PROCESS OF HIGH RELIABILITY FOR COMMUNICATIONS BETWEEN A MASTER INSTALLATION AND SECONDARY INSTALLATIONS AND DEVICE FOR CARRYING OUT THIS PROCESS

• US 3,717,844 A
• Filed: 04/02/1970
• Issued: 02/20/1973
• Est. Priority Date: 04/03/1969
• Status: Expired due to Term

• Current Assignee: Gerard Jourdan, Jacques Harbonn, Jean Pierre Barret
• Original Assignee: Gerard Jourdan, Jacques Harbonn, Jean Pierre Barret
• Inventors: Barret, Jean Pierre, Jourdan, Gerard, Harbonn, Jacques
• Primary Examiner(s): Farley, Richard A.
• Application Number:
  US05/025,017
• Time in Patent Office: 1,055 Days
• Field of Search: 340/5,16C,171A 325/37,44,47,393,30,59,61,163,33,34
• US Class Current: 367/2
• CPC Class Codes: C09B 67/0025 Crystal modifications; Special X-ray patterns
• CPC Class Codes: E21B 47/14 using acoustic waves
• CPC Class Codes: G08C 23/02 using infrasonic, sonic or ultrasonic waves
• CPC Class Codes: H04B 11/00 Transmission systems employing sonic, ultrasonic or infrasonic waves
• CPC Class Codes: H04Q 9/12 using combinations of frequencies
• CPC Class Codes: Y10S 367/901 Noise or unwanted signal reduction in nonseismic receiving system

Abstract

A process of transmission wherein each transmitted message is constituted by sequences containing element of information numerically coded by amplitude modulation of a carrier wave through at least one subcarrier oscillation. The coded values of each subcarrier oscillation are selected between two values close to a basic frequency of this subcarrier oscillation. The apparatus for carrying out this process includes in combination a number of means providing for a high reliability of the transmission.

Claims

1. A process for transmitting messages consisting of signals between two installations comprising the combination of the following steps:

a. transmitting from one of said installations messages comprising at least one sequence of signals containing at least one element of information, the element of information being numerically coded through the frequency of at least one subcarrier oscillation which amplitude modulates a carrier wave, the frequency having a coded value selected from at least two values close to a basic frequency of said subcarrier oscillation, and b. determining at the other installation the value of the frequency of said subcarrier frequency, the determined frequency being representative of the numerical value of said element of information.

2. A process according to claim 1, wherein said sequence of signals is transmitted over a period of at least one second and the signals contained in said sequence are detected at the other installation exclusively after establishment of stationary conditions of reception of said sequence.

3. A process according to claim 1, wherein each sequence of signals includes an element of information representative of a serial number of said sequence in the transmitted message.

4. A process according to claim 1, wherein the transmission of said messages between said installations is effected through at least one transmission cable.

5. A process according to claim 1, wherein said messages are transmitted between said installations by means of electromagnetic waves.

6. A process according to claim 1, wherein said messages are transmitted by means of acoustic waves.

7. A process according to claim 1, wherein said messages are made distinctive according to their nature by the number of sequences assigned to each message.

8. A process according to claim 1, whereiN one of said installations effects the setting into a state of reception of another installation by transmitting a call message having a single frequency, this signal constituting a carrier wave and said signal is identified at said other installation by the presence of said single frequency exclusively in said signal.

9. A process according to claim 8, wherein at the receiving of said call message said other installation is kept in a state of reception during a determined time interval for analyzing a message following said call message.

10. A process according to claim 1, wherein for the transmission of messages between a master station and a plurality of secondary installations, the master station places at least one secondary installation into a stage of reception by transmitting a call signal thereto and following said call signal, the master station transmits sequences of coded informations, the group of said sequences constituting an address characteristic of said secondary installation, the informations contained in the different sequences being represented by a group of different modulating subcarrier frequencies, said sequences being decoded at said secondary installations and wherein is set in condition of conversation with the master installation exclusively, the secondary installation having an address which corresponds to said address following said call signal.

11. A process according to claim 1, wherein said sequences are constituted by a group of different basic subcarrier frequencies, wherein at least one of said subcarrier frequencies represents, according to a binary code, the value of an information, and at least one other of said subcarrier frequencies represents a serial number of said sequence, so that two sequences differ at least by the value of at least one of said subcarrier frequencies.

