FR2675932A1 - REMOTE MONITORING DEVICE, ESPECIALLY BUT NOT EXCLUSIVELY FOR PROTECTION AGAINST THEFT OF PRESENTATION ITEMS. - Google Patents

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 TO ARTI THEFT PROTECTION
PRESENTATION KEYS.

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 displayed, 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 the objects to be monitored.

They are usually designed so as to pass from the standby state to the state triggered during a flight or attempted theft and to transmit a signal of change of state on the transmission line.

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

It turns out that these devices have a certain number of drawbacks: - they only include a relatively limited 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 subject of a theft, or even a location of these products and therefore of the places where thefts take place - they do not allow a selective neutralization of local units, in particular to ensure a breakdown service or a refitting of a local unit without interrupting the surveillance carried out by the rest of the device.

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, in particular due to the fact that in the applications of the type of those previously mentioned, - the BUS which must have a relatively large length must include a number as small as possible of conductors, which limits all the more the number of units usable local units, - 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 d relatively complex entry / exit, - local units must, in general, have an address identifiable by the central unit, which makes a change relatively complex configuration.

The invention therefore more particularly aims to eliminate 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, via 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 mounted in series on the two lines of the network and each comprise an input and an output of clock 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 device counting, viz. a first selector mounted between the clock input and 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 data input 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 enabling the counting device and the selector devices to be initialized.

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

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

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

FIG. 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 the detection of theft of articles displayed on 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 U1, U2 ...

One distributed inside the store, for example one per department. The link between the central unit and the local units takes place via an RT transmission network on which the local units
U1, U2 ... Un are connected in series.

The central unit UC, managed by a microprocessor has at least the following functions - Supply of local units U1, U2 ... One via one or more lines of the communication network RT.

- Display of the status of local units Ul, U2 ... Un (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 concerned, the outlet number and the operator code, and this as they are activated.

- Interruption of the entire installation, for example by a key or a 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 level of the local unit concerned .

Each local unit comprises a detection and dialogue module CD connected to the transmission network RT and intended to monitor the state of a plurality of detection members which here consist of loops B formed by flexible conductors and secured to the articles that we 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 the loop B and / or local unit Un.

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

In this example, the local units U1, U2 ... Un 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 for the active state, deactivated 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 the '' buzzer 10 stops sound signal.

It is important to emphasize that the detection module CD is only sensitive to the change of state of the B loops (open loops / closed loops), which makes it possible to leave unused B loops open without, however, causes theft detection effectiveness.

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 this is an authorized manipulation not theft.

In the example shown in FIG. 2, the local units U1, U2 comprise a transmission circuit CT (broken lines) connecting two inputs Din and CLKin and two outputs Dout and CLKout. The circuit is connected in series on data transmission lines LD and clock LK of the transmission network RT. 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 state change detection circuit DE of the loops B1 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 reset 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 F1, F2, F3 successively changing state, the first F1 following the first pulse of the clock signal CLK, the second F2 following the second pulse and the third F3 following the third impulse.

The two multiplexers MU1, 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 P1) to an unconnected terminal (intermediate position P2) and to the CLKin input (position
P3 final where the CLK clock signal from the central unit UC can be transmitted to the next local unit).

The multiplexer MU1 makes it possible to connect the output Dout, successively to the output of the detection circuit DE (initial position PI) to the output of the deactivation switch ID (intermediate position P'2) and to the input Din (final position P'3) in which it allows transmission to the central unit
CU of data supplied to the line by subsequent local units.

The operation of the previously described apparatus takes place as follows a) Firstly, the central unit UC transmits on the first reset line RG, a reset signal which resets the output of the flip-flops F1 ,
F2, F3, which causes the passage of the multiplexers MU1,
MU2 in the initial position P1, P'1, 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 (U1, U2 ... Un ).

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 U1.

- only the first local unit U1 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 flip-flop F1 goes to 1, flip-flops F2 and F3 remaining at zero. The output Dout of the first local unit U1 transmits to the central unit UC a detection signal (which indicates the state of the various loops B1 to B6 associated with the local unit UC, possibly with an identification code). The other local units U2 ... One which do not receive the clock signal remain in the initial state and cannot communicate with the central unit UC.

c) At the second edge of the clock signal, the output Q of the flip-flop F2 goes to 1 and causes the multiplexers MU1, MU2 to pass from the initial position P1, Pt1 to the intermediate position P2, P'2. In this position, the multiplexer MU1 of the first central unit UC1 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 UC1. The lines LD and LK remain interrupted by the local units U1, U2 ... Un.

On the third edge of the clock signal, the output Q of the flip-flop F3 goes to 1, causing the multiplexers MU1, MU2 to pass to their third positions P3, P'3.

