Abstract:
A communication device and method for electronic price label (EPL) systems which use EPL components. The device includes a microcontroller, a first EPL circuit enabled by the microcontroller which sends a first signal to an EPL computer in response to a first polling signal from the EPL computer indicating that data from the microcontroller is ready for transmission, a number of second EPL circuits which store the data from the microcontroller and which send the data to the EPL computer in response to a second polling signal from the EPL computer, a third EPL circuit which receives a second signal from the EPL computer acknowledging receipt by the EPL computer of the data, and which signals the microcontroller of the receipt of the data, a keypad coupled to the microcontroller for recording the data from an operator, and a display for displaying the data as it is recorded and for displaying an indication of the receipt of the data.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    The present invention is related to commonly assigned and co-pending U.S. application Ser. No. ______, entitled, “Remote Control Device and Method for Electronic Price Label Systems”, filed, 1997, and invented by Adamec. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    The present invention relates to electronic price label (EPL) systems used in transaction establishments, and more specifically to a communication device and method for EPL systems.  
           [0003]    EPL systems typically include a plurality of EPLs for each merchandise item in a store. EPLs typically display the price of corresponding merchandise items on store shelves and are typically attached to a rail along the leading edge of the shelves. A store may contain thousands of EPLs to display the prices of the merchandise items. The EPLs are coupled to a central server from where information about the EPLs is typically maintained in an EPL data file. Price information displayed by the EPLs is obtained from the PLU file.  
           [0004]    EPLs today may be wired or wireless. Wireless EPLs may employ infrared or radio frequency (RF) transmitters. EPLs systems of the assignee of the present invention employ RF transmitters and modulated backscatter techniques. An EPL computer transmits polling signals to one or more EPLs. In order to respond to the poll, an EPL “reflects” the polling signal back to the EPL computer within a predetermined time interval of receiving the polling signal. A good analogy of the RF modulated backscatter acknowledgment signal is a mirror reflection. If two men face each other, one with a flashlight and the other with a mirror, the man with the mirror can send an acknowledgment to the man with the flashlight by reflecting the beam of light back to him. Similarly, the man with the mirror may indicate the opposite by not reflecting the light of the flashlight.  
           [0005]    Modulated backscatter techniques are taught in U.S. Pat. No. 5,640,683, to Evans et al., entitled “Modulated Backscatter Wireless Communication System Having An Extended Range”, issued Jun. 17, 1997. This patent is hereby incorporated by reference.  
           [0006]    Remote control and communication with a host EPL computer system would be desirable anytime the EPL system installer, user, or administrator is performing EPL related tasks away from the host EPL computer. One such task that might be performed by an EPL system administrator is adding or removing an EPL tag to a shelf. Normally, the administrator must perform administrative tasks at the host processor before placing the tag on the shelf. These tasks include initializing the EPL tag and adding the ID of the EPL tag to an EPL database. It would be advantageous to perform these administrative tasks remotely as the system administrator is adding or removing the tag from the shelf.  
           [0007]    Hand-held terminals have been developed which communicate with the EPL computer, effectively allowing remote communication with the host processor. However, these terminals are costly and can introduce noise that may interfere with the EPL system. When a hand-held terminal device is introduced that does not share the same communication protocol or hardware as the EPL system, there is some likelihood that the device will interfere with existing EPL system communication. In order to avoid interference, the EPL system must sacrifice performance by giving up radio frequency bandwidth to the device.  
           [0008]    Therefore, it would be desirable to provide a communication device and method for EPL systems that would allow an operator to remotely control the EPL computer from anywhere in a store using the existing EPL infrastructure.  
         SUMMARY OF THE INVENTION  
         [0009]    In accordance with the teachings of the present invention, a communication device and method for EPL systems is provided.  
           [0010]    The device includes a microcontroller, a first EPL circuit enabled by the microcontroller which sends a first signal to an EPL computer in response to a first polling signal from the EPL computer indicating that data from the microcontroller is ready for transmission, a number of second EPL circuits which store the data from the microcontroller and which send the data to the EPL computer in response to a second polling signal from the EPL computer, a third EPL circuit which receives a second signal from the EPL computer acknowledging receipt by the EPL computer of the data, and which signals the microcontroller of the receipt of the data, a keypad coupled to the microcontroller for recording the data from an operator, and a display for displaying the data as it is recorded and for displaying an indication of the receipt of the data.  
           [0011]    The device may be used as a remote control device in which the data includes functions to be executed by the EPL computer from a list of functions maintained by the EPL computer.  
           [0012]    In more detail, the second EPL circuits each include a first portion including first control circuitry having a first unique address and a first state out of first and second operational states, and a second portion including second control circuitry having a second unique address and a second state out of the first and second operational states. The EPL computer interprets a binary data “0” when the first state is equal to the first operational state and the second state is equal to the second operational state, and interprets a binary data “1” when the first state is equal to the second operational state and the second state is equal to the first operational state.  
           [0013]    The method of the present invention includes the steps of loading a number of EPL data circuits having first and second portions with a portion of data by a microcontroller, and transmitting the data to the EPL computer by the EPL data circuits in response to a polling message from the EPL computer. Loading involves the substeps of enabling acknowledgment of polling messages by the first portions of a first group of the EPL data circuits and disabling acknowledgment of the polling messages by the second portions of the first group of EPL data circuits to form a data value equal to zero, and disabling acknowledgment of polling messages by the first portions of a second group of the EPL data circuits and enabling acknowledgment of the polling messages by the second portions of the second group of EPL data circuits to for a data value equal to one.  
           [0014]    It is accordingly an object of the present invention to provide a communication device and method for EPL systems.  
           [0015]    It is another object of the present invention to provide a communication device and method for EPL systems which would allow an operator to remotely send data to an EPL computer from anywhere in a store.  
           [0016]    It is another object of the present invention to provide a remote control device and method for EPL systems which would allow an operator to remotely control an EPL computer from anywhere in a store.  
           [0017]    It is another object of the present invention to provide a communication device and method for EPL systems that utilizes the existing EPL infrastructure. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]    Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which this invention relates from the subsequent description of the preferred embodiments and the appended claims, taken in conjunction with the accompanying drawings, in which:  
         [0019]    [0019]FIG. 1 is a block diagram of an EPL system;  
         [0020]    [0020]FIG. 2 is a block diagram of a communication device in accordance with the present invention;  
         [0021]    [0021]FIGS. 3A and 3B are block diagrams illustrating further detail associated with the communication device of FIG. 2; and  
         [0022]    [0022]FIG. 4 is a flow diagram illustrating operation of the communication device of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0023]    Referring now to FIG. 1, EPL system  10  includes computer  12 , storage medium  14 , communication base station (CBS)  16 , electronic price labels (EPLs)  18 , and communication device  24 . EPL system  10  makes use of modulated backscatter communication techniques.  
         [0024]    Computer  12  executes EPL control software  20 , remote control software  22 , and other applications  30 . EPL control software  20  records, schedules, and transmits all messages to EPLs  18  and device  24  through CBS  16 , and receives and analyzes messages from EPLs  18  and device  24  through CBS  16 .  
         [0025]    EPL control software  20  maintains and uses EPL data file  28 . EPL data file  28  contains item information, EPL identification information, and status information for each of EPLs  18  and portions  70   a  and  70   b  of device  24  (FIG. 3).  
         [0026]    EPL control software  20  primarily includes data scheduler  34  and CBS manager  36 . Data scheduler  34  schedules EPL price change messages to be sent to EPLs  18  through CBS  16 . Data scheduler  34  schedules polling and EPL computer acknowledgment messages to be sent to device  24  through CBS  16 .  
         [0027]    Remote control software  22  causes EPL control software  20  to poll device  24  and uses the responses received from device  24  to signal EPL computer  12  to perform predetermined functions.  
         [0028]    Remote control software  22  maintains a function list  26  which is a look-up table that associates responses from device  24  with functions to be implemented when those responses are received. Such functions include gathering signal and noise data, starting or stopping a promotion or a group of promotions, signaling EPL computer  12  to perform a diagnostic test on CBS  16  while a technician physically examines CBS  16  where it is mounted in a ceiling, turning on and off EPL electronic signage. Advantageously, any of the functions described above may be performed at any time and in any order.  
         [0029]    Remote control software  22  calls other applications  30  and/or EPL control software  30  to perform the functions. Remote control software  22  accepts function codes which it interprets or decodes by referencing function list file  26 , and accepts secondary and tertiary data which represent arguments to the requested function or action. It then signals some other application  30  to perform the requested action by making an application program interface (API) call, and passes the secondary and tertiary data to the other application  30  using the appropriate API or series of APIs.  
