(51) Int Cl.: G05B 19/05 ( )

Transcription

1 (19) (11) EP B1 (12) EUROPEAN PATENT SPECIFICATION (4) Date of publication and mention of the grant of the patent: Bulletin 07/2 (1) Int Cl.: G0B 19/0 (06.01) (21) Application number: (22) Date of filing: (4) Programmable controller with RF wireless interface Programmierbare Steuerung mit drahtloser Radiofrequenz-Schnittstelle Commande programmable avec une interface RF sans fil (84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR IE IT LI LU MC NL PT SE SK TR () Priority: US (43) Date of publication of application: Bulletin 03/11 (60) Divisional application: / (73) Proprietor: Siemens Energy & Automation, Inc. Alpharetta, GA (US) (72) Inventor: Licht, Harold Jay Johnson City, TN (US) (74) Representative: Humphrey-Evans, Edward John et al c/o Siemens AG P.O. Box München (DE) (6) References cited: EP-A EP-A DE-A DE-A DE-A DE-A US-A US-A ZINGER D S ET AL: "Incorporating radio frequency communication into a computer integrated manufacturing test facility" INDUSTRY APPLICATIONS CONFERENCE, 199. THIRTIETH IAS ANNUAL MEETING, IAS 9., CONFERENCE RECORD OF THE 199 IEEE ORLANDO, FL, USA 8-12 OCT. 199, NEW YORK, NY, USA,IEEE, US, 8 October 199 ( ), pages , XP ISBN: EP B1 Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). Printed by Jouve, 7001 PARIS (FR)

2 1 EP B1 2 Description Field of the Invention [0001] The present invention generally concerns communication modules for programmable controllers that are used to control industrial assembly applications. In particular, the invention concerns an interface module employing radio frequency identification (RFID) technology to facilitate wireless communication between the programmable controller and other devices both within the controller and external to the controller. Background of the Invention [0002] In the field of programmable logic controllers (PLCs), communication between a PLC and other devices, such as external devices, is typically accomplished by electro-mechanical means through a backplane or fixed connector on the PLC. For example, PLCs have traditionally been programmed by transmission of information through a cable that is attached to a program port on the body of the PLC. Such attachment can be cumbersome, unreliable, and relatively costly. [0003] The prior art has in some instances used modems to control, monitor and test/debug PLCs from remote locations. The modem devices are also typically connected to a PLC through the backplane or a fixed connector on the PLC. [0004] Radio frequency identification ("RFID") technology has been used in various fields as a means of identifying articles. RFID technology has been used for identifying parcels, luggage, and other materials. An RFID system generally consists of an antenna; a transmitter/ receiver and; a transponder (called an RF chip set or tag) that is electronically programmed with unique identification information. The antenna emits radio signals that activate the RFID tag and write and read data to and from the RFID tag. For example, an antenna mounted on a toll booth may monitor various aspects of traffic by sending RF signals to an RF tag mounted within each passing automobile. [000] RFID tags are available in many different sizes/ shapes and are generally characterized as either passive or active. Active tags are internally powered and are typically readable and writable. Active tags have relatively large amounts of memory. Passive tags operate without an internal power source. Passive tags obtain operating power generated from the reader. Passive tags are typically read-only. RFID systems provide for wireless communication through many materials. RFID tags can also be read at high speeds. [0006] In one example, RFID technology is implemented through an integrated chip set with a PROM for programming an identification (ID) code. The RFID chip set is placed on an article and the ID code may be transmitted to, and stored in, the RFID chip. The ID code is then scanned by a transmitter/receiver. The RFID chip is passive and employs the power of the transmitting signal to energize the RFID coil and to return a signal including the ID code or a signal affirming the ID code. [0007] The use of RFID technology has been limited essentially to identification applications and has not been implemented as a means for transferring data in machines, such as PLCs. It would also be advantageous to have the wireless RFID interface as an integral part of the PLC eliminating the need for communication through the backplane and cables. [0008] US 01/ A1 describes an automation