In this position, the multiplexers MU1, 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 starts a process similar to that just carried out by the first local unit Ul, so that at the end of this process, the first two local units U1 and U2 ensure at the level of lines LD, LK the connections between the central processing unit UC and the third local unit
U3. This process is repeated until the last local unit One is put in communication with the central 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 processing 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 involves a processor of the conventional type (produced for example around a microprocessor 80C31 from the firm INTEL) connected, by means of a BUS of the DO data and a BUS of the addresses AD , - 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 local units U1,
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 - to a ROM type ROM - to a RAM type RAM - to 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 the inputs of which are respectively connected to the six loops B to B6, represented here by a conductor in series with a resistor, the assembly being 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 via a filter constituted by an exclusive OR 19 and of a circuit
RC.

This combinatorial chain involves the passage to zero of the exit Q of rocker D and to 1 of its complementary
Q upon detection of a change of state of a loop B1 to B6. These outputs Q and Q are respectively connected to the input P'1 of the multiplexer MLT1 and to the control input of the alarm AL.

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

However, in the case where the RT network has a long length, the deformations of the data signal can be avoided by inserting buffer registers on the data and clock transmission lines.
LD, LK in Din inputs, CLKin and in Dout output, CLKout of local units U1, U2 ... One, buffer registers.

Of course, the supply of electric current to the local units Ul, U2, etc. 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 each connected to a multiplicity of local units U1,
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 in particular allow instant display and 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 it is transmitted in digital form, this information can be viewed on an AF display incorporated into the receiver.

However, they can advantageously be converted, before transmission, into audio messages by a text-to-speech system. The receiver could then consist of a conventional type radio receiver, fitted with a loudspeaker for the sound diffusion of messages.

The RP receivers may also be equipped with TE remote control means, for example with 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 (14)

 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 (Ul ... Un) each managing a plurality of detection (B1 ... B6), these local units (U1 ... Un) being connected to each other and to a central unit (UC) via a transmission network (RT) comprising at least two lines of transmission, 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 (Ul ... Un) are connected in series on the two lines (LD, LK) of the network (RT) and each include a clock input and a clock output (CLKin, CLKout), as well as a data input and output (Din, Dout) respectively connected to sections of these two lines (LD, LK).  end of pulses by the counting device.  mined which corresponds to the counting of a predefined number  boasts (U2) that at the end of a predetermined period of time  clock signal mission to the following local unit  (CLKout) and do not set it up to allow trans  sound between said input (CLkin) and said output  (MU2) being designed to interrupt the connection  the clock output (CLKin, CLKout), this selector  a first selector (MU2) mounted between the input and - each local unit (U1 ... Un) includes a counting device (F1 to F3) of the pulses it receives on its clock input (CLKn) and two selectors (MU1, MU2) controlled by this counting device , to know  (U1 ... Un) located downstream.  data from at least one local unit  transmit signals to the central processing unit (CPU)  at the data entry (Din), so that you can  local (U1 ... Un) then at the end of said period of time  at least one sensor (Bî ... B6) connected to the unit  drant a data signal representative of the state  (Doubt) at least one detection device engen  successively connect said data output  a second selector device (MU1) capable of  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 (F1 ... F3) and the selector devices (MU1, MU2) at the start of each operating cycle.  3. Device according to one of the preceding claims, characterized in that the aforesaid detection members consist of loops formed by flexible conductors whose opening is detected.  4. Device according to one of the preceding claims, characterized in that each local unit (Ul ... Un) comprises a detection circuit which detects changes in the state of the detection members and which generates an alarm signal which can include an identification code of the loop and / or the local unit (Un), this alarm signal being applied to the second selector device (MU1).  5. Device according to one of the preceding claims, characterized in that each local unit (Ul ... Un) comprises an alarm device making it possible to locally issue 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 to the selector device (MU2) a deactivation signal.  6. Device according to one of the preceding claims, characterized in that the transmission network comprises a second reset line enabling the central unit to reset the detection circuit.  7. Device according to one of the preceding claims, 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 P1), to a terminal possibly not connected (intermediate position) and to the clock input (CLKin) (final position) and in that the aforesaid second selector consists of a second synchronous multiplexer of the first, and making it possible to connect the aforesaid data output (Dout ) successively, to the above-mentioned detection circuit (initial position), to the output of the deactivation key (intermediate position) and to the above-mentioned data input (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 rocker causes the passage of the multiplexers from the initial position to the intermediate position and in what the change of state of the third rocker causes the passage of the multiplexers, from the intermediate position to the final position.  9. Device according to one of the preceding claims, characterized in that it comprises several central units (UC) connected, each to a multiplicity of local units (Ul ... Un), these central units (UC) being connected to a central processor (PC).  10. Device according to claim 9, characterized in that the processor (PC) is associated with a keyboard / screen console allowing instant 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 an information transmission intended for portable receivers (RP).  12. Device according to claim 11, characterized in that the aforesaid receivers (RP) comprise 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 one of the preceding claims, characterized in that the aforesaid receivers (RP) are equipped with remote control means (TE) of the local units (U1 ... Un).