Abstract:
Vehicle identification number (VIN) data acquisition and stamping center control, wherein a main computer supplies VIN data to a PLC disposed at the stamping center, and the PLC stores a quantity of VIN data, up to a predetermined maximum, in an input buffer memory of the PLC in order to permit the stamping center to continue operating even when the network connection with the main computer is broken. The PLC also includes an output buffer memory in which stamped VINs may be stored until the network connection is restored, at which point the stamped VINs are transmitted to the main computer. Alternative semi-automatic and manual modes of operation permit the stamping center to continue operating even when the supply of VIN data from the input buffer memory is exhausted.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention is generally directed toward stamping operations and, more particularly, toward data communications for vehicle identification number stamping operations.  
           [0003]    2. Description of Related Art  
           [0004]    Vehicle identification numbers (sometimes referred to as VINs hereinafter), which are stamped on or adjacent the dashboard of vehicles, and must be carefully controlled to correspond, in a one-to-one relationship, with the resulting vehicles. Traditionally, the VINs are generated by a dedicated computer system, such as a mainframe computer, a central computer system, or the like (hereinafter referred to as the main computer). The generated VINs are transmitted individually, via a data communications link such as a factory-wide network, to a programmable controller provided at a remote VIN stamping center. The VIN stamping center, upon receipt of the VIN, adjusts a series of ring dies so that the desired VIN is stamped into a vehicle dashboard, and the stamping center communicates confirmation of same to the main computer. Thereafter, the main computer generates and transmits a subsequent VIN to the stamping center, and the stamping process continues.  
           [0005]    The foregoing system works well under normal conditions. However, should there be an interruption in the network connection between the stamping center and the main computer, the VIN stamping operation is interrupted. Conventionally, if the network connection is interrupted, the VIN stamping operation must either stop, or must proceed manually. Manual operation is problematic, as it requires significant care to ensure that the appropriate VIN is selected and stamped, and to ensure that the stamped VIN is correctly recorded at the time of stamping and then later in the main computer when the network connection is restored.  
           [0006]    In response to this problem, it has been proposed to provide a local computer adjacent the VIN stamping center. In this countermeasure, the local computer is connected to the main computer via the network connection and receives one or more VINs to be used sequentially. The local computer transfers the VINs to the stamping center PLC via a further network connection, and transfers stamped VINs (VINs used in the stamping operation) to the main computer. When the local computer has exhausted its supply of stored VIN&#39;s, it transmits a request to the main computer, and further VIN&#39;s are transmitted to the local computer for subsequent use.  
           [0007]    Unfortunately, even in this improved system, if any interruption in communication is experienced, the VIN stamping operation is interrupted. For example, if there is break in the network connection between the local computer and the stamping center, of if the local computer fails, the VIN stamping operation will be interrupted. Further, if there is a break in the network connection between the local computer and the main computer, the supply of VINs to the stamping center will ultimately be interrupted.  
           [0008]    Therefore, there exists a need in the art for a method and for a system that will insure that an interruption in communication of VINs from the main computer to the stamping center will not prevent normal stamping of VINs by the stamping center. There further exists a need in the art for method and system for locally storing stamping results in the event that data communication to the main computer is interrupted.  
         SUMMARY OF THE INVENTION  
         [0009]    The present invention is directed toward a method and a system for insuring that a temporary break in communication between the main computer and the stamping center will not prevent normal stamping of VINs by the stamping center. The present invention is further directed toward a method and system for locally storing stamping results in the event that data communication to the main computer is interrupted, and for subsequent communication of stored stamping results to the main computer when data communications are restored. Finally, the present invention is directed toward a system and method comprising alternative VIN data input means to the stamping center, as may be necessary during extended or prolonged interruption of a data communication between the main computer and the stamping center.  
           [0010]    In accordance with the present invention, a vehicle identification number data acquisition and stamping method for a vehicle identification number stamping center is provided. The method includes the steps of generating a plurality of vehicle identification numbers in a main computer, transmitting the plurality vehicle identification numbers to a programmable logic controller disposed at the stamping center, storing the plurality of individual vehicle identification numbers in an input buffer memory of the programmable logic controller, and serially accessing individual ones of said plurality of vehicle identification numbers for use in a stamping operation.  
           [0011]    In further accordance with the present invention, a quantity of vehicle identification numbers is monitored and, when the quantity falls below a predetermined minimum, the main computer is requested to send further vehicle identification numbers to the programmable logic controller. In this manner, the programmable logic controller normally contains a quantity of vehicle identification numbers between the predetermined minimum and the predetermined maximum, the predetermined minimum being selected such that the stamping operation can continue uninterrupted even when the communications link between the programmable logic controller and the main computer is not operational.  
