Patent Publication Number: US-2012042038-A1

Title: Point-of-sale system, wireless transmission device, and data transmission method implemented by the point-of-sale system

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority of Taiwanese Application No. 099127108, filed on Aug. 13, 2010. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a point-of-sale system, more particularly to a point-of-sale system utilizing wireless transmission technology. 
     2. Description of the Related Art 
     Point-of-sale (POS) systems have been broadly utilized in stores such as convenient stores, malls, restaurants, etc. Generally, data transmission between a POS host and a client device is conducted through a transmission line. However, the physical transmission line imposes restrictions on the deployment distances between the POS host and the client devices, and the deployed regions or locations of the client devices are limited thereby. Moreover, the transmission lines and power lines of the POS system make the stores look messy, and have an adverse affect on the aesthetic and integrity of the store decoration. 
     SUMMARY OF THE INVENTION 
     Therefore, an object of the present invention is to provide a point-of sale (POS) system capable of transmitting data wirelessly. 
     Accordingly, the POS system of this invention includes a POS host, a plurality of client devices, and a wireless transmission device. The wireless transmission device includes a host-end wireless communication module coupled to the POS host, and a plurality of client-end wireless communication modules coupled respectively to the client devices. The POS host is operable to configure the host-end wireless communication module for generating a plurality of virtual COM ports. Each of the virtual COM ports is matched with a respective one of the client-end wireless communication modules, such that the POS host is able to communicate wirelessly with the client devices through the host-end wireless communication module and the client-end wireless communication modules. 
     Another object of the present invention is to provide a wireless transmission device that is able to generate a plurality of virtual COM ports for wireless signal communications. 
     Accordingly, the wireless transmission device of this invention is adapted for establishing wireless transmission between a point-of-sale (POS) host and a plurality of client devices. The wireless transmission device includes a host-end wireless communication module adapted to be coupled to the POS host for transmitting and receiving signals wirelessly, and a plurality of client-end wireless communication modules adapted to be coupled to the client devices, respectively, for transmitting and receiving signals wirelessly. Moreover, the host-end wireless communication module is configurable via the POS host to generate a plurality of virtual COM ports. Each of the virtual COM ports is matched with a respective one of the client-end wireless communication modules, such that the POS host is able to communicate wirelessly with the client devices through the host-end wireless communication module and the client-end wireless communication modules. 
     Still another object of the present invention is to provide a data transmission method implemented by a point-of-sale (POS) system so that data may be transmitted without loss. 
     Accordingly, the data transmission method of this invention is to be implemented by a point-of-sale (POS) system that includes a POS host and a plurality of client devices. The data transmission method includes the steps of: 
     (A) coupling a host-end wireless communication module to the POS host, and coupling each of a plurality of client-end wireless communication modules to a respective one of the client devices; 
     (B) using the POS host, configuring the host-end communication module to generate a plurality of virtual COM ports, each of the virtual COM ports being matched with a respective one of the client-end wireless communication modules; 
     (C) upon detection by the host-end wireless communication module that one of the virtual COM ports has received data from a matching one of the client-end wireless communication modules, configuring the host-end wireless communication module to send an acknowledge signal to the matching one of the client-end wireless communication modules; and 
     (D) upon detection by one of the client-end wireless communication modules that data has been received from the host-end wireless communication module, configuring said one of the client-end wireless communication modules to send an acknowledge signal to the host-end wireless communication module. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which: 
         FIG. 1  is a block diagram illustrating connecting relationships among software and hardware modules of a preferred embodiment of the POS system of the present invention; 
         FIG. 2  is a diagram similar to  FIG. 1 , but illustrating that a wireless transmission device may generate a plurality of virtual COM ports, each of which is matched with a respective one of the client-end wireless communication modules; 
         FIG. 3  is a schematic diagram of an operation interface of a matching utility program, illustrating that the matching utility program may be executed to search for surrounding client-end wireless communication modules; 
         FIG. 4  is a diagram similar to  FIG. 3 , but illustrating that the matching utility program has been executed to match each of the virtual COM ports with the respective one of the client-end wireless communication modules; 
         FIG. 5  is a flowchart illustrating steps involved when a host-end wireless communication module transmits data to the client-end wireless communication modules; and 
         FIG. 6  is a flowchart illustrating steps involved when one of the client-end wireless communication modules transmits data to the host-end wireless communication module. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIG. 1 , a preferred embodiment of the POS system of the present invention includes a POS host  1 , a plurality of client devices  2 , and a wireless transmission device  3 . In this embodiment, each of the client devices  2  is a respective one of a client-end display, a bar code scanner and a printer, and each of the client devices  2  includes a RS232 interface  21 . The POS host  1  includes a USB interface  13 . The wireless transmission device  3  is operable for wireless communication according to the IEEE 802.11 standard, and for data transmission in the 2.4 G ISM frequency band, at a bit rate of 250 kbps, at a baud rate ranging from 4800 Bd to 38400 Bd, and at a transmission distance ranging from 0 to 30 meters. 
