(19)
(11)EP 2 399 400 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
26.08.2015 Bulletin 2015/35

(21)Application number: 10708021.0

(22)Date of filing:  19.02.2010
(51)Int. Cl.: 
H04Q 1/14  (2006.01)
(86)International application number:
PCT/US2010/024717
(87)International publication number:
WO 2010/096643 (26.08.2010 Gazette  2010/34)

(54)

CROSS CONNECT PATCH GUIDANCE SYSTEM

CROSSCONNECT-PATCH-FÜHRUNGSSYSTEM

SYSTÈME DE GUIDAGE DE RACCORDEMENT DE RÉPARTITEUR


(84)Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK SM TR

(30)Priority: 19.02.2009 US 153876 P
18.02.2010 US 708223

(43)Date of publication of application:
28.12.2011 Bulletin 2011/52

(73)Proprietor: Panduit Corp.
Tinley Park, IL 60487 (US)

(72)Inventors:
  • CAVENEY, Jack, E.
    North Palm Beach FL 33408 (US)
  • NORDIN, Ronald, A.
    Naperville IL 60540 (US)

(74)Representative: Roberts, Gwilym Vaughan et al
Kilburn & Strode LLP 20 Red Lion Street
London WC1R 4PJ
London WC1R 4PJ (GB)


(56)References cited: : 
EP-A2- 1 788 825
US-A1- 2008 122 579
US-A1- 2007 032 124
US-A1- 2008 253 556
  
      
    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).


    Description

    Technical Field



    [0001] The present application relates to network documentation and revision systems, and more particularly to a system for implementing intelligent cross-connect patching and guidance.

    Background



    [0002] Communications networks are growing in number and complexity, and are continually being interconnected to satisfy customers' needs. Patch panels are used in communications networks as intermediate elements between endpoint devices (such as computers and telephones) and upstream devices such as network switches. In a LAN, for example, the patch panel connects the network's computers to switches or routers that enable the LAN to connect to the Internet or another wide area network (WAN). Connections are made with patch cords. The patch panel allows connections to be arranged and rearranged by plugging and unplugging the patch cords.

    [0003] When physical connections between endpoint devices and network switches are added, moved, or removed, patch panels are the points at which technicians complete the required installations or removals of patch cords within patch fields. Patch panels offer the convenience of allowing technicians to quickly change the paths of selected signals.

    [0004] Patch panels are typically deployed in one of two configurations: cross-connect, and interconnect. In a cross-connect configuration, two patch panels are disposed between end user devices and a network switch, and in an interconnect configuration, only one patch panel is disposed between the end-user devices and a network switch.

    [0005] Human error associated with the implementation and maintenance of physical cable connections between pieces of network communication equipment can result in significant negative impact to a network. Such negative impact can be avoided through improved control and verification of network cable installation and removal work orders implemented by network technicians. It is also desirable to provide an easy-to-understand indication system for technicians to follow when performing moves, adds, and changes (MAC's) to patch cords and connections in a patch field, including visual guidance of steps to follow during a MAC procedure.

    [0006] EP 1 788 825 A2 discloses a network documentation and revision system including first and second devices connected by a patch cord. The first device has provisioning and signal ports with corresponding contact assemblies. The second device has a switch port without a contact assembly. The patch cord has signal and control wires, a first connector that connects the signal wires into a signal port and the control wire to a corresponding contact assembly, and a second connector that connects the signal wires to the switch port and terminates the control wire. The second connector contains an indicator controlled by control circuitry, detection circuitry detecting whether the second connector is plugged into the second device, and ID circuitry providing an ID number through the first connector. Installation or removal of the patch cord is guided by indicators on the patch cord and first device without retrofit contacts being added to the second device.

    [0007] A similar system is disclosed in US 2008/0253556, Commscope, published on 16 October 2008.

    Summary



    [0008] According to the present invention, there is provided a system for guiding patch cord insertions and removals, according to claim 1.

    [0009] In some embodiments of the present invention, systems for guiding patch cord installations and removals in a cross-connect deployment are provided. Patch cords are provided with circuitry and lights, such as light-emitting diodes (LED's), within patch cord plugs, to allow for the provision of easily followed instructions to a technician performing patch cord MAC's in a cross-connect patch field.