         [0030]    Storage medium  14  is preferably a fixed disk drive. Storage medium  14  stores EPL data file  28  and function list file  26 .  
         [0031]    CBS  16  preferably includes one transmit antenna  37  and up to four receive antennas  38  for transmitting and receiving messages between CBS  16  and EPLs  18  and between CBS  16  and device  24 . CBS  16  includes CBS circuitry  39  which controls operation of CBS  16 . EPL system  10  preferably includes a plurality of CBSs  16  connected together in series.  
         [0032]    CBS manager  36  schedules transmission of price change messages to EPLs  18  and polling messages to device  24 . CBS manager  36  controls reception of status messages from EPLs  18  and control messages from device  24  for predetermined time slots.  
         [0033]    Turning now to FIG. 2, device  24  is shown in more detail. Device  24  includes microcontroller  40 , handshake communications circuitry  44 , data communications circuitry  50 , keypad  54 , and display  56 .  
         [0034]    Microcontroller  40  controls operation of device  24  and includes its own read-only memory (ROM), random-access memory (RAM), and peripheral interface controller. A separate microcontroller and peripheral interface adapter are also envisioned.  
         [0035]    Handshake communications circuitry  44  transfers commands to EPL computer  12  and receives acknowledgments from EPL computer  12 . For that purpose, handshake communications circuitry  44  includes send switch  46  and receive switch  48 .  
         [0036]    Send switch  46  receives transmit enable signals from microcontroller  40  over transmit enable control line  47 . Control line  47  is preferably an unused display control line. The state of control line  47  can be either high (enabled) or low (non-enabled).  
         [0037]    EPL computer  12  polls send switch  46 . When EPL computer receives a signal from send switch  46  indicating that the state of send switch  46  has changed, EPL computer  12  starts polling data switches  52 .  
         [0038]    Receive switch  48  sends a read acknowledgment signal to microcontroller  40  over receive acknowledgment control line  49 . The state of control line  49  can be either high (data received) or low (not received or unknown). Control line  49  is preferably an unused display control line.  
         [0039]    EPL computer  12  transmits an acknowledgment signal to receive switch  48  after EPL computer  12  has successfully received the data in data switches  52 . The acknowledgment signal from EPL computer  12  causes receive switch  48  to change its state.  
         [0040]    Data communications circuitry  50  includes data switches  52  which transmit data words to EPL computer  12  after communication between device  24  and EPL computer  12  has been initiated by handshake communications circuitry  44 . EPL computer  12  polls data switches  52  to signal data switches  52  to transmit their contents.  
         [0041]    Data communications circuitry preferably consists of six data switches  52 . Data switches  52  receive data from microcontroller  40  over data lines  53 . The state of data lines  53  can be either high (binary “1”) or low (binary “0”). Data lines  53  are preferably unused display control lines.  
         [0042]    Keypad  54  records operator keystrokes for initiating functions in functions list  26 . For example, a “price update” function for updating the price displayed by an EPL may be entered into device  24  using keypad  54 . Microcontroller  40  converts the keystrokes into binary data that can be transmitted via data switches  52 .  
         [0043]    Display  56  displays recorded keystrokes and system status messages, including indications to an operator that a message from EPL computer  12  was acknowledged.  
         [0044]    Turning now to FIG. 3A, each of switches  46  and  52  are illustrated.  
         [0045]    Switches  46  and  52  are each a combination of two EPLs  18  coupled to control lines or data lines, as appropriate. Here, the components of the two EPLs are represented as portions  70   a  and  70   b.  Each portion has a unique EPL identification number to which EPL computer  12  addresses messages.  
         [0046]    Each of switches  46  and  52  has two valid data states as indicated in Table I below:  
                                             TABLE I                       Data State   State of portion 70a   State of portion 70b                                0   not acknowledging   (0)   acknowledging   (1)       1   acknowledging   (1)   not acknowledging   (0)                  
 
         [0047]    Thus, to send a data state “0”, device  24  ensures that only portion  70   b  acknowledges a polling message from EPL computer  12 . To send a data state “1”, device  24  ensures that only portion  70   a  acknowledges a polling message from EPL computer  12 . Sending a binary one in each of the two data states allows EPL computer  12  to verify that device  24  is not out of range or inoperative.  
