Patent Publication Number: US-8112498-B2

Title: Mapping between objects representing different network systems

Description:
TECHNICAL FIELD 
     The present invention relates to a gateway apparatus connecting two or more network systems with one another for exchanging data, a gateway setup tool performing a setup of the gateway apparatus, a setup of intermediate object and its use. 
     BACKGROUND ART 
     Conventionally, some gateway apparatuses are placed between a network transmitting and receiving a command for monitoring or controlling building equipment such as air conditioning or lighting equipment installed in a building or the like and a host system of building management performing a total operation of monitoring and controlling an equipment group of those. Others are placed between two or more network systems whose protocols are different from each other. The conventional gateway apparatuses mutually connect those networks and systems. According to those conventional gateway apparatuses, an object handling the systems to be processed and mapping to an object as a mutual correspondence are to be set up individually for each system and held in software produced for each applicable article in some cases. In other cases, several preset items of setup information are held and one to be used is selected from among those. Accordingly, it is necessary to update software when the setup information is altered. 
     As a second conventional example, some including Japanese Unexamined Patent Publication No. HEI 05-173795 are directed to solving such a problem. They are provided with a relation management object for managing bi-directional related information between two or more objects. Then, it attempts to perform the maintenance of mapping and the like between objects by handling this relation management object. 
     According to the conventional gateway apparatuses mentioned above which have built-in individual software provided for each article, data is exchanged by way of a gateway apparatus which has built-in software holding statistically objects handled by the network systems of both sides and mapping relating information as a mutual correspondence, in the case where a network transmitting and receiving a monitor or control command to and from building equipment such as air conditioning or lighting equipment and a building management system which performs a total operation of controlling and monitoring a group of such equipment are configured based on different protocols from each other in a building system, for example. 
     For that reason, it is needed to update the software itself when the setup information is altered. As a result, a lot of time and cost are required when the state of a system connected has been changed or the mapping specification has been altered. 
     Still more, in the case of connecting a large number of network systems to one another, since it is necessary that the gateway apparatus should hold all the information relating to those connected networks, a larger amount of memory capacity is required. Therefore the gateway apparatus has become expensive. 
     As a third conventional and concrete example, Japanese Unexamined Patent Publication No. HEI 6-169315 has proposed a method for solving such a problem. According to this method, mapping information is generated according to a connected system through a mapping process provided on the gateway apparatus. Then, the mapping information is updated according to a change in the state of a connected system through a mapping update process provided on the gateway apparatus. 
     A setup of mapping information in the conventional gateway apparatuses is made as mentioned above. This has posed a problem of a lot of time and cost required when a connected system has a change in such as its configuration or the mapping specification (correspondence) is altered. 
     Another problem is that since a setup of mapping requires full knowledge of the connected systems of both parties and deep understanding of interrelation with the object relating to the systems, a highly skilled engineer is needed. 
     With referring to the second conventional example, the mapping information between the objects of both parties is held by the relation management object. For that reason, a mapping setter should have full knowledge of the systems of both parties for mapping at the same time. Another problem is that when a change occurs with one system, it is needed that the setup of mapping is reset and made again under reconsideration of the state of the other system. 
     With referring to the third conventional example, the generation and updating process of mapping is performed on the gateway apparatus. For that reason, in order to handle a change in the system to be processed and an alteration in the mapping algorithm and the like, it is needed to update the built-in software. 
     In addition, since the generation and updating process is performed on the gateway apparatus, the processing load of the gateway apparatus becomes large. As a result, the gateway apparatus becomes expensive. 
     The present invention is directed to solving such problems mentioned above. It is an object to obtain the mapping device for gateway apparatus in which a setup of mapping may be made without full knowledge of the network system of the other party in the system where an interconnection is made between different network systems A and B run based on different protocols from each other through a mutual mapping of objects representing the respective systems. In addition, it is designed that even if a change occurs in one of the network systems, the change does not influence the setup information of the other network system. 
