowing first if it is among them in the archive or not. Often said files are identified by a progressive number and are inserted within big files, numbered as well. Thus, personnel will know the outcome of the search only when have found the relevant big file.

The same applies to the car agencies, needing managing client files, as well as libraries with a huge number of books continuously lent to a client and then to be put again on the shelves. A second drawback is due to the fact that in order to connect RFID reader to a high number of antennas, it is presently necessary inserting one or more RFID multiplexer and all the network RFID multiplexers must be cascade connected each other. It implies on one side a remarkable increase of insertion losses due to the sum of the insertion losses of multiplexers cascade connected.

If for example a RFID reader must be connected to 16 antennas and RFID multiplexer with 8 exits should be used. In order to realise said connection it is necessary using three multiplexers and not only two, since, as it is well known, multiplexer elements must be connecter each other according to binary tree topology.

A third drawback, natural consequence of the above, is represented by the high number of cables necessary for connecting each exit of a RFID multiplexer wit a relevant antenna, space required, wiring problems and cost for realising the necessary structures.

A further drawback is due to the fact that, in case of use of a plurality of cascade connected multiplexer, in order to ensure that antennas transmit necessary power for detecting tags, much powerful RFID readers, or even industrial RFID readers are used, originally realised for different objects, the purchasing of which further increases costs. Moreover, in many cases manufacturers decide piloting RFID multiplexers only by industrial RFID readers.

Object of the present invention is that of overcoming said drawbacks, providing a RFID network permitting connecting a plurality of antennas connected by a bus architecture to a single RFID reader without the use of a multiplexed, managing said antennas and said RFID reader by a control module, suitable to enable only the specific antenna to which

RFID reader must be connected, thus drastically reducing wiring, power necessary for RFID readers and thus costs for realising network, as well as costs for installing and managing the same network.

According to the invention, said control module is a module for controlling multiple RFID antenna architectures (RFID Multiple-Antennas Architecture Generic controller).

It is also possible providing, when realising a large RFID network, one or more further control-organizer modules for distributed

RFID systems (RFID Distributed Environment Controller Organizer), each one managing one or more modules for controlling multiple antennas RFID architectures.

In the following, in order to simplify terminology, RFID Multiple- Antennas Architecture Generic controller and RFID Distributed Environment Controller Organizer will be respectively indicated by names "Manager" control module and "Director" control-organizer module.

The invention will be better understood by the following specific description of the same and with reference to the enclosed drawings showing, for exemplificative purposes, a preferred embodiment. In the drawings: figure 1 shows an embodiment of the invention; figure 2 shows a modification to the embodiment of figure 1 ; figures 3 and 4 show a particular relevant to an antenna, respectively when enabled and not enabled; figure 5 schematically shows an example of antennas configuration; figures 6 and 7 respectively show schematically a "Manager" control module and a "Director" control-organizer module making reference to the figures, a network is shown in the first embodiment, comprising: one or more tags T containing information concerning the good on which they are applied; at least a RFID reader L receiving the information stored on said tags T; - at least an antenna A for each RFID reader L detecting tags T present within its detection field; a coaxial buss BC connecting said RFID reader L with said antenna A; a "Manager" control module M for each RFID reader L enabling a single antenna per time; a RS485 B1 bus connecting said "Manager" M control module with said antenna A; a host computer P suitable to be connected with each "Manager" M control module. According to a peculiar feature of the invention, said antenna A associated with corresponding RFID reader L is an antenna with optimised interface (Optimised Antenna for Multiple Antennas). Receiving a command from said "Manager" M control module, said antenna A is suitable to be cascade connected with the coaxial bus BC with other antennas A by relays circuit R1 , maintaining reading performances of tag T as if it was the sole antenna A connected with RFID reader L. In other words, when relays circuit R1 is in an operative position (fig. 4) it permits connection of antenna A with coaxial bus BC as terminal load of the same bus BC, while in a resting position it prolongs path of coaxial bus BC to the following antenna A (fig. 3).

Advantageously, use of relays circuits R1 involves a reduction of the insertion losses typical of cascade connections of multiplexers, reducing them substantially at zero.

A further advantage of the use of relays circuits R1 is that of ensuring galvanic insulation of antennas A of relevant control circuits; enabled antenna A will be thus galvanically connected with corresponding RFID reader L.

Antenna A is provided with a suitable circuit decoding digital addresses permitting selection of same antenna A, as well as activation of relays circuit R1.

