Patent Publication Number: US-9897411-B2

Title: Apparatus and method for powering and networking a rail of a firearm

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/684,062, filed Aug. 16, 2012, the contents of which is incorporated herein by reference thereto. 
     Reference is also made to the following applications, U.S. patent application Ser. No. 12/688,256 filed Jan. 15, 2010; U.S. patent application Ser. No. 13/372,825 filed Feb. 14, 2012; U.S. Provisional Patent Application Ser. No. 61/443,085 filed Feb. 15, 2011; and U.S. Provisional Patent Application Ser. No. 61/528,728 filed Aug. 29, 2011, the contents each of which are also incorporated herein by reference thereto. 
     BACKGROUND 
     Embodiments of the invention relate generally to a powered rail mounted on a device such as a firearm to provide power to accessories, such as: telescopic sights, tactical sights, laser sighting modules, and night vision scopes. 
     Current accessories mounted on a standard firearm rail such as a MIL-STD-1913 rail, Weaver rail, NATO STANAG 4694 accessory rail or equivalents thereof require that they utilize a battery contained in the accessory. As a result multiple batteries must be available to replace failing batteries in an accessory. Embodiments of the present invention utilize multiple battery power sources to power multiple accessories through the use of a power and data system, mounted on a standard firearms rail. 
     Accordingly, it is desirable to provide a method and apparatus for remotely powering and communicating with accessories secured to a rail of a firearm. 
     SUMMARY OF THE INVENTION 
     In one exemplary embodiment a rail for a weapon is provided, the rail having: a plurality of slots and a plurality of ribs each being located in an alternating fashion on a surface of the rail; a first plurality of pins each having an end portion located on a surface of one of a first plurality of the plurality of ribs; a second plurality of pins each having a first end portion and a second end portion located on a surface of a second plurality of the plurality of ribs. 
     In yet another embodiment, a weapon or firearm is provided, the weapon having: an upper receiver; a lower receiver; a powered accessory mounted to a rail of the upper receiver; and an apparatus for providing power and data to the powered accessory, wherein the data is exclusively provided to the powered accessory from one of a plurality of coils or in another embodiment a plurality of contacts located within the rail; and wherein the powered accessory further comprises a plurality of coils or in another embodiment a plurality of contacts and the powered accessory is configured to determine when one of the plurality of coils or plurality of contacts of the powered accessory is adjacent to the one of the plurality of coils or plurality of contacts of the rail. 
     In still another embodiment, a weapon or firearm is provided, the weapon having: an upper receiver; a lower receiver; a powered accessory mounted to a rail of the upper receiver; and an apparatus for networking a microcontroller of the powered accessory to a microcontroller of the upper receiver and a microcontroller of the lower receiver, wherein the data is exclusively provided to the powered accessory from one of a plurality of coils or in another embodiment a plurality of contacts located within the rail; and wherein the powered accessory further comprises a plurality of coils or contacts and the powered accessory is configured to determine when one of the plurality of coils or contacts of the powered accessory is adjacent to the one of the plurality of coils or contact of the rail. 
     In still another alternative embodiment, a method of networking a removable accessory of a weapon to a microcontroller of the weapon is provided, the method including the steps of: transferring data between the accessory and the microcontroller via a first pair of coils or in another embodiment a first pair of contacts exclusively dedicated to data transfer; inductively transferring power to the accessory via another pair of pair of coils or in another embodiment another pair of contacts exclusively dedicated to power transfer; and wherein the accessory is capable of determining the first pair of coils or first pair of contacts by magnetizing a pin located on the weapon. 
     A rail for a weapon, the rail having: a plurality of slots and a plurality of ribs each being located in an alternating fashion on a surface of the rail; a first plurality of pins each having an end portion located on a surface of one of a first plurality of the plurality of ribs; a second plurality of pins each having a first end portion and a second end portion located on a surface of a second plurality of the plurality of ribs; and a plurality of pins located in the rail for power and data transfer, wherein the plurality of pins have an exposed contact surface comprising tungsten carbide and wherein the plurality of pins located in the rail for power and data transfer are configured to conductively transfer at least one of power or data to an accessory removably secured to the rail. 
     In combination, a powered accessory and a rail configured to removably receive and retain the powered accessory; an apparatus for conductively providing power and data to the powered accessory, wherein the data is exclusively provided to the powered accessory from a source in the rail; and wherein the rail has: a plurality of slots and a plurality of ribs each being located in an alternating fashion on a surface of the rail; a first plurality of pins each having an end portion located on a surface of one of a first plurality of the plurality of ribs; a second plurality of pins each having a first end portion and a second end portion located on a surface of a second plurality of the plurality of ribs; and a plurality of pins located in the rail for power and data transfer, wherein the plurality of pins have an exposed contact surface comprising tungsten carbide. 
     A weapon, having: an upper receiver; a lower receiver; a powered accessory removably mounted to a rail of the upper receiver; and an apparatus for conductively providing power and data to the powered accessory; and wherein the rail has: a plurality of slots and a plurality of ribs each being located in an alternating fashion on a surface of the rail; a first plurality of pins each having an end portion located on a surface of one of a first plurality of the plurality of ribs; a second plurality of pins each having a first end portion and a second end portion located on a surface of a second plurality of the plurality of ribs; and a plurality of pins located in the rail for power and data transfer, wherein the plurality of pins have an exposed contact surface comprising tungsten carbide, the exposed contact surface being configured to conductively transfer power and data to the powered accessory. 
     A method of networking a removable accessory of a weapon to a microcontroller of the weapon, the method comprising the steps of: conductively transferring data between the accessory and the microcontroller via at least one pin having an exposed surface comprising tungsten carbide; conductively transferring power to the accessory via at least one pin having an exposed surface comprising tungsten carbide; and wherein the microcontroller is capable of determining whether to transfer data or power via magnetization of at least one pin located on the weapon. 
     A method of networking a removable accessory of a weapon to a microcontroller of the weapon, the method comprising the steps of: conductively or inductively transferring data between the accessory and the microcontroller via at least one pin having an exposed surface comprising tungsten carbide; conductively or inductively transferring power to the accessory via at least one pin having an exposed surface comprising tungsten carbide; and wherein the microcontroller is capable of determining whether to transfer data or power via magnetization of at least one pin located on the weapon. 
     Other aspects and features of embodiments of the invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the present invention will now be described, by way of example only, with reference to the attached Figures, wherein: 
       Other features, advantages and details appear, by way of example only, in the following description of embodiments, the description referring to the drawings in which: 
         FIG. 1  is a perspective view of an inductively powering rail mounted on a MIL-STD-1913 rail; 
         FIG. 2  is cross section vertical view of a primary U-Core and a secondary U-Core; 
         FIG. 3  is a longitudinal cross section side view of an accessory mounted to an inductively powering rail; 
         FIG. 4  is a block diagram of the components of one embodiment of an inductively powered rail system; 
         FIG. 5  is a block diagram of a primary Printed Circuit Board (PCB) contained within an inductively powering rail; 
         FIG. 6  is a block diagram of a PCB contained within an accessory; 
         FIG. 7  is a block diagram of the components of a master controller; 
         FIG. 8  is a flow chart of the steps of connecting an accessory to an inductively powering rail; 
         FIG. 9  is a flow chart of the steps for managing power usage; 
         FIG. 10  is a flow chart of the steps for determining voltage and temperature of the system; 
         FIG. 11  is a perspective view of a portion of a rail of a networked powered data system (NPDS) in accordance with an embodiment of the present invention; 
         FIGS. 12A-12C  are cross-sectional views of an accessory mounted to a networked powered data system (NPDS); 
         FIGS. 13A and 13B  are perspective views of an upper receiver with rails of the networked powered data system (NPDS) mounted thereto; 
         FIGS. 13C and 13D  illustrate alternative embodiments of the upper receiver illustrated in  FIGS. 13A and 13B ; 
         FIGS. 14A and 14B  are perspective views of rails of the networked powered data system (NPDS); 
         FIGS. 14C and 14D  illustrate alternative embodiments of the rails illustrated in  FIGS. 14A and 14B ; 
         FIGS. 15A-15C  illustrate the mounting an the rails of the networked powered data system (NPDS); 
         FIGS. 15D-15F  illustrate alternative embodiments of the rails illustrated in  FIGS. 15A-15C ; 
         FIG. 16  is schematic illustration of power and data transfer between components of the networked powered data system (NPDS); 
         FIG. 17  is schematic illustration of a circuit for inductive power transfer in accordance with one exemplary embodiment of the present invention; 
         FIG. 18  is a perspective view of a portion of a weapon with the networked powered data system (NPDS) of one embodiment of the present invention; 
         FIG. 18A  is a perspective view of a portion of a weapon with the networked powered data system (NPDS) according to an alternative embodiment of the present invention; 
         FIGS. 19A-19D  are various views of a component for inductively coupling power and data between an upper receiver and a lower receiver of a weapon used with the networked powered data system (NPDS); 
         FIGS. 20A-20F  are various views of an alternative component for inductively coupling power and data between an upper receiver and a lower receiver of a weapon used with the networked powered data system (NPDS); 
         FIG. 21  is a perspective view of a pistol grip for use with the upper receiver illustrated in  FIG. 18A ; 
         FIG. 22  is a perspective view of a portion of a weapon with the networked powered data system (NPDS) according to another alternative embodiment of the present invention; 
         FIG. 23  is a perspective view of a pistol grip for use with the upper receiver illustrated in  FIG. 22 ; 
         FIG. 24  illustrates a battery pack or power supply secured to a pistol grip of an exemplary embodiment of the present invention; 
         FIG. 25  illustrates an alternative method and apparatus for coupling a battery pack or power supply to an alternative embodiment of the pistol grip; 
         FIG. 26  is a schematic illustration of a power system of the networked powered data system (NPDS) according to one exemplary embodiment of the present invention; 
         FIGS. 27A-27B  illustrate a rail for conductively transferring data and power according to various alternative embodiments of the present invention; 
         FIGS. 28A-28C  are cross-sectional views of an accessory mounted to a rail of the conductive networked powered data system (CNPDS) in accordance with various embodiments of the present invention; 
         FIG. 29A  is a bottom view of an accessory mount according to an embodiment of the present invention; 
         FIGS. 29B-32  illustrate the accessory mount secured to the rail of  FIGS. 27A and 27B ; 
         FIG. 33  is a perspective view of an accessory pin or contact and a rail pin or contact according to various alternative embodiments of the present invention; 
         FIG. 34  is a side cross-sectional view of the rail illustrated in  FIGS. 27A and 27B ; 
         FIG. 35  is a side view of a pin or contact for the conductive rail according to various alternative embodiments of the present invention; 
         FIG. 36  is a perspective view of the accessory base according to an embodiment of the present invention; 
         FIGS. 37A-37D  are various views of a pin or contact contemplated for an accessory base according to an embodiment of the present invention; 
         FIGS. 38A-38C  are various views of a pin or contact contemplated for the conductive rail according to an embodiment of the present invention; 
         FIG. 39  is a perspective view of the accessory base secured to a rail section according to an embodiment of the present invention; 
         FIG. 40  is a perspective cross-sectional view of a rail section according to an embodiment of the present invention; 
         FIG. 41  is a schematic illustration of a communication system for a conductive networked powered data system; 
         FIG. 42  is a schematic illustration of a comparison of 10Base2 to 10/100Base T Ethernet Physical Links; 
         FIG. 43  is a schematic illustration of a Dual MII Switch Approach; 
         FIG. 44  is a schematic illustration of a single MII Switch Approach; and 
         FIG. 45  is a schematic illustration of a Data Contact Switch and Protection. 