     In addition, it provides simple and easy development in setup, monitor and control by using a view, so that the format is intelligible for the user as well. 
     Another object is to generate a more precise and appropriate mapping. 
     Still another object is to obtain the apparatus which is responsive to an operation based change in the network system without difficulties. 
     Still another object is to provide the gateway apparatus which requires neither updating built-in software provided in the gateway apparatus nor having complicated operations performed on the gateway apparatus such as the generation and updating process of mapping information based on setup data even when a connected system is changed, the mapping specification is altered, or the mapping algorithm is changed. Hence, the development cost, engineering cost, and hardware cost of the gateway apparatus are held down low. 
     Still another object is to provide the gateway setup tool which allows an easy setup without full knowledge of interrelation between the connected systems of both parties. In addition, it is possible to use a sophisticated user interface in making a setup. Hence, the setup efficiency and the engineering cost of the gateway setup tool are high and held down low, respectively. 
     Still another object is to provide the gateway apparatus and the gateway setup tool which may be produced by using a generally and widely available application program such as a WEB browser. Hence, the development cost and the engineering cost of the gateway apparatus and the gateway setup tool are held down low. 
     DISCLOSURE OF THE INVENTION 
     A gateway apparatus according to the present invention is provided in a configuration where data of an object representing a component of a system is available for another system. 
     The gateway apparatus includes an intermediate model which is set up by one system, and the intermediate model includes an intermediate object corresponding to the component. The one system maps an item of a corresponding component of the one system to the intermediate object, and transfers data to a mapped item. 
     Then, the another system obtains the data corresponding to the item of the intermediate object when the data of the intermediate object is needed as component data. 
     Alternatively, it is in a configuration where the data of an object is mutually used by another systems, when the data is defined as a component composing a system. 
     It is provided with an intermediate model which is mutually accessible. This intermediate model has an intermediate object which corresponds to the component therein. Each system maps an item of a corresponding component of itself to the intermediate object, and transmits data to a mapped item. Then, the each system, when component data of the another system is needed, accesses the intermediate object to obtain the data corresponding to the item. 
     In addition, each system, when accessing the data of the intermediate object, performs mapping to the intermediate object whose component items agree more than a predetermined rate with items to be accessed of the each system as the intermediate object. 
     Still further, the intermediate object is added with supplemental information, and each system accesses the intermediate object based on the supplemental information. 
     Still further, when mapping is performed between the system and the intermediate model, the intermediate model and its intermediate objects, and the system and its components are displayed on the same screen. 
     Still more, mapping to the intermediate object is performed by data which is written in a structured data description language. 
     It comprised a system A communicating section transmitting and receiving a communication command A of a system A, a system B communicating section transmitting and receiving a communication command B of a system B built on a protocol which is different from a protocol on which the system A is built, a system A object database exchanging the communication command A with the system A, interpreting a content of the communication command A, and holding object data, a system B object database exchanging the communication command B with the system B, interpreting a content of the communication command B, and holding object data, a mapping database holding mapping data representing a correspondence between the object data of the system A object database and the object data of the system B object database, a mapping executing section exchanging object data A with the system A object database, exchanging object data B with the system B object database, performing mapping between the object data A and the object data B based on the mapping database, and mutually exchanging the object data A and the object data B, and a setup data transmitting and receiving section exchanging the object data A with the system A object database, exchanging the object data B with the system B object database, exchanging the mapping data with the mapping database, and exchanging the object data A, the object data B, and the mapping data with an external device. 
