Abstract:
A control unit can be in communication with an plurality of displaced duct sensors. Sensors can be placed in supply and return ducts of an HVAC-type fluid delivery systems. The unit can communicate status information as well as sensor sensitivity or other parameter values, on a per sensor basis, to a remote accessory unit via a communication protocol. The units can communicate via a wired or wireless medium.

Description:
FIELD  
       [0001]     The invention pertains to ambient condition detectors which can be coupled to various types of heating and/or air conditioning ducts. More particularly, the invention pertains to duct detectors which incorporate one or more programmable processors to provide predetermined functions.  
       BACKGROUND  
       [0002]     One duct detector structure has been disclosed in U.S. Pat. No. 6,124,795 entitled “Detector Interconnect System”, issued Sep. 26, 2000. The &#39;795 patent is assigned to the Assignee hereof and is incorporated herein by reference.  
         [0003]     Many of the known duct smoke detectors incorporate a smoke sensor and a power supply board which incorporates power supply circuitry and alarm indicating relays. In such smoke detectors, the smoke sensor unit makes an alarm determination. The circuitry on the power board then receives a signal from the smoke sensor indicating an alarm condition and responds thereto by activating local alarm indicating relays, and/or light emitting diodes to indicate an alarm condition. Such power boards are unable to make decisions based on multiple detected conditions where the unit incorporates more than one smoke sensor. This results in the sensor having to contain the filtering and processing algorithms. Thus, multiple sensors requires multiple algorithm processing capability. Further, such power boards are unable to signal the condition of the respective sensors to a displaced display/input unit in the absence of extra conductors.  
         [0004]     There is thus a continuing need for duct detectors which can more effectively support multiple local sensors and signal remote indicating or accessory devices than have heretofore been available. Complex processing can thus be handled by one device rather than at each individual sensor, therefore simplifying the design. Preferably such duct detectors could be flexible enough to incorporate a plurality of sensing units and be able to communicate with remote indicators or accessory units, either via cables or wirelessly, without substantial additional expense or manufacturing complexity.  
     
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0005]      FIG. 1  is block diagram of a system in accordance with the invention. 
     