     
    
    
     DETAILED DESCRIPTION 
     Reference is also made to the following U.S. Pat. Nos. 6,792,711; 7,131,228; and 7,775,150 the contents each of which are incorporated herein by reference thereto. 
     Disclosed herein is a method and system for an inductively powering rail on a rifle, weapon, firearm, (automatic or otherwise), etc. to power accessories such as: telescopic sights, tactical sights, laser sighting modules, Global Positioning Systems (GPS) and night vision scopes. This list is not meant to be exclusive, merely an example of accessories that may utilize an inductively powering rail. The connection between an accessory and the inductively powering rail is achieved by having electromagnets, which we refer to as “primary U-Cores” on the inductively powering rail and “secondary U-Cores” on the accessory. Once in contact with the inductively powering rail, through the use of primary and secondary U-cores, the accessory is able to obtain power though induction. 
     Embodiments avoid the need for exposed electrical contacts, which may corrode or cause electrical shorting when submerged, or subjected to shock and vibration. This eliminates the need for features such as wires, pinned connections or watertight covers. 
     Accessories may be attached to various fixture points on the inductively powering rail and are detected by the firearm once attached. The firearm will also be able to detect which accessory has been attached and the power required by the accessory. 
     Referring now to  FIG. 1 , a perspective view of an inductively powering rail mounted on a MIL-STD-1913 rail is shown generally as  10 . 
     Feature  12  is a MIL-STD-1913 rail, such as a Weaver rail, NATO STANAG 4694 accessory rail or the like. Sliding over rail  12  is an inductively powering rail  14 . Rail  12  has a plurality of rail slots  16  and rail ribs  18 , which are utilized in receiving an accessory. An inductively powering rail  14  comprises a plurality of rail slots  20 , rail ribs  22  and pins  24 , in a configuration that allows for the mating of accessories with inductively powering rail  14 . It is not the intent of the inventors to restrict embodiments to a specific rail configuration, as it may be adapted to any rail configuration. The preceding serves only as an example of several embodiments to which inductively powering rail  14  may be mated. In other embodiments, the inductively powering rail  14  can be mounted to devices having apparatus adapted to receive the rail  14 . 
     Pins  24  in one embodiment are stainless steel pins of grade 430. When an accessory is connected to inductively powering rail  14 , pins  24  connect to magnets  46  and trigger magnetic switch  48  (see  FIG. 3 ) to indicate to the inductively powering rail  14  that an accessory has been connected. Should an accessory be removed the connection is broken and recognized by the system managing inductively powering rail  14  Pins  24  are offset from the center of inductively powering rail  14  to ensure an accessory is mounted in the correct orientation, for example a laser accessory or flashlight accessory could not be mounted backward, and point in the users face as it would be required to connect to pins  24 , to face away from the user of the firearm. Pin hole  28  accepts a cross pin that locks and secures the rails  12  and  14  together. 
     Referring now to  FIG. 2 , a cross section vertical view of a primacy U-Core and a secondary U-Core is shown. Primary U-Core  26  provides inductive power to an accessory when connected to inductively powering rail  14 . Each of primary U-core  26  and secondary U-core  50  are electromagnets. The wire wrappings  60  and  62  provide an electromagnetic field to permit inductive power to be transmitted bi-directionally between inductively powering rail  14  and an accessory. Power sources for each primary U-core  26  or secondary U-core  50  may be provided by a plurality of sources. A power source may be within the firearm, it may be within an accessory or it may be provided by a source such as a battery pack contained in the uniform of the user that is connected to the firearm, or by a super capacitor connected to the system. These serve as examples of diverse power sources that may be utilize by embodiments of the invention. 
     Referring now to  FIG. 3 , a longitudinal cross section side view of an accessory mounted to an inductively powering rail  14 ; is shown generally as  40 . Accessory  42  in this example is a lighting accessory, having a forward facing lens  44 . Accessory  42  connects to inductively powering rail  14 , through magnets  46  which engage pins  24  and trigger magnetic switch  48  to establish an electrical connection, via primary PCB  54 , to inductively powering rail  14 . 
     As shown in  FIG. 3 , three connections have been established to inductively powering rail  14  through the use of magnets  46 . In addition, three secondary U-cores  50  connect to three primary U-cores  26  to establish an inductive power source for accessory  42 . To avoid cluttering the Figure, we refer to the connection of secondary U-core  50  and primary U-core  26  as an example of one such mating. This connection between U-cores  50  and  26  allows for the transmission of power to and from the system and the accessory. There may be any number of connections between an accessory  42  and an inductively powering rail  14 , depending upon power requirements. In one embodiment each slot provides on the order of two watts. Of course, power transfers greater or less than two watts are considered to be within the scope of embodiments disclosed herein. 
     In both the accessory  42  and the inductively powering rail  14  are embedded Printed Circuit Boards (PCBs), which contain computer hardware and software to allow each to communicate with each other. The PCB for the accessory  42  is shown as accessory PCB  52 . The PCB for the inductively powering rail  14  is shown as primary PCB  54 . These features are described in detail with reference to  FIG. 5  and  FIG. 6 . 
     Referring now to  FIG. 4  a block diagram of the components of an inductively powered rail system is shown generally as  70 . 
     System  70  may be powered by a number of sources, all of which are controlled by master controller  72 . Hot swap controller  74  serves to monitor and distribute power within system  7 . The logic of power distribution is shown in  FIG. 9 . Hot swap controller  74  monitors power from multiple sources. The first in one embodiment being one or more 18.5V batteries  78  contained within the system  70 , for example in the stock or pistol grip of a firearm. This voltage has been chosen as optimal to deliver two watts to each inductively powering rail slot  20  to which an accessory  42  is connected. This power is provided through conductive power path  82 . A second source is an external power source  80 , for example a power supply carried external to the system by the user. The user could connect this source to the system to provide power through conductive power path  82  to recharge battery  78 . A third source may come from accessories, which may have their own auxiliary power source  102 , i.e. they have a power source within them. When connected to the system, this feature is detected by master CPU  76  and the power source  102  may be utilized to provide power to other accessories through inductive power path  90 , should it be needed. 
     Power is distributed either conductively or inductively. These two different distribution paths are shown as features  82  and  90  respectively. In essence, conductive power path  82  powers the inductively powering rail  14  while inductive power path  90  transfers power between the inductively powering rail  14  and accessories such as  42 . 
     Master CPU  76  in one embodiment is a Texas Instrument model MSP430F228, a mixed signal processor, which oversees the management of system  70 . Some of its functions include detecting when an accessory is connected or disconnected, determining the nature of an accessory, managing power usage in the system, and handling communications between the rail(s), accessories and the user. 
     Shown in  FIG. 4  are three rails. The first being the main inductively powering rail  14  and side rail units  94  and  96 . Any number of rails may be utilized. Side rail units  94  and  96  are identical in configuration and function identically to inductively powering rail unit  14  save that they are mounted on the side of the firearm and have fewer inductively powered sail slots  20 . Side rail units  94  and  96  communicate with master CPU  76  through communications bus  110 , which also provides a path for conductive power. Communications are conducted through a control path  86 . Thus Master CPU  76  is connected to inductively powering rail  14  and through rail  14  to the microcontrollers  98  of side rails  94  and  96 . This connection permits the master CPU  76  to determine when an accessory has been connected, when it is disconnected, its power level and other data that may be useful to the user, such as GPS feedback or power level of an accessory or the system. Data that may be useful to a user is sent to external data transfer module  84  and displayed to the user. In addition data such as current power level, the use of an accessory power source and accessory identification may be transferred between accessories. Another example would be data indicating the range to a target which could be communicated to an accessory  42  such as a scope. 
     Communications may be conducted through an inductive control path  92 . Once an accessory  42 , such as an optical scope are connected to the system, it may communicate with the master CPU  76  through the use of inductive control paths  92 . Once a connection has been made between an accessory and an inductively powering rail  14 ,  94  or  96  communication is established from each rail via frequency modulation on an inductive control path  92 , through the use of primary U-cores  26  and secondary U-Cores  50 . Accessories such as  42  in turn communicate with master CPU  76  through rails  14 ,  94  or  96  by load modulation on the inductive control path  92 . 
     By the term frequency modulation the inventors mean Frequency Shift Key Modulation (FSK). A rail  14 ,  94 , or  96  sends power to an accessory  42 , by turning the power on and off to the primary U-core  26  and secondary U-core  50 . This is achieved by applying a frequency on the order of 40 kHz. To communicate with an accessory  42  different frequencies may be utilized. By way of example 40 kHz and 50 kHz may be used to represent 0 and 1 respectively. By changing the frequency that the primary U-cores are turned on or off information may be sent to an accessory  42 . Types of information that may be sent by inductive control path  92  may include asking the accessory information about itself, telling the accessory to enter low power mode, ask the accessory to transfer power. The purpose here is to have a two way communication with an accessory  42 . 