system wherein data from at least one sensor is transmitted by way of a radio transmission device to a radio receiver associated with a control device. EP-A describes a lubrication system in which various lubricant dispensers may communicate wirelessly with a central station used to monitor the dispensers. Only conventional radio communications are envisaged in these prior documents, however. Summary of the Invention [0009] The present invention provides a programmable logic controller (PLC) comprising a housing containing at least one circuit board including circuitry for performing controller functions. The controller includes a radio frequency identification (RFID) transponder and a coil associated therewith for implementing wireless communication both within the controller, and between the controller and remotely-located modules. Two or more circuit boards within the controller housing each include a said RFID transponder and a said coil; and each said RFID transponder is coupled to the circuitry of the circuit board on which it is mounted. [00] In certain embodiments, the RFID coil of the RFID transponder is etched into the circuit board on which it is mounted. [0011] In certain embodiments, a mount is provided for mounting the RFID transponder to the circuit board. The mount may be selected from the group comprising: a standard surface mount, a through-hole mounting device, and a chip-on-board mounting device. [0012] In certain embodiments, the circuitry of one of the circuit boards comprises an integrated circuit and the associated RFID transponder forms part of the schematic of the integrated circuit. [0013] In certain embodiments, the controller comprises a processor that receives radio frequency signals carrying programming instructions for execution by the processor. [0014] In certain embodiments, the RFID transponder is shielded to prevent radio frequency communication with the RFID transponder from interfering with the operation of the controller. [001] In certain embodiments, the RFID transponder operates in a frequency range outside of frequencies at which the controller operates to prevent radio frequency communication with the RFID transponder from interfer- 2

3 3 EP B1 4 ing with the operation of the controller. [0016] In certain embodiments, the wireless communication carries signals representing wireless testing instructions. The wireless communication may carry testing signals during manufacturing process of the controller during a manufacturing process. [0017] ln certain embodiments, the programmable logic controller further comprises a network interface for interfacing the programmable logic controller to a network. The network interface may communicate information received from one of said RFID transponders over said network. In certain embodiments, the network interface interfaces to the Internet. [0018] The present invention also provides a method for providing wireless communication with a programmable logic controller, the programmable logic controller comprising a housing containing least one circuit board including circuitry for performing controller functions. The method comprises providing, on each of two or more circuit boards within the housing, a radio frequency identification (RFID) transponder and a coil associated therewith adapted to implement wireless communication both within the programmable logic controller, and between the programmable controller and remotely-located modules, whereby two or more circuit boards within the housing each include a said RFID transponder and a said coil associated therewith; and whereby each said RFID transponder is coupled to the circuitry of the circuit board on which it is mounted. [0019] The wireless communication may carry programming instructions for the controller; alternatively, the wireless communication may carry error notification signals indicating when there is a problem in the controller. Brief Description of the Drawings [00] Fig. 1 shows the general construction of a PLC that may embody the wireless communications interface in accordance with the invention. Fig. 2 shows a circuit board of a PLC incorporating a wireless communications interface in accordance with the invention. Fig. 3 shows the circuit board of Fig. 2 in various uses employing the wireless communication feature embodied by the invention. Detailed Description of the Invention [0021] Fig. 1 shows the PLC of the invention incorporating the wireless communications interface. The PLC includes a housing 2 that contains an input module 4, a central processing unit 7 and an