Abstract:
A switching facility has a plurality of input ports for connection to signal sources in multiple categories, each category having multiple members, a plurality of output ports for connection to signal destinations in multiple categories, each category having multiple members, and a switch fabric configurable by a control system to connect any selected input port to any unique group of one or more output ports. A control panel interacts with the control system and has a plurality of actuatable elements and a display area associated with each actuatable element for displaying a legend associated with the actuatable element. The control system is functionally connected to the control panel and is operative to change the legend associated with an actuatable element.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims benefit of U.S. Provisional Application No. 60/925,273 filed Apr. 18, 2007, the entire disclosure of which is hereby incorporated by reference herein for all purposes. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to a switching facility having a control panel with relegendable buttons. 
     SUMMARY OF THE INVENTION 
     In accordance with the invention there is provided a switching facility having a plurality of input ports for connection to signal sources, the signal sources having multiple categories and each category having multiple members, a plurality of output ports for connection to signal destinations, the signal destinations having multiple categories and each category having multiple members, a connection means configurable to connect any selected input port to any unique group of one or more output ports, a control system for controlling the configuration of the connection means, and a control panel for interacting with the control system and having a plurality of actuatable elements and a display area associated with each actuatable element for displaying a legend associated with the actuatable element, and wherein the control system is functionally connected to the control panel and is operative to change the legend associated with an actuatable element such that in an initial state of the switching facility the display area associated with a first actuatable element displays a legend associated with input ports of the facility and the display area associated with a second actuatable element displays a legend associated with output ports of the facility, and upon actuating the first element when the facility is in the initial state, the control system causes the facility to change to a second state in which the display areas associated with a first group of actuatable elements display respective legends associated with categories of input ports and upon actuating the second element when the facility is in the initial state, the control system causes the facility to change to a third state in which the display areas associated with a second group of actuatable elements display respective legends associated with categories of output ports. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: 
         FIG. 1  is a schematic illustration of a video production truck, 
         FIG. 2  illustrates schematically a computing machine that may be used in a switching facility embodying the present invention, 
         FIG. 3  illustrates a router control panel, 
         FIG. 4  illustrate one button of the router control panel, 
         FIG. 5  illustrates two buttons of the router control panel in an initial state of the router, 
         FIG. 6  illustrates several buttons of the router control panel in a subsequent state of the router, 
         FIGS. 7-9  illustrate buttons of the control panel in successive states of the router, and 
         FIG. 10  is a flow chart illustrating steps in an algorithm that may be used to operate the video router. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates schematically a video router  10  that might be installed in a television production truck  12  for establishing and modifying connections among resources that are connected to the router. The resources are in two categories, namely sources and destinations, although some resources may be a source in one mode of operation and a destination in another mode. Some of the resources are located within the truck and others are located outside the truck. The truck may have several spigots  14  for connection to resources, such as cameras, outside the truck and may be equipped internally with resources such as storage devices (VTRs and disk storage devices) and display monitors. 
     The router  10  comprises a switch  16  that may have several hundred input ports and several hundred output ports and is operable to connect any one input port selectively to any unique group of one or more output ports in response to control signals received from a router control system (RCS)  12 . The router control system controls the configuration of the router, i.e. the pattern of connections established by the switch. 
     The router control system may be implemented by a software application running on a computing machine  20  of generally conventional topology, as shown in  FIG. 2 . The computing machine may comprise one or more processors  21 , random access memory  22 , read-only memory  23 , mass storage (such as hard disk drives)  24 , I/O devices  25 , and a user interface  26 . The mass storage  24  stores the RCS application software, which is loaded into the RAM for execution by the processor(s)  21 . Commands for changing the patterns of connections established by the switch  16  are output through the I/O devices  25 . The I/O devices include a network interface device for communicating with an Ethernet network  27 . 