     The wireless transmission device  3  includes a host-end wireless communication module  31  coupled to the POS host  1 , and a plurality of client-end wireless communication modules  32  coupled respectively to the client devices  2 . The host-end wireless communication module  31  includes a host-end USB interface  312  for connecting with the POS host  1 , a first microprocessor control unit (MCU)  313  connected electrically to the host-end USB interface  312 , a first radio frequency circuit  314  connected electrically to the first MCU  313 , and a first antenna  315  connected electrically to the first radio frequency circuit  314  for transmitting and receiving signals wirelessly. The host-end wireless communication module  31  is pluggable for connecting electrically to the POS host  1  via the host-end USB interface  312 , and is supplied with power from the POS host  1 . In other embodiments, the host-end wireless communication module  31  may be built-in and integrated with the POS host  1 . 
     Each of the client-end wireless communication modules  32  includes a client-end RS232 interface  325  for connecting with a respective one of the client devices  2 , a second MCU  324  connected electrically to the client-end RS232 interface  325 , a jumper  326  connected electrically to the second MCU  324 , a converting circuit  323  connected electrically to the second MCU  324 , a second radio frequency circuit  322  connected electrically to the converting circuit  323 , and a second antenna  321  connected electrically to the second radio frequency circuit  322  for transmitting and receiving signals wirelessly. Each of the client-end wireless communication modules  32  is pluggable for connecting electrically to a respective one of the client devices  2  via the client-end RS232 interface  325 . In other embodiments, each of the client-end wireless communication modules  32  maybe built-in and integrated with a respective one of the client devices  2 . 
     Each of the jumpers  326  is operable to set a device type of the respective one of the client devices  2  to which the respective one of client-end wireless communication module  32  is coupled, for example inserting the jumper  326  into one of a set of terminals (not shown) of the client-end wireless communication module  32  so as to set that the client-end wireless communication module  32  is connected electrically to a corresponding one of the client-end display, the bar code scanner, or the printer. Each of the jumpers  326  maybe replaced by a dual in-line package switch in other embodiments of this invention. The converting circuits  323  is for converting format of transmitted data between a USB data format and a RS232 data format. In this embodiment, each of the client-end wireless communication modules  32  is supplied with a direct current as input power, and the input power ranges from 5V to 12V. 
     The POS host  1  is installed with a driver program  11  and a matching utility program  12 . In this embodiment, the driver program  11  and the matching utility program support conventional operating systems, such as Windows 2000, Windows XP, Windows Vista, Windows 7, Windows CE, etc. The POS host  1  drives and configures the host-end wireless communication module  31  when the driver program  11  is executed thereby, such that the host-end wireless communication module  31  is configured to generate a plurality of virtual COM ports  311 , each of which is to be matched with a respective one of the client-end wireless communication modules  32  as shown in  FIG. 2 . Subsequently, the POS host  1  matches each of the virtual COM ports  311  generated by the host-end wireless communication module  31  with the respective one of the client-end wireless communication modules  32  when the matching utility program  12  is executed thereby. 
