FR3074000A1 - METHOD AND SYSTEM FOR DISPLAYING FRAMES OF A RECORD CASH TICKET ON IMAGES OF A VIDEO SURVEILLANCE CAMERA - Google Patents

Abstract

The invention particularly relates to a method for displaying frames of a cash register receipt on the images of a video surveillance camera that films the transaction scene, said method comprising the steps of: - connecting at least one cash register to a computer network, which box is adapted to successively transmit, in said network, the frames of a cash receipt according to a TCP transport protocol, - install a video surveillance camera so as to film the transaction scene at the cash desk recorder, - connect a video recorder on the one hand to the camera to record the images of the transaction scene and on the other hand to the computer network to receive receipt of cash register frames issued by the cash register, said recorder being configured from in order to display said frames on the images of the transaction scene, characterized by the fact that the The invention further comprises a step of connecting an electronic module to the computer network so that said module: - receives the successive frames transmitted by the body, through the computer network and according to the TCP transport protocol, - aggregates at least two frames received, - transmits the aggregation of frames to the video recorder, the transmission being performed through the computer network, according to the UDP transport protocol.

Description

.. 1.

METHOD AND SYSTEM FOR DISPLAYING FRAMES OF A

CASH TICKET RECORDER ON THE IMAGES OF A

VIDEO SURVEILLANCE CAMERA

Description

Technical field of the invention.

The subject of the invention is a method and a system for displaying frames of a cash register receipt on the images of a video surveillance camera which films the transaction scene. The invention also relates to an electronic module allowing the implementation of the process.

It concerns the technical field of methods and systems for marking camera images to control the smooth running of transactions carried out from a cash register.

Technical condition.

The display of a cash register receipt on the images of a video surveillance camera filming the collection scene makes it possible to control the smooth running of transactions by simply and effectively verifying that all of the products delivered have been entered correctly. and billed to customers. By viewing the sales receipt embedded in the video recording, the user can later check the compliance of transactions made by a cashier.

-2 To date, several techniques are used to embed receipts in video surveillance images such as the "Video Controt POS System" solution offered by the company CAPVIGIE Technologie.

Figure 1 shows schematically an installation where several cash registers Ci, C2, C3, C4 are installed in a point of sale (for example a restaurant or a supermarket), are each under the surveillance of a camera, respectively Garni, Cam2, Cam3 , Canru, notably filming the transaction scenes. The cash registers Ci, C2, C3, C4 are connected to an EV video recorder through a computer network R. The Garni, Cam2, Cam3, Carru cameras are also connected to the EV video recorder, via a common bus by example. The principle consists in embedding the transaction data of each box Ci, C2, C3, C4 (type and quantity of products sold, total of the order, sum collected, sum returned, ...) in the video surveillance images of the camera partner Garni, Cam2, Cam3, Canu. For example, the EV video recorder must be able to display the details of transaction tickets issued by the Ci cash register on the Garni camera images.

The computer network R generally makes it possible to recover all the data recorded by the cash registers Ci, C2, C3, C4, on a server S adapted in particular for making statistical analyzes, marketing and / or financial. Also, the cash registers Ci, C2, C3, C4 are generally configured to transmit their data over the network R according to a TOP transport protocol.

The TOP transport protocol (for English “Transmission Control Protocol” is a standard protocol for controlling transmissions, in particular documented in RFC 793 of the IETF (Internet Engineering Task Force), to which a person skilled in the art may refer. The TCP protocol cuts the transaction data from the cash registers Ci, C2, C3, C4 (which correspond to the different lines of a receipt) into small sequences.

-3or wefts. These frames are sent to the server S which will send an acknowledgment message to each of the cash registers. If a cash register does not receive this acknowledgment of receipt, it will retransmit the missing frame (s). The TCP protocol thus ensures error-free data transmission across the R computer network.

Several problems arise when the receipt frame is transmitted to the EV video recorder.

First of all, most video recorders on the market do not include a processor powerful enough to handle the simultaneous reception of frames sent by cash registers Ci, C2, C3, C4.

In addition, there is a high response time, or latency, on the part of the EV recorder. When two or more boxes Ci, C2, C3, C4 simultaneously transmit frames to the EV recorder, the latter must send an acknowledgment of receipt to each of said boxes. However, the EV recorder is generally not configured to send these acknowledgments to the various cash registers simultaneously. It will therefore send the acknowledgments with a certain time difference. And until a caisse receives this acknowledgment, it cannot transmit a new frame and / or will re-transmit the old frame for which it has not received an acknowledgment. There is therefore a time difference between the moment when the cashier performs a physical action on the cash register (which action corresponds to the transmission of a frame) and the moment when the EV recorder will process this frame to display it on the video images. An expensive solution to solve this problem is to provide one video recorder per cash register.