12. A process according to claim 11, wherein at the reception each of said sequences is validated only after the presence of all of said subcarrier frequencies has been ascertained and after the element of information represented by each of said subcarrier frequencies has been verified, and a sampling of the signals contained in said sequence is effected after validation of said sequence.

13. A process according to claim 10, wherein a '"'"''"'"''"'"''"'"'ready-to-operate'"'"''"'"''"'"''"'"' response-message is transmitted from said secondary installation, in response to the setting of said secondary installation into a condition of conversation, said response-message comprising the address of said installation.

14. A process according to claim 13 wherein after reception of said response-message at said master installation, said master installation transmits coded instructions representing operations to be carried out on at least one regulating member of said secondary installation, said instructions being transmitted to means for actuating said regulating member arranged on said secondary installation, exclusively when said secondary installation is in a condition of conversation, the instruction being coded with the frequency of the carrier wave and at the same time with all the different subcarrier frequencies of said group of subcarrier frequencies.

15. A process according to claim 14, wherein at the reception of an instruction a response-message is transmitted from said secondary installation, said response message being characteristic for the received instruction.

16. A process according to claim 10, wherein at the setting of said secondary installation in condition of reception a device is actuated for automatically resetting said secondary installation into a condition of reduced activity when a determined time has elapsed after the reception of each sequence of a received message other than an instruction from the master station of returning to the condition of reduced activity, and wherein said automatic device is set back to its initial position exclusively upon receiving of a new message of the conversation when this message is received during said time interval.

17. A device for transmitting messages consisting of signals between two installations, comprising in combination means for transmitting, from one of said installations, messages comprising at least one sequence of signals which contains at least one element of information, means for producing a carrier wave, means for producing at least one subcarrier oscillation, means for amplitude modulation of said carrier wave by said subcarrier oscillation, means for numerically coding said element of information, adapted to give the frequency of said subcarrier oscillation a coded frequency selected from at least two values close to a basic frequency of said subcarrier frequency and means determining at the other installation the value of the frequency of said subcarrier frequency, said frequency being representative of the numerical value of said element of information.

18. An apparatus according to claim 17 comprising at a first of said installations, means for transmitting messages and at a second installation, means for receiving these messages, said receiving means including a retarding device adapted to place said second installation in a state of reception during a fixed time interval, at the receiving of a characteristic call message, said time interval being at least equal to the duration of a message of information to be transmitted to said second installation after said call message, means at said second installation for validating said message of information, said validating means being adapted to keep said second installation in a condition of conversation with said first installation by blocking said retarding device exclusively when said message of information is validated.

19. An apparatus according to claim 18, wherein said second installation includes means for placing automatically said second installation back into a condition of reduced activity at the end of a predetermined time interval after the receiving of each message of information and in the absence of the reception of new message of information and in the absence of the reception of new messages emanating from said first installation.

20. An apparatus according to claim 17, wherein each of said installations includes means for transmitting sequences of acoustic signals, said sequences having a duration greater than one second and means, in combination with said transmitting means, for receiving said sequences of signals. condition of reception of said sequence has been established.

21. An apparatus according to claim 17 wherein at said second installation includes means for controlling the transmission of a response-message containing the address of said second installation and addressed to said first installation.

22. An apparatus according to claim 18, wherein said first installation comprises means for displaying the informations received from said second installation, in combination with means adapted to validate the sequences of said message containing informations, prior to the displaying of these informations.

23. An apparatus according to claim 17, wherein at said second installation includes means for sampling signals of said sequences.

24. An apparatus according to claim 23, wherein said second installation includes means for blocking the operation of said sampling means during the transmission periods of said second installation and during a fixed time interval following each transmission period.

