COMBINED ALARM TRANSMISSION AND SERVICE CALL SYSTEM

• US 3,700,823 A
• Filed: 09/02/1971
• Issued: 10/24/1972
• Est. Priority Date: 09/02/1971
• Status: Expired due to Term

• Current Assignee: William Chulak
• Original Assignee: William Chulak
• Inventors: Chulak, William
• Primary Examiner(s): Blakeslee, Ralph D.
• Application Number:
  US05/177,389
• Time in Patent Office: 418 Days
• Field of Search: 179/5R,18EB,18B,18BB,19,18AG,18AH
• US Class Current: 379/1.01
• CPC Class Codes: H04Q 3/0016 Arrangements providing connection between exchanges

Abstract

Multifrequency signaling equipment is used to transmit alarm initiation and alarm cancelling signals and also signals for connecting calls over channels selected from a plurality connecting two locations at each of which a large access switch is located. Just after a channel is seized by a connection through one switch a multifrequency signal is sent over the connection and channel to direct the connection at the other switch. Alarm signals bypass the second switch. A reply tone releases the transmitter lockout circuit dropping the multifrequency signaling equipment off the call and allowing it to process another call. Alarm signals are periodically repeated if not acknowledged by reply tone. The system may operate in both directions or a one way system may be used with manual calling in the other direction. An alternative form of systems uses a particular channel for the signaling function and in this case alarm signals do not pass through either of the large access switches. The system is designed particularly for operator assistance, information and repair service calls into a telephone company service center.

Claims

1. An audio pulse signaling system both for transmitting alarm signals from an outlying communication central office to a communications service center and for completing call connections between outgoing trunk circuits organized in groups at said office and incoming trunk circuits organized in gRoups at said center, comprising:

a. an audio pulse coding transmitter at said outlying office adapted to send a single pulse or a sequence of not more than three independently coded pulses on each transmission;

b. means at said outlying office for deriving alarm initiating and alarm cancelling signals from the condition of a plurality of alarm detectors and an alarm reporting circuit associated therewith adapted to be activated by said means;

c. lockout circuits respectively associated with each outgoing trunk circuit and with each alarm signal deriving means for sequencing demands for signal transmission concurrently presented to said transmitter;

d. means associated with each of said lockout circuits for coding said transmitter in accordance with switching information related to the circuits associated with said lockout circuit at said central office or in accordance with alarm information related to one of said alarm signal deriving means associated with said lockout circuit;

e. a switch or combination of switches at said office associated with said outgoing trunk circuits and with said alarm reporting circuit and a switch or combination of switches at said center associated with said incoming trunk circuits, said switches being also associated with a plurality of communication channels connecting corresponding elements of the said respective switches or combinations of switches;

f. an audio pulse decoding receiver at said center adapted to decode said coded pulses or pulse sequences and to activate the said switch or combination of switches at said center in response to a pulse or sequence of pulses coded in accordance with switching information and likewise to register changes in alarm detector conditions in response to a pulse or sequence of pulses coded in accordance with an alarm initiating or alarm cancelling signal;

g. a reply tone generator at said center associated with the aforesaid receiver;

h. a reply tone receiver at said office associated with said audio pulse coding transmitter;

i. means for causing said reply tone generator to transmit a pulse in response to actuation of said switch as aforesaid by said audio pulse decoding receiver and likewise in response to registration of a change in alarm detector conditions by said audio pulse decoding receiver;

j. means associated with said reply tone receiver and responsive to reception of a reply tone pulse adapted to release one of said lockout circuits and thereby permit activation of another;

k. time-out means for releasing one of said lockout circuits and permitting activation of another in the event said release means associated with said reply tone receiver does not operate in normal sequence, and l. means operative after the release by said time-out of a lockout circuit associated with one of said alarm signal deriving circuits for causing the timed-out alarm signal to be repeated at intervals until its transmission is followed by reception of a reply tone pulse in normal sequence.