In addition, the EV recorder generally only transcribes the frames of the receipt one by one. The frames are not displayed together on the video images, but are displayed one after the other, a previous frame being replaced and erased by a following frame. The EV recorder is therefore not configured to redial a receipt in its entirety

-4and control the display. Elements such as color, background, font, text size cannot be configured.

Current solutions therefore generally only work with one cash register at a time, for one type of cash register, and with one type of video recorder. As soon as a modification occurs on the cash register and / or on the video recorder, it is generally no longer possible to embed tickets in the images. The use of current solutions is therefore not satisfactory for controlling collections in a multi-box installation.

The invention aims to solve the aforementioned technical problems.

In particular, an objective of the invention is to propose a system making it possible to optimally manage the reception of frames transmitted simultaneously by several cash registers.

Another objective of the invention is to propose a system which does not induce any processing latency when the cash registers transmit frames in a computer network, according to the TCP protocol.

Yet another objective of the invention is to provide a system in which the video recorder is capable of displaying a receipt in its entirety, with perfect mastery of the display.

An additional objective of the invention is to provide a system which is compatible with a large number of cash register and / or video recorder models, without the need to modify said cash registers and / or said video recorder.

Disclosure of the invention.

The solution proposed by the invention is a method for displaying frames of a cash register receipt on the images of a

-5 video surveillance which films the transaction scene, said process comprising the steps consisting in:

- connect at least one cash register to a computer network, which cash register is adapted to successively transmit, in said network, the frames of a receipt according to a TCR transport protocol,

- install a video surveillance camera to film the transaction scene at the cash register,

connect a video recorder on the one hand to the camera to record the images of the transaction scene and on the other hand to the computer network to receive frames of the receipt issued by the cash register, said recorder being configured so as to displaying said frames on the images of the transaction scene.

This method is remarkable in that it further comprises a step consisting in connecting an electronic module to the computer network so that said module:

- receives the successive frames sent by the cash register, through the computer network and according to the TCP transport protocol,

- aggregates at least two received frames,

- transmits the aggregation of frames to the video recorder, the transmission being carried out through the computer network, according to the UDP transport protocol.

The electronic M module now acts as an interface or gateway between cash registers and the video recorder. The use of the UDP protocol allows a very simple transmission between the module and the recorder, the latter no longer having to manage the simultaneous reception of the frames sent by the cash registers. In addition, the aggregation of frames allows the video recorder to transcribe all the useful frames of the sales receipt which will be displayed together on the video images.

Other advantageous characteristics of the process according to the invention are listed below. Each of these characteristics can be considered alone or in combination with the remarkable characteristics defined above, and be the subject, if necessary, of one or more divisional patent applications:

- Advantageously, the method further comprises the steps of: connecting several cash registers to the computer network so that they simultaneously transmit frames to the electronic module; associate a port number to each cash register so that the frames are sent by integrating this port number; - record these different frames in a memory of the electronic module, which recording is carried out by grouping the frames integrating the same cash register port number.

- Preferably, we register the frames incorporating the same port number of a cash register until the recognition, by the electronic module, of a field linked to a receipt at the cash register associated with said port number.

- Preferably, the recognition of the field linked to a collection is the trigger for the transmission of the aggregation of frames to the video recorder.

- The method advantageously comprises a step consisting in deleting from the memory the frames transmitted to the recorder, which deletion is carried out as soon as said frames are transmitted.

- The method advantageously comprises a step consisting in recording in a memory of the electronic module, only frames integrating a field recognized by said module.

- The method advantageously includes the steps of: connecting several cash registers to the computer network so that they simultaneously transmit frames to the electronic module; associate an identification number with each cash register so that the frames are sent by integrating this identification number; simultaneously return, from the electronic module, acknowledgments of receipt of frames to the different cash registers, according to the identification number integrated in each of the frames.