     A gateway setup tool according to the present invention includes a setup data inputting section setting up groups of objects representing a system A and a system B, respectively, a system A object setup database holding object data of the system A which is set up by the setup data inputting section, a system A object data processing section receiving data from the system A object setup database, compressing the data, and returning it, an all system A object database including model data of an object available for the system A which exchanges data with the system A object setup database, a system B object setup database holding object data of the system B which is set up by the setup data inputting section, a system B object data processing section receiving data from the system B object setup database, compressing the data, and returning it, an all system B object database including model data of an object available for the system B which exchanges data with the system B object setup database, a mapping setup database holding mapping data for mapping which is set up by the setup data inputting section, a mapping data processing section receiving data from the mapping setup database, compressing the data, and returning it, an all mapping database including model data of mapping between an object available for the all system A object database and an object available for the all system B object database, and exchanging data with the mapping setup database, a mapping generating section performing mapping between each data of the system A object setup database and each data of the system B object setup database with reference to the all mapping database, and transmitting it to the mapping setup database, a setup data displaying section displaying data as needed of the system A object setup database, the system B object setup database, the mapping setup database, the all system A object database, the all system B object database, or the all mapping database, and a setup data transmitting and receiving section for exchanging data among the system A object setup database, the system B object setup database, and the mapping setup database. Then, the gateway setup tool transmits and receives data to and from the gateway apparatus through the setup data transmitting and receiving section. 
     In addition, it is configured to assign supplemental information for mapping to object setup data of one of the system A object setup database and the system B object setup database, so that the mapping generating section generates mapping data between objects based on the supplemental information. 
     In addition, it is configured to exchange data written in a structured data description language with the gateway apparatus. 
     In addition, it is configured to exchange data written in a structured data description language with the gateway setup tool. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a conceptual view illustrating mapping of intermediate models between systems according to a first embodiment of the present invention; 
         FIG. 2  is a structural view illustrating mutually used systems and an intermediate model in concrete according to the first embodiment; 
         FIG. 3  is a diagram illustrating a mapping display window of intermediate object components according to the first embodiment; 
         FIG. 4  is a structural view illustrating mutually used systems and an intermediate model in concrete according to a second embodiment of the present invention; 
         FIG. 5  is a structural view illustrating mutually used systems and an intermediate model in concrete according to a third embodiment of the present invention; 
         FIG. 6  is a block diagram of a gateway apparatus and a gateway setup tool according to a fourth embodiment of the present invention; 
         FIG. 7  shows an example of data in an all object database of the gateway setup tool according to the fourth embodiment of the present invention; 
         FIG. 8  shows an example of data in an all mapping database of the gateway setup tool according to the fourth embodiment of the present invention; 
         FIG. 9  is a block diagram illustrating connection types between the gateway apparatus and the gateway setup tool according to the fourth embodiment of the present invention; 
         FIG. 10  shows an example of data in a system A object setup database, a system B object setup database, a mapping setup database of a gateway setup tool according to a fifth embodiment of the present invention; 
         FIG. 11  is a flow chart illustrating an automatic mapping generation procedure in the gateway setup tool according to the fifth embodiment of the present invention; 
         FIG. 12  shows an example of the system A object setup data and the system B object setup data in the gateway setup tool which are written in a structured data description language according to a sixth embodiment of the present invention; and 
         FIG. 13  shows an example of the mapping setup data in the gateway setup tool which is written in the structured data description language according to the sixth embodiment of the present invention. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Embodiment 1. 
     A first embodiment of the present invention will be discussed below with reference to  FIG. 1 ,  FIG. 2  and  FIG. 3 .  FIG. 1  is an explanatory block diagram of a system for implementing inter-network mapping performed between different networks according to the present invention. 
     The figure shows a BACnet system  105  and a LON system  107  as an example of networks to be connected to each other. These are objects as real entities. 
     Mapping and connecting these systems mutually means that setting up an inter-object mapping  111 , or establishing a correspondence between a BACnet object  106  defined by the BACnet system  105  and a LON object  108  defined by the LON system  107 . 