2. An audio pulse signaling system between a principle and a subsidiary switching center adapted both to transmit a variety of automatic technical alarms and also to complete connections between outgoing and incoming trunk circuits organized in groups at said switching centers, comprising:

a. an audio pulse coding transmitter at each of said switching centers adapted to send a single pulse or a sequence of not more than three independently coded pulses on each transmission;

b. means at one or both of said centers for deriving alarm initiating and alarm cancelling signals from the condition of a plurality of alarm detectors and an alarm reporting circuit associated therewith adapted to be activated by said means;

c. lockout circuits respectively associated with each outgoing trunk circuit and with each alarm signal deriving means for sequencing demands for signal transmission concurrently presented to each of said transmitters;

d. means associated with eaCh of said lockout circuits for coding one of said transmitters in accordance with switching information related to the circuits associated with said lockout circuit or in accordance with alarm information related to one of said alarm signal deriving means associated with said lockout circuit;

e. a switch or a combination of switches at each of said centers associated with said outgoing and incoming trunk circuits at least one of said switches or combinations of switches being also associated with one of said alarm reporting circuits, both of said switches being also associated with a plurality of communication channels connecting corresponding elements of the said respective switches or combinations of switches;

f. an audio pulse decoding receiver at each of said centers adapted to decode said coded pulse sequences and to actuate one of the said switches or combinations of switches in response to a pulse or a sequence of pulses coded in accordance with switching information, at least one of said receivers being further adapted to register changes in alarm detector conditions in response to a pulse or a sequence of pulses coded in accordance with an alarm initiating or alarm cancelling signal;

g. a reply tone generator at each of said centers associated with the said audio pulse coding transmitter at said center;

h. a reply tone receiver at each of said centers associated with the said audio pulse decoding receiver;

i. means for causing each of said reply tone generators to transmit a pulse in response to actuation of one of said switches as aforesaid by said associated audio pulse decoding receiver and means for causing at least one of said reply tone generators likewise to transmit a pulse in response to registration as aforesaid of a change in alarm detector conditions by said associated audio pulse decoding receiver;

said means being arranged either for immediate transmission of said pulse or for transmission thereof after a single intervening audio pulse transmission in the direction opposed to that of the last previous audio pulse transmission;

j. means associated with said reply tone receiver responsive to reception of a reply tone pulse adapted to release one of said lockout circuits and thereby permit activation of another;

k. time-out means at each of said centers for releasing one of said lockout circuits and permitting activation of another in the event said release means associated with said reply tone receiver at said center does not operate in normal sequence, and l. means operative after the release by said time-out means of a lockout circuit associated with one of said alarm signal deriving circuits for causing a timed-out alarm report to be repeated at intervals until the transmission of the alarm signal is followed by reception of a reply tone pulse in normal sequence.

3. An audio pulse signaling system as defined in claim 2 in which the said coding transmitter at one of said switching centers is adapted, upon failure of a transmission or of a portion of a transmission to be followed by reception of a reply tone pulse in normal sequence, to repeat said transmission or said portion of said transmission without first releasing the active lockout circuit, but in which at the other of said switching centers under corresponding conditions said time-out means is adapted to release the active lockout circuit at said other switching center.

4. An audio pulse signaling system as defined in claim 3 in which said time-out means, when releasing a lockout circuit associated with a trunk circuit and not an alarm signal deriving means is adapted to apply an intermittent tone (of the type connoting a busy condition) to said trunk circuit.

5. An audio pulse signaling system as defined in claim 3 in which:

m. one of the switching centers is a service center normally having much incoming traffic, including all the alarm signals, and relatively little outgoing traffic;

n. at said service center at least part of the inComing trunk circuits may be reached from similar systems serving other routes;

o. the said audio pulse receiver at said service center is adapted to cause selective connection of one of said incoming trunk circuits to the said switch or combination of switches at said service center, and p. the said audio pulse transmitter at said service center is the transmitter adapted to release a lockout circuit upon failure of the said reply tone receiver at said service center to receive a reply tone pulse in normal sequence.

6. An audio pulse signaling system as defined in claim 5 in which:

q. the said audio pulse receiver at the said service center is adapted to provide to a called service position an indication of the origin of the call when it activates the said switch or combination of switches to connect a trunk circuit that may be reached from similar systems serving other routes.