     Within each category of resources, there may be multiple categories of devices and within each category of devices there may be multiple devices. For example, with respect to sources, the categories of devices may include cameras and VTRs and the devices in the cameras category may be camera  1 , camera  2 , etc. It is sufficient in many cases to have just three levels in the hierarchy of resources (devices, categories of devices, and categories of resources) but it may in particular cases be desirable to have at least one additional level in the hierarchy. 
     The router is provided with several router control panels  18  that are used by operators to control the configuration of the router by issuing commands to the router control system. The commands are communicated to the router control system over the network  27 , which also communicates messages from the router control system to the control panels. 
     The router also includes a database management system (DBMS) that runs on the same computing machine as the RCS and communicates with the RCS. The database management system maintains at least one table that defines the current configuration of the router by reference to the connections made by the router. For example if output port  2  and output port  5  are both connected to input port  1 , the table includes a record associated with output port  2  reflecting a connection to input port  1  and also includes a record associated with output port  5  reflecting a connection to input port  1 . The DBMS may also maintain a table containing a set of user-specified aliases, i.e. alternative names or mnemonics assigned to the input ports and output ports and typically referring to the resources connected to the input and output ports. If input port  1  is connected to a camera, arbitrarily designated camera  3 , output port  2  is connected to VTR  4  and output port  5  is connected to satellite feed  7 , the alias table may associate (directly or indirectly) input port  1  with the mnemonic CAM  3 , output port  2  with the mnemonic VTR  4  and output port  5  with the mnemonic SAT  7  respectively. 
     The user-specified aliases are used in the operator interface of the router to identify the truck resources. When an operator uses a control panel to command the router to establish a connection between VTR  4  and CAM  3 , the router control system uses the DBMS to translate the operator&#39;s instruction into a command to connect output port  2  to input port  1 . The RCS utilizes this command to configure the router to make the appropriate connection and updates the connection table accordingly. 
     The truck may also contain a production switcher  28  having several input ports, some of which are connected to respective output ports of the router  10 . It will be understood by those skilled in the art that the router configuration is set up in advance of a broadcast and does not normally change during the broadcast, whereas the production switcher is used during the broadcast to connect the switcher input ports selectively to an on-air output port in a sequence determined by a technical director (TD) in order to produce a television program for distribution. The technical director and other production personnel issue commands to the production switcher using switcher control panels  30 , which are also connected to the network  27  for communicating messages between the production switcher and the switcher control panels. 
       FIG. 3  illustrates a router control panel  18  in greater detail. The operator uses this control panel to view the current configuration of the router and change the configuration as necessary in preparation for the next broadcast by connecting output ports of the switch  16  to the proper inputs. The control panel includes three rows of relegendable buttons  32 . Each button can be illuminated selectively in one of at least three colors, by selective energization of suitable LEDs built into the button, and each button can also display up to three lines of text, each containing up to 8 characters ( FIG. 4 ). Each button controls a single switch (not shown). Each time the button is pressed, the condition of the switch (conductive or non-conductive) changes. When the switch is conductive, the button is considered to be depressed; when the switch is non-conductive, the switch is considered to be non-depressed. Such relegendable buttons are commercially available. 
     The control panel  18  also includes a status display panel  34  that is capable of displaying several rows of text characters. 
     A network interface device  36  in the control panel receives messages from the RCS over the network specifying the characters to be displayed in the three lines of text in each button. Such messages may be in the form of a PRINT command containing the arguments (control panel ID, button ID, line number, text). The network interface device  36  also receives messages from the RCS for controlling the illumination color of the button (purple, green, etc.) and the illumination status of the button (high tally, low tally or not illuminated) and transmits messages to the RCS regarding the status of each button (depressed or non-depressed). 