     With this embodiment, a shared concept, a characteristic, an original model or the like of these systems as real entities is used and introduced to establish an intermediate model  102  as an unreal and virtual model. A setup of mapping of an object of each network system is not performed directly between the real BACnet object  106  and the real LON object  108  by themselves, but performed to an intermediate model object  103  defined by this intermediate model  102 . For example, the BACnet object  106  is not mapped directly to the LON object  108 , but to the intermediate model object  103  (step  109 ). (Hereinafter, a step is used to express such an operation.) Similarly, the LON object  108  is not directly mapped to the BACnet object  106 , but to the intermediate model object  103  (step  110 ). As a result, the BACnet object  106  and the LON object  108  as objects of the systems of real entities have been mapped to the shared intermediate object  103 , which establishes the setup  111  that they have been mapped to each other. 
     Next,  FIG. 2  shows a concrete example in a very simple format. 
     Note, a BACnet system  207  and a LON system  214  are adopted as before as systems as real entities. Although an intermediate model  201  established based on these systems is configured similar to the object of the LON system here since the substance of the apparatus is f considered, it is an original model. 
     First, a description will be given assuming that mapping is performed to the intermediate model  201  from the BACnet system  207 . It is assumed that with a Binary Output object  208  with ID=10 which is a BACnet object, a Present Value property  209  is mapped to an Operating Status property  203  of an air conditioner  202  which is an intermediate model object on a property basis (step  220 ). Similarly, Present Value  211  of a Binary Output object  210  with ID=11 is mapped to an Operating Status  206  of a lighting device  205  (step  221 ). Present Value  213  of a Multistate Output object  212  is mapped to an Operation Mode  204  of the air conditioner  202  (step  222 ). This completes a setup on the BACnet side. 
     Then, mapping is performed to the intermediate model  201  from the LON system  214 . It is assumed that an Air Conditioner object  215  with ID=5001, an LON object, is mapped to an air conditioner  202  of an intermediate model object on an object basis (step  223 ). Similarly, a lighting device  218  of an LON object is also mapped to the lighting device  205  of an intermediate model object on an object basis (step  224 ). 
     For an object based mapping, a property level mapping is performed collectively in objects. As a result, a Start/Stop property  216  and an Operation Mode property  217  of the air conditioner  215  of an LON object are mapped, respectively, to the Operating Status property  203  and the Operation Mode property  204  of the air conditioner  202  of an intermediate model object. Similarly, a Light-On/Light-Off property  219  of the Lighting Device object  218  is mapped to the Operating Status property  206  of the Lighting Device object  205  (step  224 ). This completes a setup also on the LON side. 
     After completing the setup on each side, a setup of mapping between real entity objects, i.e., a BACnet object and an LON object here, is obtained based on a setup status on the intermediate model  201 . With the air conditioner  202  of an intermediate model object, the Present Value property  209  of the Binary Output  208  in a BACnet object and the Start/Stop property  216  of the air conditioner  215  in an LON object are mapped to the Operating Status property  203 . This proves that the Present Value property  209  of the Binary Output  208  in a BACnet object and the Start/Stop property  216  of the air conditioner  215  in an LON object have been mapped consequently to each other in real term (step  225 ). Similarly, it is proved that the Present Value  211  of the Binary Output  210  is mapped to the Light-On/Light-Off property  219  of the lighting device  218  (step  226 ), and the Present Value  213  of the Multistate Output  212  is mapped to the Operation Mode property  217  of the air conditioner  215  in real term (step  227 ). 
     Alternatively, such a setup of mapping may be performed through a setup window  301 , for example, like one example shown in  FIG. 3 . 
     Specifically, with reference to the figure, it is a possible method that a content  302  of an intermediate model, a content  306  of a BACnet object, and a content  309  of an LON object are displayed, and then a corresponding object (at the instance level. Alternatively, a class level mapping may be applied.), a corresponding property, or the like is selected from among those. For example, a BACnet object  308  is mapped to an intermediate model object  304 , and an LON object  310  is mapped to the intermediate model object  304 . As a result, the BACnet object  308  and the LON object  310  will be mapped to each other. The mapping setup window  301  may display at the same time objects of both network systems which are wished to be mapped to each other like the example shown in the figure. Alternatively, however, each one of the objects may be displayed at a time for the purpose of allowing the engineer in each network system to make a setup easier. Still alternatively, an input method in the form of chart or the like may be used other than the GUI based setup window introduced here. 