    [0010] Systems according to the present invention make use of patch cords having conductors and contacts that are provided for the purpose of patch cord management. Patch cords according to embodiments of the present are "ten-wire" patch cords. This term is used in connection with a traditional "eight-wire" copper Ethernet patch cord, comprising four conductive pairs. A "ten-wire" patch cord according to the present invention has two extra conductors dedicated to patch cord management, which may be termed "patch cord management conductors." While the terms "ten-wire" and "ninth" and "tenth" conductors will be used to describe the present invention, it is to be understood that the principles of this invention can be extended to copper patch cords having more or fewer than eight conductors, and also to optical patch cords and copper-fiber hybrid patch cords.

    [0011] These and other aspects of the present invention are explained to those of ordinary skill in the art in the following detailed description, with reference to the drawings. It should be understood that the embodiments noted herein are not intended to limit the scope of the invention.

    Brief Description of Figures



    [0012] 

    Figure 1 illustrates patch panel ports of intelligent patch panels in a cross-connect deployment connected by a ten-wire patch cord for use with one embodiment of the present invention;

    Figure 2 is a schematic diagram of circuitry within intelligent patch panels in a cross-connect configuration and a ten-wire patch cord;

    figure 3 is a schematic diagram of circuitry within intelligent patch panels and a ten-wire patch cord illustrating operation when one plug of the patch cord is plugged Into an intelligent patch panel port: and

    Figure 4 is a schematic diagram of circuitry within intelligent patch panels and a ten-wire patch cord illustrating operation when both plugs of the patch cord are plugged Into Intelligent patch panel ports.


    Detailed Description



    [0013] Fig. 1 shows a ten-wire cross-connect patch cord 10 for use with one embodiment of the present invention. The ten-wire cross-connect patch cord 10 has a first plug 12, adapted for insertion into a port 14 of a first intelligent patch panel 16; and a second plug 18, adapted for insertion into a port 20 of a second intelligent patch panel 22. While the first plug 12 and the second plug 18 are specially designed for use with the present invention, in one embodiment these plugs are designed to be capable of insertion into any RJ-45 jack. While only one port is shown per patch panel, it is to be understood that patch panels according to the present invention are preferably provided with many ports. For example, in one embodiment 24 ports may be provided on each patch panel.

    [0014] In addition to standard communication contacts 23, the first plug 12 has ninth and tenth contacts 24a and 24b adapted to make contact with ninth and tenth panel contacts 25a and 25b provided at the port 14 of the first intelligent patch panel 16. The second plug 18 is also provided with ninth and tenth contacts 26a and 26b adapted to make contact with ninth and tenth panel contacts 27a and 27b provided at the port 20 of the second intelligent patch panel 22. Each of the first and second plugs 12 and 18 is provided with a switch mechanism, respectively 28 and 30, that allows a determination of whether or not the plug is inserted into a port of an intelligent patch panel, as explained in further detail below.

    [0015] As shown in Fig. 1, the ports 14 and 20 are connected to respective horizontal communication cables 32 and 34. The intelligent patch panels 16 and 22 are connected to frame and infrastructure grounding 36.

    [0016] As shown in Fig. 2, the intelligent patch panels 16 and 22 are provided with control and detection circuits 38 and 40. The control and detection circuits 38 and 40 are capable of controlling a voltage placed on ninth and tenth wires and detecting patch cord plug insertion or removal states based on resulting electrical states. Each control and detection circuit is provided with a voltage input 46 and a plurality of controls w, x, and z. Digital input/output gates 48 and 49 are also provided, and allow for digital communications between the patch panels as well as the generation and routing of connection management signals within a patch panel (which may, in turn, be connected to a network management system).

    [0017] Each of the first and second plugs 12 and 18 is provided with plug circuitry 50 and 52, respectively. The plug circuitry of each plug comprises a capacitor 54a,b; a light emitting diode 56a,b; and a switch 58a,b that is actuated by a plunger 60a,b in a switch mechanism 30a,b. According to one embodiment, the capacitors 54a,b are identical and have a capacitance of 4.7 µF.

