WO2013013706A1

WO2013013706A1 - Method for the wireless interchange of data, and access device for accessing a data memory

Info

Publication number: WO2013013706A1
Application number: PCT/EP2011/062809
Authority: WO
Inventors: Thomas Grosch; Bruno Kiesel; Patrick SCHULZ
Original assignee: Siemens Aktiengesellschaft
Priority date: 2011-07-26
Filing date: 2011-07-26
Publication date: 2013-01-31

Abstract

In a data memory (10) with which memory data are interchanged via a wireless data link (14, 18, 24), the problem may exist that during interchange of data between the data memory (10) and an access device (12, 16, 22) the transmission signal from a further access device (12, 16, 22) can disturb the access device (12, 16, 22) which is already communicating with the data memory (10). It is an object of the present invention to allow memory data to be interchanged between a data memory (10), on the one hand, and a plurality of access devices (12, 16, 22), on the other hand. In the method according to the invention, if the access devices (12, 16, 22) are situated in an environment of the data memory (10) at the same time then the access devices (12, 16, 22) interchange communication data with a coordinate device (12, 16, 22), which is different from the data memory (10), and coordinate a respective access behaviour in respect of the data memory (10) among one another. The invention also relates to an access device (12, 16, 22) for interchanging memory data with a data memory (10).

Description

description

Method for wireless exchange of data as well

Access device for accessing a data store

The invention relates to a method for the direct wireless transmission of memory data between a

Data storage on the one hand and multiple access devices

on the other hand. The invention also relates to an access device for the immediate wireless exchange of memory data with a data memory. In this case, a data storage means, in particular, a mobile RFID data storage (RFID - Radio Frequency Identification). The data store may also be another data store

act, which can be accessed via a radio interface. An access device can be a read device for

Reading the memory data of the data memory, a write-only device for storing memory data in the

Data memory or a read-write device, with the latter memory data can be stored both in the data memory and read from this.

In a data memory with which memory data is exchanged over a wireless data connection, the

There is a problem that during an exchange of data between the data store and an access device the

Attempting another access device to also communicate with the data store, interfere with or even interrupt the data exchange with the first access device. The transmission signal of the further access device forms in such a case for that already with the data memory

namely communicating access device in the rule

Noise signal. For this purpose, the CSMA technology (CSMA - Carrier Sense Media Access) is known, which prevents uncontrolled transmission by another access device, if already one

so-called productive data connection between the Data storage and another access device exists over which memory data is exchanged. In connection with RFID technology, such a CSMA access method is known as listen-before-talk for a data exchange with an RFID data memory, which can be used in the field of UHF RFID technology (see, for example, the ETSI specification TS 102 562). In CSMA technology, if multiple access devices are located in and want to access a data storage environment, the order in which the access devices ultimately exchange storage data with the data store is random and equal. Therefore, it is difficult to give privileged access to a particular device. There is one associated with the Listen Before Talk for accessing UHF RFID data storage

An additional problem is that an access device, even with very weakly recognized signals from another access device, changes channel and then pauses, i. even a remote access device can very easily disturb the local communication.

It is an object of the present invention to enable an exchange of memory data between a data memory on the one hand and a plurality of access devices on the other hand.

The object is achieved by a method according to claim 1 and by an access device according to claim 8. Advantageous developments of the method and the access device according to the invention are characterized by the

Subordinate claims given.

The method according to the invention makes it possible for a plurality of access devices to exchange storage data directly with a data memory wirelessly, that is to say each of them

Access devices can be over a wireless

Communication interface of the data memory access to this. In the event that the access devices

at the same time in an environment of memory, The access devices tune their respective access behavior to the data memory. For this purpose they exchange communication data with a coordination device. This is not the data store itself, but a different device. With the

Surrounding the data memory is meant here the area in which two access devices must not simultaneously send out a signal for the data memory, if a fault is to be avoided.

By the method according to the invention there is the advantage that the access to the data carrier by a

Communication interface is coordinated between the participating access devices and the

Coordination device is established. The

Communication connections of the access devices to the

Communication interface of the coordination device thus exists in parallel and independent of the individual productive data connections that are possible between the data memory on the one hand and the access devices on the other hand. The access devices are via the coordination interface of the coordinator (independent of the

Productive data connection) to a parallel one

Communication network connected. The to the

Communication interface through the access devices

set up established communication links

Synchronization connections, over which

Communication data for coordinating the individual accesses, so coordination data to be exchanged. By doing

Disk itself therefore no coordination mechanism must be provided. Thus, the method is also particularly favorable in connection with the use

Data storage, such as mobile RFID data carriers (English: RFID tag or RFID transponder).