     Referring to  FIG. 1  and  FIG. 3 , when the matching utility program  12  is executed, users are able to select an “Enter Configuring Mode” option in a first page, which is generated by the matching utility program  12 , displayed on a display screen of the POS host  1 . Users subsequently select a “Search For Unmatched Client Device” option so that the host-end wireless communication module  31  is enabled to search for any unmatched client-end wireless communication module  32 , and address of the unmatched client-end wireless communication module  32  thus found is shown in an unmatched address block  123 . Next, users may select a pull down menu  122  and choose the address of the to-be-matched client-end wireless communication module  32 . 
     Referring to  FIG. 1  and  FIG. 4 , users may subsequently select a “COM Port A Requesting For Matching” option to establish a match between one of the virtual COM ports  311  and a respective one of the client-end wireless communication modules  32 . The address of the matched client-end wireless communication module  32  will be displayed in a matched address block  121  after matching is established. Users may establish matching between the other two virtual COM ports  311  and the other client-end wireless communication modules  32  by following the steps described above. Users may change a target to be matched via selecting a “Clear” option to disable the previous match followed by establishing a new match with another one of the client-end wireless communication modules  32  by the steps described above. After finishing the configuration operation, users may select a “Save Configurations” option followed by selecting a “Leave Configuring Mode” option to exit the configuring mode. It is worth mentioning that the host-end wireless communication module  31  and the client-end wireless communication modules  32  are configured to store erasable matching information associated with the virtual COM ports  311 . 
     Referring to  FIG. 1  and  FIG. 5 , after matching, when the POS host  1  intends to send information to the client-end wireless communication modules  2  (for example, the POS host  1  sending information to the printer for printing receipts or sending information to the client-end display for showing customers&#39; transaction amount), as depicted in step  301 , the information that is to be transmitted by the POS host  1  is transmitted via the host-end wireless communication module  31  to the intended client-end wireless communication module  32 . Referring to step  302 , each of the client-end wireless communication modules  32  detects whether information was received from the POS host  1 . If affirmative, referring to step  303 , the client-end wireless communication module  32  sends an acknowledge signal to the host-end wireless communication module  31 . Otherwise, the host-end wireless communication module  31  continues sending the information until the acknowledge signal is received from the client-end wireless communication module  32 . 
     Referring to  FIG. 1  and  FIG. 6 , when one of the client-end wireless communication modules  32  intends to send information to the POS host  1  (for example, the bar code scanner sending information of commodity purchased by customers to the POS host  1 ), as depicted in step  304 , the information that is to be transmitted by one of the client devices  2  is transmitted via the respective one of the client-end wireless communication modules  32  to the host-end wireless communication module  31 . Referring to step  305 , the host-end wireless communication module  31  detects whether any of the virtual COM ports  311  has received data from the respective one of the matched client-end wireless communication modules  32 . If affirmative, referring to step  306 , the host-end wireless communication module  31  sends an acknowledge signal to the respective one of the client-end wireless communication modules  32 . Otherwise, the client-end wireless communication modules  32  continues sending the information until the acknowledge signal is received from the host-end wireless communication module  31 . 
     In summary, the POS system of the present invention enables the POS host  1  to communicate wirelessly with the client devices  2  via the host-end wireless communication module  31  and the client-end wireless communication modules  32  of the wireless transmission device  3 . The host-end wireless communication module  31  is able to be matched and to communicate with a plurality of the client devices  2  by means of the virtual COM ports  311  generated by the host-end wireless communication module  31 , and the POS host  1  may regard the virtual COM ports  311  as physical COM ports to communicate in a conventional way. Furthermore, users need not worry about loss of data attributed to going beyond an area of coverage during operation due to the data transmission method implemented by the POS system. Thus, the POS system of the present invention enables the deployment locations and distances between the POS host  1  and the client devices  2  to be not limited by physical transmission lines, and reduces affect on aesthetic and integrity of the store decoration by virtue of substituting wireless communication for wired communication. 
     While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.