Abstract:
An electrical unit, such as an ambient condition detector, incorporates pattern discrimination circuitry. A received pattern is analyzed and, if it is in accordance with a predetermined pattern, the unit outputs an audible and/or visible indicium synchronized with the incoming pattern for the duration thereof. The unit also includes circuitry for emitting a corresponding output signal pattern to at least one other detector. A system which incorporates a plurality of electrical units, at least one of which has the pattern discrimination circuitry produces at least one synchronized audible or visible output indicative of a predetermined condition throughout the system. Patterns can include predetermined tonal alarm indicating output patterns as well as predetermined visible alarm indicating output patterns.

Description:
FIELD OF THE INVENTION 
     The invention pertains to monitoring systems. More particularly, the invention pertains to such systems which are capable of outputting synchronized audible or visible indicia indicative of the presence of an alarm condition. 
     BACKGROUND OF THE INVENTION 
     A variety of alarm systems for monitoring various ambient conditions in regions of interest are known. These systems, which include fire detection, gas detection or intrusion detection devices, often incorporate ancillary output devices such as horns or speakers or piezoelectric tone generating devices to produce various types of condition indicating audible outputs. Visible outputs which produce various pulsed light patterns are also known. 
     Advantages of standardized audible alarm signals have been recognized. One known standardized alarm signal with a predetermined temporal pattern has been defined by American National Standard Institute S3.41. It is also been recognized that various foreign jurisdictions might specify a different standard. 
     Beyond publicly issued standards, it has been recognized that there are advantages to synchronizing the various audible and visible outputs. One known synchronizing approach is disclosed and claimed in U.S. Pat. 5,850,178 entitled “Alarm System having Synchronizing Pulse Generator and Synchronizing Pulse Missing Detector” assigned to the assignee hereof and incorporated herein by reference. While known synchronization approaches and methods have been found to be useful, there continues to be a need for synchronization systems and methods which respond to evolving needs. 
     SUMMARY OF THE INVENTION 
     An electrical device usable in a multiple device communication system incorporates control circuitry for receiving and analyzing received signal patterns. In response to a received predetermined signal pattern, a synchronized output is generated. In one aspect, the output can be produced by a transducer. Exemplary transducers include audible output devices and visual output devices. 
     In yet another aspect of the invention, the unit includes discrimination circuitry which initially recognizes that a predetermined pattern has been received and which energizes an output transducer in accordance with subsequently received predetermined patterns. In this embodiment, the output transducer will continue to be driven, in synchronism with the received patterns until the incoming patterns cease. 
     The output transducer can be driven to produce a pattern identical to a received pattern. Alternately, the synchronized output can be provided in the form of a different pattern. 
     In another aspect, the control circuitry incorporates a programmed processor and associated pre-stored executable instructions along with at least one pre-stored output pattern. Upon receipt of an incoming pattern which is substantially similar to the pre-stored output pattern, the processor in turn causes the output transducer, which could be audible or visible, to emit a synchronized pattern. As noted above, the synchronized pattern can be identical to the. received pattern. Alternately, it can be synchronized to the received pattern but distinguishable therefrom. 
     The electrical unit can in turn generate at a selected output port an output pre-determined synchronizing pattern to be coupled to other electrical units. In such an event, the coupled output synchronizing pattern from the first unit causes the subsequent units to emit a synchronized audible and/or visible output signal corresponding to the received signal. Alternately, the audible and/or observable output signals can be synchronized with a received input pattern but can be distinguishable therefrom. 
     In one embodiment, an electrical unit which has recognized the presence of a predetermined condition, such as fire, gas or intrusion, can enter a state indicative thereof. That unit can in turn output a synchronizing pattern to units coupled thereto. In response to receipt of the synchronizing pattern, those units can emit a synchronized audible/visible output either substantially identical thereto or synchronized therewith but distinguishable therefrom. 
     In another embodiment, a common control element can be coupled to the various electrical units. The synchronizing audible/visible signal can be originated by the common control element in response to detection of an alarm condition. 
     The synchronizing signal can in turn be coupled to a plurality of electrical units in the system either directly or in daisy-chain fashion by causing the units to emit a signal corresponding to the received synchronization signal from the panel. The emitted signal is received by other electrical units in the system causing same to output a synchronized audible/visible indicia. 
     In yet another embodiment, a signal discrimination module can be coupled to the control element. This module can in turn detect the presence of a synchronizing output-signal from the control element. It can in turn couple that signal to a plurality of electrical units which do not incorporate the above noted discrimination circuitry. 
     Numerous other advantages and features of the present invention will become readily apparent from the following detailed description of the invention and the embodiments thereof, from the claims and from the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram of a system which embodies the present invention; 
     FIG. 2 is a flow diagram illustrating various aspects of the operation of the system of FIG  1 . 
     FIG. 3 is a block diagram of an another system which embodies the present invention; 
     FIG. 4 is a flow diagram illustrating various aspects of the operation of the system of FIG. 3; 
     FIG. 5 is a block diagram of yet another embodiment of the present invention; 
     FIG. 6 is a flow diagram of various aspects of the operation of FIG. 5; and 
     FIG. 7 is a block diagram of an exemplary electrical unit usable in the systems of FIGS. 1 and 3. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     While this invention is susceptible of embodiment in many different forms, there are shown in the drawing and will be described herein in detail specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated. 
