WO1992020051A1

WO1992020051A1 - Remote monitoring device particularly but not exclusively useful for protection against the theft of items on display

Info

Publication number: WO1992020051A1
Application number: PCT/FR1992/000363
Authority: WO
Inventors: Véronique ROULLEAUX ROBIN
Original assignee: Roulleaux Robin Veronique
Priority date: 1991-04-26
Filing date: 1992-04-23
Publication date: 1992-11-12
Also published as: FR2675932A1; AU1786492A; EP0536380A1; FR2675932B1

Abstract

A device employing multiple local units (U1...Un) each of which controls a plurality of sensors (B), wherein said local units (U1...Un) are connected to one another and to a central processing unit (UC) via a communication network (RT) which includes at least one data transmission line (LD) and a clock signal transmission line (LK). Each of the local units (U1...Un) includes a device (F1, F2, F3) for counting the impulses it receives at its clock input, and two selectors (MU1, MU2) driven by said counting device, namely one selector for allowing clock signal transmission to the next local unit only after a predetermined time interval, and another selector for successively connecting the data transmission line to the abovementioned sensors and then to the local unit located downstream. The device is useful for providing protection against the theft of items which are on display or being demonstrated.

Description

REMOTE MONITORING DEVICE, ESPECIALLY BUT NOT EXCLUSIVELY FOR PROTECTION AGAINST THEFT OF PRESENTATION ARTICLES.

The present invention relates to a remote monitoring device which can be used in particular but not exclusively for the protection against theft of display or demonstration articles exhibited for example in department stores or in exhibition stands.

For this type of application, devices have already been proposed, in particular by US patents 4,746,909 and 3,972,039, involving a multiplicity of local units connected to each other and to a central unit by a transmission line (BUS). can also be used for food.

Each local unit comprises a plurality of connection elements to which detection elements can be connected by means of flexible cables.

In their simplest version, the detection elements are of the binary type (standby / alarm state) and consist, for example, of switches whose movable contacts are actuated following a prohibited movement of objects to monitor. They are usually designed so as to pass from the standby state to the state triggered during a theft or an attempted theft and to transmit on the transmission line a signal for a change of state.

Upon receipt of this change of state signal, the central unit triggers an alarm system associated with it.

It turns out that these devices have a certain number of drawbacks:

- they include only a relatively limited number of local units and detection elements per local unit

- they are not designed so as to be able to generate both an alarm at the level of the local unit concerned and an alarm at the level of the central unit

- they do not make it possible to carry out, at the level of the central unit, an identification of the products which are the object of a flight, nor even a localization of these products and therefore of the places where the flights are made

- they do not allow selective neutralization of local units, in particular to provide troubleshooting or redevelopment of a local unit without interrupting the surveillance exercised by the rest of the system.

Furthermore, it turns out that the solution consisting in using, as transmission line, a BUS connected to a central microprocessor unit, and on which the local units are mounted in parallel, does not make it possible to adequately resolve all of these problems, notably due to the fact that in applications of the type of those mentioned above, - the BUS, which must have a relatively large length, must include as small a number of conductors as possible, thereby limiting the number of usable local units all the more,

- the dialogue between the central unit and the local units involves a relatively complex exchange protocol, and very often the use of costly "intelligent" local units connected to the BUS via interfaces relatively complex input / output,

- local units must, in general, have an address identifiable by the central unit, which makes a change of configuration relatively complex.

The invention therefore more particularly aims to suppress all these drawbacks. To this end, it offers a device of simple design, which is particularly reliable, and which also has great flexibility, both as regards its implementation and its maintenance.

As previously mentioned, this device involves a multiplicity of local units each managing a plurality of detection members, these local units being connected to each other and to a central unit, by means of a transmission network comprising at least two transmission lines, namely, a data transmission line and a clock signal transmission line.