     Thus, the intermediate model and its constituent intermediate objects, and the system and its system components are displayed on the same window. As a result, it is effective in making mapping much easier. 
     Note that the intermediate model of the present invention may be placed inside a gateway apparatus and involved even in the execution of a gateway function. Alternatively, however, it may be equipped on a setup tool, which is provided separately from the gateway apparatus, for making various types of setups for the gateway apparatus so that the gateway apparatus is allowed to have minimum required functions for executing the gateway functions only. In this case, it becomes possible to provide a higher performance and lower-cost gateway apparatus. 
     Another possible approach is that when two systems A and B exchange data with each other, for example, the system A starts to convert it into the intermediate object of the intermediate model and then transmits it, and then the other system B only uses it. This is effective in the case where a subordinate layer system uses data of a host system. Still alternatively, a time gap may exist between setting and using instead of them being done at exactly the same time. Still more, another possible approach is that an intermediate object which has been set up by the system A is set up in advance for use or will be set up at a later time by the system B, and then shortly after data is set up, the intermediate object transits item data. 
     Furthermore, although a description has been given above in the case where the system starts to set up the intermediate object, another possible approach is that the intermediate model is setup first and then mapping is made to the systems A and B from the intermediate model, and in other words, a correspondence is established between the systems in advance based on the intermediate model. In this case, data is exchanged via the intermediate model at the time of setup, but it is allowed during the operation of the systems to exchange data directly between the systems. 
     Only to exchange data directly, or only to retrieve an intermediate object, including this case, it is enough that a gateway apparatus has a simple configuration including such as a table. Then, exclusively for mapping, a separately provided setup tool may be used. 
     Thus, according to this implementation system of mapping between different networks, the intermediate model  102  is established through modeling based on the concept and property shared by the network systems  105  and  107  to be mapped, or using an original model. Then, each of the systems  105  and  107  performs mapping exclusively to the intermediate model  102 . Consequently, the BACnet object  106  of the BACnet system  105  which is one of the network systems mapped to the shared object  103  of the intermediate model and the LON object  108  of the LON system  107  which is the other system are mapped to each other. This allows any engineer to set up mapping even if he/she does not have full knowledge about the both network systems. 
     In addition, even if a change occurs at one of the network systems, the change will not affect the setup information of the other network system. 
     Additionally, by the method of mapping with the view of the intermediate model  102  being provided and the view of each network  105 ,  107  being established, the mapping may be performed further with ease. 
     Embodiment 2. 
     A second embodiment of the present invention will be discussed below with reference to  FIG. 4 . As cited in the first embodiment, a BACnet system  408  and a LON system  410  will be cited also here as the network systems of real entities. 
     Based on the first embodiment, a BACnet object  409  and a LON object  411  will be mapped to each other in the case where they are mapped to a shared intermediate model object when they are mapped to an intermediate model  402 . However, it is also possible to map the real entities to each other not by thus mapping to an intermediate model object which is completely in agreement therewith or a shared or common object alone, but by another method. Specifically, different intermediate model objects are setup temporarily, and these intermediate models are combined based on those pieces of mapping information. After the intermediate models are combined, the real entities are to be mapped to each other. 
     More specifically, it may be accomplished, even if the intermediate model is not completely in agreement therewith, by mapping between ones whose parents are in the same class, whose properties agree more than a given rate (for example, 80% or more), or the like. For example, since the properties of intermediate model objects  403  and  405 , and the properties of intermediate model objects  404  and  406  agree more than a given rate, respectively, it is assumed that they are to be mapped to each other, respectively. In this case, the BACnet object  409  which is mapped through mapping  412  to the intermediate model object  403  and the LON object  411  which is mapped through mapping  413  to the intermediate model object  405  are to be mapped to each other through mapping  414  after the intermediate model objects  404 ,  406  and the intermediate model objects  403 ,  405  are combined, respectively. 