output module 9. The PLC includes one or more circuit boards 11 (See Fig. 2). [0022] Further, a network interface 12 may be provided for connecting the PLC to a network, such as an on-line network as a Local Area Network or the Internet. Information received or stored on the chip, therefore, may be communicated over the network. One skilled in the art of network communications, particularly TCP/IP, will understand readily how such communications are to be implemented. [0023] As shown in Fig. 2, the wireless interface 1 is to be mounted on a circuit board 11 contained within the housing 2 of the PLC. The wireless interface employs a standard RFID chip set, such as Texas Instruments Tag it. ln a preferred embodiment, the RFID is a passive receiver/transmitter. According to the invention, the RFID chip set 1 is mounted to an integrated circuit on the circuit board 11 of the programmable controller. This will allow separate integrated circuits to be in communication via wireless connection. The RFID chip set 1 may contact the active elements of the integrated circuit by standard surface mount, a through hole mount, or a chip-onboard mount. The RFID chip set 1 may also be a part of the schematic of the integrated circuit. [0024] In addition, integrated circuits equipped with the wireless interface on a board can facilitate communication between the PLC and other devices, such as any of the components in the computer. Thus, the circuit board may communicate wirelessly using radio frequency with other circuit boards similarly equipped with the RFID chip set, without requiring communication through connectors 19. [002] As shown in Fig. 3, with such a modified device, a PLC equipped with the RFID chip set may communicate wirelessly with remotely-located modules such as a card and rack system 22; a programming device, such as a hand held programmer 27; or a computer 31. The concept may also be extended to process automation in general and may be further applicable to other industrial applications. For example, it is contemplated that the invention may be applicable to automotive diagnostics. In this case, the invention may communicate with different areas of a car or may communicate between different devices in an automobile. [0026] As is also shown in Fig. 3, the invention may be employed to perform wireless testing from an operator s terminal 3 during the manufacturing process or to communicate wireless error code messages to a remote computer 31 during operation. This enables quick troubleshooting. In a PLC with numerous modules, the technician is able to locate the problematic module quickly, particularly in a large system where a proliferation of modules may make troubleshooting difficult. [0027] Traditionally, a PLC (such as the S7-0 or S7-0, Siemens Energy & Automation, Johnson City, TN) is programmed using a cable. The dependence upon cables is eliminated so that a programmer in the field need not worry about hardware compatibility issues. PLCs may be programmed via the wireless interface of the invention. [0028] Any possibility of interference with the operation of the PLC caused by the radio frequency nature of the communication by the RFID chip set 1 may be alleviated 3

4 EP B1 6 through suitable shielding. Another way to address this problem is to limit the frequency range of the RFID chip set outside of the normal PLC operating frequencies. Another approach limits the proximity to one another of the RFID s 1 on the modules. [0029] The use of the wireless interface may also create problems in compliance with FCC and CE (EU) regulations. This problem may be overcome by limiting the range of the interface. Limiting the range may be accomplished by use of shielding or reducing the power output. [00] In addition, the invention may be connected to a micro-chip or circuitry. The RFID chip set 1 may be etched into the circuit board rather than a stick on label as is the current situation. The RFID chip set 1 is relatively inexpensive and may alleviate connection defects that commonly occur with plug-type connectors in the backplane of the PLC. The RFID should provide a more reliable connection. [0031] Those skilled in the art will realize that numerous modifications and variations of the present invention are possible in light of the above teachings and embodiments. Therefore, the invention should not be construed as limited to any of the foregoing embodiments, but instead should be viewed within the scope of the appended claims. 