Patent Publication Number: US-11665022-B2

Title: Sequential node identification in multiple-compartment dispensing enclosures

Description:
The present application is directed to storage and dispensing enclosures and, more particularly, to systems and methods in which networked nodes, such as door controls, dispensing modules, or other accessories housed within the enclosure, are automatically assigned a sequential identification value, such as incremented numerical value, without requiring the manual assignment of such values to the individual nodes. 
     BACKGROUND 
     Storage and dispensing enclosures may include a plurality of internal compartments for holding items to be dispensed, such as in multi-tiered, locker-like cabinets, and/or a variety of active dispensing units, such as the “pushers” used in some vending machines to dispense individual items, and/or a variety of passive dispensing units that track the presence, withdrawal, and, potentially, return of items, such as in rack-and-bin and bin-in-drawer systems that dispense bulk parts or individual tools (using bulk sensors such as load cells, counting sensors such as break beams, radio frequency identification sensors and radio frequency responsive tags attached to individual items or tools, etc.). The number, size and/or arrangement of the compartments, active dispensing units, and passive dispensing units may vary from enclosure to enclosure based upon an end user&#39;s practices and needs. In addition, such enclosures are significant capital equipment, and thus manufacturers have begun to modularize compartment access controls, active dispensing units, and passive dispensing units for such enclosures to allow for customized configuration and, potentially, reconfiguration of individual enclosures. 
     Such storage and dispensing enclosures require the installation of accessory components that are operatively connected to a controller programmed to, e.g., control the operation of an access door based upon payment or authorization, and/or control the operation of an active dispensing module based upon payment or authorization, and/or monitor a passive dispensing module so to provide an activity/audit trail. Potential accessory components include: compartment access controls such as door locks and door position sensors; motors, solenoids, actuators, and switches for active dispensing units such as the aforementioned pushers; load cells, break beam emitters/detectors, and RFID sensors for passive dispensing units such as the aforementioned bin systems; etc. Accessory components could also include annunciators, cameras, in-compartment environmental sensors, etc. Each of those accessory components would conventionally be wired to a central controller that has been configured to directly operate the accessory components. Alternately, some enclosures may include a master controller configured to indirectly operate such accessory components via networked slave controllers provided in accessory modules. For example, U.S. patent application Ser. No. 14/466,040, published as U.S. Patent App. Pub. 2016/0053514 and incorporated herein by reference in its entirety, discloses modular door assemblies providing door locks, door position sensors, and annunciators (indicator lights) for controlling access to individual compartments within an enclosure, where each modular door assembly is directly controlled by an in-module (slave) microcontroller and indirectly controlled by an in-enclosure (master) controller. However, and particularly in the case of highly customizable enclosures, installing and configuring such accessory modules can still be a complex, time-consuming, and costly process because the networked controllers should be logically associated with a particular compartment or dispenser in a particular location within the enclosure. 
     SUMMARY 
     A sequential identification value that has a simple and easily comprehended meaning to a human operator, who could be responsible for the initial configuration of an enclosure, the in-the-field repair of a malfunctioning enclosure, or the reconfiguration of an existing enclosure, would be superior to the complex hardware identifiers fused, burned, or otherwise permanently associated with most networked microcontrollers and networking peripherals. This application discloses a system and method for automatically associating sequential identification values with the complex and generally nonsequential hardware or network address identifiers generally used to address the controllers of networked modules, networked accessories, and other such “nodes.” 
     In a first aspect, disclosed is a system for automatically assigning sequential identification values to a plurality of networked nodes. The system includes a host controller operatively interconnected with a plurality of client controllers by a shared, multi-drop communications bus. The host controller is further operatively interconnected with a first controller of the plurality of client controllers by an initial segment of a daisy-chained, point-to-point communications bus, with each previous controller of the plurality of client controllers being operatively connected to a subsequent controller of the plurality of client controllers by another segment of the point-to-point communications bus. The host controller includes control logic to (i) issue a token to the first of the plurality of client controllers via the initial segment of the point-to-point communications bus, (ii) following issue of the token, query the plurality of client controllers via the multi-drop communications bus, (iii) receive a reply via the multi-drop communications bus and, upon receiving the reply, associate a replying client controller with a sequential identification value, and (iv) command via the multi-drop communications bus passing of the token via the point-to-point communications bus. The client controllers include control logic to (i) receive the token via the point-to-point communications bus, (ii) receive the query via the multi-drop communications bus, (iii) if that controller has the token, issue the reply to the query via the multi-drop communications bus, and (iv) receive the command via the multi-drop communications bus and, if that controller holds the token, pass the token via the point-to-point communications bus to a subsequent controller of the plurality of client controllers. 