    [0018] In Fig. 2, the patch cord 10 is not plugged into either intelligent patch panel port, and thus no electrical connection exists between the ninth and tenth panel contacts of the panels (25a,b and 27a,b) and the ninth and tenth contacts of the patch cord 10 (24a,b and 26a,b). The intelligent patch panel ports 14 and 20 are in a "ready" state, and they are prepared to detect insertion of either plug 12 or 18 into either patch panel port 14 or 20. In the embodiment shown in Fig. 2, the control and detection circuit 38 of the first intelligent patch panel port 14 is identical to the control and detection circuit 40 of the second intelligent patch panel port 20, and the plug circuitry 50 of the first plug 12 is identical to the plug circuitry 52 of the second plug 18.

    [0019] In one embodiment, in the situation shown in Fig. 2, the detection that no cord is inserted into a port of either intelligent patch panel is determined by reading the digital input/output gate 48 or 49 in the intelligent patch panel circuitry when control w=on, control x=off, and control z=on. If the reading at the digital input/output gate is logically high and there is no communication between panels via the digital input/output gates 48 and 49, then it is determined that there is no patch cord inserted into either patch panel port. If the reading at the digital input/output gate 48 is logically low, or if there is communication between the digital input/output gates 48 and 49, then the system determines that a cord has been inserted and the type of cord must next be determined.

    [0020] Fig. 3 shows electrical connections in the condition when the first plug 12 is plugged into the first intelligent patch panel port 14, but the second plug 18 is not plugged into any patch panel port. For illustration purposes the plug 12 is not shown physically plugged into the port 14, but the electrical connections between, respectively, contacts 25a and 24a, and 25b and 24b, are shown by lines 62. In the plug 12 that has been plugged into the port 14, the plunger 60 has been depressed, so that the switch 58a has effectively removed the light emitting diode 56a from the resulting electrical circuit. In the second, unplugged plug 18, plunger 60b remains in its extended state. Thus, the switch 58b allows the the light emitting diode 56b to remain in the circuit such that it can be illuminated when current flows through the ninth and tenth wires 42 and 44.

    [0021] With control w=on, control x=off, and control z=on at the first port 14, current flows in the control and detection circuitry 38 as indicated by arrowed lines in Fig. 3. The presence of the patch cord can be detected by reading the characteristic capacitance resulting from the capacitor 54b. The LED 56b is illuminated by turning controls w and z on, allowing the "loose end" of the patch cord to be illuminated and indicated to a technician during an installation operation.

    [0022] Fig. 4 shows electrical connections in the condition when the first plug 12 is plugged into the first intelligent patch panel port 14, and the second plug 18 is plugged into the second intelligent patch panel port 20. Again, the plugs 12 and 18 are not shown physically plugged into the ports 14 and 20, and lines 62 indicate the electrical connections between the ninth and tenth contacts of the intelligent patch panel ports 14 and 20 and their respective ninth and tenth contacts on the patch cord 10. In this condition, both plungers 60a and 60b have been depressed upon insertion of the respective plugs 12 and 18 into the ports 14 and 20. Thus, both LED's 56a and 56b have been effectively removed from the resulting electrical circuit. In this state, the LED's 56a and 56b cannot be illuminated by current flowing in the ninth and tenth wires 42 and 44, and the ninth and tenth wires 42 and 44 can therefore be used to carry signals between the first and second ports 14 and 20 without interference from the LED's 56a and 56b. We note that while wires 42 and 44 are referred to as "ninth and tenth" wires, they may be considered first and second patch cord management conductors. The insertion states of both plugs 12 and 18 into their respective ports 14 and 20 can be detected by the ability of ports 14 and 20 to communicate with one another, for example via the digital input/output gates 48 and 49. Arrows are shown within the control and detection circuits 38 and 40 to indicate signal pathways between the ports 14 and 20 when the patch cord 10 connects the ports.

    [0023] Intelligent patch panel systems according to the present invention are preferably provided with circuitry and logic to enable a number of functions in cooperation with a ten-wire cross-connect patch cord, including guiding additions and removals of patch cords in a cross-connect deployment.

    [0024] The system can also visibly identify, in a visible patch cord trace operation, the patch cord end points of a particular patch cord connected between two intelligent patch panel ports by illuminating LED's provided next to the intelligent patch panel ports. Detection of patch cord connections as described above allows the monitoring and reporting of unauthorized patch cord removals or insertions at patch panel ports.

    [0025] With reference to Fig. 1, an example patch cord addition process according to one embodiment of the present invention begins when the intelligent patch panel ports 14 and 20 have respective port LED's 64 and 66 illuminated to guide a technician to the correct ports to plug the patch cord plugs into. The first plug of the patch cord 10 is next plugged into one of the ports, and the LED provided within the corresponding plug is switched out of the signal path. For example, with reference to Fig. 1, if the first plug 12 is inserted into the first port 14, the LED 56a corresponding to the first plug 12 is removed from the signal path comprising the ninth and tenth wires of the patch cord 10 at this step. Next, the LED 56b associated with the unplugged plug 18 is illuminated, indicating to the technician the correct plug to be plugged into the second port 20 (whose LED 66 will still be illuminated) guiding the technician to the port. Once the system has verified that the correct ports have been connected, the LED's 64 and 66 associated with the ports 14 and 20 are turned off, and the LED's 56a and 56b remain out of the signal pathway between the two ports.

    [0026] A patch cord trace function is also enabled when only one plug is plugged into a port. In this trace function, the port LED associated with the port is illuminated, and so is the LED provided in the unplugged plug of the patch cord. This is of particular benefit when there are several patch cords in a patch field, and determining which patch cord plug is correct could otherwise involve a time-consuming manual tracing of the patch cord from a patch panel port to the correct plug at the unplugged end of the patch cord.

    [0027] While the terms "ninth" and "tenth" have been applied herein to contacts, conductors, and the like, this is done in the exemplary context of use with a four-pair Ethernet cable. From the standpoint of the management functions of this invention, they may be considered first and second elements.

    [0028] While particular embodiments of the present invention have been showed and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the general scope of this disclosure. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.


    Claims

    1. A system for guiding patch cord insertions and removals comprising:

    a patch cord (10) having a first plug (12) and a second plug (18), said patch cord (10) comprising first and second dedicated patch cord management conductors (42, 44), each of said plugs (12, 18) having respective first and second plug contacts (24a, 24b; 26a, 26b) making electrical contact, respectively, with said first and second dedicated patch cord management conductors (42, 44), wherein the first and second dedicated patch cord management conductors (42, 44) are dedicated to patch cord management;

    a first intelligent patch panel (16) comprising a plurality of ports (14), each of said ports (14) comprising first and second panel contacts (25a, 25b), said first and second panel contacts (25a, 25b) being adapted to make contact with first and second plug contacts (24a, 24b; 26a, 26b) of said plugs (12, 18) when said plugs (12, 18) are plugged into said ports (14), said first intelligent patch panel (16) further comprising a first control and detection circuit (50);

    a second intelligent patch panel (22) comprising a plurality of ports (20), each of said ports (20) comprising first and second panel contacts (27a, 27b), said first and second panel contacts (27a, 27b) being adapted to make contact with first and second plug contacts (24a, 24b; 26a, 26b) of said plugs (12, 18) when said plugs (12, 18) are plugged into said ports (20), said second intelligent patch panel (22) further comprising a second control and detection circuit (52);

    wherein said first and second control and detection circuits (38, 40) comprise control circuits and digital input/output gates (48, 49), and detection of insertion of patch cords (10) into the ports (14, 20) of the first and second intelligent patch panels (16, 22) is accomplished by reading the status of the digital input/output gates (48, 49) when the control circuits (38,40) are placed in predefined states.


     
    2. The system of claim 1 wherein each of said first and second plugs (12, 18) is provided with plug circuitry (50, 52) comprising a light emitting diode (56a, 56b).
     
    3. The system of claim 2 wherein said plug circuitry (50, 52) in each of said first and second plugs (12,18) further comprises a switch (58a, 58b).
     
    4. The system of claim 3 wherein each of said first and second plugs (12, 18) further comprises a plunger (60a, 60b) that actuates said switch (58a, 58b).
     
    5. The system of claim 3 wherein said switches (58a, 58b) in said first and second plugs (12, 18) enable or disable said light emitting diodes (56a, 56b) depending on whether said switches (58a, 58b) are opened or closed.
     
    6. The system of claim 5 wherein the light emitting diode (56a, 56b) in one of said first and second plugs (12, 18) is disabled when said plug (12, 18) is plugged into one of said ports (14, 20).
     
    7. The system of claim 1 wherein each of said first and second plugs (12, 18) is provided with plug circuitry (50, 52) comprising a capacitor (54a, 54b) and the presence or absence of a plug (12, 18) in said ports (50, 52) of said intelligent patch panel (16, 22) is detected by reading the characteristic capacitance resulting from the capacitor (54a, 54b).
     


    Ansprüche

    1. System zum Führen des Einführens und Entfernens von Patchkabeln, das Folgendes enthält:

    ein Patchkabel (10), das einen ersten Stecker (12) und einen zweiten Stecker (18) aufweist, wobei das Patchkabel (10) einen ersten und einen zweiten dedizierten Patchkabelmanagementleiter (42, 44) enthält, wobei jeder der Stecker (12, 18) jeweilige erste und zweite Steckerkontakte (24a, 24b; 26a, 26b) aufweist, die jeweils einen elektrischen Kontakt mit dem ersten und dem zweiten dedizierten Patchkabelmanagementleiter (42, 44) herstellen, wobei der erste und der zweite dedizierte Patchkabelmanagementleiter (42, 44) speziell für das Patchkabelmanagement vorgesehen sind;

    ein erstes intelligentes Patchpaneel (16), das mehrere Ports (14) enthält, wobei jeder der Ports (14) einen ersten und einen zweiten Paneelkontakt (25a, 25b) enthält, wobei der erste und der zweite Paneelkontakt (25a, 25b) dafür ausgelegt sind, einen Kontakt mit ersten und zweiten Steckerkontakten (24a, 24b; 26a, 26b) der Stecker (12, 18) herzustellen, wenn die Stecker (12, 18) in die Ports (14) gesteckt werden, wobei das erste intelligente Patchpaneel (16) des Weiteren einen ersten Steuerungs- und Detektionskreis (50) enthält;

    ein zweites intelligentes Patchpaneel (22), das mehrere Ports (20) enthält, wobei jeder dieser Ports (20) einen ersten und einen zweiten Paneelkontakt (27a, 27b) enthält, wobei der ersten und der zweite Paneelkontakt (27a, 27b) dafür ausgelegt sind, einen Kontakt mit ersten und zweiten Steckerkontakten (24a, 24b; 26a, 26b) der Stecker (12, 18) herzustellen, wenn die Stecker (12, 18) in die Ports (20) gesteckt werden, wobei das zweite intelligente Patchpaneel (22) des Weiteren einen zweiten Steuerungs- und Detektionskreis (52) enthält;

    wobei der erste und der zweite Steuerungs- und Detektionskreis (38, 40) Steuerungskreise und digitale Eingabe/Ausgabe-Gatter (48, 49) enthalten, und die Detektion des Einführens von Patchkabeln (10) in die Ports (14, 20) des ersten und des zweiten intelligenten Patchpaneels (16, 22) durch Lesen des Status der digitalen Eingabe/Ausgabe-Gatter (48, 49) bewerkstelligt wird, wenn die Steuerungskreise (38,40) in zuvor festgelegte Zustände versetzt werden.


     
    2. System nach Anspruch 1, wobei der erste und der zweite Stecker (12, 18) mit Steckerschaltungen (50, 52) ausgestattet ist, die eine Leuchtdiode (56a, 56b) enthalten.
     
    3. System nach Anspruch 2, wobei die Steckerschaltungen (50, 52) in dem ersten und in dem zweiten Stecker (12, 18) des Weiteren einen Schalter (58a, 58b) enthalten.
     
    4. System nach Anspruch 3, wobei der erste und der zweite Stecker (12,18) des Weiteren einen Kolben (60a, 60b) enthalten, der den Schalter (58a, 58b) betätigt.
     
    5. System nach Anspruch 3, wobei die Schalter (58a, 58b) in dem ersten und dem zweiten Stecker (12, 18) die Leuchtdioden (56a, 56b) in Abhängigkeit davon aktivieren oder deaktivieren, ob die Schalter (58a, 58b) geöffnet oder geschlossen sind.
     
    6. System nach Anspruch 5, wobei die Leuchtdiode (56a, 56b) in dem ersten oder in dem zweiten Stecker (12, 18) deaktiviert wird, wenn der Stecker (12, 18) in einen der Ports (14, 20) gesteckt wird.
     