As alternative to said decoding circuit, it is provided a control circuit suitable to connect it to the coaxial bus BC and comprising a micro controller E suitable to receiving activation control of relays circuit R1 by a communication circuit RS485.

Said micro-controller E and said relays circuit R1 are mounted on a printed board S suitably realised, also comprising a supply (not shown), a communication interface RS485 F toward "Manager" M control module, an antenna tuning circuit N (figures 3 and 4).

Antenna A is a modular assembly of said printed board S with a known loop circuit G comprising inductive part of the antenna A.

For some versions of said board S it is possible providing that micro-controller E can also make an automatic adjustment of antenna tuning.

Advantageously, a further relays circuit or de-tuning circuit R2 is provided, apt to reduce antenna A merit factor when it is not enabled, thus remarkably reducing effects of coupling a not-enabled antenna A close to the enabled antenna A, in order to prevent that corresponding RFID reader L detects tags T not present within detection field of said enabled antenna A but within the field of the not-enabled one close to the first antenna.

Said relays circuit R2 is controlled by micro-controller E so that when antenna A is not enabled, same antenna is de-tuned, while when the same antenna is enabled, it is not de-tuned.

A further advantage is due to the fact that antenna A provides at least a digital entrance for possible industrial controls and at least a digital exit for outside signal and control. For example, by said digital exit it is possible activating a local signal of enabled antenna A with which a set tag T is positioned. In this case, said at least a digital exit can be represented by a LED.

Antenna A is able to automatically configuring both its own address, as periphery of bus RS485 B1 , monitoring a suitable inlet signal arriving from "Manager" M control module, and addresses of following antennas A, thus generating by itself a suitable exit signal that will be an inlet signal for the following antenna A.

Configuration procedure of antennas A is started and controlled by "Manager" M control module piloting said antennas so as to assign to each of them an univocal address. Two connection pins are provided on said "Manager" M control module, respectively on inlet pin and one exit pin, used for transmission/reception of signals and respectively suitable to transmit an exit or "check-out" signal to antennas and receiving an inlet or "check-in" signal from same antennas. Each antenna A has an inlet and an outlet connected with the inlet of the following antenna.

In example shown in figure 5, exit pin of "Manager" M control module is connected with inlet of antenna A farthest from said "Manager" module, while its inlet pin is connected with outlet of antenna A closer. First, each pin of "Manager" M module has a low logic level, and each antenna A has no address on busRS485 B1 , and has the exit at low logic level.

"Manager" M control module commutes its "check-out" signal at high logic level so as to make inlet of antenna A being commuted, and exit pin is connected at high logic level. In order to assign address "1" to an antenna, "Manager" M control module sends a Broadcast message on bus RS485 B1 , thus assigning said address "1".

Said message is read by each antenna A, but it is interpreted only by antenna A, having its inlet at high logic level, thus acquiring address "1".

"Manager" M control module does not know if Broadcast message previously sent has been received, thus sending a further message, with address "1" on bus RS485 B1 so that antenna A that acquired address "1" commutes its exit from low logic level to high logic level.

Antenna A with address "1" responds to a further message from "Manager" M control module, confirming commutation of its exit at high logic level. Thus, "Manager" M control module detects that address "1" was assigned and that configuration of antenna with said address was completed.

It is evident that once configured first antenna, following antenna A has its own inlet at high level. In order to assign address "2", "Manager" M control module sends a Broadcast message to bus RS485 B1. Said message is read by each antenna A without address, but it is only interpreted by antenna A with its inlet at high logic level and acquires address "2".

In order to detect if said Broadcast message was received, "Manager" M control module sends a further message, with address "2" on bus RS485 B1 by which asks to antenna A having address "2" to commute its exit from low logic level to high logic level.

Antenna A with address "2" responds to a further message from "Manager" M control module, commutating its exit at high logic level. Thus, "Manager" M control module detects that address "2" was assigned and that configuration of antenna with said address was completed.

Antennas configuration process prosecutes until inlet pin of "Manager" M control module commutes from low logic level to high logic level, until when "check-in" signal is at high logic level.