     By the term load modulation the inventors mean monitoring the load on the system  70 . If an accessory  42  decreases or increases the amount of power it requires then master CPU  76  will adjust the power requirements as needed. 
     Accessory  104  serves as an example of an accessory, being a tactical light. It has an external power on/off switch  106 , which many accessories may have as well as a safe start component  108 . Safe start component  108  serves to ensure that the accessory is properly connected and has appropriate power before turning the accessory on. 
     Multi button pad  88  may reside on the firearm containing system  70  or it may reside externally. Multi button pad  88  permits the user to turn accessories on or off or to receive specific data, for example the distance to a target or the current GPS location. Multi-button pad  88  allows a user to access features the system can provide through external data transfer module  84 . 
     Referring now to  FIG. 5  a block diagram of a primary Printed Circuit Board (PCB) contained within an inductively powering rail is shown as feature  54 . 
     Power is received by PCB  54  via conductive power path  82  from master controller  72  (see  FIG. 4 ). Hot swap controller  74  serves to load the inductively powering rail  14  slowly. This reduces the amount of in rush current during power up. It also limits the amount of current that can be drawn from the inductively powering rail  14 . Conductive power is distributed to two main components, the inductively powering rail slots  20  and the master CPU  76  residing on PCB  54 . 
     Hot swap controller  74  provides via feature  154 , voltage in the range of 14V to 22V which is sent to a MOSFET and transformer circuitry  156  for each inductively powering rail slot  20  on inductively powering rail  14 . 
     Feature  158  is a 5V switcher that converts battery power to 5V for the use of MOSFET drivers  160 . MOSFET drivers  160  turn the power on and off to MOSFET and transformer circuitry  156  which provides the power to each primary U-Core  26 . Feature  162  is a 3.3V Linear Drop Out Regulator (LDO), which receives its power from 5V switcher  158 . LDO  162  provides power to mastel CPU  76  and supporting logic within each slot. Supporting logic is Mutiplexer  172  and D Flip Flops  176 . 
     The Multiplexer  172  and the D Flip-Flops  176 ,  177  are utilized as a serial shift register. Any number of multiplexers  172  and D Flip-Flops  176 ,  177  may be utilized, each for one inductively powered rail slot  20 . This allows master CPU  76  to determine which slots are enabled or disabled and to also enable or disable a slot. The multiplexer  172  is used to select between shifting the bit from the previous slot or to provide a slot enable signal. The first D Flip Flop  176  latches the content of the Multiplexer  172  and the second D Flip-Flop  177  latches the value of D Flip-Flop  177  if a decision is made to enable or disable a slot. 
     Hall effect transistor  164  detects when an accessory is connected to inductively powering rail  14  and enables MOSFET driver  160 . 
     Referring now to  FIG. 6  a block diagram of a PCB contained within an accessory such as  42  is shown generally as  52  Feature  180  refers to the primary U-Core  26  and the secondary U-Core  50 , establishing a power connection between inductively powering rail  14  and accessory  42 . High power ramp circuitry)  82  slowly ramps the voltage up to high power load when power is turned on. This is necessary as some accessories such as those that utilize XEON bulbs when turned on have low resistance and they draw excessive current. High power load  184  is an accessory that draws more than on the order of two watts of power. 
     Full wave rectifier and DC/DC Converter  186  rectifies the power from U-Cores  180  and converts it to a low power load  188 , for an accessory such as a night vision scope. Pulse shaper  190  clamps the pulse from the U-Cores  180  so that it is within the acceptable ranges for microcontroller  98  and utilizes FSK via path  192  to provide a modified pulse to microcontroller  98  Microcontroller  98  utilizes a Zigbee component  198  via Universal Asynchronous Receiver Transmitter component (UART  196 ) to communicate between an accessory  42  and master controller  72 . The types of information that may be communicated would include asking the accessory for information about itself, instructing the accessory to enter low power mode or to transfer power. 
     Referring now to  FIG. 7 , a block diagram of the components of a master controller  72  is shown (see  FIG. 1 ) Conductive power is provided from battery  78  via conductive power path  82 . Hot swap controller  74  slowly connects the load to the inductively powering rail  14  to reduce the amount of in rush current during power up. This also allows for the limiting of the amount of current that can be drawn. Feature  200  is a 3.3 v DC/DC switcher, which converts the battery voltage to 3.3V to be used by the master CPU  76 . 
     Current sense circuitry  202  measures the amount of the current being used by the system  70  and feeds that information back to the master CPU  76 . Master controller  72  also utilizes a Zigbee component  204  via Universal Asynchronous Receiver Transmitter component (UART)  206  to communicate with accessories connected to the inductively powering rail  14 ,  94  or  96 . 
     Before describing  FIGS. 8, 9 and 10  in detail, we wish the reader to know that these Figures are flowcharts or processes that run in parallel, they each have their own independent tasks to perform. They may reside on any device but in one embodiment all would reside on master CPU  76 . 
     Referring now to  FIG. 8 , a flow chart of the steps of connecting an accessory to an inductively powering rail is shown generally as  300 . Beginning at step  302 , the main system power switch is turned on by the user through the use of multi-button pad  88  or another switch as selected by the designer. Moving next to step  304  a test is made to determine if an accessory, such as feature  42  of  FIG. 4  has been newly attached to inductively powering rail  14  and powered on or an existing accessory  42  connected to inductively powering rail  14  is powered on. At step  306  the magnets  46  on the accessory magnetize the pins  24  thereby closing the circuit on the primary PCB  54  via magnetic switch  48  and thus allowing the activation of the primary and secondary U-cores  26  and  50 , should they be needed. This connection permits the transmission of power and communications between the accessory  42  and the inductively powering rail  14  (see features  90  and  92  of  FIG. 4 ). 
     Moving now to step  308  a communication link is established between the master CPU  76  and the accessory via control inductive control path  92 . Processing then moves to step  310  where a test is made to determine if an accessory has been removed or powered off. If not, processing returns to step  304 . If so, processing moves to step  312  where power to the primary and secondary U-Cores  26  and  50  for the accessory that has been removed. 
       FIG. 9  is a flow chart of the steps for managing power usage shown generally as  320 . There may be a wide range of accessories  42  attached to an inductively powering rail  14 . They range from low powered (1.5 to 2.0 watts) and high powered (greater than 2.0 watts). Process  320  begins at step  322  where a test is made to determine if system  70  requires power. This is a test conducted by master CPU  76  to assess if any part of the system is underpowered. This is a continually running process. If power is at an acceptable level, processing returns to step  322 . If the system  70  does require power, processing moves to step  324 . At step  324  a test is made to determine if there is an external power source. If so, processing moves to step  326  where an external power source such as  80  (see  FIG. 4 ) is utilized. Processing then returns to step  322 . If at step  324  it is found that there is no external power source, processing moves to step  328 . At step  328  a test is made to determine if there is an auxiliary power source such as feature  102  (see  FIG. 4 ). If so processing moves to step  330  where the auxiliary power source is utilized. Processing then returns to step  322 . If at step  328  it is determined that there is no auxiliary power source, processing moves to step  332 . At step  332  a test is made to determine if on board power is available. On board power comprises a power device directly connected to the inductively powering rail  14 . If such a device is connected to the inductively powering rail  14 , processing moves to step  334  where the system  70  is powered by on board power. Processing then returns to step  322 . If at step  332  no on board power device is located processing moves to step  336 . At step  336  a test is made to determine if there is available power in accessories. If so, processing moves to step  338  where power is transferred to the parts of the system requiring power from the accessories. Processing then returns to step  322 . If the test at step  336  finds there is no power available, then the inductively powering rail  14  is shut down at step  340 . 
     The above steps are selected in an order that the designers felt were reasonable and logical. That being said, they do not need to be performed in the order cited nor do they need to be sequential. They could be performed in parallel to quickly report back to the Master CPU  76  the options for power. 
       FIG. 10  is a flow chart of the steps for determining voltage and temperature of the system, shown generally as  350 . Beginning at step  352  a reading is made of the power remaining in battery  78 . The power level is then displayed to the user at step  354 . This permits the user to determine if they wish to replace the batteries or recharge the batteries from external power source  80 . Processing moves next to step  356  where a test is made on the voltage. In one embodiment the system  70  utilizes Lithium-Ion batteries, which provide near constant voltage until the end of their life, which allows the system to determine the decline of the batteries be they battery  78  or batteries within accessories. If the voltage is below a determined threshold processing moves to step  358  and system  70  is shut down. If at step  356  the voltage is sufficient, processing moves to step  360 . At this step a temperature recorded by a thermal fuse is read. Processing then moves to step  362 , where a test is conducted to determine if the temperature is below a specific temperature. Lithium-Ion batteries will typically not recharge below −5 degrees Celsius. If it is too cold, processing moves to step  358  where inductively powering rail  14  is shut down. If the temperature is within range, processing returns to step  352 . 
     With regard to communication between devices in system  70  there are three forms of communication, control path  86 , inductive control path  92  and Zigbee ( 198 ,  204 ). Control path  86  provides communications between master CPU  76  and inductively powered rails  14 ,  94  and  96 . Inductive control path  92  provides communication between an accessory such as  42  with the inductively powered rails  14 ,  94  and  96 . There are two lines of communication here, one between the rails and one between the accessories, namely control path  86  and inductive control path  92  Both are bidirectional The Zigbee links ( 198 ,  204 ) provide for a third line of communication directly between an accessory such as  42  and master CPU  76 . 
     Referring now to  FIGS. 11-19D  alternative embodiments of the present invention are illustrated. As with the previous embodiments, a rail configuration designed to mount accessories such as sights, lasers and tactical lights is provided. In accordance with an exemplary embodiment a Networked Powered Data System (NPDS) is provided wherein the rail or rails is/are configured to provide power and data through a weapon coupled to accessories. Furthermore and in additional embodiments, the power and data may be exchanged between the weapon and/or a user coupled to the weapon by a tether and in some applications the user is linked a communications network that will allow data transfer to other users who may or may not also have weapons with rail configurations that are coupled to the communications network. 