Another aspect of the invention relates to a system for displaying frames of a cash register receipt on the images of a video surveillance camera which films the transaction scene, said system comprising:

- at least one cash register connected to a computer network and adapted to successively transmit, in said network, the frames of a receipt according to a TCP transport protocol,

- a video surveillance camera installed to film the transaction scene at the cash register,

a video recorder connected on the one hand to the camera to record the images of the transaction scene and on the other hand to the computer network to receive frames of the receipt issued by the cash register, said recorder being configured so as to display said frames on the images of the transaction scene,

- an electronic module connected to the computer network so as to communicate with the cash register and with the video recorder, which electronic module is suitable for: - receiving the successive frames sent by the cash register, through the computer network and according to the protocol of TCP transport; - aggregate at least two received frames; - transmit the aggregation of frames to the video recorder, the transmission being carried out through the computer network, according to the UDP transport protocol.

Other advantageous characteristics of the system according to the invention are listed below. Each of these characteristics can be considered alone or in combination with the remarkable characteristics defined above, and be the subject, if necessary, of one or more divisional patent applications:

- Advantageously, several cash registers are connected to the computer network so that they simultaneously transmit frames to

-8 electronic module; each cash register is associated with a port number so that the frames are transmitted by integrating this port number; the electronic module comprises a memory in which the different transmitted frames are recorded, which recording is carried out by grouping the frames integrating the same cash register port number.

- The electronic module is advantageously adapted to record the frames integrating the same port number of a cash register until the recognition, by the electronic module, of a field linked to a collection at the level of the cash register associated with said number of port.

- The electronic module is advantageously adapted to separate the frames grouped in its memory by a special character which is recognized by the video recorder as being a line break.

- The electronic module is advantageously adapted to recognize fields integrated in the frames.

Yet another aspect of the invention relates to an electronic module integrating software for implementing the method.

Description of the figures.

Other advantages and characteristics of the invention will appear better on reading the description of a preferred embodiment which will follow, with reference to the appended drawings, produced by way of indicative and nonlimiting examples and in which:

- Figure 1 above shows a multi-box installation according to the prior art,

- Figure 2 shows schematically a system suitable for implementing the process object of the invention,

- Figure 3 shows schematically the arrangement of different components of an electronic module according to the invention,

- Figure 4 shows schematically a video image on which are embedded the details of a receipt.

Preferred embodiments of the invention.

The system and method which are the subject of the invention generate manipulations of physical elements, in particular signals (electrical or magnetic) and digital data, capable of being stored, transferred, combined, compared, etc., and allowing '' achieve a desired result.

The invention implements one or more computer applications executed by computer equipment. For the sake of clarity, it should be understood in the sense of the invention that "an equipment does something" means "the computer application executed by the processor or microprocessor of the equipment does something". Just like "the computer application does something" means "the computer application executed by the processor or microprocessor of the equipment does something".

Again for the sake of clarity, the present invention may refer to one or more "logical computer processes". These correspond to the actions or results obtained by the execution of instructions from different computer applications. Also, it must also be understood in the sense of the invention that "a logical computer process is suitable for doing something" means "the instructions of a computer application executed by a processor or microprocessors do something".

Again for the sake of clarity, the following clarifications are made to certain terms used in the description and the claims:

- "Computer resource" can be understood in a nonlimiting way as: component, hardware, software, file, connection to a computer network, amount of RAM memory, hard disk space, bandwidth, processor speed, number of CPUs, etc. .

- "Central processing unit" can be understood in a nonlimiting way as: processor, microprocessors, CPU (for Central Processing Unit).

"Software" can be understood as: computer application, computer programs or software.

- "Computer network" or "network" can be understood in a non-limiting way as: computer bus, person network! (PAN), local area network (LAN, WLAN, ..), wide area network (WAN), internet network, intranet network, extranet network. The computer network is a set of computer equipment linked together to exchange, securely or not, information and / or data according to a communication protocol (TCP, UDP, ...).

- "Database" can be understood in a nonlimiting way as a structured and organized set of data recorded on supports accessible by computer equipment and which can be queried, read and updated. Data can be inserted, retrieved, modified and / or destroyed. The management and access to the database can be ensured by a set of software which constitute a database management system (DBMS).

The system object of the invention makes it possible to display frames of a cash register receipt on the images of a video surveillance camera which films a transaction scene. All the lines of the sales receipt, or at least the essential lines of this receipt, can thus be embedded in the video images of the transaction scene. It is particularly intended for the sector of bars, hotel restaurants, supermarkets, supermarket chains, or others, and whose managers wish to control collections. For example, a manager can view the video sequence of a transaction carried out from a cash register, to check that this transaction has gone smoothly according to what is written on the sales receipt. For example, if two drinks have been billed and cashed, the manager can check if these

- 11 two drinks were well served to the customer (and not just one drink, or one more drink).

