DATA STORAGE AND TRANSMISSION SYSTEM

• US 3,742,463 A
• Filed: 11/24/1971
• Issued: 06/26/1973
• Est. Priority Date: 03/02/1970
• Status: Expired due to Term

• Current Assignee: Carl M. Solar, Donald E. Haselwood
• Original Assignee: Carl M. Solar, Donald E. Haselwood
• Inventors: Haselwood, Donald E., Solar, Carl M.
• Primary Examiner(s): Shaw, Gareth D.
• Assistant Examiner(s): Nusbaum, Mark Edward
• Application Number:
  US05/201,919
• Time in Patent Office: 580 Days
• Field of Search: 340/172.5 235/157
• US Class Current: 714/47.3
• CPC Class Codes: H04H 2201/30 characterised by the use of a return channel, e.g. for collecting users' opinions, for returning broadcast space/time information or for requesting data
• CPC Class Codes: H04H 60/32 Arrangements for monitoring conditions of receiving stations, e.g. malfunction or breakdown of receiving stations
• CPC Class Codes: H04H 60/43 for identifying broadcast channels
• CPC Class Codes: H04H 60/94 Telephonic networks for accessing the Internet H04H60/84

Abstract

A system for economically monitoring via telephone a large number of remotely located television receivers or the like. Remotely located data handling systems check the status of receiver groups once every 30 seconds. Whenever a change in status is detected, the altered status is recorded as a '"'"''"'"''"'"''"'"'change line data set'"'"''"'"''"'"''"'"' in a continuously circulating memory which can store forty such data sets. At periodic intervals a central unit contacts the remotely located data handling systems via telephone. The data sets are then repeatedly transmitted to the central unit in the form of a frequency modulated audio tone. With the aid of a marker bit that reverses its sign each time the circulating memory fully circulates, the central unit is able to extract the 40 data sets from the modulated tone and is also able to check for transmission errors.

Claims

1. A data storage and presentation system for continuously monitoring a plurality of digital variables presented by digital variable presentation means, said system comprising:

a memory;

resettable time measuring means for measuring time intervals and for generating numbers proportional to the length of time intervals;

storage means connecting said time measuring means and said digital variable presentation means to said memory for storing within said memory data supplied by said digital variable presentation means and representing the status of said digital variables and also numbers supplied by said time measuring means and representing the length of time intervals;

comparison means connected to said digital variable presentation means for comparing stored data representing the present status of the digital variables to the actual present status of the digital variables as indicated by said presentation means and for actuating said storage means and for reinitiating said time measuring means whenever the digital variables change their status; and

message generator means for presenting the memory contents as a message suitable for transmission.

2. A data storage and presentation system in accordance with claim 1 wherein broadcast receivers are connected to the digital variable presentation means and wherein the broadcast receivers include means for generating digital variables representing the tuning condition and the on-or-off status of the broadcast receivers.

3. A data storage and presentation system in accordance with claim 2 wherein the broadcast receivers are television receivers.

4. A data handling system for continuously monitoring a plurality of digital variables presented by digital variable presentation means, said system comprising:

a circulating memory having a fixed capacity which includes means for repeatedly presenting, and which contains at least one marker bit, and further including memory datA gates disposed in the memory circulation path for reversing the sign of this marker bit each time the memory data fully circulates;

storage means for intermittently storing within the circulating memory in sequentially spaced memory locations data sets containing records of the fluctuations in the associated digital variables, whereby each new data set automatically replaces the oldest data set within the fixed capacity memory; and

message generator means for continuously converting the memory output signal into a message signal.