     FIG. 1 illustrates a system  10  in accordance with the present invention. The system  10  includes a control panel  12  of a conventional variety as would be understood by those of skill in the art. Conductors  12   a  and  12   b  are coupled from panel  12  to a plurality of devices  16 . The conductors  12   a ,  12   b  can be used to provide electrical energy from the control panel  12  to devices  16 . Additionally, as is known to those of skill in the art, they can be used to transmit information from the panel  12  to the various devices  16  or, alternately, from one or more of the devices  16  to the panel  12 . 
     The plurality of devices  16  includes devices  16   a ,  16   b ,  16   c , and so on to the extent that the conductors  12   a ,  12   b  can adequately service the remaining devices  16   m ,  16   n.    
     The members of the plurality  16  are, for example, ambient condition detectors such as the detector  16   i  illustrated in block diagram form in FIG.  7 . The detector  16   i  includes a housing generally indicated at  20  which supports the components thereof. 
     Detector  16   i  includes control circuitry  22  which could be implemented, for example, as an application specific integrated circuit (ASIC) or, preferably as a programmed processor. Processor  22  is coupled via interface circuits  24  to conductors  12   a ,  12   b . Processor  22  in combination with circuits  24  carries out processing of a known type relative to control panel  12  which would be understood by those of skill in the art. 
     Processor  22  is also coupled to and receives signals from an ambient condition sensor  28 . Sensor  28  could be implemented for example as a fire sensor to sense heat, smoke, flame or the like, all without limitation. Alternately, sensor  28  can be implemented as a gas sensor, a switch closure such as a fire alarm pull switch, a position indicator, a movement or intrusion detector, also without limitation. 
     Processor  22  includes alarm detection software  22 a whereby signals from sensor  28  are analyzed in processor  22 , using alarm detection software  22   a  to determine if an alarm condition is present. If so, processor  22  via interface circuits  24  can notify the alarm control panel  12 . Additionally, the device  16   i  carries a local alarm output transducer  30  which is coupled to and can be driven by processor  22 . Transducer  30  could be implemented for example as an audio sounder such as a piezoelectric output device or horn. Alternately, it could be implemented as a strobe light for generating pulses of human discernable radiant energy. 
     Hence, in response to the determination of an alarm at programmed processor  22 , the alarm output transducer can be energized to produce an audible output or a visual output. One known audible output has been specified by American National Standard Institute S3.41. 
     Device  16   i  also includes-pattern input/output interface circuitry  32  coupled to control circuitry  22 . Control circuitry  22 , via interface  32  monitors input signals for the presence of predetermined patterns as discussed below. 
     With reference to FIG. 1, system  10  includes a synchronization synch signal communication line  12   c . The line  12   c  extends between the devices, such as the device  16   i  of FIG.  7 . The pattern input/pattern output interface  32  is coupled between synchronization line  12   c  and the control element, preferably program processor  22 . 
     In the event that electrical device  16   i  has detected the presence of an alarm condition and entered an alarm state in addition to driving the local alarm output transducer  30 , it will in turn produce an electrical signal on the line  12   c  which exhibits a synchronizing pulse pattern, corresponding to the pulse pattern being used to drive transducer  30  to the remaining devices in the plurality  16 . The remaining devices in a plurality  16  will in turn detect the presence of a pre-specified pattern on the line  12   c  and will in turn drive their local alarm output transducer in synchronism with the same pattern as is used to drive the output transducer of the electrical device, such as the device  16   i  which has gone into alarm. This provides a synchronized audio and/or visible output signal at each of the devices in the plurality  16 . 
     The members of the plurality  16  can be programmed to either match the incoming recognized alarm pattern, from line  12   c  and output the same pattern at their local output transducer or detect an acceptable incoming signature and then output a different pattern. 
     FIG. 2 illustrates a flow diagram of the processing carried out by the processor  22  in a device  16   i  in a quiescent state. The processor  22  will monitor line  12   c  for the presence of a synchronizing signal in step  100 . In the event that one or more of the pre-defined signals is recognized in a step  102 , the local alarm transducer  30  will be activated in synchronism in a step  104  in response to the incoming pattern on the sync line  12   c.    
     So long as the incoming pattern continues to be repeated on the line  12   c , in a step  106 , the device  16   i  will continue to drive the local output transducer  30  in synchronized fashion. When the incoming pulse train on the line  12   c  ceases, the processor  22  ceases to drive the local output transducer  30  in a step  108 . In such an event, if the device  16   i  is not in alarm, step  110 , it will return to quiescent state and continue to monitor the sync line  12   c.    
     On the other hand, if the device  16   i  is in alarm, it will in a step  112  activate the local alarm output transducer  30  indicating the-presence of an alarm condition at device  16   i . Additionally, by means of interface  32 , in a step  114  a modulated synchronizing output pulse train will be coupled to line  12   c . This signal will in turn activate remaining devices in the plurality  16  causing them to emit a synchronized audible and/or visual output signal. 
