POINT OF SALE SYSTEM

Abstract: A point of sale system includes a master terminal (24), a backup terminal (26), a plurality of satellite terminals (30), a master file device (12) and a backup file device (18). The master file device (12) includes a master file (14) and associated file controller (14) and the backup file device (18) includes a backup file (22) and associated file controller (20). The master file (16) responds to a request for price look up from any of the satellite terminals (30) regardless of any operation of the master terminal or the backup terminal. The master file (16) or the backup file (22) acts or operates as the main operating file to update the system when the other file (16, 22) is down.

Description: POINT OF SALE SYSTEM Technical Field This invention relates to point of sale systems of the kind including a plurality of satellite terminals adapted to input information on sold goods, and a master terminal coupled to said satellite terminals and adapted to transmit and receive sales information. The invention also relates to a method of controlling the flow of information in a point of sale system. Background of the Invention In the field of data processing, the use of point of sale (POS) terminals has required and also has enabled rapid and accurate transfer of information from one location to another in a business operation. In the case of department stores, the sales data may be transmitted or communicated from one or more terminals throughout the store to a central computer or processing unit. A filing system may be provided to maintain inventory and price data on the huge number of items that are sold in the store. The filing system and the control therefor provide means for retrieving and updating data and information regarding the constantly changing inventory and prices for the overall operation. U.S. Patent No. 4,468,750 discloses a point of sale system including a primary media terminal, a plurality of satellite terminals constructed and operated in a similar manner to the media terminal, and a backup media terminal. A diskette inserted into the primary media terminal receives and stores data from the satellite terminals. In the event of a malfunction of the primary media terminal, the backup media terminal may be converted into the primary media terminal for the system by transferring- the diskette from the faulty primary media terminal and inserting it into the backup media terminal. The conversion of the backup media terminal to the primary media terminal is thus a relatively slow and cumbersome manual operation, and interrupts the normal operational usage of the system. Disclosure of the Invention It is an object of the present invention to provide a point of sale system of the kind specified which can continue to respond rapidly to a request from a satellite terminal despite a failure of malfunction in the system. Therefore, according to the present invention, there is provides a point of sale system of the kind specified, characterized by file means coupled to said terminals and including point of sale data file means and file control section means adapted to read and update said data file means upon polling said terminals during predetermined time intervals in a cycle of operation, the updating of said data file means being in response to requests from said terminals, in that said file control section means is arranged to control data communication with the terminals, and in that said file means includes at least two file devices, such that one file device operates a main file device to control data communication and, upon failure of said main file device, another file device operates as the main file device and maintains updating of said point of sale data. According to another aspect of the present invention, there is provided a method of controlling the flow of information in a point of sale system having a plurality of satellite terminals coupled to a master terminal, characterized by the steps of: providing a plurality of file devices including respective point of sale data files and respective file control sections adapted to access and to update the associated data files upon polling said terminals during predetermined time intervals in a cycle of operation, updating said data files in response to requests from said terminals, arranging said plurality of file devices such that any one of said file devices operates as a main file device to control the data communication within the point of sale data files of the remaining file devices, and operating one of the remaining file devices as a main file device upon failure of the main file device to operate within said predetermined time intervals in said cycle of operation and to control the data communication. It will be appreciated that a point of sale system or method according to the invention has the advantage that burdens on both satellite and master terminals are reduced. Thus, since the master terminal provides registration of goods, the additional burdens imposed if a data file were included in the master terminal, are avoided. Furthermore, since a master terminal normally includes peripheral devices such as a keyboard, a display, a printer, and a bar code reader, the failure or malfunction of any of such peripherals may cause the master file to slow down to alleviate the problem. Where a data file is included in the master terminal, such slowing down could result in a slowing down of a response to a request from a satellite terminal. Thus, a point of sale system and method according to the invention greatly reduces the burden on the terminals, enabling rapid access by the terminals to the data file, and reducing the effects of device failure. Brief Description of -the. Drawings One embodiment .of the present invention will now be described by. way of example, with reference to the accompanying drawings, in which: .. Fig. 1 is a block diagram showing the structure of the file control system for use in a POS system according to a preferred embodiment of the present invention; Fig. 2 is a block diagram showing the structures of the main file device and of the backup file device according to the present invention; Fig. 3 is a flow chart illustrating the operation of