According to the invention, this device is characterized in that,

The central unit is connected to one end of the network, the local units are connected in series on the two lines of the network and each comprise a clock input and output as well as a data input and output respectively connected to sections of these two lines,

each local unit includes a device for counting the pulses it receives on its clock input and two selectors controlled by this counting device, namely:

. a first selector mounted between the clock input and the clock output, this selector being designed so as to interrupt the connection between said input and said output and not to establish it, to allow the transmission of the clock signal to the following local unit, that at the end of a predetermined period of time which corresponds to the counting of a predetermined number of pulses by the counting device,

. a second selector device capable of successively connecting said data output to at least one device generating a data signal representative of the state of at least one sensor connected to the local unit, then to the input of data so as to be able to transmit data signals from at least one local unit located downstream to the central unit.

Advantageously, the network may also include a reset line for initializing the metering device and the selector devices.

An embodiment of the invention will be described below, by way of nonlimiting example, with reference to the appended drawings in which: Figure 1 is a block diagram of a remote monitoring installation according to the invention.

FIG. 2 is a schematic representation illustrating an embodiment of the local units and their connection to each other and to the central unit.

Figure 3 is a diagram showing the hardware architecture of the central unit.

Figure 4 is the block diagram of an embodiment of a detection circuit used in a local unit.

The monitoring installation shown diagrammatically in FIG. 1 is more particularly intended, but not exclusively, for detecting theft of articles on display in store shelves, that is to say articles which the customers can possibly handle but which are not in themselves intended for sale, the customer buying a similar article packed in its packaging.

This installation consists of a central unit UC connected to a multiplicity of local units Ui, U2 ... One distributed inside the store, for example by reason of one per department. The link between the central unit and the local units is effected by means of a transmission network RT on which the local units Ui, U2, etc. are connected in series.

The central unit UC, managed by a microprocessor has at least the following functions:

- Supply of local units Ui, U2 ... n through one or more lines of the RT communication network. - Display of the status of local units Ui. U2 ... One (indication of the number of local units transmitting an alarm signal or a fault signal).

- Recording, for example using a printer of the date, time and type (manipulation or theft) of events that occur with the number of the local unit U concerned, the socket number and the operator code, and this as and when they are activated.

- Interruption of the entire installation, for example by a key or a code keypad.

- Emission of an alarm signal, for example sound and / or light each time a theft has been detected, the stopping of this alarm signal being obtained, by an appropriate action at the unit local concerned.

Each local unit includes a CD detection and dialogue module connected to the RT transmission network and intended to monitor the state of a plurality of detection members which here consist of loops B formed by flexible and integral conductors items you want to protect against theft. These loops B are provided so as to allow manipulation of the protected product only in a determined zone and to open only when the product is moved beyond this zone. Of course, this opening is easily detected by the CD detection module (interruption of a current flowing in the loop - variation of the resistance of the loop) which generates an alarm signal which can include an identification code of loop B and / or local unit Un-

Advantageously, this local unit identification code Un can be programmed by the user according to its position on the transmission network RT by means of miniature switches. Such a program- Mation can also be carried out from the central unit.

In this example, the local units Ui, U2 ••• U each include a device making it possible to locally emit an audible alarm (buzzer) 10 when a flight has been detected, a display device 11 of the active, deactivated state of the local unit and a deactivation key 12 which behaves like a switch vis-à-vis the local unit UC and causes the emission of a deactivation signal on the transmission network RT as well as possibly stopping the sound signal emitted by the buzzer 10.

It is important to insist on the fact that the detection module CD is sensitive only to the change of state of the loops B (open loops / closed loops), which allows the unused loops B to be left open without however jeopardizing the effectiveness of theft detection.

Of course, if the key 12 is placed in the deactivated position to carry out the manipulation of a loop B, the deactivation signal transmitted on the transmission network RT will inform the central unit UC that it is a question of '' authorized handling and not theft.

In the example shown in FIG. 2, the local units Ui, U2 comprise a transmission circuit CT (interrupted lines) connecting two inputs Din and CLKin and two outputs Dout e CLKout- The circuit is mounted in series on transmission lines LD and LK clock data from the RT transmission network. This circuit can be reset by the central unit by means of a general reset line RG provided in the transmission network RT. This transmission circuit is connected to a circuit for detecting the change of state DE of the loops Bi to B6, and to the deactivation switch ID.