     Thus, according to the implementation system of mapping between different networks of this embodiment, when each network system  408 ,  410  of a real entity performs mapping to the middle model  402 , even if the objects  409 ,  411  of the respective network systems have been mapped differently from each other to the intermediate model objects  403 ,  405 , respectively, mapping is performed based on similarity between the intermediate model objects  403  and  405 . As a result, a simpler and easier setup may be performed. Hence, it becomes possible to aim at reduction of engineering cost. 
     Embodiment 3. 
     A third embodiment of the present invention will be discussed below with reference to  FIG. 5 . As cited in the first and second embodiments, a BACnet system  505  and a LON system  510  will be cited also here as the network systems of real entities. 
     Based on the first and second embodiments, if a BACnet object  506  and a LON object  511  are mapped to an intermediate model  502  so as to obtain mapping  517  between the real entities, the mapping information is to be obtained based on the condition that they have been mapped to a shared intermediate model object, or that they have been mapped to different intermediate model objects to which the respective objects have been mapped, respectively. According to this embodiment, however, in addition to that, supplementary information assigned individually to the objects of the network systems of the real entities is employed. Note that the intermediate model may be handled through the method of the first embodiment or that of the second embodiment.  FIG. 5 , specifically, shows the case of using the method of the first embodiment. This supplemental information is defined as information that is used to characterize the entity of each object and map the network systems to each other. 
     Note, for example, that installation location information is used as the supplemental information in the example shown in  FIG. 5 . This supplemental information specifies the location where the objects to be combined have been installed. As the supplemental information of the BACnet object  506 , installation location  507  has a value of “Meeting Room A”. Similarly, it is assumed that installation location  509  of the BACnet object  508  has a value of “Meeting Room B”. Installation location  512  of the LON object  511  has a value of “Meeting Room A”. Installation location  514  of the LON object  513  has a value of “Corridor”. Mapping information between the objects of the real entities are obtained based on those pieces of information in addition to the same method as that of the first embodiment. In FIG.  5 , it seems that the BACnet object  506  and the LON object  511 , which are mapped to a shared intermediate model object  503 , have been mapped to each other. However, if the supplemental information of those objects is obtained, it is known that they share the installation location of “Meeting Room A”. This also proves that this is an appropriate mapping. 
     Note that, as the supplemental information, other than the installation location (Room Name, Room Number, Space Name (Corridor, Stair Landing, Shared Space, etc.), Floor Number, Section Number, Direction, etc.) shown in  FIG. 5 , the use of Device Model/Model Name, Model Number, Used Scene (normal, emergency, breakdown, etc.), Specific Sign or ID Number defined assigned to each article or the like may be effective. 
     Thus, according to the implementation system of mapping between different network systems of this embodiment, the supplemental information for mapping between the objects of the network systems  505  and  510  is defined, the supplemental information is assigned to the respective objects of the network systems  505  and  510 , and mapping is performed in consideration of this supplemental information. This allows a more precise mapping to be generated, and also mapping appropriateness to be judged. In addition, since each object is assigned the supplemental information and mapping is performed based on this information, supplemental information based analogy becomes possible even if it is separated from the intermediate model as a result of failing to make an initially established mapping assumed to the intermediate model  502  which is caused by an operational change in the network systems  505  and  510  or the like. Thus, it becomes possible to analogize and maintain the relation of mapping between the network systems  505  and  510 . Hence, it becomes possible to aim at reduction of engineering cost. 
     Thus, with the supplemental information added, there is an effect of providing a more precise matching when component data of other systems is used. 