     In a second aspect, disclosed is storage and dispensing enclosure including a host controller and a plurality of accessory modules, each including a respective client controller, disposed within the enclosure. The storage and dispensing enclosure also includes a shared, multi-drop communications bus operatively interconnecting the host controller with the plurality of accessory modules via the respective client controllers. The storage and dispensing enclosure further includes a daisy-chained, point-to-point communications bus operatively interconnecting the host controller with a first of the plurality of accessory modules via an initial segment, and each previous accessory module of the plurality of accessory modules being with each subsequent accessory module of the plurality of accessory modules via additional segments. The host controller includes control logic to (i) issue a token to the first of the plurality of accessory modules via the initial segment of the point-to-point communications bus, (ii) following issue of the token, query the plurality of accessory modules via the multi-drop communications bus, (iii) receive a reply via the multi-drop communications bus and, upon receiving the reply, associate a replying accessory module with a sequential identification value, and (iv) command via the multi-drop communications bus passing of the token via the daisy-chained, point-to-point communications bu. The accessory modules include control logic to (i) receive the token via the point-to-point communications bus, (ii) receive the query via the multi-drop communications bus, (iii) if that accessory module has the token, issue the reply to the query via the multi-drop communications bus, and (iv) receive the command via the multi-drop communications bus and, if that accessory module holds the token, pass the token via the point-to-point communications bus to a subsequent accessory module of the plurality of accessory modules. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic view of a first aspect of a system architecture for a storage and dispensing enclosure. 
         FIG.  2    is a schematic view of an exemplary host or master controller for use with the system architecture shown in  FIG.  1   . 
         FIG.  3    is a schematic view of an exemplary client or slave controller for use with the system architecture shown in  FIG.  1   . 
         FIG.  4    is a schematic view of an exemplary physical architecture for a storage and dispensing enclosure. 
         FIG.  5    is a block diagram illustrating a method of identifying and assigning sequential identification values to client controllers in one or more storage and dispensing enclosures. 
         FIG.  6    is an illustration of a prior art system architecture for point-to-point data communications, for an exemplary touchscreen video node, in a storage and dispensing enclosure. 
         FIG.  7    is an illustration of a second aspect of a system architecture for a storage and dispensing enclosure that employs serialization within high speed structured cabling for point-to-point communications. 
     
    
    
     DETAILED DESCRIPTION 
     In certain processing environments, it is desirable to be able to automatically assign simple, sequential identification values to networked client nodes depending upon the order in which they are physically connected to a host node via a linear bus. That ability can be important when functionally random and unique identification numbers such as Globally Unique Identifiers (GUIDs), Media Access Control (MAC) addresses, or the like must be logically associated with a relative physical location within a network or device. An example of such an environment would be a storage and dispensing disclosure, where accessory modules may be installed in various locations within an enclosure frame, and the relative physical location of the accessory module within the enclosure frame is the principal distinguishing characteristic to a human operator configuring or maintaining the device. 
     In some existing storage and dispensing enclosures, such as vending machines, the physical locations of motor and switch elements can be laid out in a fixed X-Y grid topology that is addressable using fixed row and column wiring. Each element can then be efficiently identified and addressed by well-known column and row addressing methods so long as there is a single input device and/or single output device per node and per-location. That efficiency is lost, however, when complex wiring harnesses begin to be required to support complex input/output requirements for multi-functional modules or nodes, when differently sized accessories begin to be installed in varying locations within an enclosure, and when an enclosure may be configured with different accessories having different input/output requirements. For example, a customer may want a series of enclosures that include four different-sized compartments in two or more different configurations, and where some of the compartments are both access-controlled and environmentally monitored. Grid wiring and fixed wiring harnesses directly connected to a central controller are not well-suited for use in such architectures. 
     Accordingly, in a first aspect schematically illustrated in  FIG.  1   , a storage and dispensing enclosure may include a host controller  100 . The host controller  100  includes control logic stored in a memory such as a read-only memory, a non-volatile and re-writeable memory, or a combination thereof. In some constructions, the control logic of the host controller  100  may indirectly control access to compartments in the storage and dispensing unit based upon a payment or an authorization. In some constructions, the control logic of the host controller  100  may indirectly control the operation of active dispensing modules based upon a payment or an authorization. In some constructions, the control logic of the host controller  100  may monitor events communicated by passive dispensing modules so as to record an indication of a dispensing event. Constructions may include any one or more of the foregoing functionalities. 
     The storage and dispensing enclosure also includes a plurality of client controllers  200 , e.g., a first client controller  200   a , a second client controller  200   b , and a third client controller  200   c . Each client controller may have a unique ID  201 , e.g., IDs  201   a ,  201   b , and  201   c , respectively. The unique ID may be a hardware identifier such as a GUID or a MAC address, or may be an assigned unique ID such as an IP address. The client controllers  200  also include control logic stored in a memory such as a read-only memory, a non-volatile and re-writeable memory, or a combination thereof. For example, a client controller  200  such as controller  200   a  may, responsive to host controller  100 , directly control a door lock so as to control access to a compartment of the storage and dispensing unit. For further example, a client controller such as controller  200   b  may, responsive to host controller  100 , directly control the operation of an active dispensing module, such as a “pusher,” so as to dispense an item via the active dispensing module. For yet further example, a client controller  200  such as controller  200   c  may monitor a passive dispensing module, such as a bin resting upon a load cell, and communicate to host controller  100  a dispensing event when the passive dispensing module senses the removal of an item from the bin. 
     The host controller  100  is operatively interconnected with the plurality of client controllers  200  by a shared, multi-drop communications bus  300 . The multi-drop communications bus  300  may be, for example, an RS-485-compliant bus. The multi-drop communications bus  300  may be, for example, a Controller Area Network (CAN)—specification-compliant bus. Other shared, multi-drop communications bus technologies usable with the system and method will be readily apparent to those skilled on the art. 
     The host controller  100  is also operatively connected to a first controller of the plurality of client controllers  200  by a segment of daisy-chained, point-to-point communications bus  350 . The point-to-point communications bus  350  may be, for example, an RS-422-compliant bus. Other daisy-chainable, point-to-point communications bus technologies usable with the system and method will also be readily apparent to those skilled on the art. The first controller of the plurality of client controllers, e.g., controller  200   a , is operatively connected to a second of the plurality of client controllers  200 , e.g., controller  200   b , by a different segment of the daisy-chained, point-to-point communications bus  350 , and so on, so that, in general, each previous controller of the plurality of client controllers  200  is operatively connected to a subsequent controller of the plurality of client controllers  200  by another segment of the daisy-chained, point-to-point communications bus  350 . Consequently, the host controller  100  can communicate via the multi-drop communications bus  300  with each of the plurality of client controllers  200 , but via the point-to-point communications bus  350  with only the first of the plurality of client controllers  200 . The first controller of the plurality of client controllers  200  can communicate via the point-to-point communications bus  350  with only a controller attached to the same segment, and so on. Preferably, each previous controller of the plurality of client controllers  200  can only transmit via the point-to-point communications bus  350  to a subsequent controller of the plurality of client controllers  200 . 
     The host controller  100  includes control logic to issue a token to the first of the plurality of client controllers  200  via the point-to-point communications bus  350 . The token may be a simple unique number, a data packet including a token flag or a unique number, or the like. The token is used to control the discovery and identification of the plurality of client controllers  200  via the multi-drop communications bus  300 . A client controller  200  that has received and not yet passed on the token may reply to the host controller  100  during commissioning of the system, such as during initial configuration of an enclosure, maintenance involving the replacement of a node in an enclosure, or reconfiguration of the nodes installed in an enclosure. Other client controllers that have passed on the token, i.e., have been discovered and associated with a sequential identification value, or have not yet received the token, i.e., have not yet been discovered and not yet been associated with a sequential identification value, will remain silent. The daisy-chained, point-to-point communications bus  350  and the orderly passing of the token along that bus consequently enables sequential identification values to be associated with the plurality of client controllers  200  based upon the order in which they are physically connected to the host controller  100  via that bus. The point-to-point communications bus  350  may be disposed within the storage and dispensing enclosure in a configuration readily observable by a human operator (e.g., by being visible from the front or rear of the enclosure, potentially after the removal of a fascia, panel, or the like), allowing the operator to observe the sequence in which each node is physically connected to that bus. 
     The host controller  100  further includes control logic to, following issue of the token, query the plurality of client controllers via the multi-drop communications bus  300 . Each of the plurality of client controllers  200  includes control logic to receive the token issued via the point-to-point communications bus  350 , to receive the query via the multi-drop communications bus  300 , and, if that controller has the token, to reply to the query via the multi-drop communications bus  300 . The reply to the query may include the unique ID  201  and/or other information such as the type of module controlled by that client controller  200  and the version of the control logic in that client controller  200 . 
     The host controller  100  further includes control logic to receive the reply via the multi-drop communications bus  300 , to associate the replying client controller with a sequential identification value, and to transmit an acknowledgement to the replying client controller via the multi-drop communications bus  300 . The host controller may associate the replying client controller with a sequential identification value by associating a replying client controller&#39;s unique ID  201  with the sequential identification value. However, if the replying client controller does not have a unique ID  201 , the host controller may associate the replying client controller with a sequential identification value by assigning the replying client controller the sequential identification value as a local address on the multi-drop communications bus  300 . The acknowledgement may include the associated sequential identification value, which may be stored by the replying client controller within a non-volatile and rewritable memory. The sequential identification value may be used by the replying client controller as its local address on the multi-drop communications bus  300 . The sequential identification value may also or alternately be displayed by the node of the replying client controller as a visible indication of the associated sequential identification value at the node. The acknowledgement, whether or not including the associated sequential identification value, may trigger the replying client controller to set an association status flag within a non-volatile and rewritable memory signifying that the controller has been associated with a sequential identification value. The status stored by the association status flag may be displayed by the node as a visible indication of whether the host controller  100  has associated client controller  200  with the sequential identification value. The host controller  100  may subsequently increment a counter to create a subsequent sequential identification value or increment an index to reference a subsequent sequential identification value from a list, array, table, matrix, or other store for a predetermined sequence. The reader will appreciate that the sequential identification value could be a numerical value (e.g., 1, 2, 3 . . . ), an alphanumerical value (e.g., value from a hexadecimal sequence), or a value from a predetermined sequence (for sake of illustration, “first,” “second,” “third” . . . ). 
     The host controller  100  yet further includes control logic to command via the multi-drop communications bus  300  passing of the token (e.g., transmits a broadcast command to all client controllers  200  for any having the token to pass the token to a subsequent client controller), and each of the plurality of client controllers  200  further includes control logic to receive the command via the multi-drop communications bus  300  and, if it holds the token, pass the token via the point-to-point communications bus  350  to a subsequent controller of the plurality of client controllers  200 . 
     After issuing the command over the multi-drop communication bus  300 , the host controller control logic iterates the querying, receiving, associating, transmitting, and commanding logic until the last of the plurality of client controllers  200  is identified and associated or a fault occurs. The host controller  100  may assume completion of the commissioning (identification and association) process if a reply is not received within a timeout. Alternately, the last of the plurality of client controllers  200  may send an end-of-bus, negative acknowledgement, or similar message if it has the token and is commanded to pass the token, if the point-to-point communications bus  350  has a connection-sensing capability. Faults may be indicated by the aforementioned display of the node. For example, an alphanumeric display may display a character indicating whether the client controller of the node is in commissioning mode (awaiting receipt of the token) or has been identified and associated (has received and passed on the token). Such a display may also indicate whether a node has the token, which may be useful for identifying a faulty connection between that client controller  200  and the multi-drop communications bus  300 . An alternate, multiple position or multiple color LED display may illuminate particular LEDs or illuminate particular colors to provide the same indications. 
     Turning to  FIG.  2   , an exemplary host controller  100  may comprise a microcontroller or central processing unit  110 , a memory  120 , a first bus interface  130  to the multi-drop communications bus  300 , and a second bus interface  140  to the point-to-point communications bus  350 . The memory  120  is preferably non-volatile and rewriteable (so as to serve as a repository for upgradable control logic and the association information described above), but may be volatile random access memory paired with firmware. In one construction, the first bus interface  130  includes a universal asynchronous receiver/transmitter (UART)  132  and an RS-485-compliant transceiver  134 . In another construction, the bus interface  130  includes a CAN controller  136  and CAN transceiver  138  (alternate operative connections shown using broken lines). In the illustrated constructions, the second bus interface  140  includes a second universal asynchronous receiver/transmitter (UART)  142  and an RS-422-compliant transmitter  144 . It will be appreciated that in other constructions, the transmitter could be a transceiver and the bus interface may not require a UART. 
     Turning to  FIG.  3   , an exemplary client controller  200  may comprise a microcontroller or central processing unit  210 , a memory  220 , a first bus interface  230  to the multi-drop communications bus  300 , and a second bus interface  240  to the point-to-point communications bus  350 . The memory  220  is again preferably non-volatile and rewriteable (so as to serve as a repository for upgradable control logic and the association information described above), but may be volatile random access memory paired with firmware. In one construction, the first bus interface  230  includes a universal asynchronous receiver/transmitter (UART)  232  and an RS-485-compliant transceiver  234 . In another construction, the bus interface  230  includes a CAN controller  236  and CAN transceiver  238  (alternate operative connections shown using broken lines). In the illustrated construction, the second bus interface  240  includes a second universal asynchronous receiver/transmitter (UART)  242  and at least one RS-422-compliant transceiver  244 . In the illustrated construction, a single RS-422-compliant transceiver receives from a prior segment of the point-to-point communications bus  350  and transmits to a subsequent segment of that bus so that communication through the bus  350  is one-directional. It will be appreciated that in other constructions, a transceiver may provide bidirectional communications, there may be paired transceivers to connect to the previous and subsequent segments, and the bus interface may require other UARTs or controllers. 
     Turning to  FIG.  4   , a preferred physical construction of the system combines the multi-drop communications bus and point-to-point communications bus in twisted pair cabling (e.g., “category 5” or ANSI/TIA/EIA-568-A cabling; used pairs are shown as single lines for clarity of illustration). The multi-drop communication bus  300  is continuous between input  250  and output  260  ports of each client controller  200 /node, with a drop connecting to the first bus interface  230  of the node, so that a first wire pair of the cabling forms an uninterrupted bus segment across all connected controllers  100 ,  200 . The point-to-point communication bus  350  is interrupted by the second bus interface of the node so that another wire pair, or single wire in one-way implementations of the bus, forms a daisy-chain of interrupted bus segments across all connected controllers  100 ,  200 . Accordingly, a linear bus having an arbitrary shape and length can be formed by daisy-chaining controllers  100 ,  200  of the nodes using readily available structured cabling. 
       FIG.  5    summarizes a method  500  reflecting the control logic described above. In a system including a host controller  100  and a plurality of client controllers  200 , with the host controller  100  operatively connected to the plurality of client controllers  200  via a multi-drop communications bus  300 , the host controller  100  operatively connected to a first controller of the plurality of client controllers  200  via a segment of a point-to-point communications bus, and each previous controller of the plurality of client controllers  200  operatively connected to a subsequent controller of the plurality of client controllers  200  via another segment of the point-to-point communications bus  350 , a host controller  100  may transmit a commissioning order  510  to a plurality of client controllers  200  via the multi-drop communications bus  310 . Such a commissioning order may trigger the plurality of client controllers  200  to cease transmitting on the multi-drop communications bus, to discard any stored sequential identification value and/or reset any association status flag, and to enter a commissioning mode. The reader will appreciate that this step is considered optional, since a host controller  100  and plurality of client controllers  200  may be manually placed into a commissioning mode or ordered to enter a commissioning mode by other means. 
     The host controller  100  issues a token  520  to a first controller of the plurality of client controllers via the point-to-point communications bus  350 . The host controller  100  queries  530  the plurality of client controllers  200  via the multi-drop communications bus  300 . A client controller receiving the query and having the token replies  540  to the host controller  100  via the multi-drop communications bus  300 . The host controller  100  receives  550   a  the reply, associates  550   b  the replying client controller with a sequential identification value, and acknowledges  550   c  the association to the replying client controller via the multi-drop communications bus  300 . The replying client controller, receiving the acknowledgement and having the token, stores  560  the acknowledgement event. The storage may include storing an associated sequential identification value, setting an association status flag, or a combination of the foregoing. The host controller  100  and replying client controller may optionally use an associated sequential identification value as a local address  565  of the replying client controller on the multi-drop communications bus  300 , such as when the plurality of client controllers  200  includes client controllers that do not include a pre-assigned unique ID. 
