Abstract:
An ambient condition monitoring system includes a plurality of detectors such as smoke detectors, gas detectors, or fire detectors. Each of the detectors has two sets of input/output ports. One port can communicate with a system control unit. The second port can communicate with a local wired network to which is coupled a plurality of output devices. The output devices can be activated by the respective detector using a modulated control signal.

Description:
FIELD 
       [0001]    The invention pertains to ambient condition detectors which might be part of a monitoring system. More particularly, the invention pertains to such detectors which can communicate via a local medium with one or more output devices. 
       BACKGROUND 
       [0002]    Various types of ambient condition monitoring systems are known. These include fire monitoring systems. Such systems usually include a common control unit, or panel which communicates via a wired or wireless medium, or both, with a plurality of ambient condition detectors such as smoke detectors, fire detectors, gas detectors or the like. Output devices such as horns, sounders or strobes can be coupled to the control unit via the same, or, a second, different medium. 
         [0003]    Current fire detectors can be considered mainly as input devices, since they collect information from the environment and transmit it to the control panel. Their ability to interact with the environment, for example giving an audible message in case of alarm, is very limited, unless special combined devices (detectors with integrated sounder, strobes or both) or dedicated stand alone sounder/strobes are used. 
         [0004]    Usually just 1 or 2 LEDs (light emitting diodes) are available as outputs. They have a limited number of states: steady on, steady off, blink whenever a valid communication has been received. Some detectors have another output, called “remote output”, where the user can connect a load (typically an external LED) that can be controlled by the control panel in the same way as the detector&#39;s LED. 
         [0005]    So the possibility for driving the user loads directly by the detector is very limited, just switching the output device on or off. With current systems, if it is necessary to install both a detector and an audio/visible device in a room (for example in a hotel room), either a combined device can be chosen (expensive both for the end user and the manufacturer) or a detector, a sounder and a strobe (or a combined sounder/strobe) must be installed (expensive for the user, increases system complexity for the control panel). It would be desirable to be able to reduce the cost and time of making such installations. 
         [0006]      FIG. 1  illustrates a prior art system  10  which includes a system control unit or panel  12 . Unit  12  could be implemented with one or more processors  12   a  and associated control software  12   b.    
         [0007]    System  10  includes a plurality of detectors  20 , of which  20   i  is a member. These detectors communicate with the unit  12  via a bidirectional communications medium  14 . Detectors, such as  20   i  include a remote output port which via a wire  22  can be used to drive an LED  24  as discussed above. 
         [0008]      FIG. 2  illustrates additional details of detector  20   i.  The detector  20   i  can include a programmable processor or microcontroller  26 - 1  and associated control software. An internal power supply  26 - 2  can be energized via the medium  14 , conductors  14   a,b.  A switch  26 - 3  under control of circuits  26 - 1  can be used to energize the LED  24  via conductor  22 . 
         [0009]    The signal on line  22  can be an intermittently applied voltage which causes the load  24  to blink and provide a visual status output. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a diagram which illustrates a portion of a prior art detector system; 
           [0011]      FIG. 2  is a more detailed diagram of the system of  FIG. 1 ; 
           [0012]      FIG. 3  is a diagram which illustrates a system which embodies the present invention; and 
           [0013]      FIG. 4  is a more detailed diagram of the system of  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    While embodiments of this invention can take many different forms, specific embodiments thereof are shown in the drawings and will be described herein in detail with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention, as well as the best mode of practicing same, and is not intended to limit the invention to the specific embodiment illustrated. 
         [0015]    Embodiments of the invention include ambient condition detectors having a remote device output circuit which includes a local input/output port to which are coupled a power supply for a displaced output device and circuits that implement a predetermined output device communications protocol. This input/output port can be coupled, via a local medium, to a variety of output devices such as sounders (with selectable tones), strobes (with different flash modes), solenoids or other types of actuators, another external LED, or input devices such as pull stations, or, switches all without limitation. Such embodiments make it possible to drive and control different output loads using a local medium. The local medium is different from a communications medium which the detector might use to communicate with a fire control unit or panel. 
         [0016]    These loads will be activated directly by the detector, relieving part of the communication burden of the control panel. With embodiments of the invention, an output device such as a sounder or strobe can be easily coupled to a local detector where both devices need to be in relatively close proximity to one another. Such embodiments should reduce both device installation costs as well as cable installation costs. 
         [0017]    In a disclosed embodiment, both the communications signals and the power supply can be provided at a common detector output contact or port. Amplitude, frequency or other types of modulation of the output voltage at the port can be used to communicate with the various output devices. Commands can be transmitted between the detector and the connected user load, or output devices, via a local medium such as an electrical cable. 
         [0018]    The remote output driver of the respective detectors performs this modulation and receives an acknowledge from the respective output devices or load. The user loads include a decoding circuit to receive the command and to answer with an acknowledge signal. The control panel can program the detectors in advance with the commands that can be sent to the output devices when activated. 
         [0019]      FIG. 3  illustrates a system  40  which embodies the present invention. System  40  includes a monitoring system control unit or panel  42  which could be implemented with one or more processors  42   a  and associated software  42   b  which functions generally as described above. 
         [0020]    Control unit  42  can be coupled via a wired or wireless bidirectional medium  14  to a plurality of detectors  50 . Detector  50   i  is representative of the members of the plurality  50 . Detector  50   i  includes an ambient condition sensor, such as a smoke sensor, a flame sensor, a thermal sensor or the like all without limitation. Detector  50   i  is coupled to elements  14   a,b  of medium  14  by terminals  50   i - 1 ,- 2  best seen in  FIG. 4 . 
         [0021]    Detector  50   i  can be coupled via a local medium  52  to a plurality of output devices  54  which could include sounders, strobes sounder/strobes, audible output devices, as well as one or more LEDs such as LED  24 . The output devices  54  can be controlled locally by the detector  50   i.    
         [0022]      FIG. 4  illustrates additional details of the detector  50   i  as well as a representative output device such as  54   i.  Detector  50   i  can include a local processor  60 - 1 , a power source  60 - 2  activated by electrical energy from conductors  14   a,b,  switch and communications driver circuitry  60 - 3  which might include acknowledgement detecting circuits  60 - 4 . An ambient condition sensor  60 - 5  can be coupled to control circuits  60 - 1 . 
         [0023]    Detector  50   i  includes a local output port  50 - 3  which can be in bidirectional communication with output devices  54  via medium  52 . Control circuits  60 - 1  can include local control software  60   a  which can include parametric information for purposes of controlling the devices  54 . For example, detector  50   i  can selectively control tone, volume, or flash characteristics of the output devices  54  based on information prestored in circuits  60 - 1  and used by the control software  60   a.    
         [0024]    The output devices, such as  54   i  can include communications circuitry  64 - 1  which can respond to incoming modulated signals on medium  52  from output port  50   i - 3 . Circuitry  64 - 1  can also generated acknowledgement, or response signals on the medium  52  which are to be received by circuits  60 - 3 . 
         [0025]    Circuits  64 - 1  can in turn drive the output devices  64 - 2  in accordance with the modulated signals received via medium  52 . Those signals can specify output parameters such as tone or strobe output characteristics of the respective output device  64 - 2 . 
         [0026]    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.