     As used herein rails may refer to inductively powered rails or Networked Powered Data System rails. As previously described, the rails will have recoil slots that provide data and power as well as mechanically securing the accessory to the rail. 
     In this embodiment, or with reference to the NPDS rail, specific recoil slots have been dedicated for power only while other recoil slots have been configured for data communication only. In one non-limiting exemplary embodiment, one of every three rail slots is dedicated for data communication and two of every three rail slots are dedicated to power transfer. Therefore, every three slots in this embodiment will be functionality defined as two power slots and one communications slot. In one non-limiting configuration, the slots will be defined from one end of the rail and the sequence will be as follows: first slot from an end of the rail is dedicated to data, second slot from the end is dedicated to power, third slot from the end is dedicated to power, fourth slot from the end is dedicated to data, fifth slot from the end is dedicated to power, six slot from the end is dedicated to power, etc. Of course, exemplary embodiments of the present invention contemplate any variations on the aforementioned sequence of data and power slots. 
     Contemplated accessories for use with the NPDS rail would optimally have either a 3 slot or 6 slot or longer multiples of power-data sequence to benefit from interfacing with power and data slot sequence mentioned above. Accordingly, the accessory can be placed at random anywhere on the rail. In this embodiment, the accessory will have the capability to discern which recoil slot is dedicated to power and which recoil slot is dedicated to data. 
     In contrast, to some of the prior embodiments data and power was provided in each slot however and by limiting specific slots to data only higher rates of data transfer were obtained. 
     As illustrated in  FIG. 11 , a perspective view of an inductively powered NPDS rail is shown generally as  410 . As in the previous embodiments, an inductively powering rail  414  is slid over a rail  412  that has a plurality of rail slots  416  and rail ribs  418 . Alternatively, the rail  414  may be integral with the upper receiver and replace rail  412 . The inductively powering rail  414  has a plurality of rail slots  420 , rail ribs  422  and pins  424 ,  425 . The rail slots and ribs are arranged for mating of accessories with inductively powering rail  414 . As discussed above, pins  424  are associated with powered slots “P” while pins  425  are associated with data slots “D”. It is not the intent of the inventors to restrict embodiments to a specific rail configuration, as it may be adapted to any rail configuration. The preceding serves only as an example of several embodiments to which inductively powering rail  414  may be mated. 
     In one embodiment each slot provides on the order of four watts. Of course, power transfers greater or less than four watts are considered to be within the scope of embodiments disclosed herein. 
     Pins  424  and  425  are in one embodiment stainless steel pins of grade 430. Of course, other alternative materials are contemplated and the embodiments of the present invention are not limited to the specific materials mentioned above. Referring now to  FIGS. 12A and 12B  and when an accessory  442  is connected to inductively powering rail  414 , pins  424  and  425  are magnetized by magnets  446  located within each portion of the accessory configured to be positioned over the ribs  422  of the rail  414  such that pins  424  and  425  are magnetized by the magnets  446 . As illustrated in  FIG. 12A , which is a cross sectional view of a portion of an accessory coupled to the rail, each pin  425  is configured such that a first end  445  is located on top of rib  422 , an intermediate portion  447  of pin  425  is located above magnetic switch  448  and a second end  449  is also located on rib  422 . Accordingly and when pin  425  is magnetized by magnet  446  in accessory  442  when the accessory is placed upon the rail, the magnetized pin  425  causes magnetic switch  448  to close to indicate to the inductively powering rail  414  that an accessory has been connected to the data slot D. 
     In addition and in this embodiment, accessory  442  is provided with a magnetic accessory switch  451  that is also closed by the magnetized pin  425  which now returns to the surface of rib  422 . Here, the accessory via a signal from magnetic switch  451  to a microprocessor resident upon the accessory will be able to determine that the secondary coil  450  associated with the switch  451  in  FIG. 12A  is located above a data slot D and this coil will be dedicated to data transfer only via inductive coupling. Accordingly, the data recoil slot is different from the power slot in that the associated type 430 stainless steel pin is extended to become a fabricated clip to conduct the magnetic circuit from the accessory to the rail and back again to the accessory. The clip will provide a magnetic field which, will activate the solid state switch or other equivalent item located within the rail on the one side and then will provide a path for the magnetic field on the other side of the rail reaching up to the accessory. Similarly, the accessory will have a solid state switch or equivalent item located at each slot position which, will be closed only if it is in proximity with the activated magnetic field of the data slot. This provides detection of the presence and location of the adjacent data slot. In accordance with various embodiments disclosed herein, the accessory circuitry and software is configured to interface with the rail in terms of power and data communication. 
     In contrast and referring to  FIG. 12B , which is a cross sectional view of an another portion of the accessory secured to the rail, the secondary coil  450  associated with switch  451  of the portion of the accessory illustrated in  FIG. 12B  will be able to determine that the secondary coil  450  associated with the switch  451  in  FIG. 12B  is located above a power slot P and this coil will be dedicated to power transfer only via inductive coupling. As mentioned, above the complimentary accessory is configured to have a secondary coil  450 , magnet  446  and switch  451  for each corresponding rib/slot combination of the rail they are placed on such that the accessory will be able to determine if it has been placed on a data only D of power only P slot/rib combination according to the output of switch  451 . 
     It being understood that in one alternative embodiment the primary coils associated with a rib containing pin  424  or pin  425  (e.g., data or power coils) may in one non-limiting embodiment be on either side of the associated rib and accordingly the secondary coils of the accessory associated with switch  451  will be located in a corresponding location on the accessory. For example, if the data slots are always forward (from a weapon view) from the rib having pin  425  then the accessory will be configured to have the secondary coils forward from its corresponding switch  451 . Of course and in an alternative configuration, the configuration could be exactly opposite. It being understood that the ribs at the end of the rail may only have one slot associated with it or the rail itself could possible end with a slot instead of a rib. 
     Still further and in another alternative embodiment, the slots on either side of the rib having pin  425  may both be data slots as opposed to a single data slot wherein a data/power slot configuration may be as follows: . . . D, D, P, P, D, D, . . . as opposed to . . . D, P, P, D, P, P . . . for the same six slot configurations however, and depending on the configuration of the accessory being coupled to the rail a device may now have two data slots (e.g., secondary coils on either side of switch  451  that are now activated for data transfer). Of course, any one of numerous combinations are contemplated to be within the scope of exemplary embodiments of the present invention and the specific configurations disclosed herein are merely provided as non-limiting examples. 
     As in the previous embodiment and should the accessory be removed and the connection between the accessory and the rail is broken, the change in the state of the switch  451  and switch  448  is recognized by the system managing inductively powering rail  414 . As in the previous embodiment, pins  424  can be offset from the center of inductively powering rail  414  to ensure an accessory is mounted in the correct orientation. 
     In yet another alternative and referring now to  FIG. 12C , a pair of pins  425  are provided in the data slot and a pair of separate magnets (accessory magnet and rail magnet are used). Here the pins are separated from each other and one pin  425 , illustrated on the right side of the FIG., is associated with the accessory magnet  446  and rail switch  448  similar to the  FIG. 12A  embodiment however, the other pin  425  illustrated on the left side of the FIG., is associated with the accessory switch  451  and a separate rail magnet  453 , now located in the rail. Operation of accessory switch  451  and rail switch  448  are similar to the previous embodiments. 
     Power for each primary  426  or secondary  450  can be provided by a plurality of sources. For example, a power source may be within the firearm, it may be within an accessory or it may be provided by a source such as a battery pack contained in the uniform of the user that is connected to the firearm, or by a super capacitor connected to the system. The aforementioned serve merely as examples of diverse power sources that may be utilize by embodiments of the invention. 
     Although illustrated for use in inductive coupling of power and/or data to and from an accessory to the rail, the pin(s), magnet(s) and associated switches and arrangements thereof will have applicability in any type of power and data transfer arrangement or configurations thereof (e.g., non-inductive, capacitive, conductive, or equivalents thereof, etc.). 
     Aside from the inductive power transferring, distributing and managing capabilities, the NPDS also has bidirectional data communication capabilities. As will be further discussed herein data communication is further defined as low speed communication, medium speed communication and high speed communication. Each of which according to the various embodiments disclosed herein may be used exclusively or in combination with the other rates/means of data communication. Thus, there are at least three data transfer rates and numerous combinations thereof, which are also referred to as data channels that are supported by the system and defined by their peak rates of 100 kb/s, 10 Mb/s and 500 Mb/s. Of course, other data rates are contemplated and exemplary embodiments are not specifically limited to the data rates disclosed herein. The three data channels are relatively independent and can transfer data at the same time. The three data channels transfer data in a serial bit by bit manner and use dedicated hardware to implement this functionality. 
     The 100 kb/s data channel, also called the low-speed data communication channel, is distributed within the system electrically and inductively. Similarly to the inductive power transfer, the low speed channel is transferred inductively by modulating a magnetic field across an air gap on the magnetic flux path, from the rail to the accessory and back. The data transfer is almost not affected by the gap size. This makes the communication channel very robust and tolerant to dirt or misalignment. This channel is the NPDS control plane. It is used to control the different accessories and transfer low speed data between the NPDS microprocessors and the accessories. One slot of every three rail slots is dedicated to the low speed communication channel. 
     The 10 Mb/s data channel, also called the medium-speed data communication channel, is distributed within the system electrically and inductively. It is sharing communication rail slots with the low speed data channels and the data is transferred to the accessories inductively in the same manner. The NPDS is providing the medium speed data channel path from one accessory to another accessory or a soldier tether coupled to the rail, and as it does not terminate at the Master Control Unit (MCU) this allows simultaneous low speed and medium speed communications on the NPDS system. The MCU is capable of switching medium speed communications data from one accessory to another accessory. When the communication slot is in medium speed mode then all of the related circuit works at a higher frequency and uses different transmission path within the system. The low or medium speed communication channel functionality can be selected dynamically. 
     The 500 Mb/s data channel, also called the high-speed data communication channel, is distributed within the system electrically and optically. It is using a dedicated optical data port at the beginning of the rail (e.g., closest to the pistol grip). The high-speed data channel is transferred optically between optical data port and the accessories. Similarly to the medium speed channel, NPDS is providing the high-speed data channel path from an accessory to the soldier tether, and as it does not terminate at the Master Control Unit (MCU) this allows simultaneous low speed, medium speed and high speed communications on the NPDS system. 