    7. System nach Anspruch 1, wobei der erste und der zweite Stecker (12, 18) mit Steckerschaltungen (50, 52) ausgestattet ist, die einen Kondensator (54a, 54b) enthalten, und das Vorhandensein oder Fehlen eines Steckers (12, 18) in den Ports (50, 52) des intelligenten Patchpaneels (16, 22) durch Lesen der aus dem Kondensator (54a, 54b) resultierenden Kennkapazität detektiert wird.
     


    Revendications

    1. Système destiné à guider des insertions et enlèvements de cordon de raccordement, comprenant :

    un cordon de raccordement (10) présentant un premier branchement (12) et un second branchement (18), ledit cordon de raccordement (10) comprenant des premier et second conducteurs de gestion de cordon de raccordement dédiés (42, 44), chacun desdits branchements (12, 1 8) ayant des premiers et seconds contacts de branchements respectifs (24a, 24b ; 26a, 26b) formant le contact électrique, respectivement, avec lesdits premier et second conducteurs de gestion de cordon de raccordement dédiés (42, 44), dans lequel les premier et second conducteurs de gestion de cordon de raccordement dédiés (42, 44) sont dédiés à la gestion de cordon de raccordement ;

    un premier tableau de raccordement intelligent (16) comprenant une pluralité de ports (14), chacun desdits ports (14) comprenant des premier et second contacts de tableau (25a, 25b), lesdits premier et second contacts de tableau (25a, 25b) étant adaptés pour former le contact avec des premiers et seconds contacts de branchement (24a, 24b ; 26a, 26b) desdits branchements (12, 1 8) lorsque lesdits branchements (12, 18) sont branchés dans lesdits ports (14), ledit premier tableau de raccordement intelligent (16) comprenant en outre un premier circuit de commande et de détection (50) ;

    un second tableau de raccordement intelligent (22) comprenant une pluralité de ports (20), chacun desdits ports (20) comprenant des premier et second contacts de tableau (27a, 27b), lesdits premier et second contacts de tableau (27a, 27b) étant adaptés pour former le contact avec des premiers et seconds contacts de branchement (24a, 24b ; 26a, 26b) desdits branchements (12, 1 8) lorsque lesdits branchements (12, 1 8) sont branchés dans lesdits ports (20), ledit second tableau de raccordement intelligent (22) comprenant en outre un second circuit de commande et de détection (52) ;

    dans lequel lesdits premier et second circuits de commande et de détection (38, 40) comprennent des circuits de commande et des portes logiques d'entrée/sortie numériques (48, 49), et la détection de l'insertion de cordons de raccordement (10) dans les ports (14, 20) des premier et second tableaux de raccordement intelligent (16, 22) est accomplie en lisant le statut des portes logiques d'entrée/sortie numériques (48, 49) lorsque les circuits de commande (38, 40) sont placés dans des états prédéfinis.


     
    2. Système selon la revendication 1, dans lequel chacun desdits premier et second branchements (12, 18) est prévu avec un ensemble de circuits de branchement (50, 52) comprenant une diode électroluminescente (56a, 56b).
     
    3. Système selon la revendication 2, dans lequel ledit ensemble de circuits de branchement (50, 52) dans chacun desdits premier et second branchements (12, 18) comprend en outre un commutateur (58a, 58b).
     
    4. Système selon la revendication 3, dans lequel chacun desdits premier et second branchements (12, 18) comprend en outre un piston (60a, 60b) qui actionne ledit commutateur (58a, 58b).
     
    5. Système selon la revendication 3, dans lequel lesdits commutateurs (58a, 58b) dans lesdits premier et second branchements (12, 18) activent ou désactivent lesdites diodes électroluminescentes (56a, 56b) en fonction du fait que lesdits commutateurs (58a, 58b) sont ouverts ou fermés.
     
    6. Système selon la revendication 5, dans lequel la diode électroluminescente (56a, 56b) dans un desdits premier et second branchements (12, 18) est désactivée lorsque ledit branchement (12, 18) est branché dans un desdits ports (14, 20).
     
    7. Système selon la revendication 1, dans lequel chacun desdits premier et second branchements (12, 18) est prévu avec un ensemble de circuits (50, 52) comprenant un condensateur (54a, 54b) et la présence ou l'absence d'un branchement (12, 18) dans lesdits ports (50, 52) dudit tableau de raccordement intelligent (16, 22) est détectée en relevant la capacité caractéristique résultant du condensateur (54a, 54b).
     




    Drawing















    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