By means of the coordinating device, the order in which the access devices successively access the data memory can be defined at any time access. In particular, it is now also possible to give a particular access device privileged access to the data memory. Another advantage is that in the inventive method to the existing protocols for the productive data exchange, ie the exchange of memory data between the data memory and one of the access devices, no extensions or

Changes must be made. The access devices and the data memories thus remain fundamentally compatible with existing applications.

In an advantageous development of the method according to the invention, the access devices exchange the

Communication data among each other. In other words, in this development, the coordination device is provided by one or more of the access devices themselves or by corresponding devices in all access devices

provided. The coordination device can thus be distributed to the access devices. An exchange of communication data between the access devices is then to be understood as meaning that an access device exchanges the data necessary for the coordination of the access behavior with a component of the coordination device which is located in at least one of the other access devices. This has the advantage that no additional device for

Coordinate the access devices must be provided. To realize the synchronization connections between the individual access devices current radio standards can be used. This includes in particular the possibility of ad hoc networking, which allows the simple construction of a radio network between the participating access devices. A particularly simple realization of this

However, development of the invention can also be, for example, that one of the access devices with a

Transmitter is equipped while another access device has a corresponding receiver. In this case, it can then be provided that the access device with the receiver waits for access to the data memory or even one already in progress with the data memory when it receives the sender's signal.

By the method according to the invention is particularly the

Access from access devices to a data storage via a wireless communication link according to the RFID standard coordinated in an advantageous manner. Due to the low bandwidth of the productive data connection, you are otherwise dependent on the listen-before-talk procedure. However, this method only exists in the UHF RFID range. In the HF range (HF radio frequency), there are no radio signals but only a magnetic field which is "influenced" by the tag The use of the method according to the invention is therefore particularly advantageous in connection with HF RFID data carriers So far there is no coordination method for this band, since the transmission signal for generating the productive data connection is only one

Magnetic field is. According to an HF-RFID standard

communicate a disk and an access device at a transmission frequency of 13.56 MHz. In connection with the

However, the invention is generally understood to be a radio frequency that is less than 100 MHz. For the HF-RFID standard no CSMA procedure is standardized. In addition, the transmitters of the RF-RFID access devices have relatively short ranges and therefore, in some cases, two access devices located on opposite sides of a data carrier can not always reliably detect each other via a listen-before-talk procedure.

The exchange of the communication data is preferably carried out via a communication connection according to a technical standard, which is different from a standard, according to which by the access devices in each case to the

Data store is accessed. Preferably, the access devices communicate with the coordinating device, that is to say optionally with one another, eg wirelessly via a WLAN (wireless local area network) or Bluetooth or wired via a LAN. A wired industrial network (DP - Distributed I / O, PROFINET, PNIO) is another example of a possible one

Communication technology of access devices with the

Coordination device. Preferably, a technology for forming a so-called ad hoc network is used.

According to one embodiment of the method according to the invention, at least part of the memory data is transmitted by at least one of the access devices from the latter to the data memory and stored there. In other words, in this embodiment, as the access device, a writing device is used for storing data in the data memory. By the method according to the invention can always be this

ensure that none of the other access devices receive inconsistent data. Because of the inventive method is an effective mechanism for

Coordination of parallel read or write access given. As a result, an interactive use of the

For example, during a disk

Production process allows.

According to an advantageous embodiment of the method according to the invention by the communication data

Access tokens exchanged, by which one

Access device in which the access token is at a particular time, the permission to access the data memory is displayed. The

Coordination facility in this case includes the

Access token itself and each release device on each of the access devices, which only releases the access to the disk, even if the access token is in the corresponding access device. By passing an access token, it is not necessary to use one of the

Access devices as a central coordinator too

determine. The invention also includes in another aspect

Access device for the immediate wireless exchange of memory data with a data memory. For this purpose, the

Access device to a data transmission device, which is designed for directly wireless exchange of memory data between the access device and the data memory. Such a data transmission device may be, for example, an HF antenna and an associated control circuit.

The access device according to the invention further comprises a detection device for detecting a presence of another access device in an environment of the access device. With the detection device, it is possible for the additional device to access the data memory

Check if there is another access device nearby that might also want to access the data store. In addition to the data transmission device has the

Access device according to the invention yet another

Communication device, by means of which a

Communication connection via a communication network, so for example a WLAN or LAN, can be established. In other words, the communication device forms an interface to this network.

Finally, the access device according to the invention has a control device, which is designed to, at

Detecting another access device through the

Recognition device via the communication device to exchange a message with a coordination device and to determine depending on the exchanged message, a time at which the memory data via the data transmission device with the data memory

be replaced. The control device can

be formed for example by a controller of the access device. By means of the access device according to the invention, access to the data memory can be reliably coordinated with the accesses of further access devices in an advantageous manner. This advantage comes especially when the

Data transmission device is designed for exchanging data for a mobile RFID data memory. For this purpose, the data transmission device then forms in particular an RF radio interface.