       FIGS. 13A and 13B  illustrate a front end of an upper receiver  471  showing an upper inductive/data rail  414  and side accessory inductive/data rails  494  and  496  wherein the side accessory inductive/data rails  494  and  496  are directly wired to upper inductive/data rail  414  via wires  486  and  482  that are located within bridges  487  fixedly secured to the upper receiver so that wires  486  and  482  are isolated and protected from the elements. Thus, the bridges provide a conduit of power  482  and data  486  from the top rail to the side rails (or even a bottom rail not shown). Bridges  487  are configured to engage complimentary securement features  491  located on rails  414 ,  494  and  496  or alternatively upper receiver  471  or a combination thereof. In addition, the bridges will also act as a heat dissipater. In one embodiment, the bridges are located towards the end of the rail closest to the user. The gun barrel is removed from this view for clarity purposes.  FIGS. 13C  and D illustrate alternative configurations of the rail bridges  487  illustrated in  FIGS. 13A and 13B . 
       FIG. 14A  is a top view of the upper receiver  471  with the upper inductive/data rail  414  and side accessory inductive/data rails  494  and  496  while  FIG. 14B  is a top view of the upper receiver  471  with the upper inductive/data rail  414  and side accessory inductive/data rails  494  and  496  without the upper receiver.  FIGS. 14C and 14D  illustrate alternative configurations of the rail bridges  487  and the rail  494  illustrated in  FIGS. 14A and 14B . 
     Referring now to  FIGS. 15A-15B  an apparatus and method for securing and positively locking the inductive/data rail (e.g., upper, side or bottom) to the existing rail  412  of the upper receiver  471 . Here, an expanding wedge feature  491  comprising a pair of wedge members  493  is provided. To secure rail  414  to rail  412  each wedge member is slid into a slot of the rail axially until they contact each other and the sliding contact causes the surface of the wedge members to engage a surface of the slot. In order to axially insert the wedge members, a pair of complimentary securement screws  495  are used to provide the axial insertion force as they are inserted into the rail by engaging a complimentary threaded opening of the rail  414 , wherein they contact and axially slide the wedge members  493  as the screw is inserted into the threaded opening. 
     Referring now to  FIGS. 15D-F , alternative non-limiting configurations of bridges  487  are illustrated, in this embodiment, bridges  487  are attached to the rails by a mechanical means such as screws or any other equivalent device. 
     With reference now to  FIG. 16 , as discussed generally above the accessories  42  and the master CPU  76  can communicate with one another in several different manners. For example, and as also described above, the master CPU  76  can vary the frequency that power or another signal is provided to the accessories  42  to provide information (data) to them. Similarly, the accessories  42  can communicate data to the master CPU  76  by utilizing load modulation. As discussed above, such communication can occur on the same cores (referred to below as “core pairs”) as are used to provide power or can occur on separate coils. Indeed, as described above, in one embodiment, one in every three coils is dedicated to data transmission. 
       FIG. 16  illustrates three different communication channels shown as a low speed channel  502 , a medium speed channel  504  and a high speed channel  506 . The low speed channel  502  extends from and allows communication between the master CPU  76  and any of the accessories  42 . The low speed channel  502  can be driven by a low speed transmitter/receiver  510  in the master CPU  76  that includes selection logic  512  for selecting which of the accessories  42  to route the communication to. 
     Each accessory  42  includes low speed decoding/encoding logic  514  to receive and decode information received over the low speed channel  502 . Of course, the low speed decoding/encoding logic  514  can also include the ability to transmit information from the accessories  42  as described above. 
     In one embodiment, the low speed channel  502  carries data at or about 100 kB/s. Of course, other speeds could be used. The low speed channel  502  passes through an inductive coil pair  520  (previously identified as primary coil  26  and secondary coil  50  hereinafter referred to as inductive coil pair  520 ) between each accessory  42  and the master CPU  76 . It shall be understood, however, that the inductive coil pair could be replaced include a two or more core portions about which the coil pair is wound. In another embodiment, the cores can be omitted and the inductive coil pair can be implemented as an air core transformer. As illustrated, the inductive coil pairs  520  are contained within the inductive powering rail  14 . Of course and as illustrated in the previous embodiments, one or more of the coils included in the inductive coil pairs  520  can be displaced from the inductive powering rail  14 . 
     The medium speed channel  504  is connected to the inductive coil pairs  520  and shares them with low speed channel  502 . For clarity, branches of the medium speed channel  504  as illustrated in dashed lines. As one of ordinary skill will realize, data can be transferred on both the low speed channel  502  and the medium speed channel at the same time. The medium speed channel  504  is used to transmit data between the accessories  42 . 
     Both the low and medium speed channels  502 ,  504  can also be used to transmit data to or receive data from an accessory (e.g. a tether) not physically attached to the inductively powering rail  14  as illustrated by element  540 . The connection between the master CPU  76  can be either direct or through an optional inductive coil pair  520 ′. In one embodiment, the optional inductive coil pair  520 ′ couples power or data or both to a CPU located in or near a handle portion of a gun. 
     To allow for communication between accessories over the medium speed channel  504 , the master CPU  76  can include routing logic  522  that couples signals from one accessory to another based on information either received on the medium speed channel  504 . Of course, in the case where two accessories coupled to the inductively powering rail  14  are communicating via the medium speed channel  502 , the signal can be boosted or otherwise powered to ensure is can drive the inductive coil pairs  520  between the accessories. 
     In another example, the accessory that is transmitting the data first utilizes the low speed channel  502  to cause the master CPU  76  to set the routing logic  522  to couple the medium speed channel  504  to the desired receiving accessory. Of course, the master CPU  76  itself (or an element coupled to it) can be used to separate low and medium speed communications from one another and provide them to either the low speed transmitter/receiver  510  or the routing logic  522 , respectively. In one embodiment, the medium speed channel  504  carries data at 10 MB/s. 
       FIG. 16  also illustrates a high speed channel  506 . In one embodiment, the high speed channel  506  is formed by an optical data line and runs along at least a portion of the length of the inductively powering rail  14 . For clarity, however, the high speed channel  506  is illustrated separated from the inductively powering rail  14 . Accessories  42  can include optical transmitter/receivers  542  for providing signals to and receiving signals from the high speed channel  506 . In one embodiment, a high speed signal controller  532  is provided to control data flow along the high speed channel  506 . It shall be understood that the high speed signal controller  532  can be located in any location and may be provided, for example, as part of the master CPU  76 . In one embodiment, the high speed signal controller  532  is an optical signal controller such as, for example, an optical router. 
       FIG. 17  illustrates an example of the MOSFET driver  154  coupled to MOSFET and transformer circuitry  156 . In general, the MOSFET driver  154  the MOSFET and transformer circuitry  156  to produce an alternating current (AC) output at an output coil  710 . The AC output couples power to a receiving coil  712 . As such, the output coil  710  and the receiving coil  712  form an inductive coil pair  520 . In one embodiment, the receiving coil  712  is located in an accessory as described above. 
     It shall be understood that it is desirable to achieve efficient power transfer from the output coil  710  to the receiving coil  712  (or vice versa). Utilizing the configuration shown in  FIG. 17  has led, in some instances, to a power transfer efficiency of greater than 90%. In addition, it shall be understood, that the accessory could also include such a configuration to allow for power transfer from the receiving coil  712  to the output coil  710 . The illustrated MOSFET and transformer circuitry  156  includes an LLC circuit  711  that, in combination with the input and output coils, forms an LLC resonant converter. The LLC circuit  711  includes, as illustrated, a leakage inductor  706 , a magnetizing inductor  708  and a capacitor  714  serially connected between input node  740  and ground. The magnetizing inductor  708  is coupled in parallel with the output coil  710 . The operation and location of the first and second driving MOSFET&#39;s  702 ,  704  is well known in the art and not discussed further herein. In one embodiment, utilizing an LLC resonant converter as illustrated in  FIG. 17  can lead to increased proximity effect losses due to the higher switching frequency, fringe effect losses due to the presence of a gap, an effective reverse power transfer topology, and additional protection circuits due to the unique nature of the topology. 
     In one embodiment, the MOSFET&#39;s  702 ,  704  are switched at the second resonant frequency of the resonant LLC resonant converter. In such a case, the output voltage provided at the output coil  710  is independent of load. Further, because the second resonant frequency is dominated by the leakage inductance and not the magnetizing inductance, it also means that changes in the gap size (g) do little to change the second resonant point. As is known in the art, if the LLC resonant converter is above the second resonant point, reverse recovery losses in rectifying diodes in the receiving device (not illustrated) are eliminated as the current through the diode goes to zero when they are turned off. If operated below the resonant frequency, the RMS currents are lower and conduction losses can be reduced which would be ideal for pure resistive loads (i.e.: flash light). However, operating either above or below the second resonant point lowers the open loop regulation, so, in one embodiment, it may be desirable to operate as close as possible to the second resonant point when power a purely resistive load (e.g., light bulb) or rectified load (LED). 
     The physical size limitations of the application can lead to forcing the resonant capacitor  714  to be small. Thus, the LLC resonant converter can require a high resonant frequency (e.g., 300 kHz or higher). Increased frequency, of course, leads to increased gate drive loss at the MOSFET&#39;s  702 ,  704 . To reduce these effects, litz wire can be used to connect the elements forming the LLC circuit  711  and in the coils  710 ,  712 . In addition, it has been found that utilizing litz wire in such a manner can increase gap tolerance. 
     The increased gap tolerance, however, can increase fringe flux. Fringe flux from the gap between the cores around which coils  710  and  712  are wound can induce conduction losses in metal to the cores. Using litz wire can combat the loss induced in the windings. However, a means of reducing the loss induced in the rails is desirable. This can be achieved by keeping the gap away from the inductively coupling rail, creating a gap spacer with a distributed air gap that has enough permeability to prevent flux fringing, or by adding magnetic inserts into the rail to prevent the flux from reaching the aluminum. 
