Abstract:
HVAC network devices are provided with radio frequency identification tags (RFID tags) which can be read by a read/write device. The read tag identification of each network device is stored in memory within the HVAC network device. A device capable of reading the RFID tags of the HVAC network devices will be used by a person to assign network addresses to each network device. In particular, the person will use information concerning the location of an HVAC network device to determine the network address that is to be assigned to the network device. The thus identified network address along with the tag identification is transmitted to a network controller for the communication network. The network controller will transmit a configuration message over the communication bus that will include the tag identification as well as the desired network address. The HVAC network device having the matching tag identification will respond to the configuration message from the network controller so as to thereby allow the desired network address to be downloaded to the particular HVAC network device.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to the configuration of an HVAC communication network so as to facilitate communications between devices connected to the network. In particular this invention relates to how a device is identified and assigned a network address within the communication network. 
     The use of a communication network to convey HVAC control information over a common communication bus to devices connected to the bus is well known. Such networks are often used when one wishes to implement a hierarchical control of several heating or cooling devices. A central or master controller in such a hierarchical control will normally communicate with the devices connected thereto over a common control bus. In order to do so, the hierarchical control needs to be able to identify each device connected to the bus so that the particular device can be addressed by the central or master controller. 
     U.S. Pat. No. 5,818,347 entitled “Identification of HVAC Systems in a Communication Network” discloses a particular approach to assigning a network identification to an HVAC device. The device is assigned a network identification or network address by a hand held device which communicates with the HVAC device so as to thereby transfer the network identification to the HVAC device. The above system however requires that the network controller know in advance the network identification assigned to the HVAC device. 
     Other systems which identify an HVAC device within a communication network include providing buttons on either an HVAC zone controller or on a wall mounted device connected to the zone controller. Depression of such a button is interpreted as a signal over the network that the zone controller awaits the assignment of a network address. The technician performing such a network address assignment must usually walk from wherever the zone controller is located to a location where either a master controller or a computer is located that will assign a network address assignment to the zone controller. The person uses information as to the location of the zone controller to provide the network address to the master controller that will thereafter assign a network address to the zone controller. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to provide a system and method for quickly, easily and reliably assigning a network address to a zone controller or other HVAC network device. 
     An HVAC communication network includes a network controller node coupled to one or more down stream nodes by a distributed communication bus. Each down stream node preferably consists of some type of HVAC network device. At least some of these devices are provided with preprogrammed tags having tag identifications which can be read by a read/write device. The tag is preferably a radio frequency identification (RFID) tag. The tag identification for each device is stored in a nonvolatile memory within the HVAC network device. This is preferably done at some point during the manufacture of the network device. 
     In accordance with the invention, a technician will use a hand held device capable of reading the RFID tags of the HVAC network devices that have been connected to the distributed communication bus. The RFID tag on a particular HVAC network device will transmit its tag identification to the hand held device when the hand held device is in the vicinity of the particular device. The technician will access a floor plan identifying locations in the building where the HVAC network devices have been installed. This location information is used to identify a particular network address that is to be assigned to the HVAC network device in that particular location. This is preferably accomplished by accessing a data base that includes network addresses for particular locations. The thus identified network address along with the tag identification is transmitted to the network controller for the communication network. The network controller will transmit a configuration message over the communication bus that will include the tag identification as well as the desired network address. The HVAC network device having the matching tag identification will respond to the configuration message from the network controller so as to thereby allow the desired network address to be downloaded to the particular HVAC network device. Once the network address for the particular network device node has been established, then additional messages addressed to the particular HVAC network device can occur without use of the tag identification. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will become more apparent by reading a detailed description thereof in conjunction with the following drawings in which: 
     FIG. 1 illustrates a plurality of HVAC network devices connected by a common bus to a network controller; 
     FIG. 2 illustrates the internal configuration of the network controller; 
     FIG. 3 illustrates the internal configuration of an HVAC network device of FIG. 1; 
     FIG. 4 illustrates the internal configuration of a hand held device that communicates with the network controller of FIG. 1; 
     FIG. 5 illustrates a process whereby a tag identification for an HVAC network device is stored in the device; 
     FIG. 6 is a process implemented by a hand held device wherein a network address is assigned to a particular HVAC network device in response to having read a tag on the device; 
     FIG. 7 is a flow chart of the process implemented by processor within the network controller whereby the network address received from the hand held device is assigned to the HVAC network device having the tag identification picked up by the hand held device; and 
     FIG. 8 is a process implemented by the processor within the HVAC network device whereby the assigned network address from the network controller is received and stored in the network device. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, a network controller  10  is connected to HVAC network devices  12  and  14  by a communication bus  16 . Each HVAC network device must have a network address which allows the network controller  10  to communicate with the particular device. The HVAC network devices may be any type of device connected to the communication bus  16  so as to communicate with the network controller or other HVAC network devices connected to the bus. This may include zone controllers for controlling air distribution systems regulating the flow of conditioned air to particular zones, HVAC devices or systems for providing conditioned air, monitoring devices such as temperature or humidity sensors connected to the bus, or any other communication device used within an HVAC network. 
