Security system for centralized monitoring and selective reporting of remote alarm conditions

A security system consists of a central digital processor system, e.g., a general purpose computer, to which plural remote units are connected by a digital communications link, e.g., telephone. The remote units include plural alarm sensors such as intrusion and heat sensors. In a data base of the central processor system are stored segments of data associated uniquely with remote premises having the remote units. The processor system includes a terminal for delivering alarm message reports, such as to a law enforcement agency. Specifically, the remote units have interrogation circuitry for interrogating the sensors to determine if they have been tripped, logic circuitry for causing transmission to the central processor system via the communications link of a sensor alarm data message in digital format signifying the sensor address and its tripped status. The central processor system includes correlation means for correlating the data message with the data base to determine logical validity or invalidity of the message. Means responsive to logical validity determination causes portions of the data message and corresponding segments of the data base to be assembled into an alarm message report for delivery by said terminal. SU BACKGROUND OF THE INVENTION The invention relates to centrally monitored security or alarm systems and more particularly to systems for centralized monitoring and selective reporting of alarm conditions at plural remote premises, especially over a wide geographic area. Many security, alarm or annunciator systems which employ central monitoring of conditions at remote locations have been known or have been described in the general and patent literature in recent years. One such system is disclosed in Streit U.S. Pat. No. 3,523,162 which teaches plural remote stations each having one or more alarm sensors and a power supply for causing an alarm signal generator (i.e., a relay) to signal a corresponding one of plural central alarm units by means of a telephone line if the sensor is tripped. A more sophisticated system disclosed by Hardy et al. U.S. Pat. No. 3,761,914 is designed for use with a community antenna (cable) television system (CATV) employing the concept of RF signaling a central office from remote premises via the cable network of alarm (e.g., fire or intrusion) conditions. For this purpose, the remote units send a coded signal. That system includes provision for ascertaining at the central office whether the system is operational or not. Even more sophistication is represented by systems employed for process monitoring (annunciator systems) much as taught by Judlowe U.S. Pat. No. 3,686,654 wherein a plurality of remote solid state alarm modules are each interconnected with a central facility which includes a recorder for recording the operation of either continuous (analog) or switch-type parameter sensing transducers at the remote modules. A multiple point alarm system having a number of alarm points arranged in groups or zones at areas remote from a central station is disclosed by Nurnberg et al. U.S. Pat. No. 3,714,646. That system includes plural zone encoders connected to the alarm switches which signal a zone identification circuit for the purpose of identifying the group or zone in which even a momentary alarm condition occurs. Neuner U.S. Pat. No. 3,855,590 describes a cyclic or monitoring system involving monitoring of plural remote process sensors from a central facility. For this purpose two data or logic streams are sent to the central facility, one of the streams being sent to a control room for operator use, the other being supplied to a special purpose computer used for controlling the facility (i.e., a nuclear power plant) which is supervised by the monitoring system disclosed. Perhaps the most sophisticated of the systems presently described in this background discussion is the monitor and results computer system disclosed by Summers et al. U.S. Pat. No. 3,855,456. That system is intended for aiding operation of processes occurring in a power generations plant. The system employs a logging technique for transforming input data from a plurality of scanned pickup points or sensors into a system variable format usable by all system functions. The computer features serve to store and organize the data in accordance on the delays associated with the sensed events or conditions. This allows the correct order of occurrence of events, etc., to be provided either by CRT devices, alphanumeric and graphic displays, or printers and plotters. Thus the computer organizes the incoming data into usable messages. These various systems representative of the prior art fail to provide one or more of the following characteristics which are desirable for a security system capable of satisfying present needs in a multiuser social environment. In the wake of today's increasing crime rate there is much need for a system capable of monitoring crime and fires. However, law enforcement agencies recite endless reports of false alarms triggered by equipment failures, unwise and careless installations. The false alarm situation has become such a nuisance in some cites, police and fire departments refuse to respond to an unverified alarm from a home or office protection system. Uneducated and inexperienced installers in the field of electronics, poorly or wrongly designed systems, substandard equipment and materials, and lack of training of the prospective user in how to use the system are the major factors that have produced the majority of false alarms. Thus, it is desirable that a security system be capable of verifying in some way the validity of the alarm condition which is being reported to a central facility from a remote unit at a subscriber's premises. It is also desirable that a security system be extensible to a wide geographic area and, for this purpose and for other reasons, employ a common carrier serving intended users. For example, the concept of using existing common carrier facilities expands the availability of existing communications services to potential users or subscribers of the available common carrier serving their respective communities. Other key attributes desirably present in a centrally monitored security system are that it be useful for both small and large subscribers; that it be readily expandible; that it be capable of responding to operation of various possible forms of sensors (e.g., intrusion, fire, heat, water, etc.); that it be responsive to short-term or momentary alarm conditions; that it identify the location of a premise having alarm conditions and specific sensors which sense alarm conditions; that its central facility not be easily overloaded by plural alarm condition reports; that it automatically keep records of vital alarm information; that it automatically keep track of changes in the operational status of subscriber units, i.e., remote units; that it require no constant, direct human monitoring and yet provide specific alarm messages useful for human intervention in alarm conditions; that it provide a