the file control section of the main file device; and Fig. 4 is a flow chart illustrating the operation of the file control section of the backup file device. Best Mode for Carrying Out the Invention Fig. 1 is a block diagram showing the structure of a preferred embodiment of the present invention. In the drawing, a main file device 12 includes a file controller or file control section 14 and a master file 16 in which point of sale (POS) data is stored. A backup file device 18 includes a file controller or file control section 20 and a backup file 22 in which POS data is stored. The file controller 20 has the same structure as file controller 14 and the backup file 22 is the same as the master file 16. A master terminal 24 and a backup master terminal 26 are coupled by means of an in-house communication line 28. The master terminal 24 and the backup master terminal 26 do not include a POS data file. A plurality of satellite terminals 30 each consisting of a POS terminal such as an electronic cash register (ECR) or the like are coupled to the terminals 24 and 26 and to the file devices 12 and 18. The master terminal 24 and the backup master terminal 26 are constructed in the same manner as that of a conventional master terminal and a backup master terminal except that a POS data file and a file control section to control the POS data file are not included in the terminals 24 and 26. Each of the satellite terminals 30 is constructed in the same manner as that of a conventional POS terminal such as an ECR or the like. It is to be noted that although a backup master terminal 26 is provided in this embodiment, the provision thereof is optional. Ad itionally, while one backup file device 18 is provided, a plurality of such backup file devices may be provided as required. In the overall operation of the system as illustrated in Fig. 1, the main file device 12 confirms whether or not transmitting or receiving of data is requested while sequentially polling the individual terminals 24, 26 and 30 within the system in the course of a predetermined cycle. When a customer buys goods, the codes thereof and the number of goods thus sold are input from a bar code reader (not shown) or a keyboard (not shown) of any one of the master terminal 24 or the backup terminal 26 or the satellite terminal 30. The goods codes and the number of sold goods (hereinafter referred to as sales information) are transmitted over the line or circuit 28 to the main file device 12 when the main file device 12 polls the respective terminals 24, 26 or 30. When the main file device 12 receives the sales information from the terminal 24, 26 or 30, the main file device 12 transmits the sales information to the backup file device 18 and simultaneously retrieves the corresponding goods codes from the master file 16. When the main file device 12 retrieves the corresponding goods codes from the master file 16, the main file device 12 updates the sales information relating to the corresponding goods codes and transmits goods da-ta -.pr ces or the like) corresponding- to the goods codes to the. terminal 24, 26 or 30 from which- .the sales, information is transmitted. The terminal 24, 26 or 30 which receives the transmitted goods data from the main file device 12 registers the sold goods based on the received goods data. Additionally, the backup file device 18 which receives the sales information from the main file device 12 updates the backup file 22 in the same manner as that of the main file device 12. Next is a description of the operation in a case in which the main file device 12 slows down. Since the main file device 12 polls the backup file device 18 in the predetermined cycle, the backup file device 18 considers that the main file ievice 12 slows down when no polling from the main file device 12 is made for a predetermined period of time. The backup file device 18 then controls the data communication with each of the terminals 24, 26 or 30 and operates as the main file device of the system. As shown in Fig. 2, the main file device 12 and the backup file device 18, respectively, consist of link control devices 32 and 34, central processing units (CPU) 36 and 38, read only memories (ROM) 40 and 42, random access memories (RAM) 44 and 46, the master file 16 and the backup file 22. The CPU 36, the ROM 40, the RAM 44 and the link control device 32 correspond to the file control section 14 in Fig. 1. The main file device 12 and the backup file device 18 include identical elements and are constructed in exactly the same manner. The files 16 and 22 may be respectively included in the RAMs 44 and 46. Each of the link control devices 32 or 34 is a line control device for controlling the in-house communication line or circuit 28. The operations of the main file device 12 and the backup file device 18, which are described in relation to Fig. 1, are respectively controlled by the CPUs 36 and 38 in accordance with processing procedures respectively stored in the ROMs 40 and 42. The operations of the file control sections 14 and 20 (Fig. 1) will be described with reference to Figs. 2, 3 and 4. Fig. 3 is a flow chart showing the operation of the file control section 14 of the main file device 12 and Fig. 4 is a flow chart showing the operation of the file control section 20 of the backup file device 18. The operation which is performed by the file control section 14 of the main file device 12 in the case wherein no request is sent from a terminal 24, 26 or 30 will be described with reference to Fig. 3. When the power source is turned on to start the operation (block 50), the file control section 14 starts a one-second timer (block 52) in order to poll the backup file device 18 in the predetermined cycle. The file control section 14 checks whether or not data transmission is requested from the terminal 24, 26 or 30 (block 54) and proceeds to blocks 62 and 64 as a result of the absence of a request from the terminal 24, 26 or 30 to confirm whether the one-second timer is or is not timed out (block 64). When the one- second timer is not timed out, the file control section 14 returns to block 54 to repeat the same process. On the other hand, when the one-second timer is timed out (block 64), the file control section 14 polls the