According to the invention, process for configuring at least one or more antennas A, each one starting without an address and is provided with an inlet and an outlet, the latter at low logic level, by "Manager" M control module having an outlet pin and an inlet pin, both at low logic level, and respectively cascade connected with inlet of first antenna and to the exit of the last antenna, substantially provides the following steps; 1. setting a K variable at 0 value and commuting outlet pin of

"Manager" M control module at high logic level and consequent commutation of inlet at high logic level by antenna A connected with said pin;

2. sending a Broadcast message for assigning address corresponding to value "K=K+ 1" on bus RS485 B1 by "Manager" M control module;

3. reading said Broadcast message by antenna A the inlet of which is at high logic level;

5. acquisition of address with value "k+1" by the same antenna; 6. sending a further message with address "X" on bus RS485

B1 by "Manager" M control module to commute exit of said antenna A at high logic level with address equal to value "K";

7. commuting exit of said antenna with an address equal to value "K" and at the same time commuting inlet of the following antenna at high logic level;

8. confirmation of commutation of said antenna A with address equal to value "K" to "Manager" M control module and detection by "Manager" M control module that said antenna A acquired its own address; 9. in case inlet pin of "Manager" M control module is at low logic level, step 2 is carried out, otherwise proceed to step 10;

10. detection by "Manager" M control module of configuration of all K values of antennas A.

Once thus configured antennas, user can, interacting with host computer P, selecting a specific "Manager" M control module on the basis of antenna A that he wishes enabling. Said "Manager" M control module enables set antenna A by activation of relays circuit R1 of same antenna

A. said relays R1 circuit connects antenna A selected by user to coaxial bus BC so that corresponding RFID reader L is connected only to said antenna A.

Consequently, in case RFID network comprises a plurality of RFID readers L, a plurality of antennas A associated to each reader L and a plurality of tags T within the detection field of each antenna A, only RFID reader L is enabled of the specific enabled antenna A, and said RFID reader L will be able to detect information stored within tags T that are in the enabled antenna field. In other words, each RFID reader L does not know the number of antennas A that can be associate to the same, but is enabled to interrogate only the enabled antenna, and exchanging information with each tag T within the detection field of said enabled antenna A.

In order that it receives instructions from host computer P, "Manager" M control module has an own micro-controller MM, a first communication interface M1 for controlling antennas A, a second communication interface M2 toward host computer P, and a third communication interface M3 toward a generic RFID reader L (figure 6).

First communication interface M1 permitting to "Manager" M control module sending enabling control to a set antenna A is a RS485 interface.

Second communication interface M2 toward host computer P is an opto-insulated RS485 interface; or a Bluetooth interface; or - an Ethernet interface; or a WiFI interface.

Third communication interface M3 toward RFID reader L is: a RS232 interface; or a RS485 interface. Said third interface M3 is suitable to permit to host computer P controlling relevant RFID reader L; "Manager" M control module behaves as "bridge" replicating, in a completely transparent way, information received from host compute P to RFID reader L and making the same for response messages of RFID reader L toward host computer P. Advantageously, presence of communication interface toward host computer P in "Manager" M control module, galvanically insulated, ensures insulation among different antenna A groups and the relevant RFID readers L.

A modification of the embodiment described in the above provides one or more "Director" D control-organizer modules, each one suitable to be connected both with host computer P and "Manager" M control module for controlling numerous RFID readers L₁ each one connected to numerous antennas A, by talking with "Manager" M control module corresponding to RFID reader L of the enabled antenna A.

Said "Director" D control-organizer module is suitable to be connected to host computer P on different known communication networks /Lan Ethernet, Lan WiFI, Intranet, Internet, ecc.) and comprises an own processing unit DM, a data base DB for directly managing serial codes of detected tags T, a first communication interface D1 toward "Manager" M module and a second communication interface D2 toward host computer (figure 7). Each one of said communication interfaces D1 and D2 is: a RS484 interface; or a Bluetooth interface; or an Ethernet interface; or a WiFI interface. In case first communication interface D1 is a RS485 interface, it is preferred that it is opto-insulated.

In this configuration, "Manager" M control module employs communication interface M2 toward "Director" D control-organizer module, by the command of which "Manager" M module activates, by bus RS485 B1 connecting the latter with each antenna A, relays circuit R1 relevant to a set antenna A to which RFID reader L is connected.

It is evident that it is "Director" D control-organizer module talking with "Manager" M control module for enabling proper antenna A and consequent connection of RFID reader L to be managed, and that knows and talks with the latter according to proprietary protocol of said

RFID reader L.

With respect to host computer P, "Director" D control-organizer module implements a communication protocol standardised and independent from the protocol implemented in RFID readers L. Data Base DB of "Director" D control-organizer module is suitable to memorise serial codes from corresponding RFID readers L connected.