     The network interface device  36  receives messages from the RCS specifying the text to be displayed in each row of the status display panel. These messages allow the status display panel to display information regarding the current configuration of the router, i.e., for each connection established by the router, the display panel shows the signal destination and the signal source of that connection. The first line of the display shown in  FIG. 3  indicates that VTR  1  is currently connected to camera  1 . The second line indicates that VTR  3  is currently connected to camera  2  and will be connected to satellite  3  on the next take (to be discussed below). 
     Let us assume that the router has input ports connected to three different categories of video signal source, e.g. cameras, VTRs, and feeds from satellites, and that there are four sources (CAM  1 , CAM  2 , CAM  3  and CAM  4 ) in the cameras category and three sources (VTR  1 , VTR  2  and VTR  3 ) in the VTRs category. Router output ports are connected to four categories of destination, e.g. monitors, VTRs, feeds to satellites, and production switcher input ports. Cameras  1  and  2  are connected to input ports  1  and  2  respectively and VTR  1  (operating as a destination) is connected to output port  1 . 
     The router control system application is used to change the legends displayed by the buttons to facilitate use of the control panel. One possible algorithm for implementing this functionality is illustrated in  FIG. 10 . It will be appreciated that  FIG. 10  illustrates the algorithm at a high level and omits routine steps that would be desirable for a robust implementation. 
     The router control system application allows the router control system to change dynamically the function of each button (what happens when the button changes from a non-depressed status to a depressed status) and to change the appearance of each button (whether it is illuminated or not, the color and level of illumination and the text displayed on the button). A high level of illumination, or high tally, indicates that a button is active and that the router is working against the resources selected by that button whereas a low level of illumination, or low tally, indicates that a button is active but that the router is not working against the resources selected by that button. 
     Let us assume an initial state ( 100 ) in which the router control system sends messages to the control panel to illuminate two buttons in purple at high tally and to display the legends “sources” and “dests” (for destinations), as shown in  FIG. 5 . Neither button has yet been depressed. The RCS repeatedly checks the “dests” button (step  110 ) to determine whether the button has been depressed. If the operator then presses the “dests” button, the network interface device  36  transmits a message to the RCS advising of the change in status of the “dests” button and the RCS responds by transmitting messages to the control panel to illuminate four buttons in green at high tally containing respectively, legends denoting the different categories of destinations, i.e. monitors, VTRs, satellites, and production switcher, as shown in  FIG. 6  (step  120 ). The four buttons that are now illuminated in green at high tally generally will not include the “dests” button, which remains illuminated in purple at high tally, indicating that the button is active and that the control panel is working against the destination resources, or the “sources” button, which is illuminated at low tally. The RCS then cycles through the destination category buttons until it detects that one of them has been depressed ( 130 ). When the RCS detects that a destination category button (e.g. VTRs) has been depressed, it issues commands to the control panel causing the control panel to illuminate at high tally buttons for the members of the selected destination category (step  140 ) and to change the illumination level of the non-selected destination category buttons to low tally (step  150 ). For example, if the operator had pressed the “VTRs” button, three buttons would be illuminated in green at high tally and contain the legends VTR  1 , VTR  2 , and VTR  3  respectively ( FIG. 7 ). The buttons may be three of the four buttons that were previously illuminated as destination categories but this need not be the case. In any event, the destination category buttons (monitors, VTRs, satellites, production switcher) are no longer available as such. The RCS also queries the database to determine the sources that are currently connected to the VTRs respectively and provides messages to the control panel so that the legend in each VTR button indicates the name of the source that is currently routed to that VTR. For example, if the router is currently configured to connect input port  1  to output port  1 , the legend in the button associated with VTR  1  (which is the alias assigned to output port  1 ) will contain VTR  1  in line  1  and CAM  1  (the alias assigned to input port  1 ) in line  2 . Line  3  is blank, which indicates that a change in source has not been defined for VTR  1 . Assume that the operator pressed the button associated with VTR  1 . The RCS cycles through the buttons for the devices in the selected destination category until it detects that the VTR  1  button has been depressed ( 160 ). 