high reliability, operational security, and speed; and that it be economical. SUMMARY OF THE INVENTION Among the several objects of the invention may be noted the provision of a centrally monitored security system; the provision of such a system which is extensible over a wide geographic area, which is readily expandible, and well-suited to large and small subscribers; the provision of such a system which employs common carrier communication links between remote units at subscriber premises and a central monitoring facility; the provision of such a system which is responsive to operation of various possible forms of sensors and to short-term or momentary operation of such sensors; the provision of such a system which can identify not only the location of premises with alarm conditions, but also the specific sensors which sense these conditions; the provision of such a system which is not easily overloaded by plural alarm condition reports; the provision of such a system which not only maintains automatic records of vital alarm information but also automatically keeps track of changes in the operational status of subscribers (remote) units, the provision of such a system which is electronically automatic in character, requiring no constant, direct human monitoring, yet which provides specific alarm messages useful for human intervention in alarm conditions; the provision of such a system which can also automatically provide messages indicative of invalid alarm condition data supplied to the central facility; and the provision of such a system having capability for extremely high reliability, operational security, speed and economy. In its apparatus aspects, the invention relates to a security system for centralized monitoring and selective reporting of alarm conditions at a plurality of distant remote units at corresponding remote premises. The system includes a central digital processor system for digitally processing information received from remote units and a communications system adapted for providing a digital communications link between the central processor system and any of the remote units. The central processor system includes a plurality of input ports to provide for simultaneous receipt of alarm data from more than one of the remote units. A data base is maintained at the central processor system. This data base is constituted by segments of stored preselected data, corresponding segments being indicative of characteristics associated uniquely with corresponding remote premises. The remote units individually adapted for responding to a plurality of sensors each having a normal status or a tripped status, the tripped condition resulting in response to occurrence of an alarm situation, such an intrusion or the presence of heat, smoke, fire or water. The central processor system has at least one output port to provide for delivery of alarm message reports to an output terminal device in a format useful for human intervention in such alarm situation. Specifically, interrogation means at individual remote units interrogate the sensors for detection of whether any sensor has changed from normal status to tripped status. Memory means at individual remote units are provided for storing sensor data signifying the address and tripped status of each tripped sensor. Communications initiation means at individual remote units, operative upon detection of such change in sensor status, is included for initiating the establishment of a communications link by the communications system between one of the input ports of the central processor system and the respective remote unit. Encoders at individual remote units encode, when enabled, said stored sensor data in a digital format suitable for transmission over the communications link. Message initiation circuitry at individual remote units is operative upon establishment of a communications link to enable the encoder for transmitting said stored sensor data as a sensor alarm message to the central processor system via the communications link. Message storage means at the central processor system stores the transmitted sensory alarm data message. Correlator means at the central processor system logically correlates the stored sensor data message with corresponding segments of said data base to determine logical validity or invalidity of the sensor alarm data message. Invalid message processing means is responsive to a logical invalidity determination for signaling that the sensor alarm data message is erroneous but valid message processing means is responsive to a logical validity determination for causing at least portions of the sensor alarm data message and corresponding segments of the data base to be assembled into an alarm message report for delivery by said output port. In its method or process aspects, the invention is concerned with a method of centralized monitoring and selective reporting of alarm conditions at the corresponding remote premises. The method involves providing each of a plurality of the remote premises with at least one electronic remote unit and a plurality of sensors associated with such remote unit. The sensors each having a normal status or a tripped status, the tripped status resulting in response to an alarm situation. This method further contemplates providing a central processor system including data base storage, storing in the data base storage segments of preselected data associated uniquely with corresponding remote premises and providing a digital communications link between the central processor system and any of the remote units. More specifically, it involves, electronically interrogating the sensors to determine if any sensor has changed from normal status to tripped status electronically detecting such change in sensor status, and electronically storing data signifying the address and tripped status of each tripped sensor. Communications readiness of the digital communications link is then electronically initiated upon detection of such change in sensor status. Then, the stored sensor data is electronically encoded in a digital format suitable for transmission over the communications link and electronically transmitted as a sensor alarm data message to the central processor system via said communications link. At the central processor system, the received sensor data message central processor system is electronically stored and thereafter is electronically logically correlated by the processor system with corresponding segments of the data base to electronically determine logical validity or invalidity of the sensor alarm data message. Then, what occurs is one of two alternatives. One is electronically signalling upon electronically determining that said sensor data message is logically invalid, that the sensor alarm data message is erroneous. The other alternative, upon electronically determining that the sensor alarm data message is logically valid, is electronically causing at least portions of the sensor alarm data message and corresponding blocks of said data base to be provided as an alarm message report in a format useful for human intervention in such alarm situation.