1 2 a chip-on-board mounting device.. The programmable logic controller according to any preceding claim, wherein the circuitry of one of the circuit boards comprises an integrated circuit and the associated RFID transponder forms part of the schematic of the integrated circuit. 6. The programmable logic controller according to any one of claims 1-, wherein the controller comprises a processor that receives radio frequency signals carrying programming instructions for execution by the processor. 7. The programmable logic controller according to any of claims 1-6, wherein the RFID transponder is shielded to prevent radio frequency communication with the RFID transponder from interfering with the operation of the controller. 8. The programmable logic controller according to any one of claims 1-7, wherein the RFID transponder operates in a frequency range outside of frequencies at which the controller operates to prevent radio frequency communication with the RFI D transponder from interfering with the operation of the controller. Claims 1. A programmable logic controller (PLC) comprising a housing (2) containing at least one circuit board (11) including circuitry for performing controller functions, the controller being characterised by a radio frequency identification (RFID) transponder (1) and a coil associated therewith for implementing wireless communication both within the controller, and between the controller and remotely-located modules; whereby two or more circuit boards within the controller housing each include a said RFID transponder (1) and a said coil; and whereby each said RFID transponder (1) is coupled to the circuitry of the circuit board on which it is mounted. 2. The programmable logic controller according to claim 1, wherein the RFID coil of an RFID transponder is etched into the circuit board on which it is mounted. 3. The programmable logic controller according to claim 1 or claim 2, further comprising a mount for mounting the RFID transponder to the circuit board. 4. The programmable logic controller according to claim 3, wherein the mount is selected from the group comprising a standard surface mount, a through-hole mounting device, and The programmable logic controller according to any one of claims 1-8, wherein the wireless communication carries signals representing wireless testing instructions.. The programmable controller according to any preceding claim, wherein the wireless communication carries testing signals during manufacturing process of the controller during a manufacturing process. 11. The programmable logic controller according to any one of claims 1-, further comprising a network interface for interfacing the programmable logic controller to a network. 12. The programmable logic controller according to claim 11, wherein said network interface communicates information received from one of said RFID transponders over said network. 13. The programmable logic controller according to claim 12, wherein said network interface interfaces to the Internet. 14. A method for providing wireless communication with a programmable logic controller, the programmable logic controller comprising a housing (2) containing at least one circuit board (11) that comprises circuitry adapted to perform controller functions, the method being characterised in that it comprises: 4

5 7 EP B1 8 on each of two or more circuit boards within the housing, providing a radio frequency identification (RFID) transponder (1) and a coil associated therewith adapted to implement wireless communication both within the programmable logic controller, and between the programmable logic controller and remotely-located modules, whereby two or more circuit boards within the controller housing each include a said RFID transponder and said coil; and whereby each said RFID transponder is coupled to the circuitry of the circuit board on which it is mounted.. Speicherprogrammierbare Steuerung gemäß einem der vorhergehenden Ansprüche, wobei die Schaltung einer der Leiterplatten eine integrierte Schaltung umfasst und der zugehörige RFID-Transponder einen Teil des Schaltbilds der integrierten Schaltung bildet. 6. Speicherprogrammierbare Steuerung (SPS) gemäß einem der Ansprüche 1-, wobei die Steuerung einen Prozessor umfasst, der Radiofrequenzsignale empfängt, welche Programmieranweisungen für die Ausführung durch den Prozessor enthalten. 1. The method of claim 14, wherein the wireless communication carries programming instructions for the controller. 16. The method of claim 1, wherein the wireless communication carries error notification signals indicating when there is a problem in the controller. Patentansprüche 1. Speicherprogrammierbare Steuerung (SPS), die ein Gehäuse (2) umfasst, welches mindestens eine Leiterplatte (11) mit einer Schaltung zum Ausführen von Steuerungsfunktionen enthält, wobei die Steuerung durch einen Radiofrequenz-Identifikations-Transponder (RFID-Transponder) (1) und eine damit verknüpfte Spule gekennzeichnet ist, um drahtlose Kommunikation sowohl innerhalb der Steuerung als auch zwischen der Steuerung und entfernt befindlichen Modulen zu implementieren, wobei zwei oder mehr Leiterplatten innerhalb des Steuerungsgehäuses jeweils einen besagten RFID-Transponder (1) und eine besagte Spule enthalten und wobei jeder RFID-Transponder (1) mit der Schaltung der Leiterplatte, auf der er montiert ist, gekoppelt ist. 2. Speicherprogrammierbare Steuerung (SPS) gemäß Anspruch 1, wobei die RFID-Spule eines RFID- Transponders in die Leiterplatte, auf die er montiert ist, geätzt ist. 3. Speicherprogrammierbare Steuerung (SPS) gemäß Anspruch 1 oder Anspruch 2, die ferner ein Bauelement für die Befestigung des RFID-Transponders an der Leiterplatte umfasst. 4. Speicherprogrammierbare Steuerung (SPS) gemäß Anspruch 3, bei der das Bauelement aus folgender Gruppe ausgewählt ist: Speicherprogrammierbare Steuerung (SPS) gemäß einem der Ansprüche 1-6, wobei der RFID-Transponder abgeschirmt ist, um zu verhindern, dass Radiofrequenzkommunikation mit dem RFID-Transponder den Betrieb der Steuerung stört. 8. Speicherprogrammierbare Steuerung (SPS) gemäß einem der Ansprüche 1-7, wobei der RFID-Transponder in einem Frequenzbereich außerhalb der Frequenzen arbeitet, mit denen die Steuerung arbeitet, um zu verhindern, dass Radiofrequenzkommunikation mit dem RFID-Transponder den Betrieb der Steuerung stört. 9. Speicherprogrammierbare Steuerung (SPS) gemäß einem der Ansprüche 1-8, wobei die drahtlose Kommunikation Signale überträgt, die drahtlose Testanweisungen darstellen.. Speicherprogrammierbare Steuerung (SPS) gemäß einem der vorhergehenden Ansprüche, wobei die drahtlose Kommunikation im Verlauf des Herstellungsprozesses der Steuerung Testsignale überträgt. 11. Speicherprogrammierbare Steuerung (SPS) gemäß einem der Ansprüche 1-, die ferner eine Netzwerkschnittstelle umfasst, um die speicherprogrammierbare Steuerung (SPS) mit einem Netzwerk zu verbinden. 12. Speicherprogrammierbare Steuerung (SPS) gemäß Anspruch 11, wobei die Netzwerkschnittstelle Informationen überträgt, die von einem der besagten RFID-Transponder über das besagte Netzwerk empfangen wurden. 13. Speicherprogrammierbare Steuerung gemäß Anspruch 12, wobei die besagte Netzwerkschnittstelle eine Verbindung zum Internet bildet. Standardmäßiges aufgelötetes Bauelement; durchkontaktiertes Bauelement und Chip-on-Board-Bauelement 14. Verfahren zum Bereitstellen von drahtloser Kommunikation mit einer speicherprogrammierbaren Steuerung (SPS), wobei die speicherprogrammierbare Steuerung (SPS) ein Gehäuse (2) umfasst, das min-

6 9 EP B1 destens eine Leiterplatte (11) enthält, welche Schaltungen umfasst, die dazu angepasst sind, Steuerungsfunktionen auszuführen, wobei das Verfahren dadurch gekennzeichnet ist, dass es Folgendes umfasst: auf jeder der zwei oder mehr Leiterplatten innerhalb des Gehäuses Bereitstellen eines Radiofrequenz-Identifikations-Transponders (RFID- Transponders) (1) und einer Spule, die damit verknüpft ist, angepasst, um drahtlose Kommunikation sowohl innerhalb der speicherprogrammierbaren Steuerung als auch zwischen der speicherprogrammierbaren Steuerung und entfernt befindlichen Modulen zu implementieren, wobei zwei oder mehr Leiterplatten innerhalb des Steuerungsgehäuses jeweils einen besagten RFID-Transponder und eine besagte Spule enthalten, und wobei jeder besagte RFID- Transponder mit der Schaltung der Leiterplatte gekoppelt ist, auf der er befestigt ist. 1. Verfahren gemäß Anspruch 14, wobei die drahtlose Kommunikation Programmieranweisungen für die Steuerung überträgt. 16. Verfahren gemäß Anspruch 1, wobei die drahtlose Kommunikation Fehlerbenachrichtigungssignale überträgt, die anzeigen, wenn es ein Problem in der Steuerung gibt. Revendications 1. Contrôleur logique programmable (PLC) comprenant un logement (2) contenant au moins une carte de circuits imprimés (11) intégrant des circuits adaptés pour exécuter des fonctions du contrôleur, le contrôleur étant caractérisé par un transpondeur d identification par radiofréquence (RFID) (1) et une bobine associée à celui-ci, adaptés pour établir une communication sans fil à la fois à l intérieur du contrôleur et entre le contrôleur et des modules à distance; de sorte que deux ou plusieurs cartes de circuits imprimés à l intérieur du logement de contrôleur comprennent chacune un transpondeur RFID (1) et une bobine précités ; et de sorte que chaque transpondeur RFID (1) précité est couplé aux circuits de la carte de circuits imprimés sur laquelle il est monté. 