     Referring now to  FIG. 18 , portions of an upper receiver and a lower receiver equipped with the inductive power and data transferring rail are illustrated. As illustrated, the pistol grip  897  is configured to have a rear connector  899  configured for a sling tether  501  to transmit power and bi-directional data from an external soldier system  540  coupled to the tether. 
     As illustrated, the pistol grip is configured to support the rear power/data connector for the sling tether. In addition, a portion  905  of the pistol grip is reconfigured to wrap up around the top of the upper receiver to provide a supporting surface for buttons  907  to control (on/off, etc.) the accessories mounted on the rails. In one embodiment, the buttons will also be provided with haptic features to indicate the status of the button or switch (e.g., the buttons will vibrate when depressed). 
     Portion  905  also includes a pair of coils  909  for inductively coupling with another pair of coils on the lower receiver (not shown). In one non-limiting exemplary embodiment, the inductive cores will be an EQ20/R core commercially available from Ferroxcube. Further information is available at the following website http://www.ferroxcube.com/prod/assets/eq20r.pdf and in particular  FIG. 1  found at the aforementioned website. A circuit board will have a coil pattern and the EQ20/Rcores will be cut into the middle of the circuit board. 
     Accordingly, portion  905  provides a means for coupling between the upper and lower receiver to transmit power and data to and from the rails. As such, data from a microprocessor or other equivalent device resident upon the upper receiver can be transferred to a microprocessor or other equivalent device resident upon the lower receiver. In addition, power may be transferred between the upper receiver and lower receiver via inductive coupling.  FIGS. 19A-19D  illustrate views of portion  905  for coupling the upper receiver portion to the lower receiver wherein the coupling has features  911  for receipt of the cores therein. 
     In addition and referring now to  FIG. 18  one of the optical transmitters/receivers  542  is located at the rear portion of the rail for optical communication with a complimentary optical transmitter/receiver  542  located on the accessory (See at least  FIG. 16 ). As illustrated, the optical transmitter/receiver  542  is coupled to a fiber optic wire or other data communication channel  506  that is coupled to another optical transmitter/receiver  542 ′ that communicates with an optical transmitter/receiver  542 ′ located on the lower receiver and is coupled to the rear connector  899  via a fiber optic wire or other data communication channel  506  located within the lower receiver. 
     Accordingly and as illustrated schematically in at least  FIGS. 16 and 18  is that portion  905  allows data and power transfer between the upper receiver and the lower receiver via the coils of the upper receiver and the lower receiver while also allowing the upper receiver to be removed from the lower receiver without physically disconnecting a wire connection between the upper and lower receiver. Similarly and in the embodiment where the high speed channel is implemented the optical transmitter/receivers  542 ′ allow the upper receiver to be removed from the lower receiver without physically disconnecting a wire connection between the upper and lower receiver. Also shown in  FIG. 18  is that a rear sight  919  is provided at the back of the NPDS rail. 
     Referring now to  FIGS. 18A and 20A -F, an alternative configuration of portion  905 , illustrated as  905 ′, is provided. As mentioned above, portion  905 ′ provides a means for providing the inductive method of bi-directionally transferring power and data from the upper receiver to the lower receiver. In this embodiment,  905 ′ is an appendage of the upper receiver. Portion  905 ′ has a housing configured to receive a circuit board  921  and associated electronics required for data and power communication. Once the circuit board  921  is inserted therein it is covered by a cover  923 . In one embodiment, cover  923  is secured to the housing of portion  905 ′ by a plurality of screws  925 . Of course, any suitable means of securement is contemplated to be within the scope of exemplary embodiments of the present invention. 
     In this embodiment, portion  905 ′ is configured to have a power core  927  and a pair of data cores  929 . As illustrated, the power core  927  is larger than the smaller two data cores  929 . Portion  905 ′ is configured to interface with the pistol grip  897  such that as the two are aligned, portion  905 ′ locks or wedges into complementary features of the pistol grip  897  such that the pistol grip is secured thereto and the power and data cores ( 927  and  929 ) are aligned with complementary power and data cores located in the pistol grip  897 . Accordingly and in this embodiment, the pistol grip  897  will also have a pair of data cores and a power core matching the configuration of those in portion  905 ′. 
     In this embodiment, the smaller data cores  929  and those of the pistol grip can be configured for low speed data (100 kbps) and medium speed data (10 Mbps) at the same time. Of course, the aforementioned data transfer rates are merely provided as examples and exemplary embodiments of the present invention contemplate ranges greater or less than the aforementioned values. 
       FIG. 21  illustrates a portion of a pistol grip  897  contemplated for use with portion  905 ′. As illustrated, a pair of complementary data cores  931  and a complimentary power core  933  are configured and positioned to be aligned with portion  905 ′ and its complementary cores (data and power) when portion  905 ′ is secured to pistol grip  897  such that inductive power and data transfer can be achieved. In one non-limiting embodiment, pistol grip  897  has a feature  935  configured to engage a portion of portion  905 ′ wherein feature  935  is configured to assist with the alignment and securement of portion  905 ′ to the pistol grip  897 . 
     Referring now to  FIGS. 22 and 23  yet another alternative method of bi-directionally transferring power and data from the upper receiver to the lower receiver is illustrated. In this embodiment, conductive data and power transmission is achieved through a connector such as a cylindrical connector  936 . In this embodiment, a generic connector  936  (comprising in one embodiment a male and female coupling) couples a conduit or cable  937  (illustrated by the dashed lines in  FIG. 22 ) of the upper receiver to a complementary conduit or cable  939  of the lower receiver (also illustrated by dashed lines in  FIG. 22 ), when the upper receiver is secured to the lower receiver. One non-limiting embodiment of such a connector is available from Tyco Electronics. 
     In order to provide this feature the upper receiver is configured to have an appendage  941  that provides a passage for the cable  937  from the upper rail to the joining cylindrical connector  936 . Similar to portion  905  and  905 ′ the appendage  941  is configured to lock and secure the pistol grip  897  to the upper receiver to align both halves of the cylindrical connector  936  (e.g., insertion of male/female pins into each other). 
     In this embodiment, the sling attaching plate  938  of the lower receiver portion has a common screw  940  to secure the pistol grip to the upper receiver to ensure alignment of both halves of the cylindrical connector. 
     Also shown is a control button  942  (for control on/off, etc. of various accessories mounted on the rails or any combination thereof) that is positioned on both sides the pistol grip  897 . In one non-limiting embodiment, the control button is configured to act as a switch for a laser accessory mounted to the weapon. The control button is found in both the conductive and inductive pistol grip configurations and is activated by the side of an operator&#39;s thumb. Requiring side activation by a user&#39;s thumb prevents inadvertent activation of the control button when handling the grip  897 . In other words, control button  942  requires a deliberate side action of the thumb to press the control button  942 . 
     In order to provide a means for turning on/off the entire system of the NPDS or the power supply coupled thereto an on/off button or switch  943  is also located on the pistol grip  897 . 
     In addition and referring now to  FIG. 24 , a power pack or battery  945  is shown attached to pistol grip  897 . In this embodiment, the battery is coupled to the pistol grip using a conductive attachment similar to the one used for power and data transfer between the upper receiver and the lower receiver via a generic connector (e.g., male/female configuration). Again, one non-limiting example of such a connector is available from Tyco Electronics and could be a similar type connector used in the embodiment of  FIGS. 22 and 23 . In order to release the battery pack  945  an actuating lever  947  is provided. 
       FIG. 25  shows an alternative method of fastening a battery pack to the bottom of the pistol grip  897  as well as an alternative method for transferring power/data inductively and bi-directionally. This method uses a power/data rail section  949  that is mounted to the bottom of the pistol grip  897 , which in one exemplary embodiment is similar in configuration to the rails used for the upper and lower receivers and accordingly, it is now possible to use the same battery pack at the pistol grip location or at a rail section elsewhere and accordingly, power the system. In addition, the mounting to the bottom of the pistol grip it is also contemplated that the rail can be used to inductively couple the battery pack to the pistol grip as any other side as long as a desired location of the battery pack is achieved. 
     In addition and since battery pack can be mounted at the pistol grip location or a rail section elsewhere on the weapon, it is now possible to transmitting data to control the battery pack mounted anywhere on the weapon or its associated systems. Such data can be used to control the power supply and the data as well as power, can be inductively transmitted between the battery pack or power supply and the component it is coupled to. Accordingly, the controller or central processing unit of the Network Powered Data System (NPDS) can determine and choose which battery pack would be activated first (in the case of multiple battery pack secured to the system) based upon preconfigured operating protocol resident upon the controller. For example and in one non-limiting embodiment, the forward rail mounted battery pack would be activated first. 
     For example and referring now to  FIG. 26 , a non-limiting example of a power system  951  for the Network Powered Data System (NPDS) according to an embodiment of the present invention is illustrated schematically. Here and as illustrated in the previous FIGS. a primary battery pack  945  is secured and coupled to the pistol grip  897  while a secondary power source or battery pack illustrated as  953  is secured to a forward rail of the upper receiver or, of course, any other rail of the weapon. In this embodiment, the secondary battery pack  953  can be a stand alone power supply similar to battery pack  945  or integrated with an accessory mounted to the rail. In one embodiment, secondary battery pack  953  is of the same size and configuration of primary battery pack  945  or alternatively may have a smaller profile depending on the desired location on the weapon. Secondary battery pack  953  can be utilized in a similar fashion as the primary battery pack  945  due to the reversible power capability of the rails as discussed above. 
     Still further, yet another source of power  955  also controlled by the system may be resident upon a user of the weapon (e.g., power supply located in a back pack of a user of the weapon) wherein an external power/data coupling is provided via coupling  957  located at the rear of the pistol grip  897  (See at least  FIGS. 21-23 ). In all cases both power and data are transmitted as the master control unit (MCU) of the NPDS communicates with the power sources (e.g., primary  945 , secondary  953  and external  955 ) and thus the MCU controls all the power supplies of the power system. 
     One advantage is that the system will work without interruption if for example, the primary battery pack  945  is damaged or suddenly removed from pistol grip  897  or rail  414  as long as an alternative power connection (e.g.,  953 ,  955 ) is active. Connection of the primary battery pack  945  or other power source device will also ensure that the rails are powered if the pistol grip  897  is damaged or completely missing including the CPU. For example and in one implementation, the default configuration of the rails will be to turn power on as an emergency mode. 