Claims

What is claimed is:

1. In a security system for centralized monitoring and selective reporting of alarm conditions at a plurality of distant remote units at corresponding remote premises, said system including a central digital processor system, a communications system for providing a digital communications link between said central processor system and any of said remote units, said remote units being individually adapted for responding to a plurality of sensors each having a normal status or a tripped status, said tripped status resulting in response to occurrence of an alarm situation, said central processor system including a data base constituted by segments of stored preselected data associated uniquely with corresponding remote premises, and terminal means for delivering alarm message reports in a format useful for human intervention in such alarm situation, the improvement comprising interrogation means at individual remote units for interrogating said sensors to determine if each sensor has changed from normal status to tripped status, means responsive to detection of such change in sensor status for causing transmission to said central processor system via said communications link of a sensor alarm data message in a digital format signifying the address and tripped status of each tripped sensor, correlation means at said central processor system for logically correlating said sensor alarm data message with said data base to determine logical validity or invalidity of said sensor data message, and means responsive to a logical validity determination be said correlator means for causing at least portions of said sensor data message and corresponding segments of said data base to be assembled into an alarm message report for delivery by said terminal means.

2. In a security system as set forth in claim 1, said interrogation means being adapted for interrogating each of a plurality of said sensors during repeating interrogation cycles.

3. In a security system as set forth in claim 1, each remote unit comprising at least one memory means for storing information indicative of a tripped sensor.

4. In a security system as set forth in claim 3, said memory means being adapted for storing sensor data signifying the address of each tripped sensor.

5. In a security system as set forth in claim 1, said remote units being adapted for responding to sensors of both an intrusion alarm sensing type and a non-intrusion alarm sensing type, the improvement further comprising means for selectively disabling response to sensors of said intrusion alarm sensing type sensors while permitting response to sensors of said non-intrusion alarm sensing type, thereby providing only a non-intrusion alarm sensing mode.

6. In a security system as set forth in claim 1, said interrogation means of each remote unit being adapted for interrogating said sensors during each of periodically repeating interrogation cycles, said means responsive to detection of change in sensor status including a counter for counting up the number of tripped sensors determined during said interrogating of said sensors, and said means responsive to detection being alternately responsive either upon the count in said counter reaching a predetermined number of tripped sensors, or at the end of an interrogation cycle during which there is detection of less than said predetermined number of tripped sensors during an interrogation cycle, whichever first occurs, for causing said transmission to said central processor system.

7. In a security system as set forth in claim 1, wherein said communications link comprises a telephone circuit, said means responsive to change in sensor status comprising means for establishing said telephone circuit between the respective remote unit and said central processor system.