     The HVAC network devices  12  and  14  each have a radio frequency identification (RFID) tag such as  18  and  20  which are preferably located on the device. The RFID tag  18  will activate and transmit its tag identification to a hand held device when the technician holding the device is within the transmitting range of the RFID tag  18 . This tag identification can be any alpha numeric code as long as it is distinct from the alpha numeric codes produced by the RFID tags associated with other network devices. As will be explained in detail hereinafter, the received tag identification will be used to identify the network address that is to be assigned to the particular HVAC network device  12 . This network address and the accompanying tag identification read from the RFID tag  18  will be transmitted to the network controller  10 . The network controller  10  will thereafter assign the transmitted address to the particular HVAC network device  12  by matching the transmitted tag identification to the internally stored tag identification within the HVAC network device  12 . 
     Referring to the network controller  10 , it is to be noted that the network controller  10  includes a receiver  24  for receiving signals from the hand held device  22 . The hand held device  22  preferably transmits an infrared signal to the receiver  24  which processes the transmitted infrared signals. The network controller also preferably includes a transmitter  25  for sending signals to the handheld device. The transmitter preferably transmits infrared signals which can be easily received and processed by the hand held device  22 . 
     Referring now to FIG. 2, the internal configuration of the network controller  10  is seen to include a processor  30  connected to the infrared receiver  24  so as to process messages transmitted from the hand held device  22 . The processor is also connected to the transmitter  25  so as to send messages to the hand held device. The processor  30  is also operative to send and receive signals to devices connected to the communication bus  16  via a bus node interface  32 . 
     Referring now to FIG. 3, the internal configuration of an exemplary HVAC network device is shown. The internal configuration includes a processor  34  connected to a bus node interface  36  so as to receive and transmit signals over the communication bus  16 . As will be explained in detail hereinafter, the processor receives a network address to be assigned to the particular node connection to the communication bus  16 . The processor is also connected to a nonvolatile memory  38  which preferably stores the received network address. The processor  34  is also preferably connected to an HVAC control interface which could be any number of different types of control interfaces depending on the HVAC function that is to be controlled. In this regard the HVAC function downstream of the control interface could be dampers in an air distribution system, or it could be a heating or cooling device that is providing conditioned air to the air distribution system, or it could be any number of functional elements within an HVAC network device if the network device is itself an air conditioning unit. 
     Referring now to FIG. 4, the internal configuration of the hand held device  22  is shown. The internal configuration is seen to include a processor  42  connected to a receiver  44  which receives infrared signals from RFID tags. The receiver  44  also preferably receives infrared signals containing messages from the transmitter  25  of the network controller. The processor is also connected to an infrared transmitter  46  which transmits signals to the receiver  24  within the network controller  10 . The processor  42  is also connected to a keypad  48  and a display  50  so as to allow data entering and display capabilities at the remote hand held device. 
     Referring now to FIG. 5, the process whereby an HVAC network device is initially programmed so as to include a tag identification is shown. The process begins by reading an RFID tag that has been selected for the particular device in a step  52 . This is accomplished by an infrared tag reader. The read tag identification is next communicated to the processor  34  within the network device. This may be done by a data entry device temporarily attached to the bus node interface  36  for the network device. On the other hand, the read tag identification could be communicated through another communication interface associated with the processor  34 . In any event, the processor  34  is operative to store the read tag identification as TAG_ID in nonvolatile memory  38  in step  54 . The processor thereafter checks to see that the read tag identification is properly stored by reading TAG_ID from memory in step  56  and inquiring as to whether the read value of TAG_ID is equal to the originally communicated tag identification read in step  52 . The processor either proceeds to step  60  or step  62  and displays an appropriate message as to whether the read tag identification was stored accurately. 