In order not to be dependent on an external server structure, which controls the exchange of messages, is in the access device advantageously the

Communication device designed to the

Establish communication link (e.g., via Bluetooth, LAN or WLAN) to the other access device. At this

Further development of the access device according to the invention, the control device is then designed to exchange the message with the other access device.

Thus, several access devices with each other

independently, i. without help from an external

Coordinating body, which can vote, rejects the

Control device advantageously even one

Coordinating facility on which to set a

Access order is designed for multiple forthcoming accesses to the data store by multiple access devices.

The invention will be described below with reference to a

Embodiment explained in more detail. This shows:

1 shows a schematic representation of three writing

Readers, each representing an embodiment of the access device according to the invention, and

2 shows a flow chart of an access method according to an embodiment of the method according to the invention, according to which one of the write methods Reading devices of FIG 1 accesses an RFID data memory.

The example illustrates a preferred embodiment of the invention

Invention.

In the example on which FIG. 1 is based, in a production plant for individual process items, e.g. For

Car, it can be determined which production step a single process material has already gone through. Each of the process items is treated differently by individual production stations, e.g. depending on a customer request. For every process material, therefore, the

corresponding production data stored. After a process material has passed through a production station, then further production data are stored for this production step, which concludes the successful completion of the production process

Document production step. The scope of the process data can be two to four kilobytes at the end of the production process.

In the production plant, the production data for a process material is carried along with it. This is on the

Prozessgut a mobile RFID data storage 10, or MDS attached. The RFID data memory 10 is a mobile RF RFID data memory in which data is stored via a (defined by an RFID standard)

Productive data connection can be stored by forming a modulated alternating magnetic field at a frequency of 13.56 MHz. For reading a generated by the RFID data carrier modulation of the magnetic

Alternate field evaluated by the receiver.

The process material is conveyed via a (not shown) conveyor belt from a (not shown) paint shop as a first manufacturing stations to a (not shown) assembly line as a second manufacturing station

transported, where used in the process material more parts should be selected in terms of their color depending on the color that has been previously applied by the painting on the process material.

At the paint shop there is a read-write device 12, which exchanges storage data with the RFID data memory 10 via a productive data connection 14. By the read-write device 12 production data are stored in the RFID data storage 10, which is indicated by which color has just been applied to the process material to which the RFID data storage 10 is attached.

At the placement system is another read-write device 16. The read-write device 16 is a

Build productive data connection 18 to the RFID disk 10 to read from this the production data regarding the color of the process material. For this purpose, the read / write device 16 must ensure that this data has already been completely written by the read / write device 12. For this purpose, the read-write device 16 waits for it to be replaced by the

Write-reader 12 receives corresponding coordination data via a network data connection 20 which has been set up on the basis of a WLAN standard. The

Network data connection 20 provides a

Synchronization connection is in the coordination data is an access token, which is a record with information about the RFID data storage 10 here. While the process material is located between the paint shop and the placement system, a person approaches with a test device 22. The test device 22 also represents a read / write device for the RFID data carrier 10. The person wants to use the test device 22 in the RFID Read data storage 10 stored production data to verify their accuracy. To read the production data, the test device 22 must establish a productive data connection 24 towards the RFID data carrier 10. This process is explained in more detail below with reference to FIG 2. A control device of the tester 22 is initially in a waiting loop in which they

repeatedly performs a step Sl. Through the step Sl, the control device checks whether an operator of the tester 22 wants to read memory data from an RFID data carrier or just want to ascribe to this. If the test device 22 receives a corresponding input from the operator, it terminates the waiting loop and checks in a step S2, first by means of a discovery service, whether there are further read / write devices (SLG) in its vicinity. The discovery service can be a technology known per se, as is known, for example, in connection with the WLAN standard and mobile devices. The tester 22 recognizes in the present example that the two read-write devices 12 and 16 are in its transmission range.

The tester 22 then builds in each case in a step S3 on an ad hoc network connection 26, 28 to each of the read-write devices 12, 16. Via the ad hoc network connections 26, 28 sends the

Tester 22 in a step S4 coordination data by which the tester 22 to the read-write devices 12, 16 indicates that the tester 22 priority in accessing the RFID data storage 10 has. Once the writing / reading device 12 has finished writing the production data,

deactivates an antenna with which the writing-reading device 12, the alternating magnetic field for the

Productive data connection 14 has maintained. Thereafter, it passes the access token to the tester 22 via the ad hoc network connection 28.