     The system  10  thus, via the plurality of electrical units  16  can emit synchronized tonal or visual output patterns at the members of the plurality  16  in response to one of those members having gone into alarm. 
     FIG. 3 illustrates an alternate system  10 ′ which includes control panel  12 ′ coupled by conductors  12   a ,  12   b  to devices  16 ′. In the embodiment of FIG. 3, a synchronizing line  12   c ′ extends between panel  12 ′ and each of the members of the plurality  16 ′. In this embodiment, a member of the plurality  16 ′, such as the device  16   i  which has gone into alarm notifies control panel  12 ′ in a conventional fashion, for example by shunting lines  12   a ,  12   b.    
     In response to the panel  12 ′ detecting the presence of an alarm condition, which might include for example a fire alarm or an intrusion alarm or a gas alarm depending on the type of device which has sensed the condition, the control panel in turn generates a synchronization output signal on the line  12   c ′ which is coupled to each of the members of the plurality  16 ′. Members of the plurality  16 ′ correspond generally to the structure previously discussed in FIG. 7 with respect to device  16   i  with those changes which would be appropriate thereto based on the subsequent discussion of the operation of the devices in the plurality  16 ′. 
     The members of the plurality  16 ′ can in turn be programmed so as to detect a pattern on the line  12   c ′ to which they were intended to respond. For example, the pattern on the line  12   c ′ might be a pattern for a fire alarm or could be a pattern for an intrusion alarm. In the former case, devices which were to indicate fire alarms would respond to the respective pattern, for example, by energizing their local fire alarm output transducer, corresponding to transducer  30  thereby producing a synchronized audible output pattern indicating a fire alarm. Alternately, in the event that panel  12 ′ issues an intrusion signal on the line  12   i , only those devices in the plurality  16 ′ which incorporated intrusion alarms would respond thereto and go off. Once again, when the panel  12 ′ terminated signals on the line  12   c ′, the output devices would also cease being activated. 
     FIG. 4 illustrates a process implementable in the members of the plurality  16 ′ which includes in a step  200  monitoring the line  12   c ′ for the presence of a signal from the panel  12 ′. In the event that a pre-defined signal is recognized on the line  12   c ′ in a step  202 , the appropriate local output transducer, for example a fire alarm or an intrusion alarm will be then energized by the respective devices in the plurality  16 ′, in a step  204  to thereby produce a pre-defined synchronized sound or visual pattern in response to the panels signals. In the event that the panel ceases driving the line  12   c ′, in a step  206 , the output is then turned off in a step  208 . 
     With respect to the systems  10  or  10 ′, the respective synchronization signals could for example include: 
     1. Pulses temporally spaced apart and corresponding to a predetermined audible or visual standard; 
     2. AC signals, for example, 3 kHz tones, sent in synchronized groups on the synchronizing lines  12   c  or  12   c ′ to produce a predetermined audible or visual output in synchronism. 
     FIG. 5 illustrates an alternate system  10 ″. The system  10 ″includes a control panel  12 ″ which is coupled via conductors  12 - 1  and  12 - 2  to a synchronizing module  50 . A synchronizing signal is coupled from panel  12 ″ to module  50  via conductor  12 - 3 . 
     In the system  10 ″, the module  50  is in turn coupled via conductors  12 - 5  and  12 - 6  to a plurality of devices  16 ″. The system  10 ″ produces synchronized audible/visible output at the devices  16 ″ in response to synchronization signals coupled thereto via module  50 . These signals in turn all originate at control panel  12 ′. The devices in the plurality  16 ″ could, for example, be fire detectors, gas detectors, or intrusion detectors, all without limitation. Additionally, they could be merely audible/visible output devices. Devices such as devices  16   i  modified to detect the patterns present on lines  12 - 5  and  12 - 6  could be used in system  10 ″. 
     FIG. 6 illustrates flow diagrams for the synchronizing device or module  50 , left column, as well as members of the plurality  16 ″ right column. As illustrated in FIG. 6, the module  50  monitors the line  12 - 3  in a step  300  for the presence of a synchronizing signal from the panel. In step  302 , in the event that it is the predefined signal, the conductors  12 - 5  and  12 - 6  are activated with a selected output voltage or current pattern in synchronism with the alarm signal from the panel  12 ″. 
     So long as the panel continues to provide the synchronizing signal on the line  12 - 3  in a step  306 , the devices in the plurality  16 ″ will continue to receive the signals from the unit  50 . Each of the members of the plurality  16 ″ monitors the lines  12 - 5 ,  12 - 6  in a step  310  for the presence of the selected signals. In the presence of any signal or signals, detected in a step  312 , the respective local output device, fire alarm or intrusion alarm is activated in a step  314 . That device will continue to be activated in a step  316  so long as the device  50  continues to provide the signals. 
     It will be understood that the device  50  as well as members of the plurality of  16 ″ could all couple alarm indicating signals to panel  12 ″. Representative devices would include fire detectors, intrusion detectors and gas detectors, all without limitation. 
     From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims.