Interrogation of remote stations via automatic dialler

• US 3,868,640 A
• Filed: 05/08/1972
• Issued: 02/25/1975
• Est. Priority Date: 05/13/1971
• Status: Expired due to Term

• Current Assignee: ABB Kent PLC (Honeywell International Inc.)
• Original Assignee: Alexander Joseph Binnie, Kenneth Bowdell, Philip James Clark
• Inventors: Binnie, Alexander Joseph, Bowdell, Kenneth, Clark, Philip James
• Primary Examiner(s): Pitts, Harold I.
• Application Number:
  US05/251,203
• Time in Patent Office: 1,023 Days
• Field of Search: 340/152R,151,163R 179/2OP
• US Class Current: 379/106.07
• CPC Class Codes: G06F 13/22 using successive scanning, e.g. polling G06F13/24 takes precedence
• CPC Class Codes: H04M 11/002 with telemetering systems telemetering in general G08C

Abstract

A system for interrogating a plurality of remote stations over the telephone company network to obtain information such as the readings of one or more consumer meters at each such station, which may be the house of a consumer. The system may operate on a frequency division multiplex or time division multiplex basis and includes interrogation apparatus located at a telephone company central office and meter readers, responsive to instructions from the interrogation apparatus, located at remote stations having lines terminating at the central office. A central data processor may be connected to several interrogation apparatuses each in turn connected to an associated plurality of remote readers.

Claims

1. Apparatus for the interrogation of a plurality of remote stations, comprising a digital computer, automatic calling means connected to the computer and responsive to an instruction signal from the computer to generate a dialing signal for application to switching circuits, thereby to establish telephonic contact with a predetermined one of the remote stations via an associated line from the switching circuits;

output means connected to the computer and responsive to an instruction signal from the computer to generate and transmit to the predetermined remote station via the switching circuits a coded interrogation signal arranged to promote the transmission of an information-carrying response signal from the remote station, the output means including means for selectively coding the interrogation signal according to the computer instruction with a code representative of a predetermined one of a plurality of sources of information available at the predetermined remote station, whereby a response signal including information from the said predetermined source is transmitted from the predetermined remote station, and input means connected to the computer and operative to receive the response signal.

2. Apparatus as claimed in claim 1, wherein the computer is programmed to cause the output means to transmit a fresh interrogation signal having a different coding once a response signal has been received by the input means, to promote the transmission of a fresh response signal including information from another of the plurality of sources thereof available at the selected remote station.

3. Apparatus as claimed in claim 1, wherein the computer is programmed so as to be operative on the automatic calling means, the output means and the input means to cause interrogation of at least some of the plurality of remote stations in a predetermined sequence.

4. Apparatus as claimed in claim 1, wherein the automatic calling means comprises means for dialling a series of conventional dialling pulses representative of a multi-digit telephone number associated with a selected remote station.

5. Apparatus as claimed in claim 4, wherein the dialling means includes a register connected to the computer for receiving and storing a selected telephone number, means for generating a series of dialling pulses, a counter arranged to count the number of dialling pulses generated, and a comparator connected to compare the first digit of the telephone number stored in the registEr with the contents of the counter and responsive to their being equal to cause the generating means to temporarily interrupt the series of dialling pulses and to clear the counter, whereby the next digit of the telephone number can be dialled in like manner.

6. Apparatus as claimed in claim 1, including a timing circuit connected to the computer, the input means and the output means and operative to control the operation of the input and output means, the computer being responsive to an indication from the automatic calling means that contact has been established with a selected remote station to initiate operation of the timing circuit.

7. Apparatus as claimed in claim 6, wherein the input means includes an input register connected to receive a digital response signal from the selected remote station and a retriggerable detector also connected to receive the response signal and connected to the computer and responsive to reception of the response signal to indicate such to the timing circuit via the computer, the timing circuit including means responsive to such an indication to supply at least one pulse to the input register for clocking in the response signal.

8. Apparatus as claimed in claim 1, wherein the output means includes means for generating a plurality of tones each within the passband of the telephone system with which the apparatus is to be used, and control means connected to the computer and the generating means and responsive to a computer instruction to cause assembly and transmission of a frequency division multiplex coded interrogation signal formed from the tones.

9. Apparatus as claimed in claim 8, wherein the control means includes a register and the generating means comprises a plurality of generators each for providing a respective one of said plurality of tones and each connected to a respective stage of the register and operative to provide the associated tone or not in accordance with the state of the stage.

10. Apparatus as claimed in claim 8, wherein the computer is operative on the control means to cause a first tone to be substantially continuously transmitted throughout contact with a selected remote reader.

11. Apparatus as claimed in claim 8, wherein the computer is operative on the control means to cause selective transmission of at least two of the tones to indicate to the selected remote station the source of information that is to be interrogated.

12. Apparatus as claimed in claim 8, wherein the output means includes means for generating a further tone and for transmitting pulses of such tone to the remote reader once contact has been established.

13. Apparatus as claimed in claim 1, wherein the output means includes means for generating at least one tone within the passband of the telephone system with which the apparatus is to be used, and control means connected to the computer and the generating means and responsive to a computer instruction to cause transmission of a time division multiplex coded interrogation signal formed from the or each tone.

14. Apparatus as claimed in claim 13, wherein the generating means is arranged to generate two tones and the control means is operative to transmit a burst of one tone to indicate the digit 1 and of the ither tone to indicate the digit 0.

15. Apparatus as claimed in claim 14, wherein the control means is operative on the generating means to suspend transmission between the bursts to provide spaces therebetween.

16. Apparatus as claimed in claim 13, wherein the control means includes a register having a serial output connected to a control input of the generating means.