8. In a security system for centralized monitoring and selective reporting of alarm conditions at a plurality of distant remote units at corresponding remote premises, said system comprising:

a central digital processor system for digitally processing information received from remote units;

a communications system adapted for providing a digital communications link between said central processor system and any of said remote units;

said central processor system having a plurality of input ports to provide for simultaneous receipt of alarm data from more than one of said remote units;

a data base at said central processor system constituted by segments of stored preselected data, corresponding segments being indicative of characteristics associated uniquely with corresponding remote premises;

said remote units being individually adapted for responding to a plurality of sensors each having a normal status or a tripped status, said tripped condition resulting in response to occurrence of an alarm situation;

said central processor system having at least one output port to provide for delivery of alarm reports to an output terminal device in a format useful for human intervention in such alarm situation;

the improvement comprising:

interrogation means at individual remote units for interrogating said sensors for detection of whether any sensor has changed from normal status to tripped status;

memory means at individual remote units for storing sensor data signifying the address and tripped status of each tripped sensor;

communications initiation means at individual remote units, operative upon detection of such change in sensor status, for initiating the establishment of a communications link by said communications system between one of the input ports of said central processor system and the respective remote unit;

encoder means at individual remote units for encoding, when enabled, said stored sensor data in a digital format suitable for transmission over said communications link;

message initiation means at individual remote units, operative upon establishment of a communications link, to enable the encoder means for transmitting said stored sensor data as a sensor alarm data message to said central processor system via said communications link;

message storage means at said central processor system for storing said sensor alarm data message;

correlator means at said central processor system for logically correlating the stored sensor data message with corresponding segments of said data base to determine logical validity or invalidity of said sensor alarm data message;

invalid message processing means responsive to a logical invalidity determination for signalling that said sensor alarm data message is erroneous; and

valid message processing means responsive to a logical validity determination for causing at least portions of said sensor alarm data message and corresponding segments of said data base to be assembled into an alarm message.

9. In a security system as set forth in claim 8, said interrogation means being adapted for interrogation a plurality of said sensors sequentially in periodically repeating interrogation cycles.

10. In a security system as set forth in claim 9, said interrogation means comprising a source of pulses, a binary counter for counting said pulses up to a predetermined number and then resetting to determine an interrogation cycle, decoder means for decoding the count in said counter, the decoded count representing the address of a sensor, address response means interconnected with each sensor for responding to a decoded count representing the address of the respective sensor, and detection means responsive to said address response means and to the tripped status of the respective sensor for causing said memory means of the respective remote unit to store the address of the tripped sensor.

11. In a security system as set forth in claim 10, said memory means at individual remote units comprising at least one random access memory.

12. In a security system set forth in claim 11, said communications initiation means comprising telephone dialer means for dialing a telephone number to establish a telephone circuit constituting said communications link.

13. In a security system as set forth in claim 12, said message initiation means being responsive to establishment of said telephone circuit to enable said encoder means to encode said sensor data stored in said random access memory for transmission of said stored data over said telephone circuit.

14. In a security system as set forth in claim 13, said encoder means being adapted for encoding said stored sensor data into different tones representative of different digits corresponding to respective tripped sensor addresses, said tones being transmittable over said telephone circuit.

15. In a security system as set forth in claim 14, said tripped sensor addresses being transmitted in the form of said tones in a sequence until all of said sensor data stored in said random access memories is transmitted over said telephone circuit.

16. In a security system as set forth in claim 15, each said random access memory of a respective remote unit being interconnected with said binary counter of the respective remote unit for identifying sensor addresses, each said remote unit comprising a further binary counter interconnected with said random access memory, the last said counter determining memory storage addresses of data stored in said memories.

17. In a security systen as set forth in claim 8, said communications system being telephonic, said communications initiation means being adapted for establishing a telephonic link between said central processor system and a respective remote unit, said encoder means being adapted for encoding said stored sensor data into different tones representative of different tripped sensor addresses, said tones being transmittable via said telephonic link.