         [0048]    Portion  70   a  includes battery  60   a,  transmit and receive antenna  62   a,  memory  67   a,  and EPL circuitry  68   a.    
         [0049]    Portion  70   b  includes battery  60   b,  transmit and receive antenna  62   b,  memory  67   b,  and EPL circuitry  68   b.    
         [0050]    Batteries  60   a  and  60   b  provide power to portions  70   a  and  70   b.    
         [0051]    Transmit and receive antennae  62   a  and  62   b  transmit data and acknowledgment messages from portions  70   a  and  70   b  and receive polling and EPL computer read acknowledgment messages from EPL computer  12 .  
         [0052]    Advantageously, since device  24  is made from circuitry within EPLs like EPLs  18 , it operates in the same frequency range.  
         [0053]    Memories  67   a  and  67   b  store messages from EPL computer  12 .  
         [0054]    EPL circuitries  68   a  and  68   b  control the internal operation of portions  70   a  and  70   b.  EPL circuitries  68   a  and  68   b  store received messages from EPL computer  12  and transmit and receive messages from EPL computer  12 .  
         [0055]    EPLs typically include displays as well, but the displays are not used since display  56  provides display functions for communication device  24 . The unused display control lines to microcontroller  40  are used as control lines  47  and data lines  53 .  
         [0056]    Inverter  58  ensures that portion  70   b  has the opposite state from portion  70   a.    
         [0057]    Turning now to FIG. 3B, switch  48  is illustrated.  
         [0058]    Switch  48  includes the components of only one EPL and has a unique EPL identification number to which EPL computer  12  addresses messages.  
         [0059]    Portion  70   c  includes battery  60   c,  transmit and receive antenna  62   c,  memory  67   c,  and EPL circuitry  68   c  which are similar in function to the components in portions  70   a  and  70   b.  An unused display control line to microcontroller  40  is used as control line  49 .  
         [0060]    Turning now to FIG. 4, the operation of communication device  24  is illustrated in more detail, beginning with START  100 .  
         [0061]    In step  102 , device  24  records keystrokes from an operator. The keystrokes are associated with one of the functions in function list  26 , such as the price update function.  
         [0062]    In step  104 , device  24  records additional keystrokes to complete function selection. For example, device  24  may record data including a price-lookup (PLU) number and price for a price for the price update function. Device  24  displays the data in display  56  as they are entered.  
         [0063]    In step  106 , device  24  converts the recorded information into binary data (data states “0” or “1”) that can be transmitted to EPL computer  12  via data switches  52 .  
         [0064]    In step  108 , device  24  loads data switches  52  with some or all of the binary data. The amount of data loaded is dependent upon the number of data switches  52  and the amount of binary data to be loaded.  
         [0065]    In step  112 , device  24  toggles transmit enable control line  47  to make the binary data ready for transmission. Toggling involves changing the state of send switch portions  70   a  and  70   b  twice (e.g., from data state “0” to data state “1” and back again to data state “0”).  
         [0066]    In step  116 , device  24  transmits the binary data to EPL computer  12  in response to a polling signal from EPL computer  12 . Here, the word transmit is used to connote modulated backscatter operation. Thus, EPL computer  12  polls data switches  52  and receives a reflected signal from data switches  52  containing the data.  
         [0067]    In step  120 , receive switch  48  receives an acknowledgment signal from EPL computer  12  indicating that EPL computer  12  has received the data. In response to the signal, receive switch  48  toggles its output (e.g., high to low to high) over receive acknowledgment line  49 .  
         [0068]    In step  122 , device  24  displays an indication to the operator of device  24  that the binary data has been successfully transmitted by device  24  and received by EPL computer  12 .  
         [0069]    In step  124 , device  24  determines whether additional data is remaining to be sent. If so, operation returns to step  102 . If not, operation waits at step  124 .  
         [0070]    After all of the data is transmitted by device  24  and received by EPL computer  12 , remote control software  22  compares the received data to data in function list  26  and executes a function from function list  26  that is associated with the received data.  
         [0071]    Remote control software  22  may additionally send another acknowledgment message to device  24 . After device  24  receives the message, it displays a message which indicates to the operator that the function has been executed by EPL computer  12 .  
         [0072]    Although the present invention has been described with particular reference to certain preferred embodiments thereof, variations and modifications of the present invention can be effected within the spirit and scope of the following claims.