2. Contrôleur logique programmable selon la revendication 1, dans lequel la bobine RFID d un transpondeur RFID est formée par gravure chimique dans la carte de circuits imprimés sur laquelle elle est montée Contrôleur logique programmable selon la revendication 1 ou la revendication 2, comprenant en outre une monture permettant le montage du transpondeur RFID sur la carte de circuits imprimés. 4. Contrôleur logique programmable selon la revendication 3, dans lequel la monture est choisie dans le groupe comprenant : une monture en surface classique, un dispositif de montage à trou traversant, et un dispositif de montage à puce sur carte.. Contrôleur logique programmable selon une quelconque revendication précédente, dans lequel les circuits de l une des cartes de circuits imprimés comprennent un circuit intégré et le transpondeur RFID associé fait partie du schéma du circuit intégré. 6. Contrôleur logique programmable selon l une quelconque des revendications 1 à, dans lequel le contrôleur comprend un processeur qui reçoit des signaux en radiofréquence transportant des instructions de programmation devant être exécutées par le processeur. 7. Contrôleur logique programmable selon l une quelconque des revendications 1 à 6, dans lequel le transpondeur RFID est antiparasité de façon à empêcher une communication par radiofréquence avec le transpondeur RFID d interférer sur le fonctionnement du contrôleur. 8. Contrôleur logique programmable selon l une quelconque des revendications 1 à 7, dans lequel le transpondeur RFID fonctionne dans une plage de fréquences en dehors des fréquences auxquelles fonctionne le contrôleur de façon à empêcher une communication par radiofréquence avec le transpondeur RFID d interférer sur le fonctionnement du contrôleur. 9. Contrôleur logique programmable selon l une quelconque des revendications 1 à 8, dans lequel la communication sans fil transporte des signaux représentant des instructions de test sans fil.. Contrôleur logique programmable selon une quelconque revendication précédente, dans lequel la communication sans fil transporte des signaux de test pendant le processus de fabrication du contrôleur. 11. Contrôleur logique programmable selon l une quelconque des revendications 1 à, comprenant en outre une interface de réseau destinée à assurer une interface entre le contrôleur logique programmable et un réseau. 6

7 11 EP B Contrôleur logique programmable selon la revendication 11, dans lequel ladite interface de réseau communique des informations reçues d un desdits transpondeurs RFID sur ledit réseau. 13. Contrôleur logique programmable selon la revendication 12, dans lequel ladite interface de réseau assure une interface avec Internet. 14. Procédé permettant d établir une communication sans fil avec un contrôleur logique programmable, le contrôleur logique programmable comprenant un logement (2) contenant au moins une carte de circuits imprimés (11) qui intègre des circuits adaptés pour exécuter des fonctions du contrôleur, le procédé étant caractérisé en ce qu il comprend les étapes consistant à : 1 installer, sur chacune des deux ou plusieurs cartes de circuits imprimés à l intérieur du logement, un transpondeur d identification par radiofréquence (RFID) (1) et une bobine associée à celui-ci, adaptés pour établir une communication sans fil à la fois à l intérieur du contrôleur logique programmable et entre le contrôleur logique programmable et des modules à distance, de sorte que deux ou plusieurs cartes de circuits imprimés à l intérieur du logement de contrôleur comprennent chacune un transpondeur RFID et une bobine précités ; et de sorte que chaque transpondeur RFID précité est couplé aux circuits de la carte de circuits imprimés sur laquelle il est monté Procédé selon la revendication 14, dans lequel la communication sans fil transporte des instructions de programmation destinées au contrôleur Procédé selon la revendication 1, dans lequel la communication sans fil transporte des signaux de notification d erreur indiquant un problème dans le contrôleur

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11 EP B1 REFERENCES CITED IN THE DESCRIPTION This list of references cited by the applicant is for the reader s convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard. Patent documents cited in the description US A1 [0008] EP A [0008] 11