           [0012]    In further accordance with the present invention, the programmable logic controller, following a successful stamping operation, transmits the stamped vehicle identification number to the main computer. When the communications link is not operational, the programmable logic controller stores the stamped vehicle identification number in an output buffer for later communication to the main computer upon reestablishment of the communications link. The output buffer is adapted to hold a quantity of stamped vehicle identification numbers that is at least equal to, and preferably significantly greater than, the predetermined maximum number stored in the input buffer to permit the stamping operation to proceed unimpeded in a manual or semi-automatic mode of operation even when the communication between the programmable logic controller and the main computer is interrupted for an extended period of time.  
         BRIEF DESCRIPTION OF THE DRAWING  
         [0013]    These and further features of the invention will be apparent with reference to the following description and drawing, which schematically illustrates a vehicle identification number acquisition and communication system according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0014]    Data flow using the method of the present invention is schematically illustrated in FIG. 1. As shown, the data flow or data communication is between the main computer  100  and the stamping center programmable logic controller or PLC  102  takes place over a network connection  104  via an intermediate communications interface  106 . The communications interface  106  is disposed locally with the PLC  102  at the stamping center  108  and may be considered to be integral with the PLC  102  so that further data links or network connections therebetween are unnecessary. Similarly, the stamping center PLC  102  is integrated into the stamping center  108  so that information from the PLC  102  is directly supplied to the stamping center controller without further data links or network connections.  
         [0015]    Generally, communication between the main computer  100  and PLC  102  is two-way, in that the main computer  100  transmits VIN data to the stamping center PLC  102  via the communications interface  106 , and the stamping center PLC  102  transmits requests for further VIN data to the main computer  100  via the communications interface  106 . Accordingly, transmission of VIN data from the main computer  100  to the PLC  102  is preferably controlled by signals or requests sent from the PLC  102 .  
         [0016]    More specifically, the PLC  102  includes an input buffer memory  112  that is capable of storing sufficient VIN data to perform stamping operations for a predetermined time period. Preferably, the predetermined time period is at least one hour in length, and may be significantly longer. By storing VIN data in the PLC  102 , the stamping center  108  is capable of performing stamping operations without interruption even when the communication link or network connection  104  between the main computer  100  and the stamping center PLC  102  is broken. By storing VIN data capable of permitting stamping operations for a period of between about one hour and two hours, sufficient time is provided to permit repair or reestablishment of the network connection  104  between the main computer  100  and the PLC  102 .  
         [0017]    The main computer  100  is adapted to generate VIN data  114 , and to send VIN data  116  to the stamping center PLC  102  in batches or lots. The communications interface  106  receives the lot of VIN data  110 , and transfers it to the PLC input buffer memory  112 . In the preferred and illustrated embodiment, each lot includes less than or equal to thirty VIN data sets. As used herein the term “VIN data” is meant to include the vehicle identification number itself as well as the lot number and any additional data related to the VIN that may be necessary or desired. Such additional data may include time, date, shift, and operator information.  
         [0018]    The VIN data sets are stored in the PLC&#39;s input buffer memory  112 . The PLC input buffer memory  112  is adapted to hold a predetermined maximum number of input VIN data sets. Preferably, the predetermined maximum number of input VIN data sets is sufficient to enable uninterrupted operation of the stamping center  108  for at least  1 . 5  hours. In the preferred embodiment of the present invention, the predetermined maximum number of input VIN data sets is equal to about  90 . Naturally, the predetermined maximum number of input VIN data sets may be greater than or less than  90  without departing from the scope and spirit of the present invention. For example, upon enlargement of the input buffer memory capacity, the predetermined maximum number of VIN data sets may be increased to permit uninterrupted operation of the stamping center  108  for two hours, four hours, or more, as desired.  
         [0019]    When the VIN data acquisition mode select  118  is in the “auto” setting  120 , the VIN data sets stored in the PLC input buffer memory  112  are sequentially or serially made available to the stamping center controller for use in a stamping operation. When any particular VIN data set is accessed by the stamping center  108 , the remaining number of VIN data sets stored in the PLC input buffer memory  112  is reduced by one.  
         [0020]    The number of VIN data sets stored in the PLC input buffer memory  112  is monitored  122 , and when the number reaches or falls below a predetermined minimum number, the PLC  102  sends a request for another lot of VIN data sets to the main computer  100  via the communications interface  106  and the network connection  104 . If communication between the PLC  102  and the main computer  100  via the communications interface  106  and network connection  104  are available  123 , the PLC&#39;s request for another lot of VIN data sets is sent immediately. Otherwise, the request is held until the communications are reestablished. Preferably, the predetermined number of VIN data sets is the number that is required to permit uninterrupted operation of the stamping center  108  for at least one hour. In the operational environment of the present invention, the predetermined minimum number is equal to sixty. Naturally, the present invention is not limited to the presently preferred number of VIN data sets, but rather may be relatively greater or less than sixty, as desired.  
