Abstract:
A patch panel system including a patch panel having a first outlet including a first conductive tab and a device having a second outlet including a second conductive tab. A patch cord has a first plug having a first screen for contacting the first tab and a second plug having a second screen for contacting the second tab. The patch cord includes a conductor electrically connecting the first screen and the second screen. An analyzer is electrically connected to the first tab and detects a connection between the first tab and the second tab along the conductor.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims the benefit of U.S. provisional patent application Ser. No. 60/537,946, filed Jan. 20, 2004, the entire contents of which are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     Patch panels are often used to provide an interconnection between telecommunication outlets and active equipment. One difficulty experienced with patch panels is knowing which port of the patch panel is connected to which port on the active equipment. One solution to this problem is disclosed in U.S. Pat. No. 6,574,586, the contents of which are incorporated herein by reference. U.S. Pat. No. 6,574,586 discloses a system in which an adapter jacket having an external contact is placed on the plug. Outlets include an adapter board having a socket contact. The socket contacts are wired to an analyzer which then can determine which sockets are connected by patch cords by applying a signal to each socket contact.  
         [0003]     A drawback to the system of U.S. Pat. No. 6,574,586 is that modifications must be made to the plug (i.e., the addition of an adapter jacket) and the outlet (i.e., the addition of the adapter board) to determine port connectivity. The adapter board requires additional space on the patch panel. Furthermore, existing commercially available patch cords do not include the adapter contact needed to engage the socket contact.  
         [0004]     U.S. Pat. No. 5,483,467, the entire contents of which are incorporated herein by reference, discloses another system for monitoring port connectivity. This system also uses extraneous hardware such as an inductive coupler at each outlet.  
         [0005]     There is a need in the art for a port connectivity monitoring system which uses existing patch cords to provide information on port connectivity with little or no space-consuming hardware components. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]      FIG. 1  depicts a patch cord for use in embodiments of the invention.  
         [0007]      FIG. 2  depicts an exemplary patch panel system in an embodiment of the invention.  
         [0008]      FIGS. 3A and 3B  depict exemplary ports in embodiments of the invention.  
         [0009]      FIG. 4  depicts an exemplary patch panel system in an alternate embodiment of the invention.  
         [0010]      FIG. 5  depicts an exemplary patch panel system in an alternate embodiment of the invention.  
     
    
     SUMMARY  
       [0011]     An embodiment of the invention is a patch panel system including a patch panel having a first outlet including a first conductive tab and a device having a second outlet including a second conductive tab. A patch cord has a first plug having a first screen for contacting the first tab and a second plug having a second screen for contacting the second tab. The patch cord includes a conductor electrically connecting the first screen and the second screen. An analyzer is electrically connected to the first tab and detects a connection between the first tab and the second tab along the conductor.  
       DETAILED DESCRIPTION  
       [0012]      FIG. 1  depicts an exemplary patch cord for use in embodiments of the invention. The patch cord  10  includes plugs  12  connected by cabling  14 . Each plug includes metallic screen  16 . In one embodiment, cabling  14  includes 8 copper wires corresponding to 4 twisted pairs. A conductor  18  connects the metallic screens  16  on the plugs  12 . Conductor  18  may be a cable screen (e.g., braid or foil shield) or may be a single wire. The screened patch cord, referred to as ScTP, is readily available and may be similar to the screened MC6™ patch cord available from The Siemon Company. Other shielded patch cords may be used such as fully shielded patch cords referenced in the art as FTP patch cords.  
         [0013]      FIG. 2  depicts an exemplary patch panel system in an embodiment of the invention.  FIG. 2  depicts a telecommunications outlet  20  connected to a patch panel  22  by horizontal cabling. The patch panel  22  is connected to a device such as active equipment  24  which may be a server, a hub, a switch, etc. An analyzer  26  is connected to both the patch panel  22  and the active equipment  24  to perform port connectivity monitoring as disclosed herein. The connection between a port on patch panel  22  and analyzer  26  may be made through a data port on the back of the patch panel  22 .  
         [0014]      FIG. 3A  depicts exemplary outlets  32  and  34  which are part of patch panel  22  and active equipment  24 , respectively. Outlet  32  includes a metal tab  36  on the interior of the outlet electrically connected to analyzer  26  by cable  37 . Similarly, outlet  34  includes a metal tab  38  on the interior of the outlet electrically connected to analyzer  26  by cable  39 . The metal tab  38  on outlet  34  is not electrically connected to other outlets on the active equipment  24 . When patch cord  10  is mated to outlet  32 , the metal screen  16  contacts tab  36 . Similarly, when patch cord  10  is mated to outlet  34 , screen  16  contacts tab  38 . Analyzer  26  can then detect that outlet  32  on patch panel  22  is connected to outlet  34  on active equipment  24  through continuity testing. This system provides port-to-port connectivity information without significant additional hardware.  
         [0015]     There are embodiments where the outlet  34  on the active equipment  24  does not include a tab  38  wired directly to analyzer  26 . As shown in  FIG. 3B , outlets  34  include tabs  38 , or more substantial screening or shielding, connected to ground. As the ground plane is electrically connected across multiple outlets, individual outlets  34  on the active equipment  24  are not detected by the analyzer  26 . In this embodiment, port-to-port connectivity is not be determined by analyzer  26 , however, a determination that a port on patch panel  22  is connected to a port on the active equipment  24  may be made by analyzer  26 .  