In this example, the detection circuit DE is designed so as to transmit both an alarm signal to the transmission circuit CT, as well as a signal for triggering an audible alarm AL, the stopping of which is obtained. by the deactivation key 12.

The resetting of the detection circuit DE is in turn controlled by the central unit UC by means of a first reset line RA provided in the transmission network RT.

The transmission circuit RT can be produced, as shown in FIG. 2 by means of a double multiplexer MU1, MU2 twice three times, controlled by a circuit for counting the pulses of the clock signal applied to the input CLKin. This counting circuit here comprises three flip-flops Fi. F2, F3 successively changing state, the first Fi following the first pulse of the clock signal CLK, the second F2 following the second pulse and the third F3 following the third pulse.

The two multiplexers MUi, MU2 operate synchronously as a function of the output states of the flip-flops F1, F2, F3. The MU2 multiplexer makes it possible, depending on these states, to connect the CLKout output successively to ground (initial position Pi) to an unconnected terminal (intermediate position P2) and to the CLKin input (final position P3 where the signal CLK clock from the central processing unit UC can be transmitted to the following local unit).

The multiplexer MUi makes it possible to connect the output Dou, successively to the output of the circuit DE detection (initial position PI) ^' . at the output of the deactivation switch ID (intermediate position P'2) and at the input Din (final position P'3) in which it allows the data supplied to the line to be sent to the central unit UC by subsequent local units.

The operation of the apparatus described above takes place as follows:

a) Firstly, the central processing unit UC transmits on the first reset line RG, a reset signal which resets the output of the flip-flops Fi, F2, F3 to zero, which causes the multiplexers to pass MUi, MU2 in initial position Pi, P'i, so that,

- the line LK for transmitting the clock signal as well as the line LD for transmitting the data signal are interrupted by each local unit (Ui, U2 ... n).

the detection circuit DE of each local unit is connected to the section of transmission line which is directly downstream, so that the central unit UC can only receive the data signal emanating from the first local unit Ui.

- Only the first local unit Ui receives the clock signal sent by the central unit UC.

b) At the first edge (rising or falling) of the clock signal which follows the reset to zero, the output Q of the flip-flop Fi goes to 1, the flip-flops F2 and F3 remaining at zero. The output D _Q ut of the first local unit Ui transmits to the central unit UC a detection signal (which indicates the state of the various loops Bi to B6 associated with the local unit UC, possibly with a code of identification). The other local units U2 • • • One which does not receive the clock signal remain at the initial state and cannot communicate with the central unit CPU.

c) On the second edge of the clock signal, the output Q of the flip-flop F2 goes to 1 and causes the passage of the multi¬ plexers MUi, MU2 from the initial position Pi, P'i to the intermediate position P2, P'2- In this position, the multiplexer MUi of the first central unit UCi transmits to the output Dout and therefore to the central unit UC a signal representative of the state (deactivated or not) of the local unit UCi. The lines LD and LK remain interrupted by the local units Ui, U2 • • • Un.

On the third edge of the clock signal, the output Q of the flip-flop F3 goes to 1, causing the passage of the multi¬ plexers MUi, MU2 to their third positions P3, P'3. In this position, the multiplexers MUi, MU2 provide the links between the central unit UC and the second local unit U2 at the lines LD and LK.

At the fourth pulse, the second local unit U2 begins a process similar to that just carried out by the first local unit Ui, so that at the end of this process, the first two local units Ui and U2 ensure at the level of lines LD, LK the connections between the central unit UC and the third local unit U3. This process is repeated until the last local unit Un communicates with the central processing unit UC.

After having received the information from the last local unit Un, the central unit no longer receives an adequate return and therefore detects the end of the list of local units (it therefore knows the number of these local units). The central unit UC then transmits a new reset signal on the line RG and then starts a new cycle.

During this operation, the central processing unit UC displays, prints and stores the data, according to the nature of the information collected.

As shown in FIG. 3, this central unit UC uses a conventional type processor (produced for example around an 80C31 microprocessor from the firm INTEL) connected, by means of a data bus DO and a data bus AD addresses,

- an I / O input / output interface connected to the lines LD, LK, RG, RA of the transmission network RT which generates the clock signal, the reset signals and which receives the data transmitted by the units local Ui, U2 ... One on the LD data transmission line

- to a PIA adapter managing the flow of information between the processor and peripherals such as a printer and a keyboard

- ROM type ROM

- a RAM type RAM

- a conventional display, for example with liquid crystal or light-emitting diodes.

In the example shown in FIG. 4, the detection of changes in the state of the loops is ensured by a logic circuit comprising five exclusive OR circuits 13 to 17, namely,

three exclusive OR circuits 13, 14, 15 whose inputs are respectively connected to the six Bi loops to B6, represented here by a conductor in series with a resistor, the extinguished assembly mounted between ground and a voltage source VCC.

a fourth exclusive OR circuit 16 whose inputs are respectively connected to the outputs of the first two exclusive OR circuits 13, 14.

a fifth exclusive OR circuit 17 whose inputs are respectively connected to the outputs of the third and fourth exclusive OR circuits 15 and 16.

The output of the exclusive OR 17 is connected to the clock input 18 of a flip-flop D by means of a filter constituted by an exclusive OR 19 and of an RC assembly.

This combinatorial chain causes the output Q of the flip-flop D to go to zero and its complementary Q to 1 when a change of state of a loop Bi to B6 is detected. These outputs Q and ~ Q are respectively connected to the P'i input of the MUi multiplexer and to the AL alarm control input.

One of the advantages of the device described above, in addition to its simplicity and reliability, consists in that the transmission network RT can have a significant length (greater than 10 km), unlike the apparatus using reillages using conventional parallel buses.

However, in the case where the RT network has a considerable length, the deformations of the data signal can be avoided by inserting buffer registers on the data and clock transmission lines LD, LK at inputs Dj. _n , CLKin and at output Dout, CLKout of local units Ui, U2 ... U, buffer registers. Of course, the supply of electric current to the local units Ui, U2 • • • Un takes place via the transmission network RT using the existing conductors of this network, for example the reset lines RA, RG or even using one or two conductors specially designed for this purpose.

Of course, a complete remote monitoring installation may include, as shown in FIG. 1, in broken lines, several central units UC connected each to a multiplicity of local units Ui, One in the manner previously indicated.

In this case, the central processing units UC can be connected to a central processor PC of the conventional type which provides centralized management of the installation.

This central processor, associated with usual peripherals such as a keyboard / screen console will allow in particular the instantaneous display and the memorization of information relating to events occurring on the installation.

It can be coupled to a transmitter E, for example with high frequency radio waves, capable of transmitting information relating to these events, intended for portable receivers RP, for example for the use of department managers or agents. assigned to surveillance.

If they are transmitted in digital form, this information can be viewed on an AF display incorporated into the receiver.

However, they can advantageously be converted before audio transmission into audio messages by a voice synthesis system. The receiver can then consist of a conventional type radio receiver, provided a loudspeaker for the sound diffusion of messages.

RP receivers can also be equipped with TE remote control means, for example with an infrared ray, capable of acting remotely on a DE deactivation circuit of one or more local units. Of course, the infrared signal emitted by these remote control means TE must be coded and the deactivation circuit DE must include appropriate decoding means.

Claims

1. A remote monitoring device which can be used in particular but not exclusively for the protection against theft of display or demonstration items, this device involving a multiplicity of local units (Ui ... U) each managing a plurality of detection (Bi ... B6), these local units (Ui ... Un) being connected to each other and to a central unit (UC) via a transmission network (RT) comprising at least two transmission lines, namely, a data transmission line (LD) and a clock signal transmission line (LK), characterized in that,

- the central unit (UC) is connected to one end of the network (RT)

- the local units (Ui ... Un) are connected in series on the two lines (LD, LK) of the network (RT) and each include a clock input and clock output (CLKin, CLKout) ι as well as 'a data input and output (Din, Dout) respectively connected to sections of these two lines (LD, LK).

- each local unit (Ui ... Un) includes a counting device (Fi to F3) of the pulses it receives on its clock input (CLKn) and two selectors (MUi, MU2) controlled by this counting device , to know :

. a first selector (MU2) mounted between the clock input and the clock output (CLKin, CLKout) / this selector (MU2) being designed so as to interrupt the connection between said input (CLkin) and said output (CLKout) and to establish it only to allow the transmission of the clock signal to the following local unit (U2) only after a predetermined period of time. mined which corresponds to the counting of a predefined number of pulses by the counting device.

. a second selector device (MUi) capable of successively connecting said data output (Dout) to at least one detection device generating a data signal representative of the state of at least one sensor (Bi ... B6) connected to the local unit (Ui ... Un) then after said time to the data input (Din), so as to be able to transmit to the central unit (UC) data signals emanating from at least one local unit (Ui ... U) located downstream.

2. Device according to claim 1, characterized in that the aforesaid transmission network further comprises a reset line allowing the central unit (UC) to initialize the counting device (Fi - F3) and the devices selectors (MUi, MU2) at the start of each operating cycle.

3. Device according to claim 1, characterized in that the aforesaid detection members consist of loops formed by flexible conductors whose opening is detected.

4. Device according to claim 1, characterized in that each local unit (Ui ... Un) comprises a detection circuit which detects changes in the state of the detection members and which generates an alarm signal which can include a code for identifying the loop and / or the local unit (U), this alarm signal being applied to the second selector device (MUi).

5. Device according to claim 1, characterized in that each local unit (Ui ... U _n ) comprises an alarm device for transmitting locally an alarm when a theft has been detected by one of the detection devices associated with this local unit, as well as a deactivation key which, when requested, makes it possible to interrupt the alarm signal and transmits at the selector device (MU2) a deactivation signal.

6. Device according to claim 1, characterized in that the transmission network comprises a second reset line allowing the central unit to perform the reset of the detection circuit.

7. Device according to claim 1, characterized in that the aforesaid first selector consists of a first multiplexer making it possible to connect the above clock output (CLKout) successively, to ground (initial position Pi), to a possible terminal ¬ also not connected (intermediate position) and to the clock input (CLKin) (final position) and in that the aforesaid second selector consists of a second synchronous multi¬ plexer of the first, and making it possible to connect the aforesaid output of data (Doubt) successively, at the above-mentioned detection circuit (initial position), at the output of the deactivation key (intermediate position) and at the above-mentioned data entry (Din) (final position).

8. Device according to claim 7, characterized in that the aforesaid counting device comprises three flip-flops successively changing state, the first following a first pulse of the clock signal, the second, following a second pulse consecutive to the first and the third following a third pulse consecutive to the second, in that the change of state of the second flip-flop causes the multiplexers to go from the initial position to the intermediate position and in what the change of state of the third rocker causes the passage of the multi¬ plexers, from the intermediate position to the final position.

9. Device according to claim 1, characterized in that it comprises several central units (UC) connected, each to a multiplicity of local units (Ui ... Un), these central units (UC) being connected to a processor central (PC).

10. Device according to claim 9, characterized in that the processor (PC) is associated with a keyboard / screen console allowing instantaneous display of information relating to events occurring on the installation.

11. Device according to claim 10, characterized in that the processor (PC) is coupled to a transmitter (E) capable of carrying out a transmission of information intended for portable receivers (RP).

12. Device according to claim 11, characterized in that the aforesaid receivers (RP) include means for displaying information transmitted by the transmitter (E).

13. Device according to claim 11, characterized in that the information is converted into audio messages before transmission, and in that the receiver (RP) comprises a loudspeaker (HP) for the sound diffusion of the messages.

14. Device according to claim 1, characterized in that the aforesaid receivers (RP) are equipped with remote control means (TE) of the local units (Ui ... U _n ).