         [0021]    The stamping center controller checks the VIN data  126  to insure that it is satisfactory. If the VIN data is determined to be defective, the data is dumped or discarded  128 , and the next or subsequent VIN data is accessed from the PLC input buffer memory  112 . If the VIN data is acceptable, the stamping center controller adjusts the ring dies to correspond with the VIN, and the VIN is stamped into the dashboard  130 . Thereafter, the VIN is copied to a file  132  and the mode of operation is checked  133 . If the mode select  118  is in the “test” mode, described hereinafter, the cycle ends without transmitting the stamped VIN to the main computer  100 . However, in the present case the mode select  118  is in the auto mode  120 , the mode select  118  is in the auto mode  120 , therefore the process continues to the communications status stage.  
         [0022]    Keeping in mind that the communication between the PLC  102  and main computer  100  is constantly monitored  134 , if communication between the PLC  102  and the main computer  100  via the communications interface  104  is available, the just-stamped VIN is sent to the main computer  100 . The main computer  100  receives the stamped VIN  137 , and uses this information for tracking, correlating, and record keeping purposes. If communication between the PLC  102  and the main computer  100  is not available, the previously stamped VIN is stored in an output buffer memory  138  provided by the PLC  102 . The output buffer memory  138  is sized so that a predetermined maximum number of stamped VINs may be stored for subsequent communication to the main computer  100  upon reestablishment of the communications link.  
         [0023]    The predetermined maximum number of stamped VINs is preferably at least as great as the predetermined maximum number of input VIN data sets that may be stored in the input buffer memory  112 , and will permit uninterrupted operation of the stamping center  108  for at least 1.5 hours, and preferably much more than 1.5 hours, should the network connection  104  between the PLC  102  and the main computer  100  be broken. In the preferred embodiment, the predetermined maximum number of stamped VINs is preferably greater than  90  and more preferably is equal to or greater than  180  to permit extended semi-manual, as will be described more fully hereinafter.  
         [0024]    In some circumstances the foregoing automatic mode  120  of stamping center operation may be undesired or impossible. For example, this could occur should the PLC  102  fail. Automatic operation could also be impossible if the network connection  104  between the main computer  100  and communications interface/PLC is interrupted for a period of time such that the VIN data stored in the input buffer memory  112  is exhausted. In these circumstances, alternative VIN input methods and modes of operation are provided in accordance with the present invention, and are described hereinafter.  
         [0025]    A first semi-automatic mode  140  of stamping center VIN data acquisition involves scanning the VIN in the form of a bar code into the stamping center controller. If a scanning mode is selected by the mode select  118 , the VIN information, in the form of a barcode, is scanned into the stamping center  108  via a conventional bar code scanner  142 .  
         [0026]    A second semi-automatic mode  144  of stamping center VIN data acquisition involves inputting the VIN via keyboard  146  into the stamping center controller. This second semi-automatic mode may be desired should scanning be inconvenient.  
         [0027]    In each of the first and second semi-automatic modes  140 ,  144  of stamping center VIN data acquisition, the data checking and storing process proceeds generally as in the automatic mode  120  described hereinbefore. Namely, the data is checked  126  to determine whether it is satisfactory. If the VIN data is determined to be defective, the data is dumped or discarded  128 , and the next or subsequent VIN data is accessed using same or different mode of VIN data acquisition. If the VIN data is acceptable, the stamping center controller adjusts the ring dies to correspond with the VIN, and the VIN is stamped into the dashboard  130 . Thereafter, the VIN is copied to a file  132  and the mode of operation is checked  133 . If the mode select  118  is in the “test” mode, described hereinafter, the cycle ends without transmitting the stamped VIN to the main computer  100 . However, in the present case the mode select  118  is in one of the semi-automatic modes of operation  140 ,  144 , so the process continues to check the communications status.  
         [0028]    If communication between the PLC  102  and the main computer  100  is available  134 , the just-stamped VIN is communicated to the main computer  100 . If communication between the PLC  102  and the main computer  100  is not available, the previously stamped VIN is stored in the output buffer memory  138  for subsequent transmission to the main computer  100  when the network connection  104  is restored.  
         [0029]    The test mode of operation  150  involves manual advance or adjustment of the stamping center ring dies, and is used to test the functionality of the stamping center and, therefore, the stamped VIN information is not communicated to the main computer  100  and is not stored in the output buffer memory  138 . Further, the previously described data verification  126  is bypassed, and the VIN, which was manually set via manipulation of the ring dies, is stamped into the vehicle dashboard  130 . The VIN is copied to a file  132  and, upon confirmation that the stamping center  108  is operating in the test mode  133 , the test cycle ends  135 .  
         [0030]    Although the present invention has been described hereinbefore with particularity, the present invention is not limited thereto. Rather, it is considered apparent that the method of the present invention is capable of numerous modifications, replacements of steps, and rearrangements of steps without departing from the scope and spirit of the invention as defined in the claims appended hereto.