backup file device 18 to restart the one- second timer (block 66) and checks to see whether or not the response to the polling is made from the backup file device 18 (block 68). When the backup file device 18 operates in the normal state, the response to the polling is rapidly made from the backup file device 18, so that the file control section 14 goes to block 70 to confirm the presence of backup file down display indicating that the backup file device 18 is down. Since no backup down display is made in the case of normal operation of the backup file device 18, the file control.section 14 returns from block 70 to block 54 to repeat the same process. Now, assuming that the backup file device 18 is down, no response to the polling is made and hence the file control section 14 returns to block 54 after the backup file down is displayed (block 72) to repeat the processes in block 54 to block 68, inclusive, and in block 72. Assuming that the backup file device 18 has been down and the power source is just turning on at the completion of the repairing thereof, the response to the polling is made from the backup file device 18 (block 68), but the backup file down is displayed (block 70), so that the file control section 14 proceeds to block 76 to perform the processing operation. This processing operation (hereinafter referred to as the backup file recovery process) is for the purpose of re-preparing the backup file 22, that is, copying the contents that are in the master file 16 to the backup file 22. Next is a description of the operation in the case wherein a request is made from a terminal 24, 26 or 30 to the main file device 12 and such operation will be described with reference to Figs. 2, 3 and 4. When the request is made from the terminal 24, 26 or 30 after the one-second timer is started in block 52 in Fig. 3, the flow proceeds from block 54 to block 56 to retrieve and update the master file 16 based on the goods codes sent from the terminal 24, 26 or 30 and to transmit the sales information or data sent from the terminal 24, 26 or 30 to the backup file device 18 (block 58) . At the completion of updating of the master file 16, the sales data such as goods prices and the like are sent to the terminal 24, 26 or 30 from which the request is made (block 60). The operations in blocks 54 to 60, inclusive, in Fig. 3 will be described with reference to Fig. 2. When the request is made from the terminal 24, 26 or 30, the flow goes from block 54 to block 56. The sales information or data sent from the terminal 24, 26 or 30 is input to the link control device 32 of the main file device 12 on the line or circuit 28 (Fig. 2). The link control device 32 sends the sales information or data thus received to the CPU 36 which, in turn, retrieves the master file 16 in accordance with the process procedure stored in the ROM 40 (block 56) and transmits the sales information or data to the backup file device 18 (block 58). Assuming that the CPU 36 (Fig. 2) receives goods code "002" from the terminal 24, 26 or 30, the CPU finds the record of the goods code "002" in the master file 16 and updates the sales information such as the number of sold goods and the proceeds from the sold goods in the record (block 56). Now, assuming that one carton of milk is sold, the number of sold goods and the proceeds are respectively updated to "5" and "¥1000". Then, the CPU 36 (Fig. 2) reads out the unit price of the milk from the master file 12 and sends the unit price thus read out to the request terminal 24, 26 or 30 from which the request is made through the link control device 32 and the line or circuit 28 (block 60). Fig. 4 illustrates the operation of the file control section 20 of the backup file device 22 and begins with block 80. As shown in Fig. 4, the backup file device 18 checks to see whether or not the sales information or data is sent from the main file device 12 in block 82. Then the CPU 38 (Fig. 2) updates the sales information on the goods code "002" milk in the backup file 22 when the sales information is received, the same as in the case of the updating of the master file 16 (block 84). Then, the CPU 38 transmits the record of the updated goods code "002" to the main file device 12 (block 86). The main file device 12 receives the updated record from the backup file device 18 and compares the record thus received with the record of the goods code "002" in the master file 16 to check to see whether or not the backup file 18 is correctly updated (blocks 62 and 74 in Fig. 3). In case the backup file 22 is correctly updated, the flow returns to block 52 (Fig. 3) to wait for the next request. However, if the backup file 18 is not correctly updated, the flow goes to block 76 to re-update the record concerned in the backup file 22 or to copy the contents that are in the master file 16 to the backup file 22. Thus, the backup file 22 is always maintained in the same state as that of the master file 16. In the above mentioned manner, the updating of the two files 16 and 22 and the response to the terminal 24, 26 or 30 in the case of the presence of requests from the terminal are thus completed. Next, the failure detection and backup processing performed by the backup file device 18 when the main file device 16 has failed or is down will be described with reference to Fig. 4. The file control section 20 of the backup file device 18 checks to see whether or not the sales information or data is sent from the main file device 12. If the sales information or data has not been sent, the process goes to block 88 to check to see whether or not the polling from the main file device 12 is made at time intervals of one second. Insofar as the main file device 12 operates in the normal state, the main file device 12 must poll the backup file device 18 at time intervals of one second as noted in blocks 64 and 66 (Fig. 3). Hence, the backup file device 18 considers the absence of polling from the main file device 12 at intervals of one second as a failure in the main file device 12 and provides a main file down display (block 90) indicating that the main file device 12 has failed or is down. The backup file device 18 then declares that such backup file device acts or operates as the main file device in place of the main file device 12 (after the declaration, the file device 18 becomes the main file device) (block 92) and starts the processing operation normally done by the main file device in Fig. 3. Thereafter, even if the file device 12 is repaired and the power source is turned on, the file device 12 then acts or operates as the backup file device unless the then main file device 18 is slowed down. As has been described above, the present invention can provide a file control system which can rapidly respond to a request from any of the terminals 24, 26 or 30. The file control system will be dependable due to the provision of the file device in which the master file function and the file control function are separated from the master terminal to provide the master file function and the file control function in addition to the function of the master terminal. In accordance with the present invention, a file device 12 or 18 includes a file 16 or 22 and a file control section 14 or 20 adapted to retrieve and update the file in response to a request from a master terminal 24 or 26 or from a satellite terminal 30. The file device 12 or 18 provides controlled transmission of price look up (PLU) data and the like to any of the terminals 24, 26 or 30 from which the request is made and to control the data communication with the terminal, thereby ensuring rapid response to the request from the terminal and in-house data communication even when the master file has failed or is down. Further, in accordance with the present invention, a plurality of file devices 12 or 18 of the type as mentioned above are provided and constructed in such a manner that one of the file devices acts or operates as a main file device and one of the remaining file devices acts or operates as a backup file. The main file device then operating controls the updating of the file data in the other file, thereby reducing the burden on the terminals. It is thus seen that herein shown and described is a file control system that enables rapid response to requests from terminals. When one of the file devices has failed or is down, another file device becomes the main file device and maintains the operation.

Claims: CLAIMS 1. A point of sale system, including a plurality of satellite terminals (30) adapted to input information on sold goods, and a master terminal (24) coupled to said satellite terminal (30) and adapted to transmit and receive sales information, characterized by file means (12, 18) coupled to said terminals (24, 30) and including point of sale data file means (16, 22) and file control section means (14, 20) adapted to read and update said data file means (16, 22) upon polling said terminals (24, 30) during predetermined time intervals in a cycle of operation, the updating of said data file means (16, 22) being in response to requests from said terminals (24, 30), in that said file control section means (14, 20) is arranged to control data communication with the terminals (24, 30), and in that said file means (12, 18) includes at least two file devices, such that one file device (e.g. 12) operates a main file device to control data communication and, upon failure of said main file device, another file device (e.g. 18) operates as the main file device and maintains updating of said point of sale data. 2. A system according to claim 1, characterized in that said file devices are arranged and constructed such that one of such file devices (e.g. 12) operates as the main file device to control the data communication and another of the file devices operates as the main file device in response to failure of the main file device to operate within said predetermined time intervals in said cycle of operation. 3. A system according to claim 1, characterized in that said file means (12, 18) include respective first and second data files (16, 22) and respective first and second file control sections (14, 20) coupled to said terminals (24, 30), one of said data files and one of said file control sections operating to maintain updating of said sale data. 4. A system according to claim 1, characterized by an in-house communication line (28) coupling said master terminal (24) and said satellite terminals (30) with said file control means (12, 18). 5. A system according to claim 1, characterized in the the polling of said master terminal (24) and said satellite terminals (30) is performed at one second intervals during said predetermined cycle. 6. A method of controlling the flow of information in a point of sale system having a plurality of satellite terminals (30) coupled to a master terminal (24), characterized by the steps of: providing a plurality of file devices (12, 18) including respective point of sale data files (16, 22) and respective file control sections (14, 20) adapted to access and to update the associated data files upon polling said terminals (24, 30) during predetermined time intervals in a cycle of operation, updating said data files in response to requests from said terminals (24, 30) r arranging said plurality of file devices (12, 18) such that any one of said file devices operates as a main file device to control the data communication within the point of sale data files (16, 22) of the remaining file devices, and operating one of the remaining file devices as a main file device upon failure of the main file device to operate within said predetermined time intervals in said cycle of operation and to control the data communication. 7. A method according to claim 6, characterized in that the polling of said terminal (24, 30) is performed at one second intervals during said predetermined cycle. 8. A method according to claim 6, characterized in that a display is presented when any one of the file devices operates as a main file device to control the data communication and to control the updating of the data files of the remaining file devices, and in that any one of the remaining file devices automatically operates as a main file device upon failure of the main file device.

Inventors: SUGIYAMA MIKIHIKO, YAMAMOTO HIROMI, YANG JINCHENG, SUGIYAMA, MIKIHIKO, YAMAMOTO, HIROMI, YANG, JINCHENG
Applicants: NCR CO, NCR CORPORATION
Application year: 1989
Main classification: G06F15
IPC codes: G06F11, G07G1