25. An apparatus for transmitting from a first installation messages destined to a second installation which is in a state of reduced activity, said messages comprising call and address messages for said second installation, so as to place in state of reception and energize said second installation at the receiving of said call and address messages and for transmitting from said second installation, in response to a call and address message a '"'"''"'"''"'"''"'"'ready-to-operate'"'"''"'"''"'"''"'"' response-message destined to said first installation, this apparatus comprising in combination:

a. at said first instAllation, means for transmitting a call message constituted by a signal at a call frequency, means for transmitting messages including at least an address message corresponding to said second installation and following said call message, said address message being constituted by at least one sequence of informations coded numerically by the value of the frequency of at least one subcarrier oscillation amplitude modulating a carrier wave, this coding frequency being selected between at least two values close to a basic frequency of said subcarrier oscillation, each sequence of the address message also including at least one information signal representative of a serial number of said sequence in said address message, and means for receiving a '"'"''"'"''"'"''"'"'ready-to-operate'"'"''"'"''"'"''"'"' response-message transmitted from said second installation, in response to said address message;

b. at said second installation, means for receiving messages emanating from said first installation and means for identifying said call message, adapted to deliver a validating signal at the receiving of a message containing only said call frequency, without containing any frequency of a subcarrier oscillation of said address message, means for analyzing and means for recording the received messages following said call message, retarding means connected to said means identifying the call signal and to said analyzing and recording means, and adapted to maintain said analyzing and recording means in operative condition during a determined time interval after receiving said validating signal, said analyzing means comprising means for isolating each subcarrier oscillation appearing in the messages received from said first installation, discriminating means, connected to said isolating means and adapted to detect the value of the frequency of each subcarrier frequency contained in each sequence of a message received from said first installation, said value being representative of the value of an element of information, said discriminating means being connected to said recording means, means for decoding the serial number of each sequence of the call message connected to said recording means, means for sampling the value of an element of information contained in each sequence of a message received from said first installation, adapted to carry out said sampling operation at a fixed instant after the beginning of the reception of said sequence, said sampling means cooperating with said discriminating means and being connected to said recording means, safety means connected to said discriminating means and adapted to transmit the sampled value to said recording means only after having verified that in each received message each of said subcarrier frequencies is present and that only one coded value is to be found for each subcarrier oscillation, means for decoding the address, connected to said retarding means and to said recording means, adapted to produce, exclusively at the receiving of an address message which is characteristic for said second installation, an energizing signal and a signal blocking said retarding means in a position placing in operative conditions said analyzing and recording means, means for energizing said second installation, connected to said means decoding the address, and adapted to be actuated by said energizing signal, and transmission means connected to said energizing means and adapted to be actuated through said energizing signal to transmit said '"'"''"'"''"'"''"'"'ready-to-operate'"'"''"'"''"'"''"'"' response message corresponding to said second installation and addressed to said first installation.

26. An apparatus according to claim 25, wherein said second installation includes means for returning said second installation to a condition of reduced activity, said last mentioned means being connected to said retarding means, to said recording means and to said transmitting means and adapted to produce, at the reception of a message for returning the installation to a condition of reduced activity, a signal for releasiNg said retarding means and a signal for producing the transmission of a message indicating the return of said second installation to its condition of reduced activity.

27. An apparatus according to claim 25, wherein said second installation and being means for returning automatically said second installation to a condition of reduced activity and being, connected to said recorded means and to said means for sampling the value of an element of information contained in each sequence of a received message and adapted to deliver to said recording means a message for return to said condition of reduced activity, at a determined time interval from the instant of said sampling, said automatic means being adapted to return to their initial condition at the instant of said sampling exclusively upon receiving of a sequence of information belonging to a new message verified through said analyzing means, when this message is received before said time interval has elapsed.

28. An apparatus according to claim 25, wherein said transmitting means at said second installation is connected to means determining the position of at least one regulating member of said second installation, said transmitting means being adapted to transmit, after said '"'"''"'"''"'"''"'"'ready-to-operate'"'"''"'"''"'"''"'"' response message, a message characterizing the position of each regulating member of said second installation.

29. An apparatus according to claim 25, wherein said first installation includes means for transmitting messages containing instructions for said second installation, said messages of instruction including at least one sequence containing at least one element of information numerically coded, by the value of the frequency of said subcarrier oscillation amplitude modulating said carrier wave, said second installation including means for controlling regulating members of said second installation, said controlling means being connected to said means for recording messages emanating from said first installation and to said energization means and adapted to deliver control signals for said regulating members, in response to said messages, exclusively when a signal produced by said energization means, at the receiving of an energizing signal, and a message of instructions emanating from said first installation and transmitted from said recording means are simultaneously received.