         [0016]     When the active equipment  24  includes outlets having a common ground plane contacting screen  16 , useful diagnostic information may still be obtained. For example, a user having difficulty at telecommunications outlet  20  may contact service personnel to report a problem. The user will provide an identifier for the telecommunications outlet  20  and the technician determines from a database the corresponding outlet on patch panel  22 . Although the port-to-port connection between patch panel  22  and active equipment  24  is not known, the technician can determine whether a port on patch panel  22  is connected to active equipment  24 . If a port is connected, the tab  36  will be grounded due to electrical connection with ground plane of outlet  34 . The analyzer  26  provides this information based on a signal level at tab  36 . If not grounded, this indicates that the telecommunications outlet  20  is not connected to active equipment  24  and a routine service call is initiated. If the tab  36  is grounded, this indicates a connection exists between the patch panel  22  and active equipment  24 . At this point, a technician could check active equipment  24  for malfunctioning ports, perform channel diagnostics, reset any ports on active equipment  24 , etc.  
         [0017]      FIG. 4  depicts an alternate embodiment in which port-to-port connectivity mapping is available, even if the active equipment  26  includes outlets electrically connected to a common ground plane. The embodiment of  FIG. 4  includes an additional device such as patch panel  23 . Patch panel  22  and patch panel  23  include outlets such as outlet  32  shown in  FIG. 3A . These outlets include electrically isolated tabs  36  that establish electrical contact with screen  16  on plugs  12 . In this configuration, analyzer  26  detects which port on patch panel  22  is connected to which port on patch panel  23  through continuity testing. The connection between telecommunications outlet  20  and patch panel  22  is already defined in a system database as known in the art. Similarly, the connection between ports on the active equipment  24  and patch panel  23  are defined in a system database as known in the art. Analyzer  26  uses the continuity data and the database information to determine port-to-port connectivity. By detecting the port-to-port connectivity between patch panel  22  and patch panel  23 , an end-to-end path from the telecommunications outlet  20  to active equipment  24  is defined. This facilitates troubleshooting of user difficulties.  
         [0018]     In one scenario, a user having difficulty at telecommunications outlet  20  contacts service personnel to report a problem. As the entire path from the telecommunications outlet  20 , patch panel  22 , patch panel  23  and active equipment  24  is known, service personnel can determine the nature of the problem. The status of ports can be checked remotely. Alternatively, a technician can be dispatched to service the equipment with the knowledge of exactly which ports on each of patch panel  22 , patch panel  23  and active equipment  24  are involved.  
         [0019]     The above described embodiments provide determination of port-to-port connectivity ( FIGS. 3A and 4 ) or determination that a patch panel port is connected to a port on the active equipment ( FIG. 3B ) while using readily available patch cords such as ScTP or FTP patch cords. No additional adapter boards are needed nor are adapter jackets needed on the plugs. This minimizes space required on racks in telecommunications rooms or data centers. These embodiments provide an intelligent patching system in either an interconnect or cross-connect configuration.  
         [0020]      FIG. 5  depicts an alternate embodiment in which the ground path between the telecommunications outlet and the active equipment  24  is interrupted in at least one location by a decoupling capacitor  42 . The ground path from telecommunications outlet  20  is connected to ground  40 , and then to the metal tab  36  on outlet  32  through decoupling capacitor  42 . Decoupling capacitor  42  is embedded in a patch panel or termination block ports and isolates incoming versus outgoing signals transmitted over the screen on ScTP or FTP patch cords.  
         [0021]     This prevents DC ground currents from reaching the active equipment  24  and provides the ability to use standard, lower cost ScTP or FTP modular patch cords. DC isolation of each port maintains a proper ground path, yet enables continuity tracking using the screen or foil of the patch cord, thereby enabling use of lower cost screened (ScTP) or fully shielded (FTP) modular patch cords. The decoupling capacitor may be used without analyzer  26  to provide advantages in standard ScTP and FTP physical layer cabling systems. The DC isolation prevents shield current ground loops as caused by connection to equipment in different parts of a building that may be at different ground potentials.  
         [0022]     Use of decoupling capacitor in physical layer ports allows use of the screen in ScTP or FTP systems for both effective grounding of the physical layer and sensing continuity between ports. Use of a decoupling capacitor to isolate incoming from outgoing connections provides DC isolation. One embodiment of the sensing method for LAN equipment is the use of the common ground of the power strip that the LAN equipment is plugged into to complete a circuit and sense connections between LAN equipment and the physical layer.  
         [0023]     Embodiments have been described with respect to copper connectors having eight contacts such as the RJ-45 type connector. It is understood that other types of wire patch cords (e.g., coaxial cable) having a screen or shield may be used to detect port connectivity as disclosed herein. Furthermore, non-wire patch cords (e.g., fiber optic connectors) may include a metallic conductor and be used to detect port connectivity as disclosed herein.  
         [0024]     While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt to a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed for carrying out this invention.