In FIG. 2, several cash registers Ci, C2, C3, C4 are connected to the computer network R. The invention must however be understood as also applying to an installation comprising only a single cash register.

The cash registers Ci, C2, C3, C4 are conventional commercial cash registers, for example marketed by the companies TOWA®, LEO2® or LASER SYMAG®. These cash registers are wired or wirelessly connected to the computer network R. They are suitable for successively transmitting, in the network R, the frames of a cash receipt according to a TCR transport protocol. The ticket frames correspond to the different lines printed on the ticket: product type, quantity, unit price, total order price, amount collected, amount returned, etc. As soon as a cashier makes an entry on a cash register Ci, C2, C3, C4, the latter sends a frame in the network R corresponding to the information of the entry. Insofar as a transaction requires several entries on the cash register, the latter successively transmits several frames.

Each box Ci, C2, C3, C4 is defined by a port number and by an identification number which is assigned to it permanently or temporarily, for example an IP address (for Internet Protocol). The frames are thus transmitted by integrating this port number and this identification number.

The boxes Ci, C2, C3, C4 are each associated with a Cami, Cam2, Cam3, Carru video surveillance camera, installed to film the transaction scenes at the corresponding box. These Cami, Cairi2, Cam3, Carri4 cameras are conventional commercial cameras, for example in high definition with a recording of 20 images per second or more. Each

- 12 Cami, Cam2, Cam3, Canri4 cameras are associated with a port number and an identification number, for example an IP address.

The EV video recorder is connected on the one hand to Garni, Canri2, Cam3, Canru cameras to record the images of the transaction scenes and on the other hand to the R computer network. These images are time-stamped and stored in a database. The images received are associated with the port numbers of the cameras, so that the EV recorder can compartmentalize the images in the database. The EV recorder has IT resources which allow it to process in real time the images provided by its cameras Garni, Cam2, Cam3, Canu; to make the computer link between the images captured by said cameras and the frames sent by the boxes Ci, C2, C3, C4; to embed all or part of the lines of the receipt in His images captured by said cameras. The EV video recorder is a conventional commercial recorder, for example marketed by the company DAHUA® under the reference NVR5208. The connection between the EV video recorder and the Garni, Cam2, Cam3, Cam4 cameras can be made by cable directly connecting said recorder to said cameras, or through the R network.

According to the invention, an electronic module M is connected to the network R so as to be able to communicate with the boxes Ci, C2, C3, C4 and with the EV recorder. This module M serves as an interface or gateway between the boxes Ci, C2, C3, C4 and the EV recorder. The M module is in the form of a box, for example of the Livebox® or Freebox® type.

Referring to FIG. 3, the module M notably comprises a central processing unit 10, one or more memories 11 and a network interface 12, which are mutually connected via the bus 13. One or more software programs are recorded in the one or more memories 11 and whose instructions, when executed by the unit 10, make it possible to carry out the functionalities described further on in the description.

The memory (s) 11 must be considered as a storage device also suitable for storing data and / or data files. It can be native memory or add-on memory such as a Secure Digital (SD) card.

The network interface 12 is a wired or wireless communication interface suitable for establishing communication with the funds Ci, C2, C ₃ , C4 and with the EV recorder, through the network R. In general, the interface network 12 has the function of managing the connections between the module M and the devices Ci, C ₂ , C ₃ , C ₄ , EV.

The module M receives all the successive frames sent by the funds Ci, C2, C3, C4, through the network R and according to the TCP transport protocol. Each frame received is associated with the port number and the identification number of the box that sent it. In accordance with the rules of the TCP protocol, the module M can therefore send an acknowledgment of return to the cash register that sent the received frame.

The latency mentioned above is now passed on to the module M. When several boxes Ci, C2, C3, C4 transmit frames simultaneously to the module M, the latter saves them in its memory 11. The computer resources of the module M can be adapted for that said module simultaneously sends back acknowledgments of receipt to the various cash registers. Indeed, its central unit 10 can be powerful enough to manage simultaneous reception. If its IT resources do not allow these simultaneous sendings, the module M returns the acknowledgments with a time difference. In all cases, it is certain that the module M receives and stores all the frames sent by the boxes Ci, C2, C3, C ₄ .

The module M stores the different frames in its memory 11 by grouping together the frames which integrate the same port number. Module M can

- 14 thus isolate the frames sent by a box, frames sent by another box. The frames are saved until the recognition of a field linked to a receipt at the level of the cash register bearing the corresponding port number. This is for example a payment by bank card, or the printing of the receipt. The frame associated with this action indeed includes a field of the “payment” or “ticket printing” type. The M module is configured to recognize this field. The frames received between two fields linked to a collection constitute the frames of a sales receipt.