5. A data handling system for continuously monitoring a plurality of digital variables presented by digital variable presentation means, said system comprising:

a circulating memory having a fixed capacity which includes means for repeatedly presenting its contents as a memory output signal;

storage means for intermittently storing within the circulating memory in sequentially spaced memory locations data sets containing records of the fluctuations in the associated digital variables, whereby each new data set automatically replaces the oldest data set within the fixed capacity memory;

message generator means for continuously converting the memory output signal into a message signal; and

counting means are provided for counting the flow of data bits through the memory and for actuating the message generator at time intervals spaced apart by the time it takes a fixed number of bits to flow through the memory, whereby the data bits comprising the memory output signal are sampled by the message generator means periodically at a sampling rate that is substantially slower than the memory output signal presentation rate, said sampling rate being chosen so that the number representing the memory bit capacity has no common primes with the ratio of the memory output signal bit presentation rate to the sampling rate.

6. A data handling system for continuously monitoring a plurality of digital variables, said system comprising:

circulating memory which repeatedly presents the memory contents as a memory output signal;

storage means for storing within the memory data sets containing records of the fluctuations in the associated digital variables;

message generator means for converting the memory contents into a message signal; and

comparison means for periodically comparing the digital variables with the record of the digital variables contained within the data set most recently placed into the memory, said comparison means actuating the storage means whenever the digital variables disagree with the record contained within the data set most recently placed into the, said comparison means includes a comparison gate into which the memory output signal is fed;

serial data presentation means for presenting the digital variables serially to the comparison gate simultaneously with the appearance of the data set most recently placed into the memory within the memory output signal.

7. A data handling system in accordance with claim 6 wherein the serial data presentation means is a data register having a parallel data input connected to the digital variables and having a serial data output.

8. A data handling system in accordance with claim 6 wherein the memory includes memory data gates disposed in the memory circulation path, wherein the serial data presentation means also presents the digital variables serially to the memory data gates, and wherein the comparison means cause the memory data gates to feed the digital variables into the memory as part of a data set which replaces the oldest data set in the memory whenever the digital variables disagree with the record contained within the data set most recently placed into the memory.

9. A data handling system in accordance with claim 8 wherein the serial data presentation means is a data register having a parallel data input connected to the digital variables and having a serial data output.

10. A data handling system for continuously monitoring a Plurality of digital variables presented by digital variable presentation means, said system comprising:

a circulating memory having a fixed capacity which repeatedly presents its contents as a memory output signal;

storage means connecting said digital variable presentation means to said memory for storing within the memory data sets containing records supplied by said digital variable presentation means and representing the status of said digital variables;

comparison means connected to said digital variable presentation means for comparing stored data representing the present status of the digital variables to the actual present status of the digital variables as indicated by said presentation means for actuating said storage means whenever the digital variable change their status; and

tone message generator means for continuously converting the memory output signal into a message signal, comprising tone generator means for generating first and second frequencies and gating means controlled by the memory output signal for presenting one or the other of said tone frequencies as an output message signal in accordance with whether the memory output signal represents a '"'"''"'"''"'"''"'"'zero'"'"''"'"''"'"''"'"' or a '"'"''"'"''"'"''"'"'one'"'"''"'"''"'"''"'"' data bit.

11. A data handling system in accordance with claim 10 which includes a message signal output terminal wherein the gating means includes a source of timing signals, a flip-flop, a data input to the flip-flop connected to the memory output signal, a toggle input to the flip-flop connected to the source of timing signals, an output from the flip-flop, and gates controlled by the flip-flop output connecting the tone signals to the message signal output terminal, whereby the bits which flow from the memory are sampled at a rate determined by the frequency of the source of timing signals.

12. A data handling system for continuously monitoring a plurality of digital variables presented by digital variable presentation means, said system comprising:

a memory;

storage means for storing within the memory data sets containing values which the digital variables have assumed, said data sets also containing a number;

periodically energized arithmetic means for periodically adding a constant value to the number in the data set most recently fed into the memory by the storage means;

variable fluctuation detection means connecting to said digital variable presentation means for detecting changes in the status of said variables and for responding to such changes by actuating said data storage means; and

time turnover detection means for actuating the storage means whenever the length of time during which the digital variables remain unchanged exceeds a fixed value.