17. Apparatus as claimed in claim 13, wherein the computer is operative on the control means to selectively transmit either a digit 1 or a digit 0 in at least two specific time slots in the multiplex to indicate to the selected remote reader the source of information that is to be interrogated.

18. Apparatus as claimed in claim 16, including a timing circuit conneCted to the computer and the control means, the computer being responsive to an indication from the automatic calling means that contact has been established with a selected remote station to initiate operation of the timing circuit and the timing circuit being adapted to supply a series of clock pulses to the control means to cause transmission of the whole time division multiplex interrogation signal and to thereafter supply a single clock pulse to the input means, the input means including a register connected to receive a digital response signal and connected to receive said single clock pulse to clock in a single bit of the response signal, said timing circuit being adapted to successively repeat these two operations until each bit of the response signal has been clocked in.

19. Apparatus as claimed in claim 1, including means connected to the computer and adapted for duplex communication of the computer with a central data processor.

20. Apparatus as claimed in claim 19, wherein said communications means includes a modem for digital communication via a telephone circuit.

21. Apparatus responsive to the receipt of an interrogation signal from an interrogator connected thereto by a line to encode information for sending back to the interrogator, comprising an input register for receiving a digital interrogation signal, a gating network having inputs connected to examine at least two stages of the register and responsive to the digits of the interrogation signal in said stages to provide a signal at an output terminal if the coding of said digits is such as to indicate that a source of information available to the apparatus is to be interrogated, and encoder means connected to the output of the gating network and responsive to said signal to encode said information into a response signal for sending back to the interrogator.

22. Apparatus as claimed in claim 21, wherein said gating network has a plurality of outputs each connected to the encoder means and is operative to decode the digits of the interrogation signal in said stages and to provide a signal at one of the outputs in accordance with the coding of said digits to cause a particular one of a plurality of sources of information available to the encoder means to be interrogated, each output being associated with a respective one of the sources.

23. Apparatus as claimed in claim 21 wherein the encoder means includes a gating network and a counter operative on the gating network for controlling the encoding operation, the counter causing the gating network to send back one bit of the response signal each time the counter is incremented.

24. Apparatus as claimed in claim 23, wherein another of the stages of the input register is connected to increment the counter, whereby one bit of the response signal is sent back each successive time the digital interrogation signal is received.

25. Apparatus as claimed in claim 25, including a clock circuit arranged to supply sufficient pulses to the counter to cause transmission of the whole response signal, the input register being connected to the timing circuit and being responsive to the arrival of an interrogation signal to initiate operation of the clock circuit.

26. Apparatus as claimed in claim 1, including a timing circuit connected to the input register for supplying clock pulses thereto to clock the interrogation signal therein, and synchronising gates having inputs connected to a plurality of other stages of the register and an output connected to the timing circuit for stopping the clocking pulses once the interrogation signal has been clocked into the register.

27. Apparatus as claimed in claim 1, including a detector for converting the interrogation signal from successive bursts of tone, as received from the line, to digital form for feeding into the input register.

28. Apparatus as claimed in claim 27, including a voltage regulator connected to receive a DC voltage applied externally to the line and a power switch connected to receivE the regulated output of the voltage regulator and to apply it to parts of the apparatus, the power switch having a control input connected to the detector for inhibiting operation of the power switch except when the detector indicates that an interrogation signal is being received.

29. Apparatus as claimed in claim 28, wherein the voltage regulator includes a trigger circuit connected to the power switch for inhibiting operation of the power switch when the DC voltage applied to the line drops below a predetermined value.

30. Apparatus responsive to the receipt of an interrogation signal from an interrogator connected thereto by a line to encode a response signal for sending back to the interrogator, comprising data selector gating means having an output and a plurality of inputs for connection to at least one source of digital information be be encoded, a counter having outputs connected to the data selector gating means for causing the inputs of the latter to be connected to the output of the latter in a predetermined sequence, and means responsive to the receipt of an interrogation signal to initiate operation of the counter so that a serial stream of encoded information will appear at the output of the data selector gating means.

31. Apparatus as claimed in claim 30, including gating means connected to receive the interrogation signal and responsive to a coding of such signal to gate the appropriate one of a plurality of sources of digital information to the data selector gating means.

32. Apparatus as claimed in claim 30 including multiplex control gating connected to the counter and responsive to the output of the counter to connect inputs of the data selector gating means, in turn, to a plurality of sections of a source of digital information.

33. Apparatus as claimed in claim 30, including a source of digital information comprising a plurality of ON-OFF switches.

34. Apparatus as claimed in claim 30, including a source of digital information comprising the stages of the counter.

35. Apparatus as claimed in claim 30, including identification means for providing digital information identifying the apparatus for multiplexing with the digital information from said source into the response signal.

36. Apparatus as claimed in claim 35, wherein the identifications means comprises means for patching a selected digital identification signal to an assigned plurality of the inputs of the data selector gating means.

37. Apparatus as claimed in claim 35, including multiplex control gating connected to the counter and responsive to the output of the counter to connect inputs of the data selector gating means, in turn, to a plurality of sections of a source of digital information, wherein the identification means comprises identification gating means having a plurality of inputs and means for patching a selected digital identification signal to such inputs, the multiplex control gating being connected to the identification gating means and operative to connect the digital pattern to the data selector gating means in turn with the sections of the source of digital information.

38. Apparatus as claimed in any of claims 30 to 37, including a tone generator connected to receive the output of the data selector gating means and arranged to generate a burst of a first frequency on receipt of the digit 1 and a burst of a second frequency on receipt of a digit 0.