    
     DETAILED DESCRIPTION  
       [0006]     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.  
         [0007]     A duct detector in accordance with the invention incorporates a one or more ambient condition sensors or detectors, a programmable control processor along with a control program, a state machine or a field programmable gate array (FPGA). A plurality of relays and visual alarm indicating devices can also be provided.  
         [0008]     The programmable processor, in combination with the control software or state machine or FPGA, can receive data from one or more ambient condition sensors coupled thereto. The processor and control software or state machine or FPGA can process and filter the data and make an alarm determination relative to each of the ambient condition sensors of the unit. Types of sensors include smoke sensors, gas sensors and the like all without limitation.  
         [0009]     The programmable processor and associated control program or state machine or FPGA can evaluate the condition of one or more ambient condition sensors and determine, for example, precise sensitivity of the respective device as well as any other parameters of interest. In that regard, the programmable processor or state machine or FPGA can adjust alarm thresholds, filter data received from the respective sensors as well as carryout alarm condition processing using data from one or more of the associated sensors. Further, in conjunction with a remote test/display unit, the programmable processor or state machine or FPGA and associated control circuitry can provide information as to condition, sensitivity, and alarm state on a per sensor basis. Additionally, the programmable processor or state machine or FPGA and associated control circuitry can provide control signals to one or more local alarm indicating visual output devices such as light emitting diodes.  
         [0010]     In accordance with the invention, the programmable processor and associated control program or state machine or FPGA can assign different priorities to the various sensors. Priorities could be used to make decisions as to driving common alarm indicating relays without effecting the state of visible status indicators associated with each sensor. Trouble conditions and sensitivity can also be determined on a per sensor basis.  
         [0011]     In another aspect of the invention, the programmable processor and associated control program or state machine or FPGA can receive one or more test or inquiry signals from a remote test/display unit. Such signals can be responded to, on a per sensor basis, by the local program processor and control program or state machine or FPGA. Feedback can be provided to the remote test/display unit on a per sensor basis as to whether or not the respective sensor is in a standby condition, indicating a need for maintenance or whether the sensor is indicating a trouble condition. The remote test/display unit can also be notified of each sensor&#39;s precise sensitivity.  
         [0012]     In yet another aspect of the invention, the present programmable processor and associated control program or state machine or FPGA can communicate with displaced sensors. In this embodiment, one sensor could be located for example in the supply air side of an air handling unit. The other could be located in the return air side of an air handling unit. In other configurations, the multiple sensors could be incorporated into a common housing with the programmable processor and associated control software or state machine or FPGA.  
         [0013]     Transmissions between control unit  12 , and the sensors  16   a,b  and media  16   c   1 ,  16   c   2  can be implemented using a predetermined binary transmission protocol. Hence neither the number nor the extent of commands or data impact the selected media such as  16   c   1 ,  16   c   2 . For example, two conductor cable can be used to transmit modulated, binary or analog, signals between unit  12  and sensors  16   a,b . Only a single optical fiber would be needed in the case of an optical medium. Alternately, a wireless medium could be used, all without departing from the spirit and scope of the invention.  
         [0014]     Further, preferably the unit  12  makes alarm determinations based on received sensor information. Unit  12  can also issue commands to respective sensors which can include commands to illuminate visual indicators such as  40 - 3 ,  42 - 3 , or audible indicators which can be used to indicate alarm, test, trouble conditions or the like without limitation.  
         [0015]      FIG. 1  illustrates system  10  in accordance with the invention. The system  10  includes a control/power unit  12  which is in wired or wireless communication with a plurality of sensors such as sensor  16   a  and sensor  16   b . It will be understood that the type of sensor is not a limitation of the invention. Sensors  16   a,b  could include smoke sensors of various types, as well as gas sensors all without limitation. Further, one or more of the sensors such as  16   a,b  could be coupled to the control and power unit  12 .  
         [0016]     The system  10  can also incorporate a remote test/display unit  18 . The unit  18  can be in wired or wireless communication with the control/power unit  12  via medium  20 .  
         [0017]     Each of the sensors  16   a ,  16   b  can also be in wired or wireless communication with the control/power unit  12  via medium  16   c   1 - c   2 . Communications can be implemented via a binary or analog transmission protocol.  
         [0018]     Control/power unit  12  can include control circuitry implemented as a programmable processor  26   a  and associated control software  26   b  or a state machine or a FPGA. The control hardware and software  26   a,b  or state machine or FPGA can be coupled via interface circuitry  28  to local condition indicating relays  30 , as well as to the various sensors  16   a,b  and remote accessory unit  18 . If desired, local visual displays  32  could also be coupled to interface circuitry  28 . The unit  12  can be incorporated into a closed housing  34  if desired.  
         [0019]     Unit  12 , as noted above, via medium  16   c   1 ,c 2  is in bidirectional communication with respective sensors indicated at  16   a ,  16   b . The sensors can be the same or different without departing from the scope and spirit of the present invention. In  FIG. 1 , sensor  16   a , incorporates a sensing chamber which could be a smoke sensing chamber  40 - 1  which is in turn coupled to interface and control circuitry as appropriate  40 - 2 . The circuitry  40 - 2  is in bi-directional communication via medium  16   c   1  with the unit  12 . Sensor  16   a  can incorporate visual output devices  40 - 3  and be carried in a housing  40 - 4 .  
         [0020]     The sensor  16   b  can also incorporate an ambient sensing chamber, such as a smoke sensing chamber  42 - 1  which is in turn coupled to control and interface circuitry  42 - 2 . The sensor  16   b  is in bi-directional communication via control interface circuitry  42 - 2  and medium  16 - 2  with unit  12 . Sensor  16   b  can also incorporate visual output devices such as the light emitting diodes  42 - 3 . The sensor  16   b  can also be carried by or within a housing  42 - 4 .  
         [0021]     The programmable control unit  26   a  and associated control software  26   b  or state machine or FPGA of unit  12  can communicate with the sensors such as sensors  16   a,b  by sending one or more commands over the respective medium  12   c   1 ,  12   c   2 . Commands can be used for example to control visual output devices such as  40 - 3 ,  42 - 3  as well as to query the respective sensors such as  16   a,b  for data.  
         [0022]     Data could also be provided by the respective sensor on a predetermined basis to the unit  12 . The unit  12  can filter incoming sensor signals in hardware or software. Various processes could be executed in determining the existence of an alarm, maintenance or trouble condition. The data can also be used to determine the precise sensitivity of the sensor. The unit  12  can initiate an alarm condition based on an analysis of data received from the respective sensor, and can activate the relays  30  in accordance therewith as well as visual output devices such  32 ,  40 - 3  as well as  42 - 2 . Further, the unit  12  can notify the remote accessory  18  via medium  20  as to the existence of a determined alarm state. The unit  12  can also indicate a trouble condition or the need for maintenance as would be understood by those of skill in the art.  
         [0023]     The remote test accessory  18  can send one or more test signals to the control/power unit  12 . The unit  12  will in turn evaluate the condition of the respective sensors and communicate with the remote accessory  18  accordingly. Sensor status can include standby, alarm, maintenance, trouble, and sensor sensitivity.  
         [0024]     The unit  12  in communicating with accessory  18  via medium  20  can utilize a predetermined communications protocol for the transfer of information therebetween. Where the medium  20  is a wired medium, the use of a communication scheme results in needing fewer wires between the unit  12  and the remote accessory  18  to communicate the desired information. The communications protocol between units  12  and  18  is not a limitation of the present invention. A variety of protocols as would be understood by those of skill in the art for transmitting digital or analog signals between the units  12  and  18  could be used without departing from the spirit and scope of the present invention. In summary, the unit  12  can communicate the precise sensitivity and the status of multiple sensors, whether they are in a standby condition, alarm condition, maintenance or trouble condition independently of the state or states any other sensor such as  16   a  or  16   b  is exhibiting.  
         [0025]     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.