13. A data handling system in accordance with claim 12 wherein the number within each memory data set is initially zero, and wherein the time turnover detection means comprises a circuit which responds to the presence of an arithmetic carry overflow signal of said arithmetic means which overflow signal indicates that the time interval storage capacity of the data set has been exceeded.

14. A data handling system in accordance with claim 13 wherein the memory is a circulating memory, further including memory data gates in the memory circulation path for reversing the sign of memory data bits in response to a carry signal, further including a carry flip-flop which is set and which generates the carry signal when the number within the most currently recorded data set begins to flow from the memory, further including gate means responsive to a '"'"''"'"''"'"''"'"'zero'"'"''"'"''"'"''"'"' data bit flowing from the memory for clearing the carry flip-flop, and wherein the time turnover detection means comprises means for generating a signal that is a carry signal strobed after the number within the most currently recorded data set has completely flowed out of the memory and in which said strobed carry signal is the arithmetic carry overflow signal.

15. A data handling system in accordance with Claim 13 wherein the memory is a circulating memory, further including a change line pulse generator which generates a pulse each time the most recently recorded data set flows from the memory, wherein the storage means comprises memory data gates in the memory circulation path for loading the values of the digital variables and the number zero into the memory in response to a new change line signal and for inverting the memory data bits in response to a carry signal, wherein the new change line signal is initiated by either the comparison means or by the time turnover detection means, wherein means are provided for inhibiting the change line pulse generator from terminating the change line pulse during the time when a new data set is fed into the memory, wherein the arithmetic means are actuated by the change line pulses to generate the carry signal while the bits up to and including the first '"'"''"'"''"'"''"'"'zero'"'"''"'"''"'"''"'"' bit in the number portion of the data set most recently stored flow through the memory data gates.

16. A data handling system in accordance with claim 12 wherein the memory is a circulating memory containing an extra marker bit in addition to a fixed number of data sets, wherein a data signal generator generates a data signal each time a data set flows out of the memory, wherein a marker bit signal generator generates a marker bit signal when the marker bit flows from the memory, and wherein the marker bit signal inhibits the data signal generator while the marker bit flows out of the memory.

17. A data handling system in accordance with claim 16 and further including memory data gates in the memory circulation path, said memory data gates responding to the marker bit signal by reversing the sign of the marker bit as the marker bit circulates through the memory data gates.

18. A data handling system for continually monitoring a plurality of digital variables presented by digital variable presentation means, said system comprising:

a memory;

data storage means connecting to said memory and to said digital variable presentation means for transferring data defining the state of said variables from said presentation means into said memory;

timing means for measuring the passage of time and including means for generating data representing elapsed time; and

means for intermittently actuating said data storage means and for transferring data from said timing means into, said means for intermittently actuating including variable fluctuation detection means connected to said digital variable presentation means for detecting changes in the status of said variables and for responding to such changes by actuating said data storage means and by transferring data from said timing means into said memory when said storage means is actuated.

19. A data handling system in accordance with claim 18 wherein said timing means includes means for generating as data a number proportional to the length of a time interval the beginning of which interval is determined by a reset means which reset the value of said number whenever said storage means is actuated.

20. A data handling system in accordance with claim 19 wherein the reset means comprise means for storing a number in said memory whenever data defining the state of said variables is fed into said memory by said storage means, and wherein the timing means additionally comprises means for periodically adding a constant to the number most recently placed in said memory by said reset means, whereby the memory location occupied by the number most recently placed in said memory forms a part of said timing means.

21. A data handling system in accordance with claim 20 wherein the memory is a circulating memory which repeatedly presents the memory contents as a memory output signal, and which system includes memory data gate means disposed in the memory circulation path for reversing the sign of the memory data bits in response to a carry signal, and wherein the arithmetic means includes means for initiating sAid carry signal periodically as the number most recently placed in said memory flows through the data gates and also includes means for terminating the carry signal after the least significant '"'"''"'"''"'"''"'"'zero'"'"''"'"''"'"''"'"' bit within the number is inverted by the memory data gate means.