After receiving the access token, the tester 22 in turn builds the productive data link 24 in one step S5 by means of its own RF-RFID antenna and reads the desired storage data from the RFID disk 10 via the productive data connection 24. Afterwards it in turn deactivates its antenna, whereby the magnetic

Alternate field for the productive data connection 24 is reduced. Finally, it passes the access token to the read / write device 16 via the ad hoc network connection 26. The tester 22 then restarts to execute the wait loop. In the event that the tester 22 no

Read-write device detected by the discovery service, it changes immediately from step S2 to step S5.

After receiving the access token, the read / write device 16 can now also build up the productive data connection 18 to the RFID data memory 10 and read out the color data.

The example shows that multiple devices can access a wirelessly writable volume, allowing for spontaneous interaction, such as for maintenance or auditing purposes. The

Interaction is about a parallel

Coordinates communication interface that is established between the participating read-write devices. It was also shown how to detect the presence of another network device. Will one or more others

Network devices detected, it may initially be accessed on the disk. Instead, one becomes

Communication connection established between the participating read-write devices. Once the communication link is established, it can be replaced by exchanging an access token or by designating one of the read-write devices

Coordinator (as it is known, for example, from the standard ZigBee) the flow of communication between the read-write devices are controlled. In the event that a coordinator has been determined, the access request of a read-write device is first communicated to it. To ensure that the read-write devices do not interfere with each other, a unique order of access is then determined. It can different methods are used. Examples are "first-come-first-serve" methods, or any conceivable priority-based method, and the coordinator could also sequentially pass access tokens to read / write devices, and then a read / write device completes its access to the RFID media the

Informs the coordinator about the synchronization connection, which in turn decides according to the selected algorithm on the further access order. This procedure ensures that each read-write device writes the data in a consistent manner to the disk or reads it from the disk. The approach described is universal and thus also applicable in the HF range. He sets no coordination possibilities in the

Productive data communication (with the RFID data carrier) itself ahead.

Claims

claims

A method for directly wirelessly transferring storage data between a data storage device (10) on the one hand and a plurality of access devices (12, 16, 22) on the other hand, wherein in the event that the access devices (12, 16, 22) simultaneously in an environment of the data memory (10), the access devices (12, 16, 22) are communication data with one different from the data memory (10)

Coordinating device (12, 16, 22) exchange and thereby a respective access behavior to the

Data memory (10) vote with each other.

2. The method of claim 1, wherein by the

Coordinating means (12, 16, 22) an order is determined in which the access devices (12, 16, 22) successively access the data memory (10).

3. The method according to claim 1 or 2, wherein the

Access devices (12, 16, 22) the communication data

exchange with each other.

4. The method according to any one of the preceding claims, wherein the access devices (12, 16, 22) on the data memory (10) via a wireless communication link (14, 18, 24) after the RFID and in particular after the HF RFID Standard access.

5. The method according to any one of the preceding claims, wherein the access devices (12, 16, 22) the

Communication data with the coordination device (12, 16, 22) via a communication link (20, 26, 28) according to a technical standard, in particular LAN or WLAN or Bluetooth exchange, which of a technical

Standard is different, according to which by the

Access devices (12, 16, 22) in each case the data memory (10) is accessed.

6. The method according to any one of the preceding claims, wherein at least a part of the memory data by

at least one of the access devices (12) thereof

Data memory (10) out and transmitted there from the

Data memory (10) are stored.

7. The method according to any one of the preceding claims, wherein on the basis of the communication data

Access Token is replaced, by which the access device (12, 16, 22), in which the

Access token at any given time, the permission to access the data store (10) is displayed.

8. access device (22) for immediate wireless

Exchanging memory data with a data memory (10), comprising

- A data transmission device for immediate

wireless exchanging (S5) the storage data between the access device (22) and the data storage (10),

a recognition device for recognizing (S2) a

Presence of another access device (12, 16) in an environment of the access device (22),

a communication device for establishing (S3) a communication connection via a communication network (20, 26, 28),

- A control device, which is designed, upon detection of the further access device (12, 16) by the

Recognition device via the communication device to exchange a message with a coordinating device and to determine depending on the exchanged message a time for exchanging (S5) of the memory data via the data transmission device.

9. Access device according to claim 8, wherein the

Data transmission device for exchanging data with a mobile RFID data memory (10) is designed, wherein the data transmission device for this purpose in particular has an RF radio interface.

10. Access device according to claim 8 or 9, wherein the communication device is adapted to the

Communication link (26, 28) to the other

Access device (12, 16) build, and the control device is adapted to the message with the other

Access device (12, 16) exchange.

11. Access device according to one of claims 8 to 10, wherein the control means comprises a coordinating means, which is designed to specify an access order for several upcoming accesses to a data memory (10) by a plurality of access devices (12, 16, 22).