"Director" D control-organizer module is suitable to repetitively and autonomously update contents of said database. "Director" D control-organizer module can divide data base DB of serial codes of tags T into zones, marking each zone by a control code and using said control codes in order to permit verification between its own data base DB and the one of host computer P by communication of said control codes. Advantageously, in this way, "Director" D control-organizer module communicates to host computer P only a limited number of information relevant to said control codes, without the need of transmitting all the tags T serial codes.

Taking into consideration software, it is necessary a managing protocol for RFID systems (RFID administration protocol) suitable to permit to host computer P to manage RFID network as an assembly of antennas A, topographically identified, to which said tags T are interfaced. Controls in said protocol are not influenced by RFID readers L and the complex procedure sequences involved in a single macro-control.

Said managing protocol comprises the whole of controls exchanged between "Director" D control-organizer modules and "Manager" M modules, between host computer P and "Director" D control- organizer modules and between "Manager" M modules and antennas.

The present invention has been described for illustrative but not limitative purposes, according to its preferred embodiments, but it is to be understood that modifications and/or changes can be introduced by those skilled in the art without departing from the relevant scope as defined in the enclosed claims.

Claims

1. RFID network for tracking documents and goods: - one or more tags (7), each one apt to contain information relevant to the good on which it is applied;

- one or more RFID readers (L), each one suitable to detect information stored within said one or more tags (T);

- one or more antennas (A) for each RFID reader (L), each of which is suitable to detect tags (T) present within its detection field, characterised in that said antennas (A) are suitable to be connected, in groups of antennas and with a bus architecture, to each one of said RFID readers (L), and in that a control module is provided for each group of antennas (A) and each RFID reader (L) relevant to the antenna (A), said control module being suitable to be connected to a host computer (P) and to receive instructions from said computer for enabling a single antenna (A) per time by activation of a relays circuit (R1) so that relevant RFID reader (L) is connected only to said enabled antenna (A) and detects information contained within tags (T) present within the detection field of the enabled antenna (A).

2. RFID network according to claim 1 , characterised in that said control module is an architecture control module with multiple antennas or "Manager" M module, a "Manager" M module being provided for each RFID reader (L).

3. RFID network' according to previous claim, characterised in that it comprises: a coaxial bus (BC) connecting said RFID reader (L) with each antenna (A); and a RS485 (B1) bus connecting said "Manager" (M) control module with said antenna (A).

4. RFID network according to previous claim, characterised in that said antenna (A) is suitable to be cascade connected with the coaxial bus (BC) with other antennas (A) by activation of relays circuit (R1).

5. RFID network according to previous claim, characterised in that when relays circuit (R1) is activated, antenna (A) is connected with coaxial bus (BC) as terminal load of the same bus BC, while when relays circuit (R1) is deactivated path of coaxial bus BC is prolonged to the following antenna A.

6. RFID network according to claim 4, characterised in that said antenna (A) is an antenna with optimised interface.

7. RFID network according to previous claim, characterised in that said antenna (A) is provided with a suitable circuit decoding digital addresses permitting selection of same antenna (A), as well as activation of relays circuit R1.

8. RFID network according to claim 6, characterised in that said antenna (A) is provided with a control circuit suitable to connect it to the coaxial bus (BC) and comprising a micro controller (E) suitable to receiving activation control of relays circuit (R1) by a suitable communication circuit.

9. RFID network according to previous claim, characterised in that said communication circuit is a RS485 communication circuit.

10. RFID network according to claim 6, characterised in that said micro-controller (E) and said relays circuit (R1) are mounted on a printed board (S) suitably realised.

11. RFID network according to previous claim, characterised in that, said printed board (S) comprises a supply (not shown), a communication interface RS485 (F) toward "Manager" (M) control module, as well an antenna tuning circuit (N).

12. RFID network according to claim 10 or 11 , characterised in that a further relays circuit or de-tuning circuit (R2) is provided on said board (S) apt to reduce antenna (A) merit factor when it is not enabled, thus remarkably reducing effects of coupling a not-enabled antenna (A) close to the enabled antenna (A).

13. RFID network according to one of claims 10 - 12, characterised in that said antenna (A) is modular assembly of said printed board (S) with a known loop circuit (G) comprising inductive part of the antenna (A).

14. RFID network according to one of claims 6 - 13, characterised in that said antenna (A) provides at least a digital entrance for possible industrial controls.