18. In a security system as set forth in claim 8, said remote units being adapted for responding to sensors of both an intrusion alarm sensing type and a non-intrusion alarm sensing type, the improvement further comprising means at remote units for selectively disabling response by a respective remote unit to tripped conditions of intrusion alarm sensing type sensors while permitting response to tripped conditions of non-intrusion alarm sensing type sensors, thereby to provide only a non-intrusion sensing mode, and means for causing said encoder means at remote units for encoding in a digital format sensing mode signals representative of whether or not said response is selectively disabled, said sensor mode signals being adapted for transmission to said central processor system.

19. In a method of centralized monitoring and selective reporting of alarm conditions at corresponding remote premises, said method including providing each of a plurality of said remote premises with respective remote units and a plurality of sensors each having a normal status or a tripped status, said tripped status resulting in response to an alarm situation, providing a central processor system including data base storage, storing in said data base storage segments of preselected data associated uniquely with corresponding remote premises, providing a digital communications link between said central processor system and any of said remote units, the improvement comprising electronically interrogating said sensors to determine if any sensor has changed from normal status to tripped status, electronically detecting such change in sensor status and, in response to such change, electronically transmitting a sensor alarm data message in a digital format signifying the address and tripped status of each tripped sensor to said central processor system via said communications link, electronically correlating, by means of said central processor system, said sensor alarm data message with said data base to determine logical validity of said sensor alarm data message, and causing, by means of said central processor system, at least portions of said sensor alarm data message and corresponding segments of said data base to be provided as an alarm message report in a format useful for human intervention in such alarm situation.

20. In a method as set forth in claim 19, the further improvement comprising electronically storing, by means of said remote unit, data signifying the address and tripped status of each tripped sensor in response to said detecting change in sensor status.

21. In a method as set forth in claim 20, said electronically transmitting a sensor alarm data message comprising transmitting the electronically stored data.

22. In a method as set forth in claim 21, the further improvement comprising electronically initiating communications readiness of said digital communications link prior to said transmitting a sensor alarm data message.

23. In a method as set forth in claim 19, said alarm message report being provided only if said logical validity of said sensor alarm data message is determined to exist.

24. In a method as set forth in claim 23, the improvement further comprising electronically signalling if logical invalidity of said alarm data message is determined to exist.

25. In a method as set forth in claim 19, wherein said sensors of a remote unit are of intrusion alarm sensing types and of non-intrusion alarm sensing types, the improvement further comprising selectively disabling determination of the tripped status of intrusion alarm sensing type sensors, thereby providing only a non-intrusion alarm sensing mode.

26. In a method as set forth in claim 25, the improvement further comprising electronically transmitting a sensing mode signal from a remote unit to said central processor system, signifying said non-intrusion alarm sensing mode, if said disabling is effected.

27. In a method of centralized monitoring and selective reporting of alarm conditions at corresponding remote premises, said method including providing each of a plurality of said remote premises with at least one electronic remote unit and a plurality of sensors associated with said remote unit, said sensors each having a normal status or a tripped status, said tripped status resulting in response to an alarm situation, providing a central processor system including data base storage, storing in said data base storage segments of preselected data associated uniquely with corresponding remote premises, providing a digital communications link between said central processor system and any of said remote units, the improvement comprising:

electronically interrogating, by means of said remote unit, said sensors to determine if any sensor has changed from normal status to tripped status;

electronically detecting, by means of said remote unit, such change in sensor status;

electronically storing, by means of said remote unit, data signifying the address and tripped status of each tripped sensor;

electronically initiating, by means of said remote unit, communications readiness of said digital communications link upon detection of such change in sensor status;

thereafter electronically encoding, by means of said remote unit, said stored sensor data in a digital format suitable for transmission over said communications link; and

electronically transmitting, by means of said remote unit, said encoded sensor data as a sensor alarm data message to said central processor system via said communications link;

electronically storing the received sensor alarm data message at said central processor system;

thereafter electronically logically correlating, by means of said central processor system, the stored sensor data message with corresponding segments of said data base to electronically determine logical validity or invalidity of said sensor alarm data message; and then either

electronically signalling, by means of said central processor system, upon electronically determining that said sensor data message is logically invalid, that said data message is erroneous; or

electronically causing, by means of said central processor system, upon electronically determining that said sensor data message is logically valid, at least portions of said sensor data message and corresponding segments of said data base to be provided as an alarm message report in a format useful for human intervention in such alarm situation.