     Referring now to  FIGS. 27A-45 , various alternative exemplary embodiments of the present invention are illustrated. As with the previous embodiments, a rail configuration designed to mount accessories such as sights, lasers and tactical lights is provided. As mentioned above and in accordance with an exemplary embodiment a Networked Powered Data System (NPDS) is provided wherein the rail or rails is/are configured to provide power and data through a weapon coupled to accessories. Furthermore and in additional embodiments, the power and data may be exchanged between the weapon and/or a user coupled to the weapon by a tether and in some applications the user is linked a communications network that will allow data transfer to other users who may or may not also have weapons with rail configurations that are coupled to the communications network. 
     In this embodiment, the conductively powering rail  1014  similar to the above embodiments comprises a plurality of rail slots  1020 , rail ribs  1022  and pins  1024 , in a configuration that allows for the mating of accessories with conductively powering rail  1014 . However power and data transfer is facilitated by a conductive connection or coupling via power and data pins  1015  embedded into the rail  1014  and power and data pins  1017  embedded into an accessory  1042 . 
     It is not the intent of the inventors to restrict embodiments to a specific rail configuration, as it may be adapted to any rail configuration. The preceding serves only as an example of several embodiments to which the conductively powering rail  1014  may be mated. 
     Pins  1024  and  1025  in one embodiment are stainless steel pins of grade 430 and have configurations similar to those illustrated in the cross-sectional views illustrated in  FIGS. 28A and 28B . When an accessory is connected to conductively powering rail  1014 , pins  1024 ,  1025  connect to magnets  1046 ,  1047  and trigger magnetic switch  1048 ,  1051  (see  FIGS. 28A-28C ) to indicate to the conductively powering rail  1014  that an accessory  1042  has been connected. 
     Pins  1024  are offset from the center of conductively powering rail  1014  to ensure an accessory is mounted in the correct orientation, for example a laser accessory or flashlight accessory could not be mounted backward, and point in the users face as it would be required to connect to pins  1024 , to face away from the user of the firearm. 
     Referring now to  FIGS. 28A and 28B  and when an accessory  1042  is connected to conductively powering rail  1014 , pins  1024  and  1025  are magnetized by magnets  1046  located within each portion of the accessory configured to be positioned over the ribs  1022  of the rail  1014  such that pins  1024  and  1025  are magnetized by the magnets  1046 . As illustrated in  FIG. 28A , which is a cross sectional view of a portion of an accessory coupled to the rail, each pin  1025  is configured such that a first end  1045  is located on top of rib  1022 , an intermediate portion  1047  of pin  1025  is located above magnetic switch  1048  and a second end  1049  is also located on rib  1022 . Accordingly and when pin  1025  is magnetized by magnet  1046  in accessory  1042  when the accessory is placed upon the rail, the magnetized pin  1025  causes magnetic switch  1048  to close to indicate to the conductively powering rail  1014  that an accessory has been connected to the data slot D. 
     In addition and in this embodiment, accessory  1042  is provided with a magnetic accessory switch  1051  that is also closed by the magnetized pin  1025  which now returns to the surface of rib  1022 . Here, the accessory via a signal from magnetic switch  1051  to a microprocessor resident upon the accessory will be able to determine that the accessory electronics  1053  associated with the switch  1051  in  FIG. 28A  is located above a data slot D and these electronics or equivalent items will be dedicated to data transfer only via conductive coupling. Accordingly, the data slot is different from the power slot in that the associated type 430 stainless steel pin is extended to become a fabricated clip to conduct the magnetic circuit from the accessory to the rail and back again to the accessory. The clip will provide a magnetic field which, will activate the solid state switch or other equivalent item located within the rail on the one side and then will provide a path for the magnetic field on the other side of the rail reaching up to the accessory. Similarly, the accessory will have a solid state switch or equivalent item located at each slot position which, will be closed only if it is in proximity with the activated magnetic field of the data slot. This provides detection of the presence and location of the adjacent data slot. In accordance with various embodiments disclosed herein, the accessory circuitry and software is configured to interface with the rail in terms of power and data communication. 
     In contrast and referring to  FIG. 28B , which is a cross sectional view of an another portion of the accessory secured to the rail, the accessory electronics or other equivalent item  1053  associated with switch  1051  of the portion of the accessory illustrated in  FIG. 28B  will be able to determine that the accessory electronics  1053  associated with the switch  1051  in  FIG. 28B  is located above a power slot P and these electronics or equivalent items will be dedicated to power transfer only via conductive coupling. As mentioned, above the complimentary accessory may alternatively be configured to have a secondary electronics or equivalent item  1053 , magnet  1046  and switch  1051  for each corresponding rib/slot combination of the rail they are placed on such that the accessory will be able to determine if it has been placed on a data only D of power only P slot/rib combination according to the output of switch  1051 . 
     It being understood that in one alternative embodiment the electronics associated with a rib containing pin  1024  or pin  1025  (e.g., data or power) may in one non-limiting embodiment be on either side of the associated rib and accordingly the electronics or equivalent item of the accessory associated with switch  1051  will be located in a corresponding location on the accessory. For example, if the data slots are always forward (from a weapon view) from the rib having pin  1025  then the accessory will be configured to have the corresponding electronics forward from its corresponding switch  1051 . Of course and in an alternative configuration, the configuration could be exactly opposite. It being understood that the ribs at the end of the rail may only have one slot associated with it or the rail itself could possible end with a slot instead of a rib. 
     Still further and in another alternative embodiment, the slots on either side of the rib having pin  1025  may both be data slots as opposed to a single data slot wherein a data/power slot configuration may be as follows: . . . D, D, P, P, D, D, . . . as opposed to . . . D, P, P, D, P, P . . . for the same six slot configurations however, and depending on the configuration of the accessory being coupled to the rail a device may now have two data slots (e.g., secondary electronics on either side of switch  1051  that are now activated for data transfer). Of course, any one of numerous combinations are contemplated to be within the scope of exemplary embodiments of the present invention and the specific configurations disclosed herein are merely provided as non-limiting examples. 
     As in the previous embodiment and should the accessory be removed and the connection between the accessory and the rail is broken, the change in the state of the switch  1051  and switch  1048  is recognized by the system managing conductively powering rail  1014 . As in the previous embodiment, pins  1024  can be offset from the center of conductively powering rail  1014  to ensure an accessory is mounted in the correct orientation. 
     In yet another alternative and referring now to  FIG. 28C , a pair of pins  1025  are provided in the data slot and a pair of separate magnets (accessory magnet and rail magnet are used). Here the pins are separated from each other and one pin  1025 , illustrated on the right side of the FIG., is associated with the accessory magnet  1046  and rail switch  1048  similar to the  FIG. 28A  embodiment however, the other pin  1025  illustrated on the left side of the FIG., is associated with the accessory switch  1051  and a separate rail magnet  1053 , now located in the rail. Operation of accessory switch  1051  and rail switch  1048  are similar to the previous embodiments. 
     In this embodiment power and data to and from the accessory is provided by a plurality of power and data pins or contacts  1015  embedded into the rail  1014  and power and data pins or contacts  1017  embedded into an accessory  1042 . Accordingly, a galvanically coupled conductive rail power and communication distribution method for the rail system is provided. 
     In one embodiment, the exposed conductive metal rail contacts or contact surfaces  1035  and  1037  of pins  1015  and  1017  are made of Tungsten Carbide for excellent durability and corrosion resistance to most environmental elements. In one embodiment, the contact surfaces are round pads, pressed against each other to make good galvanic contact. The pads, both in the rail and the accessory, are permanently bonded to short posts of copper or other metal, that in turn, are electrically bonded to PCB substrates, rigid in the rail and flex in the accessory so that there is some give when the two surfaces are brought together. Accordingly, at least one of the pads in each contact pair provides some mechanical compliance, and in one embodiment the accessory is the item that have the mechanical compliance. Of course, this could also be in the rail or both. 
     In one embodiment and as illustrated in at least  FIGS. 29A-40  the pin/pad assemblies use an X-section ring  1019  as a seal and compressible bearing  1021 , with the internal connection end attached to a flex PCB. The pin/pad construction is shown in at least  FIG. 33 . The tungsten carbide pads provide durability where the extreme G-forces of weapon firing vibrate the accessory attachment structure. The hardness of the touching contact surfaces ensures that little if any abrasion will take place as the surfaces slip minutely against each other. The pressure of the seal bearing (x-ring) will keep the pads firmly pressed together during the firing vibration, keeping electrical chatter of the contacts at minimal levels. 
     As illustrated and in one embodiment, the slot contacts are composed of small tungsten “pucks” that are press-fit or brazed to a metal pin. Tungsten carbide exhibits a conductivity of roughly 5-10% that of copper and is considered a practical conductor. Assuming a good electrical bond between the puck and the pin, resistance introduced into the power path, accounting two traversals per round trip (Positive and Negative contacts). Alternatively, the pins are coated with tungsten carbide. In yet another alternative non-limiting embodiment the pins are coated with a tungsten composite, which in one non-limiting embodiment may be a nano coat blend of primarily tungsten and other materials such as cobalt which will exhibit similar or superior properties to tungsten carbide. 
       FIG. 34  illustrates the rail side pins and caps installed in the rail at each slot position.  FIG. 35  also illustrates a rail side pin. 
     Non-limiting examples of suitable copper alloys for the pins are provided as follows: Copper Alloy 99.99% Cu Oxygen Free; 99.95% Cu 0.001% O; and 99.90% Cu 0.04% O of course, numerous other ranges are contemplated. 
     In one embodiment, the Tungsten Carbide pad is secured to the copper pin via brazing process. Alternatively, the heads of the pins are coated with Tungsten Carbide. 
     Non-limiting examples of suitable Tungsten Carbide alloys are Tc—Co with Electrical Conductivity of 0.173 106/cmΩ and TC—Ni with Electrical Conductivity 0.143 106/cmΩ. 
     Tungsten Carbide is desired for its hardness and corrosion/oxidation resistance. The ultra-hard contact surface will ensure excellent abrasion endurance under the extreme acceleration stresses of weapon firing. In one embodiment, unpolished contact surfaces were used. 