     Referring now to FIG. 6, the process for assigning a network address to the tag identification stored in memory  38  is shown. The process begins when the hand held device  22  receives a signal from the RFID tag on a particular HVAC network device that is in the vicinity of the hand held device  22 . In this regard, the person normally holding the hand held device will note the occurrence of a message on the display  50  of the hand held device indicating that an RFID tag has been read in a step  64 . The hand held device may thereafter be used to display a floor plan of the building wherein various HVAC network devices are to be installed. The floor plan will indicate the various locations of the HVAC devices. This is done in a step  66  wherein the processor  42  within the hand held device is depicted as communicating with a floor plan database. It is to be noted that this database could either be stored in memory associated with the processor  42  in the hand held device or it could be stored in an off line storage device that can be accessed by the hand held device. It is furthermore to be appreciated that the building floor plan could merely be a document that the person operating the hand held device would consult to identify where the particular HVAC device is located on the floor plan. In any event, the processor  42  within the hand held device  22  next awaits a selection of the location in the building floor plan in a step  68 . When a selection has been entered on the keypad  48  of the hand held device, then the hand held device will proceed to determine the network address for the particular identified or selected location. Specifically, the hand held device either communicates with another device having network addresses for particular identified locations or the hand held device itself has such information stored therein for local accessing. This is done in a step  70 . The processor  42  within the hand held device may cause the determined network address to be displayed in a step  72  or it may proceed directly from step  70  to step  74  without such a display. 
     Referring to step  74 , the processor  42  preferably awaits a command entered at the keypad  48  of the hand held device to transmit both the tag identification of the read RFID tag and the network address to the network controller  10 . It is to be understood that the transmission of the tag identification of the read RFID tag and the network address is preferably accomplished through the transmitter  46  which is an infrared transmitter in the preferred embodiment. The processor  42  within the hand held device thereafter awaits confirmation that the network controller  10  has been successfully received by the network controller  10 . This will preferably be accomplished by a confirmation transmitted back to the hand held device  22  from the network controller  10 . The processor proceeds to exit from the process of FIG. 6 in the event that a message is received. In the event that a message is not received within an appropriate period of time defined in a step  78 , then the processor proceeds to display a “retry transmission” message in a step  80 . 
     Referring now to FIG. 7, the process implemented by the processor  30  within the network controller in response to receipt of a message containing the tag identification and network address from a hand held device is shown. As has been previously described, the network controller preferably includes an infrared receiver  24  for receiving such messages from the hand held device. The process begins with a step  82  wherein inquiry is made as to whether a message has been received at the receiver. When a message is received, the network controller will proceed to broadcast a message containing the received tag identification and network address from the hand held device. This message is preferably a broadcast message to all HVAC network devices attached to the bus  16 . As will be explained in detail hereinafter, the particular HVAC network device attached to the bus  16  having a TAG_ID value matching the tag identification will respond to the broadcast message. The processor  30  within the network controller awaits an acknowledgement from the particular device having the matching TAG_ID value in a step  86 . The processor exits to a step  88  in the event that an acknowledgement has not yet occurred. Referring to step  88 , the processor will merely look further for receipt of the acknowledgement unless a time period has clocked out for receiving an acknowledgement from the particular device having the matching TAG_ID value. In the event that a period for an acknowledgement has expired, the processor will proceed to a step  90  and transmit a failed status message to the hand held device. Referring again to step  86 , in the event that the acknowledgement has been received from a network device attached to the bus  16 , then the processor will proceed to step  92  and transmit a success status message via transmitter  25  to the receiver  44  of the hand held device  22 . The processor  30  within the network controller will thereafter proceed to exit the configuration mode of FIG. 7 in a step  94 . 
     Referring now to FIG. 8, the process implemented by an HVAC network device in response to the receipt of a broadcast message from the network controller is shown. The process begins with a step  96  wherein an inquiry is made as to whether a configuration broadcast message has been received by the HVAC device. In the event that a configuration broadcast message is noted as having been transmitted on the bus  16 , then the processor  34  within the HVAC device will proceed to a step  97  and inquire as to whether the network address has been previously set or configured. This could be a check of memory to see if any network address has been previously assigned. If no memory address has been assigned, then the processor will proceed to step  98  and inquire as to whether the tag identification in the message is equal to the value of TAG_ID stored in the memory  38 . In this regard, it will be remembered that the read tag identification of the RFID tag of a network device is stored in memory  38  in step  54  of FIG. 5 during the initial programming of the HVAC network device. If the tag identification received from the network controller matches the stored value of TAG_ID in memory  38 , then the processor proceeds to step  100 . The processor in step  100  sets the device network address equal to the network address received from the network controller. The processor  34  thereafter proceeds to transmit a success status message to the network controller  10  in a step  102 . The processor thereafter initiates control of any particular HVAC equipment downstream of the HVAC control interface  40  in a step  104 . 
     It is to be appreciated from the above that a series of processes have been disclosed whereby a device to be attached to a communication bus is initially assigned an RFID tag with the identification value contained in the tag being stored in its memory. The device is thereafter assigned a network address through a series of communications first between the RFID tag and a hand held device and thereafter between the hand held device and the network controller and finally between the network controller and the device attached to the bus  16  without an assigned network address. 
     Alterations, modifications and improvements to these various processes will readily occur to those skilled in the art. For instance, the hand held device could be something that is not necessarily held in ones hand. Accordingly, the foregoing description is by way of example only and the invention is to be limited by the following claims and equivalents thereto.