7. An audio pulse signaling system as defined in claim 3 in which:

r. said means for causing one of said reply tone generators to transmit a pulse is adapted to do so immediately after the reception by one of said audio pulse decoding receivers of a complete coded audio pulse transmission;

s. an audio detector is associated with each of said communication channels at each of said centers and is adapted upon the reception of the first audio pulse of a sequence to connect the said channel to the nearer of said audio pulse decoding receivers by means of a connection adapted to hold for the entire pulse sequence, including the transmission of a reply tone pulse, and which is also adapted to mark the said channel busy for the duration of said sequence;

t. means are provided in said system for blocking the operation of a hold magnet by any of said lockout circuits associated with one of said audio pulse coding transmitters during the reception of a pulse by the audio pulse decoding receiver at the same switching center and during the immediately following transmission of a pulse of reply tone, and u. means are also provided for disconnecting said audio detector from said channel when said channel is connected to a trunk circuit through the nearer of said switches or combination of switches.

8. An audio pulse signaling system as defined in claim 7 in which:

v. each coded audio pulse sequence is either a single pulse or two identical pulses, w. one of said transmitters is arranged to transmit only a single pulse for each lockout circuit activation and the other of said transmitters is arranged to transmit a repetition of a pulse when the first pulse is not followed by reception of a reply tone pulse in normal sequence, and x. said coded audio pulses are coded multifrequency pulses.

9. An audio pulse signaling system as defined in claim 7 in which:

y. coded audio pulse sequences for alarm initiating or alarm cancelling signals consists of 2 or 3 pulses, but coded audio pulse sequences for completing connections at said switches or combination of switches consist of a single pulse except when repeated for failure to receiver a reply tone pulse and z. said coded audio pulses are coded multifrequency pulses, ab. the said reply tone generator at said service center is adapted to transmit a reply tone pulse after receipt of the first pulse of an alarm initiating or alarm canceling signal, ac. the said audio pulse coding transmitter which is not at the service center is adapted to repeat said first pulse of an alarm initiating or alarm cancelling signal if the audio pulse decoding receiver at its location fails to receive a reply tone pulse in normal sequence, ad. the said reply tone generator is also adapted to transmit a reply tone pulse after receipt of a complete alarm initiating or alarm cancelling signal and the said audio pulse coding transmitter is adapted to repeat said complete alarm initiating or alarm cancelling signal at once immediately, and thereafter at intervals, until a reply tone pulse is received in normal seqUence.

10. An audio pulse signaling system as defined in claim 2 in which:

i. said lockout circuits each contain a relay adapted to be operated while its lockout circuit is active;

ii. another relay is provided to hold in one of its positions while any one of said lockout circuits is active and adapted to remain in such position during sequencing of lockout circuits not blocked by said other relay, said other relay being adapted to block lockout circuits by which access to a transmitter is sought while another lockout circuit is active.

11. An audio pulse signaling system as defined in claim 10 in which:

iii. outgoing alarm reporting circuits are adapted to cause transmission of alarm signals having not less than two nor more than three independently coded pulses;

iv. an additional set of lockout circuits is provided adapted to sequence access of alarm signals to an alarm reporting circuit, but access to lockout circuits of said additional set is available subject to random serial activation, whether or not such lockout circuit is made ready for activation while another lockout circuit was active.

12. An audio pulse signaling system as defined in claim 2 in which said alarm reporting circuits are adapted to cause transmission of alarm signals having at least one more pulse than the signals caused to be transmitted by said outgoing trunk circuit, in which said alarm reporting circuits are adapted or their associated lockout circuits are adapted to change the response frequency or frequency combination of a reply tone receiver and said audio pulse decoding receiver at said principal switching center is adapted, upon reception of an alarm signal, to make a corresponding change in the output frequency or frequency combinations of the said reply tone generator at said center.

13. An audio pulse signaling system as defined in claim 2 in which:

mm. said coding transmitter and decoding receiver and said reply tone generator and receiver at one switching center are connected to corresponding equipment at the other switching center by a channel that is not available for connections at said switches or combinations of switches;

nn. said coding transmitters and decoding receivers are adapted to transmit and receive respectively, sequences of not less than two and nor more than three multifrequency pulses, oo. said decoding receivers are adapted to be reset without interference with trunk circuits or alarm registration in the event a complete pulse sequence is not received;

pp. said decoding receivers are adapted to prepare for the transmission of a reply tone pulse after the reception of a complete pulse sequence but said reply tone generators and said coding transmitters are arranged so that if after such reception the coding transmitter at the same switching center is ready to transmit, the operation of the reply tone generator is deferred until the said transmitter finishes transmitting one complete multifrequency pulse sequence, qq. said time-out means is adapted to be reset by the operation of the reply tone generator of the same switching center and also by upon the reception of a multifrequency pulse sequence by the decoding receiver at the same switching center, in each case for the duration of said operation or reception.

14. An audio pulse system as defined in claim 13 in which the said coding transmitter at one of said switching centers is adapted, upon failure of the transmission of a sequence of multifrequency pulses to be followed by reception of a reply tone pulse in normal sequence, to repeat said transmission and to enable said time-out means to release the active lockout circuit only after the completion of said repeated transmission;

whereas the said coding transmitter at the other switching center is arranged to cause said time-out means to release the active lockout circuit following the original multifrequency pulse sequence transmission, said release by said time-out means being arranged to occur if reception of a reply tone pulse does not occur in normal sequence.

15. An audio pulse signaling system as defined in claim 13 in which the said transmitters and receivers are adapted to transmit and receiver, respectively, sequences of two multifrequency pulses.

16. An audio pulse signaling system as defined in claim 15 in which:

rr. the switching centers at which said transmitter is not arranged to repeat its transmission as stated in claim 14 is located at a service center designed to handle much incoming traffic, including all the alarm signals, and relatively little outgoing traffic, ss. at said service center at least part of the incoming trunk circuits may be reached from similar systems serving other routes, and tt. the said audio pulse receiver at said service center is adapted to cause selective connection of an idle one of said incoming trunk circuits to the said switch or combination of switches at said service center.

17. A system for directing auxiliary telephone communications and automatic alarm signals between an outlying central office and a service center separately from toll communication facilities which comprises:

a. a multiplicity of communication channels between said outlying central office and said service center, each having a facility circuit at each end;

b. a multiplicity of outgoing trunk circuits at said central office and a multiplicity of incoming trunk circuits at said service center;

c. a large access switch or combination of switches at said central office and another at said service center, each adapted to connect any of said facility circuits at its location and the associated channel to any of a greater number of said trunk circuits;

d. a signal transmitter at said outlying central office adapted to transmit coded multifrequency audio pulses;

e. at least one trunk circuit at said central office adapted to activate the transmission of alarm signals to said service center;

f. means associated with at least one alarm detector for generating alarm initiating and alarm cancelling signals in circuits individual to each signal content and for causing transmission of said signals over said alarm trunk circuits;

g. lockout circuits respectively associated with each of said outgoing trunk circuits and with each alarm initiating signal circuit and also with each alarm cancelling signal circuit adapted to activate said signal transmitter at the same time as said trunk circuit seizes one of said facility circuits, said lockout circuits being arranged also to initiate both the activating of said transmitter and the seizure as aforesaid of said facility circuit and to determine the frequency makeup of the pulses transmitted by said signal transmitter;

h. a multifrequency receiver and a reply tone generator at said service center;

i. an audio frequency detector connected at each of said facility circuits at said service center, except during progress of a call on a completed connection, and adapted to quickly connect said multifrequency receiver and said reply tone generator to said facility circuit and to make said facility busy when an audio frequency signal is received over said facility;

j. means at said multifrequency receiver to activate if available an idle trunk circuit serving a destination at said service center identified by said audio frequency signal in a manner adapted to complete a connection to said last-mentioned facility circuit, to activate said generator to transmit a reply tone pulse after completion of said connection, to hold said connection of said receiver to said facility circuit during the foregoing operations and to release it thereafter;

said connection being usable for connecting also said generator to said facility circuit;

k. means operable by said multifrequency receiver to produce an appropriate indication at said service center in response to a multifrequency pulse identifying an alarm signal, to activate said generator to transmit a reply tone pulse afTer reception of said pulse and likewise to hold said connection to said facility circuit during the foregoing operations and to release it thereafter;

l. a reply tone receiver at said outlying central office and circuits operated by the output thereof adapted to cause said transmitter to repeat a multifrequency signal once when said reply tone is not received in a predetermined interval following the first transmission of said signal;

m. means associated with each of said outgoing trunk circuits responsive to reception of reply tone by said reply tone receiver and adapted to release the said lockout circuit associated with said trunk circuit and the connection thereby made to said multifrequency transmitter, and n. means associated with each of said outgoing trunk circuits, responsive to failure of said reply tone receiver to receive reply tone within a predetermined period following the aforesaid repeated transmission of a signal adapted to release the said lockout circuit and to apply to such trunk circuit a tone signal connoting a circuit busy condition.

18. A system as defined in claim 17 in which means are provided for seizing one of said channels and associated facility circuits by a call from said service center initiated manually by an operator, in which means are also provided for indicating to such operator which of said channels are idle and in which a plurality of incoming trunk circuits are provided at said outlying central office adapted to be seized by a facility circuit at said central office without connection through said large access switch at said central office when the facility at the other end of said channel is seized by said manually initiated call as aforesaid.

19. A system as defined in claim 18 in which said manually initiated means for seizing a channel is arranged not to cut off reception by said multifrequency receiver at said service center of a signal transmitted immediately before seizure of said channel, and is further arranged to make or block an indication to the caller if said receiver receives a multifrequency signal so transmitted.

20. A system as defined in claim 17 in which means are provided for causing transmission of a pulse of a particular frequency code at intervals after said signal transmitter has been idle for a predetermined period, said means being adapted to register an alarm and cause generation of an alarm initiation signal if no reply tone pulse is received in reply and to cancel an alarm so registered and to cause generation of an alarm cancelling signal if a subsequent transmission of a pulse of said code is duly followed by reception of a pulse of reply tone.

21. A system as defined in claim 18 in which means are provided responsive to a busy condition of a predetermined proportion of said communication channels adapted to block access to the remainder of said communication channels against all traffic from said outlying office except operator assistance calls and alarm signals.

22. A system as defined in claim 17 having also:

o. means, associated with said alarm trunk circuit, responsive to failure of said reply tone receiver to receive reply tone within a predetermined period following the aforesaid repeated transmission of a signal adapted to release the said lockout circuit and thereafter to cause repetition of said alarm signal at intervals until a reply tone pulse is duly received.

23. A system as defined in claim 17 in which:

p. said lockout circuits each contain a relay adapted to be operated while its lockout circuit is active, a transistor and a diode, said diodes being connected to a common electric current supply in a manner adapted to permit only one of said diodes to conduct and one of said relays to be operated at one time;

q. another relay is provided adapted to hold in one of its positions while any one of said lockout circuits is active and adapted to remain in such position during the interval of transfer of activity from one of said diodes to another, said relay controlling contacts adapted to block access to a lockout circuit from a circuit that requests such access while said relay is in its said position, and permits such access only after previous requesting for such access have been served and the lockout circuits released.

24. A system as defined in claim 17 in which means are provided for directing calls from said service center to telephones served by said outlying central office which means comprise:

at said service center, outgoing trunk circuits, lockout circuits, a signal transmitter and a reply tone receiver and at said outlying central office audio detectors, a multifrequency receiver, a reply tone generator and incoming trunk circuits all organized together and adapted to make connections between said outgoing trunk circuits at said service center and said incoming trunk circuits at said central office through said large access switches or combinations of switches in substantially the same way as connections specified in said claim 17 for calls in the other direction, except that the said signal transmitter at the central office is not adapted to repeat a signal but instead means associated with said outgoing trunk circuits are adapted to release the associated lockout circuit and apply busy tone in the event said reply tone receiver at said central office fails to receive reply tone shortly after the first transmission of a signal by the said signal transmitted at said central office.