     Moreover, the extreme hardness of tungsten carbide, only a little less than that of diamond, has virtually no malleability or sponginess, unlike softer metals like copper and lead. This means that two surfaces forced together will touch at the tallest micro-level surface features with little or no deformation of the peaks. This consequently small contact area will yield a resistance level that is much higher, possibly by orders of magnitude, over the expected theoretical resistance. 
     In one embodiment, the conductive networked power and date system (CNPDS) is a four-rail (top, bottom, left, right) system that distributes power and provides communication service to accessories that are mounted on any of the rails as well as the base of the grip. 
     The CNPDS provides power and communications to accessories mounted on the rails, but differs from the aforementioned inductively systems through the use of direct galvanic contact of power and communications. 
     In one embodiment and wherever possible, semiconductor elements associated with the power transfer path will be moved to locations external to the CNPDS. Presumably, those external elements can be viewed and managed as field replaceable items of far less cost and effort to replace than the rail system itself. 
     All elements of system communication will have the ability to be powered down into standby mode, and a main controller unit (MCU) software will be structured to make the best use of power saving opportunities. The CNPDS will support bi-directional power. 
     Slot power control is in one embodiment a desired feature for meeting power conservation goals, and the operation will be largely based on the magnetic activation principle mentioned above. 
     In one embodiment, each power slot is unconditionally OFF when there is no activating magnet present on its respective Hall sensor. When an accessory with an appropriately located magnet is installed, the Hall sensor permits activation of the slot power but does not itself turn the power ON while the system is in normal operating state. The actual activation of the power switches is left to the MCU, allowing it to activate slots that are understood to be occupied, while keeping all others OFF. 
     In one embodiment, there are two primary system states that define the operating mode of the slot power switches. The first state is normal operating mode, either during maintenance/configuration, or in actual use. In this state, the MCU I/O extension logic controls the power switch and the switch is only activated when the MCU commands the slot logic to do so. This requires that the MCU be aware of and expect an accessory on the associated Hall activated slot, having been previously run through a configuration process. 
     The second state is defined as the Safe Power Only (SPO) mode, where the MCU is assumed to be incapacitated and is unable or not sane enough to control the slot power directly. The condition is signaled to the rails from the MCU subsystem through a failsafe watchdog hardware mechanism, using either the absence of logic supply or a separate SPO flag signal. Under SPO state, the Hall sensor signal overrides the MCU logic control to activate the respective slot power unconditionally where an accessory is attached, assuming the system main power is also present. The primary consequence of this mode is loss of light load efficiency, since the MCU would normally shut down the Hall sensors to conserve power. Accessory ON-OFF control under the SPO condition is expected to be through a manual switch in the accessory. 
     In one embodiment, the rails, and any other CNPDS element that may be found to exceed +85C under operations heavy use, may have a temperature sensor embedded into it and readable by the MCU. Still further, the rails may actually have multiple sensors, one per 6-slot segment. With this provision, the system software can take protective actions when the rail temperature exceeds +85C. 
     In other embodiments, other weapon systems may feature an electromechanical trigger, the system can be allowed to automatically limit the generation of heat by pacing the rate of fire to some predetermined level. In cases where the heat sensor participates in the fire control of the weapon, the sensor system would be necessarily engineered to the same reliability level of the Fire-by-Wire electronics. 
     The battery pack, now fully self-contained with charging system and charge state monitoring, will also contain a temperature sensor. Many battery chemistries have temperature limits for both charging and discharge, often with different temperature limits for each. The inclusion of a local temperature sensor in the battery pack will eliminate the need for the battery to depend on the CNPDS for temperature information, and thus allow the charge management to be fully autonomous. 
     The CNPDS will have slot position logic such that any accessory can be installed at any slot position on any of the rails, and can expect to receive power and communication access as long as the activation magnet is present. 
     In order to meet certain power transfer efficiencies and in one embodiment target, power and communication will not be shared among slot contacts, and will instead be arranged in a suitable power/comm. slot interleave on the rails. 
     In one embodiment, the CNPDS will unify the low-speed and medium speed buses into a single, LAN-like 10 MBit/sec shared internal bus. Communication over this bus will be performed by transceiver technology that is commonly used for Ethernet networks. This simplifies the rail to accessory data connection, merging control messages from the MCU with data stream traffic from multimedia oriented accessories, over a single connection. Accessories and the MCU will act as autonomous devices on this LAN, using addressed packet based transactions between Ethernet Switch nodes. Although the internal LAN speed will be no faster than the original NPDS medium speed link, it will be able to support multiple streaming accessories simultaneously, using industry established bus arbitration methods. The availability of LAN bandwidth for accessory control and management messages will also enhance system responsiveness, making better use of the higher capability processor that is expected to be used in the MCU. 
     In one non-limiting implementation, the CNPDS will be configured such that the slots are groups of six, which defines the basic kernel of slot count per rail. Here all four rails will be built up in multiples of the six slot kernel, where Side rails will be 6 or 12 slots each, the top rail will be 24 or 30 slots, and the bottom rail will be 12 or 18 slots. This aggregation is done to provide logical grouping of internal rail control logic resources and does not impact slot occupation rules. 
     In one embodiment, the CNPDS direct galvanic coupling can be engineered to provide over 15 Watts per slot on a single pair of contacts of course ranges greater or less than 15 Watts are contemplated. 
     The CNPDS provides a low impedance galvanic connection path between the battery pack and the contacts in the slots of the rails. Power at each slot is individually switched, using local magnetic sense activation combined with MCU command. The management logic provides the necessary control access circuitry to achieve this, as well as integrate SPO mode. The main power path is bi-directional, allowing the attachment of the battery pack on any of the rails, in addition to the grip base. 
     The CNPDS slot arrangement on each rail will be an interleave of power and data slots. A structure for the CNPDS will aggregate groups of six slots into units that are concatenated to make up rail units of desired lengths. The management logic used to control the slot power is based on the grouping, thus the longer top and bottom rails may have several management logic blocks. 
     In one embodiment, the CNPDS will have an emergency power distribution mode in the event that the intelligent management and control systems (primarily the MCU) are incapacitated due to damage or malfunction. Under this mode, system control is assumed to be inoperative and the battery power is unconditionally available through individual slot Hall sensor activation. 
     In another embodiment, the CNPDS will have an alternative tether power connection which is a unidirectional input to the CNPDS, allowing the system to be powered and batteries to be charged from a weapon “Dock”. The Tether connection provides direct access to the lower receiver power connector, battery power port, and MCU power input. By using a properly keyed custom connector for the Tether port, the OR-ing diode and any current limiting can be implemented off-weapon at the tether power source. The tether source should also contain inherent current limiting, same as the battery packs. These measures move protective components outside of the MCU to where they can be easily replaced in case of damage from power source malfunctions, rail slot overloads, or battle damage. 
     In another embodiment, the CNPDS will have a reverse power, mode wherein the slots on the rails can accept DC power that could run the system. The CNPDS is can be used with high-density rechargeable chemistry batteries such as Lithium-Ion (Li-Ion) or any other equivalent power supply. 
     The CNPDS communication infrastructure may comprise two distributed networks between the rails and the MCU in the grip. The primary communication network, defined as the data payload net, is based on 10Base2-like CSMA/CD line operation, supplying a 10 Mbit/sec Ethernet packet link from accessories on the rails to each other and/or to the Tether. The secondary network is defined as the system management net on which the MCU is master and the rails are slave devices. Both networks operate in parallel without any dependencies between them. Accessories will only ever receive the primary packet bus and all accessory bound control and data transactions will funnel through that connection. The following diagram details the basic structure of the two networks within the CNPDS. 
     The communication structure has a very similar architecture to the power distribution structure of the CNPDS. The six slot grouping will similarly affect only the control subsystem aggregation and not impose limits on accessory slot alignment. 
       FIG. 41  illustrates the integrated accessories, particularly the GPS, using the internal I2C bus for communication. Although physically possible, using the I2C bus in this way complicates the software management structure for accessories. The alternative, to make the integrated accessories follow the same structural rules as external accessories, involves using the same packet network interface. This has some real estate and power penalties, requiring investigation in the architecture phase of the CNPDS to determine the best approach for integrated accessories. Reuse of developed elements, such as the AAM design, would provide the quickest way forward to tie the internal accessories to the CNPDS communication system. 
     The accessory base illustrated in  FIG. 36  can take on many forms with respect to footprint size. Depending on the power draw of the accessory, it may straddle several rail cores or one. An example of a three slot device is shown in the illustration of  FIG. 36 . 
     Accessory clamping can be semi-permanent or quick release. In the semi-permanent scenario, this is achieved with a fork lock system illustrated in at least  FIGS. 29A-32 and 39  where the forks are pulled in to the rail with a thumb screw. Depending on the mass and geometry of the accessory, one or two fork assemblies may be required to securely mount it to the rail. 
     In the quick release scenario shown in  FIG. 39 , a lever  1033  is employed to effectively move the lock system (prong) into place and hold position. As mentioned above, the weight and center of gravity will define which type is used and how many are required for mechanical strength. 
     In one non-limiting embodiment, electronic means of ensuring the accessory is installed correctly will be employed. In this scenario the system will identify the type and location of the accessory and provide power, communication or both. The accessory and the rail both have a 10 mm pitch such as to allow the lining up of accessory to rail slots and a shear area between accessory and rail to lock longitudinal relative movement between the two assemblies. 
     The rail contains a ferromagnetic metal pin capable of transmitting the magnetic field from the accessory base, through the pin, to a Hall effect sensor located on the printed circuit board directly below the pin. See  FIG. 40 . 
     Another manufacturing challenge is the interconnection of the TCPs to the rail assemblies. In this case, the assembly process is envisioned to involve pre-assembled unpotted rail shells and preassembled rail boards. The TCPs are pre-installed into the rail shells and are either glued or potted into place (not pressed) with exposed pegs facing into the cavity of the rail shell. The 6 slot rail boards are dropped in place in the cavity over the pin rows, with holes lining up with the pegs to protrude through the board. The pegs are then soldered or riveted/welded to the rail assembly PCB. The entire assembly is then potted and tested. 
     While the invention has been described with reference to an exemplary embodiment, 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 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 embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the present application.