15. RFID network according to one of claims 6 - 14, characterised in that said antenna (A) provides at least a digital exit for outside signal and control.

16. RFID network according to one of claims 6 - 15, characterised in that said antenna (A) is able to automatically, and controlled by "Manager" (M) module, configuring both its own address, as periphery of bus RS485 B1 , monitoring a suitable inlet signal arriving from "Manager" (M) control module, and addresses of following antennas (A), thus generating by itself a suitable exit signal that will be an inlet signal for the following antenna (A).

17. RFID network according to claim 2, characterised in that said "Manager" (M) control module comprises its own micro-controller (MM), a first communication interface (M1) for controlling antennas (A), a second communication interface (M2) toward host computer (P), and a third communication interface (M3) toward a generic RFID reader (L).

18. RFID network according to previous claim, characterised in that said first communication interface (M 1) is a RS485 interface.

19. RFID network according to claim 17, characterised in that said second communication interface (M2) is an opto-insulated RS485 interface; or a Bluetooth interface; or an Ethernet interface; or a WiFI interface.

20. RFID network according to claim 17, characterised in that said third communication interface (M3) is a RS232 interface; or a RS485 interface.

21. RFID network according to claim 17, characterised in that one or more "Director" (D) control-organizer modules are provided, each one suitable to be connected both with host computer (P) and second interface (M2) of "Manager" (M) control module on different known communication networks for controlling one or more RFID readers (L), by talking with relevant "Manager" (M) control module.

22. RFID network according to claim 21 , characterised in that said "Director" (D) module comprises its own processing unit (DM), a data base (DB) for directly managing serial codes of detected tags (T), a first communication interface (D1) toward "Manager" (M) module and a second communication interface (D2) toward host computer (P).

23. RFID network according to previous claim, characterised in that each one of said communication interfaces (D1) and (D2) is a RS485 interface or a Bluetooth interface or an Ethernet interface or a WiFI interface.

24. RFID network according to previous claim, characterised in that when interface communication (D1) is a RS485 interface, it is an opto- insulated interface.

25. RFID network according to previous claim, characterised in that "Director" (D) control-organizer module is suitable to divide data base

(DB) of serial codes of tags (T) into zones, marking each zone by a control code and using said control codes in order to permit verification between its own data base (DB) and the one of host computer (P) by communication of said control codes.

26. RFID network according to previous claim, characterised in that "Director" (D) control-organizer module is suitable to repetitively and autonomously update contents of said database.

27. RFID network according to previous claim, characterised in that it is provided a managing protocol for RFID systems (RFID administration protocol) suitable to permit to host computer (P) to manage RFID network as an assembly of antennas (A), topographically identified, to which said tags (T) are interfaced.

28. RFID network according to previous claim, characterised in that said managing protocol comprises the whole of controls exchanged between "Director" (D) control-organizer modules and "Manager" (M) modules, between host computer (P) and "Director" (D) control-organizer modules and between "Manager" (M) modules and antennas (A).

29. Process for configuring one or more antennas (A) according to claim 6, each one starting without an address and is provided with an inlet and an outlet, the latter at low logic level, by "Manager" (M) control module having an outlet pin and an inlet pin, both at low logic level, and respectively cascade connected with inlet of first antenna (A) and to the exit of the last antenna (A), substantially provides the following steps;

1. setting a K variable at 0 value and commuting outlet pin of "Manager" (M) control module at high logic level and consequent commutation of inlet at high logic level by antenna A connected with said pin;

2. sending a Broadcast message for assigning address corresponding to value "K=K+1" on bus RS485 (B1) by "Manager" (M) control module;

3. reading said Broadcast message by antenna (A) the inlet of which is at high logic level;

5. acquisition of address with value "k+1" by the same antenna (A);

6. sending a further message with address "X" on bus RS485 (B1) by "Manager" (M) control module to commute exit of said antenna (A) at high logic level with address equal to value "K";

8. confirmation of commutation of said antenna A with address equal to value "K" to "Manager" (M) control module and detection by

"Manager" (M) control module that said antenna (A) acquired its own address;

9. in case inlet pin of "Manager" (M) control module is at low logic level, step 2 is carried out, otherwise proceed to step 10; 10. detection by "Manager" (M) control module of configuration of all K values of antennas (A).

30. RFID network for tracking documents and goods as substantially described and illustrated in the specification and drawings.