25. A combined system for directing the connection of telephone calls to and from a telephone service center and for the reporting of automatic alarms to said telephone service centers, which comprises:

a. audio pulse signaling equipment at said service center and at an outlying central office, b. a large access switch at said service center and another one at said outlying central office, c. a multiplicity of communication channels available for linking said switches, d. incoming and outgoing trunk circuits respectively, accessible from and having access to said switches;

e. means adapted to produce, from the output of at least one alarm detector, alarm initiation signals and alarm cancelling signals;

f. means adapted to utilize said audio pulse signaling equipment to set up connections between one of said outgoing trunk circuits and one of said incoming trunk circuits over said switches and one of said channels and then to disengage said audio pulse signaling equipment from said trunk circuits so connected;

g. means adapted to utilize said audio pulse signaling equipment to transmit alarm signals from said first mentioned means to an alarm registry at the said service center, without passing through the said switch at the said service center and, thereafter promptly to disengage said audio pulse signaling equipment, and h. lockout circuits within each of said two last-mentioned means adapted for serial processing of call connections and alarm signals on an intermixed basis.

26. A system as defined in claim 25 in which said audio pulse signaling equipment includes a multifrequency audio pulse transmitter and a multifrequency audio pulse receiver at said service center and one of each at said outlying central office and a reply tone generator and a reply tone receiver at said service center and one of each at said outlying central office and in which said reply tone generators are respectively associated with said multifrequency receivers and said reply tone receivers are associated with said lockout circuits in a manner adapted to release a lockout circuit upon reception of a pulse transmitted from one of said reply tone generators.

27. A system as defined in claim 26 in which said audio pulse signaling equipment is arranged to transmit coded pulses over one of said channels selected from those thereof that are idle in a predetermined sequence established in electric circuit logic and in which said audio pulse signaling equipment includes an audio detector for each of said channels adapted, when activated by any audio pulse, to operate an element of one of said switches, to mark said channel busy and to connect said channel to a decoding audio pulse receiver and includes also means for holding the connection established between said channel and said receiver during the time necessary to set up a connection over the aforesaid one of said switches and during transmission of a reply tone pulse or during the time necessary to operate an alarm registry circuit and to transmit a reply tone pulse thereafter.

28. A system as defined in claim 27 in which said multifrequency audio pulse transmitters and said reply tone generators are adapted to make transmissions consisting of a single pulse except that said multifrequency audio pulse transmitter at said outlying central office is adapted to repeat its pulse if it is not followed by reception of a reply tone pulse.

29. A system as defined in claim 27 in which said multifrequency audio pulse transmitters are adapted to transmit single pulse transmissions for establishing telephone connections and transmissions of a sequence of two or three pulses for transmission of alarm signals and in which the multifrequency audio pulse transmitter at the outlying central office is arranged so as to repeat once its single pulse transmissions or the first pulse of its multipulse transmissions if no reply tone pulse is received within a predetermined period following said single or first pulse transmission.

30. A system as defined in claim 2 having means responsive to the failure of reply tone to be received at said outlying central office within a predetermined period following the transmission of a complete multipulse alarm signal or of a repeated complete single pulse alarm signal adapted to cause repetition at intervals of transmission of said alarm signal until a reply tone pulse is duly received.

31. A system as defined in claim 27 in which means are provided for causing transmission of an audio pulse of a particular frequency code at intervals after both the multifrequency transmitter and the multifrequency receiver at the location where such means are provided have been idle for a predetermined period, said means being adapted to register an alarm and cause generation of an alarm initiation signal if no reply tone pulse is received in reply and to cancel an alarm registered and cause generation of an alarm cancelling signal if a subsequent transmission of a coded pulse is duly followed by reception of a pulse of reply tone.

32. A system as defined by claim 29 in which, in said means for producing said alarm signals, said lockout circuit is adapted to change the response frequency or frequency combination of said reply tone receiver at said outlying central office and in which said multifrequency receiver at said service center is adapted, upon reception of an alarm signal, to make a corresponding change in the output frequency or frequency combination of the said reply tone generator at said service center.

33. A system as defined in claim 26 in which means are provided responsive to a busy condition of a predetermined proportion of said communication channels adapted to block access to the remainder of said communication channels against all traffic from said outlying office except operator assistance calls and alarm signals.