The module M can also be configured to recognize other fields and to save in its memory only the frames integrating these recognized fields. All the frames not integrating a recognized field are therefore not saved in the memory 11. For example, in certain cases, it is not useful to save frames relating to a reduction or a promotion, and more general, frames which are not useful for controlling the smooth running of a transaction.

To recompose the receipt, the module M aggregates the frames recorded in its memory 11. At least two of the frames received by the module M are aggregated. This aggregation of frames makes it possible to transmit to the EV recorder, at a single time, the various useful frames of the receipt. The module M therefore does not successively transmit to the EV recorder the various frames of the ticket. It waits until it has received all the frames, before transmitting them by a single send to the EV recorder. The recognition of a field linked to a collection is the trigger for this transmission. As soon as this sending is carried out, the frames transmitted to the EV recorder are deleted from the memory 11 to relieve the latter.

The EV recorder can therefore now display the frames of the receipt which will be displayed together on the video images.

- 15 For aesthetic and practical reasons, it is important that the different frames of the receipt can be displayed line by line. Also, the module M separates the ticket frames gathered in its memory 11 by a special character which is recognized by the EV recorder as being a line feed. The character "\ n" can for example be chosen and integrated at the end of each frame. The EV recorder recognizes this character as a line break for formatting and displaying the sales receipt.

The aggregation of frames is transmitted to the EV recorder through the network R, and according to the UDP transport protocol. This set of frames is associated with the port number of the box Ci, C ₂ , C3, C4 having originally sent them.

The UDP transport protocol (for English “User Datagram Protocol”, in French user datagram protocol) is a standard telecommunications protocol, notably documented in RFC 768 of the IETF, to which a person skilled in the art can refer. if needed. According to the UDP protocol, data transmission is unidirectional, in the sense that it does not require the return of an acknowledgment message, unlike the TCP protocol. In the present case, the module M transmits the frames to the EV recorder without the latter returning an acknowledgment of receipt. The use of the UDP protocol therefore allows very simple transmission between the M module and the EV recorder. The latter no longer needs to manage the simultaneous reception of the frames sent by the cash registers Ci, C ₂ , C3, C4 as is the case in the configuration of FIG. 1. There is a two-way communication between the module M and the cash registers Ci, C ₂ , C3, C4; and one-way communication between the module M and the EV recorder.

The EV recorder therefore receives on the one hand the video images of the various cameras Cam-ι, Cam ₂ , Cam3, Carru, and on the other hand frame aggregations. As explained above, the video images are associated with the port number of the camera having filmed them and the frame aggregations are associated

- 16 to the port number of the cash register that generated them. The EV recorder is in fact previously configured to associate the port number of a camera with the port number of a cash register. Thus, it can associate the aggregations of frames of a box with the images of the camera filming said box. Since the video images and the frames are time-stamped, the EV recorder can overlay the frames received, and therefore the sales receipt, in the images filming the receipt of the corresponding transaction.

When a manager has doubts about a transaction, he can interrogate the EV recorder to view the sequence of the transaction. This interrogation can be done directly on the EV recorder or remotely from a terminal (PC, tablet, smart phone like Smartphone ...) connected to said recorder.

In the example in Figure 4, the manager checks the receipt # 123456. The recorder displays the video images of the cash register Ci taken by the Cami camera at the time of the transaction. Details of the T ticket issued by the cash register are displayed on the video images.

The arrangement of the various elements and / or means and / or stages of the invention, in the embodiments described above, should not be understood as requiring such an arrangement in all implementations. In any event, it will be understood that various modifications can be made to these elements and / or means and / or stages, without departing from the spirit and scope of the invention.

Claims (13)

1. Method for displaying frames of a cash register receipt on the images of a video surveillance camera which films the transaction scene, said method comprising the steps consisting in: - connect at least one cash register (Ci, C2, C3, C4) to a computer network (R), which cash register is adapted to successively transmit, in said network, the frames of a receipt according to a TCP transport protocol , - install a video surveillance camera (Cami, Cam2, Cam3, Carru) so as to film the transaction scene at the cash register level (Ci, C2, C3, C4), - connect a video recorder (EV) on the one hand to the camera (Carn-i, Cam2, Cam3, Carru) to record the images of the transaction scene and on the other hand to the computer network (R) to receive frames of the receipt issued by the cash register (Ci, C2, C3, C4), said recorder being configured so as to display said frames on the images of the transaction scene, characterized in that the method further comprises a step consisting in connecting an electronic module (M) to the computer network (R) so that said module: - receives the successive frames sent by the cash register (Ci, C2, C3, C4), through the computer network (R) and according to the TCP transport protocol, - aggregates at least two received frames, - transmits the aggregation of frames to the video recorder (EV), the transmission being carried out through the computer network (R), according to the U DP transport protocol. 2. Method according to claim 1, further comprising the steps of: - connect several cash registers (Ci, C2, C3, C4) to the computer network (R) so that they simultaneously transmit frames to the electronic module (M), - associate a port number to each cash register (Ci, C2, C3, C4) so that the frames are sent by integrating this port number, - record these different frames in a memory (11) of the electronic module (M), which recording is carried out by grouping the frames integrating the same cash register port number. 3. Method according to claim 2, consisting in recording the frames integrating the same port number of a cash register (Ci, C2, C3, C4) until the recognition, by the electronic module (M), of a field linked to a receipt at the cash register level (Ci, C2, C3, C4) associated with said port number. 4. The method of claim 3, wherein the recognition of the field related to a collection is the trigger for the transmission of the aggregation of frames to the video recorder (EV). 5. Method according to one of claims 2 or 3, comprising a step of deleting from the memory (11) the frames transmitted to the recorder (EV), which deletion is carried out upon transmission of said frames. 6. Method according to one of claims 2 to 5, comprising a step of registering in the memory (11) of the electronic module (M), only frames integrating a field recognized by said module. 7. Method according to one of the preceding claims, further comprising the steps of: - connect several cash registers (Ci, C ₂ , C3, C4) to the computer network (R) so that they simultaneously transmit frames to the electronic module (M), - associate an identification number with each cash register (Ci, C ₂ , C3, C4) so that the frames are sent by integrating this identification number, - send back, simultaneously from the electronic module (M), frame acknowledgments to the different boxes, according to the identification number integrated in each frame. 8. System for displaying frames of a cash register receipt on the images of a video surveillance camera which films the transaction scene, said system comprising: - at least one cash register (Ci, C ₂ , C3, C4) connected to a computer network (R) and adapted to successively transmit, in said network, the frames of a receipt according to a TCP transport protocol, - a video surveillance camera (Cami, Cam ₂ , Cam3, Canru) installed so as to film the transaction scene at the cash register level (Ci, C ₂ , C3, C4), - a video recorder (EV) connected on the one hand to the camera (Cami, Cam ₂ , Cam3, Carru) to record the images of the transaction scene and on the other hand to the computer network (R) to receive frames from the receipt issued by the cash register (Ci, C ₂ , C3, C4), said recorder being configured so as to display said frames on the images of the transaction scene, characterized by the fact that an electronic module (M ) is connected to the computer network (R) so as to communicate with the cash register (Ci, C ₂ , C3, C4) and with the video recorder (EV), which electronic module is suitable for: - receive the successive frames sent by the cash register (Ci, C2, C3, C4), through the computer network (R) and according to the TCP transport protocol, - aggregate at least two received frames, - transmit the aggregation of frames to the video recorder (EV), the transmission being carried out through the computer network (R), according to the UDP transport protocol. 9. The system as claimed in claim 8, in which: - several cash registers (C1, C2, C3, C4) are connected to the computer network (R) so that they simultaneously transmit frames to the electronic module (M), - each cash register (C1, C2, C3, C4) is associated with a port number so that the frames are sent by integrating this port number, - The electronic module (M) includes a memory in which the different transmitted frames are recorded, which recording is carried out by grouping the frames integrating the same cash register port number. 10. The system as claimed in claim 9, in which the electronic module (M) is adapted to record the frames integrating the same port number of a cash register (Ci, C2, C3, C4) until recognition, by the electronic module (M), of a field linked to a collection at the level of the cash register (Ci, C2, C3, C4) associated with said port number. 11. System according to one of claims 9 or 10, in which the electronic module (M) is adapted to separate the frames grouped in its memory (11) by a special character which is recognized by the video recorder (EV) as being a line break. 12. System according to one of claims 8 to 11, wherein the electronic module (M) is adapted to recognize fields integrated in the frames. 13. Electronic module (M) characterized by the fact that it incorporates software for the implementation of the method of claim 1, which implementation of the method is carried out when said software is executed by said module.