     The host controller  100  commands  570  via the multi-drop communication bus  300  passing of the token. The replying client controller, receiving the command and having the token, passes the token  580  via the point-to-point communications bus  350  to a subsequent client controller of the plurality of client controllers. Then, the steps  520  through  580  are repeated. The reader will appreciate that there may be variations of and additional steps in the method reflecting the options and alternatives described for the control logic above. 
     The system and method advantageously establish a sequential identification value that has a simple and easily comprehended meaning to a human operator, who could be responsible for the initial configuration of an enclosure, the in-the-field repair of a malfunctioning enclosure, or the reconfiguration of an existing enclosure. This logical sequential identification value may be used for addressing client controllers on the multi-drop communications bus  300 , but even more importantly may be used by a human operator to, for example, identify to the host controller  100 , or any computer executing payment, authentication, and/or stock tracking software, the items that have been stocked in a particular compartment, active dispensing unit, or passive dispensing unit. Other uses for the sequential identification value will be apparent to those working in the art. In contrast to prior systems and methods, no unique parameters must be loaded when compiling controller control logic or manually programmed during initial configuration of an enclosure. Once commissioning has been completed, the multi-drop communications bus  300  enables operation even when single or multiple nodes have failed, while during commissioning the association of sequential identification values and potential for display of commissioning status (potentially by display of association status or the associated sequential identification value itself at each node) enables ready identification of faulty nodes, defective cabling segments and the like. Finally, the system and method simply in-the-field replacement of nodes or reconfiguration of an enclosure. The nodes may be interconnected using inexpensive structured cabling by technically savvy but relatively untrained operators, so that in-the-field replacements may be performed by non-specialized field service technicians and, potentially, an end user&#39;s own technical staff. 
     Structured Cabling Serialization 
     In another aspect, a system architecture for a storage and dispensing enclosure with complex input/output requirements is disclosed. 
       FIG.  6    illustrates a prior art system architecture in which a remote node is directly controlled by a central controller  600 . The exemplary remote node  650  is a touchscreen video interface that illustrates the variety of input/output interfaces and types that may be required. The remote node  650  includes audio interface  660  for receiving a digital audio signal, such as an I2S interface, a video interface  670  for receiving a digital video signal, such as an LVDS, HDMI, or Displayport interface, and an IRQ pin  680  and I2C interface  690  for a touchscreen controller  692 , with additional use of the I2C interface for a video screen backlight controller  694 . The central controller  600 , which may be a so-called embedded personal computer, correspondingly includes an audio interface  610 , such as an I2S interface, a video interface  670  for transmitting a digital video signal, such as an HDMI or Displayport interface, GPIO pin  630  for receiving the output of the touchscreen controller IRQ pin, and I2C interface  640  connection to the I2C interface  690 . Each wiring connection between corresponding interfaces requires cables including at least one and potentially up to 30 wires. Such wiring can be costly and difficult to route within complex and cramped storage and dispensing enclosures, particularly if longer lengths are required. 
       FIG.  7    shows a system architecture in which the central controller  600  includes a plurality of digital interfaces, e.g., the audio interface  610 , video interface  620 , GPIO pin  630  and I2C interface  640 , connected to a first serializer/deserializer  700  local to the central controller. Correspondingly, the remote node  650  includes a plurality of digital interfaces connected to a second serializer/deserializer  750  local to the remote node. The first and second serializer/deserializers are interconnected by a single cable  710  which may include as few as two wires. The comparatively low data rate audio signal between audio interfaces  610  and  660 , the comparatively high data rate video signal between video interfaces  620  and  670 , and the other signals between interfaces  630  and  640  and  680  and  690 , respectively, are serialized into a single high data rate signal for transmission within cable  710  between the central controller  600  and remote node  650 . Such a cable  710  may be twisted pair cabling (e.g., “category 5” or ANSI/TIA/EIA-568-A cabling, “category 6” or ANSI/TIA-568-C.1 cabling, or other high speed structured cabling, including shielded twisted pair cabling). This advantageously substantially reduces the cost, bulk, and routing complexity of prior, interface-specific point-to-point cabling within such systems. 
     Although the invention is shown and described with respect to certain embodiments and constructions, it should be clear that modifications will occur to those skilled in the art upon reading and understanding the specification, and the present invention includes all such modifications.