     When the operator has selected a destination device, the “sources” button changes to high tally and the operator may either press the “dests” button and navigate to select another destination device (e.g. a monitor) or press the “sources” button and navigate to select a source device. Suppose that the operator wishes to change the source that is connected to VTR  1  from camera  1  to satellite  3  (which is connected to input port  4 ). The operator commences selectin of the source that is to be connected to that VTR  1  on the next take by pressing the “sources” button ( 162 ) which, it will be recalled, is illuminated at low tally. The “sources” button changes to high tally ( 170 ) and any buttons that contain destination oriented legends change to low tally ( 180 ). The operator navigates through the menu tree from the “sources” button and may select satellite  3  as the next source. The RCS updates the legend in the VTR  1  button to display SAT  3  in line  3 . When a new source has been selected ( 190 ), the RCS causes the control panel to illuminate at high tally a button that displays the legend “Take.” When the operator presses the “Take” button, the RCS reconfigures the router to break the connection of input port  1  to output port  1  and to establish a new connection between the input port  4  and output port  1 , and updates the connection table accordingly. Line  2  of the legend in the VTR  1  button changes to SAT  3  and line  3  goes blank. 
     Another example is more pertinent to a control panel that is used as a production switcher control panel  26 . Consider, for example, a broadcast of a golf tournament. In this case, there would typically be fixed cameras at each of the 18 holes and an entourage of mobile cameras following each of the major competitors. When an operator selects “sources” and then “cameras,” buttons are illuminated for fixed cameras and mobile cameras respectively. The fixed and mobile groups form an intermediate level in the navigation hierarchy. If the operator presses “mobile,” buttons displaying the names of the major players are illuminated and on pressing one of those buttons the operator is presented with buttons for the mobile cameras in that player&#39;s entourage. If, instead of pressing the “mobile” button the operator had pressed “fixed,” buttons for the 18 holes respectively would be illuminated and on pressing “18” buttons for only the fixed cameras at hole 18 would be illuminated. Suppose that the player in first place is at hole 18. The RCS (which also interfaces with the production switcher) is programmed so that after pressing “fixed” and navigating to the fixed cameras at a selected hole, the “mobile” button remains available. The operator may press “mobile” and view buttons displaying the names of the major competitors and press the button displaying the name of the player in first place. On pressing that button, the operator is presented with buttons for the mobile cameras following the player in first place as well as the buttons for the fixed cameras at hole 18. 
     As described above, the operator is able to navigate through the hierarchy of destinations and select a specific destination device, and at each step of the navigation, the only buttons that are illuminated in green at high tally are buttons that will take the operator closer to selection of a destination device. 
     Thus, the control panel buttons have dual functions (navigate and status) and the current function can be indicated not only by the legend but also by color. In the example discussed above, when a button displays “sources” or “cameras” it is a navigate button, in that the legend communicates to the operator what will happen when the button is pressed, so pressing the button allows the operator to navigate a menu tree to arrive at the opportunity to select an attribute; and when a button displays, for example, VTR  1  it is a status button, in that by pressing the button the operator is able to select a value for an attribute: the source to which the destination will be connected when the “Take” button is pressed. In addition, the status display panel enables the operator to see at a glance the current status of the router. 
     It will be appreciated that the invention is not restricted to the particular embodiment that has been described, and that variations may be made therein without departing from the scope of the invention as defined in the appended claims, as interpreted in accordance with principles of prevailing law, including the doctrine of equivalents or any other principle that enlarges the enforceable scope of a claim beyond its literal scope. Unless the context indicates otherwise, a reference in a claim to the number of instances of an element, be it a reference to one instance or more than one instance, requires at least the stated number of instances of the element but is not intended to exclude from the scope of the claim a structure or method having more instances of that element than stated. The word “comprise” or a derivative thereof, when used in a claim, is used in a nonexclusive sense that is not intended to exclude the presence of other elements or steps in a claimed structure or method.