     Note, even with the first and second embodiments, that XML (short for extensible Markup Language) as a structured data description language may be used for a simpler description when mapping to an intermediate model or an intermediate object, which will be discussed in detail in the following embodiments. 
     Embodiment 4. 
       FIG. 6  is a block diagram of a gateway apparatus and a gateway setup tool according to a fourth embodiment of the present invention. 
     With referring to the figure, it is composed of a system A  601 , a system B  602  which is built on a protocol different from that on which the system A  601  is built, and a gateway apparatus  603  which connects the system A  601  and the system B  602 . 
     The gateway apparatus  603  is composed of a setup data transmitting and receiving section  604 , a system A object database  605  holding data on various devices connected to the system A  601  and various objects to be monitored and controlled and the like by the system A  601 , a system B object database  606  holding data on various devices connected to the system B  602  and various objects to be monitored and controlled and the like by the system B  602 , a mapping database  607  showing correspondence among those databases, a mapping executing section  608 , a system A communicating section  609 , and a system B communicating section  610 . The information in the various databases is stored in a memory portion of the gateway apparatus  603 . 
     Also, a gateway setup tool  611  is provided for an external setup of the object data and the mapping data of the gateway apparatus  603 . 
     The gateway setup tool  611  is composed of a setup data inputting section  613  as a user interface  612 , a setup data displaying section  614 , an all system A object database  615 , a system A object processing section  616 , a system A object setup database  617 , an all system B object database  618 , a system B object processing section  619 , a system B object setup database  620 , an all mapping database  621 , a mapping generating section  622 , a mapping data processing section  623 , a mapping setup database  624 , and a setup data transmitting and receiving section  625 . The information in the various databases is stored in a memory portion of a computing device that implements the gateway setup tool  611 . 
       FIG. 7  shows an example of data in the all system A object database  615  and the all system B object database  618  in the gateway setup tool  611  according to a fourth embodiment of the present invention. 
     The figure shows a Logical Value object  701  and an Integer Value object  702  in the all system A object database  615 . The all system B object database  618  includes an Air Conditioner object  703  and a Lighting Device object  704 . 
     More specifically, the Logical Value object  701  has a property called Current Value, an available value of which is 0 or 1. Then, the Air Conditioner object  703  has two properties called Start/Stop and Operation Mode, the available values of which are “Start or Stop” and “Cooling or Heating or Drying”, respectively. 
       FIG. 8  shows an example of data of the all mapping database  621  in the gateway setup tool  611  according to the fourth embodiment of the present invention. 
     The figure shows a Logical Value object  801 , an Integer Value object  802 , an Air Conditioner object  803 , and a Lighting Device object  804 . 
     As shown in the figure, the Logical Value object  801  and the Integer Value object  802  correspond to the Air Conditioner object  803 , respectively. 
     More specifically, the Current Value property of the Logical Value object corresponds to the Start/Stop property of the Air Conditioner object, and the Current Value property of the Integer Value object corresponds to the Operation Mode property of the Air Conditioner object. 
     Furthermore, with referring to the value of each property, values 0, 1 of the Current Value property of the Logical Value object  801  correspond to Stop and Start, respectively, of the Start/Stop property of the Air Conditioner object  803 . Values 0, 1, and 2 of the Current Value property of the Integer Value object  802  correspond to Cooling, Heating, and Drying, respectively, of the Operation Mode property of the Air Conditioner object  803 . 
     An operation will be discussed with reference to  FIG. 6  to  FIG. 8 . 
     First, an operation will be discussed with reference to  FIG. 6  in the case where the system A  601  starts to communicate with the system B  602  for control. 
     With referring to the figure, a communication command of the system A  601  transmitted from the system A  601  and reached the gateway apparatus  603  is received by the system A communicating section  609 , where the content of the communication is interpreted. Then, it is acknowledged that the content indicates a control from the system A  601  to the system B  602 . Then, this control data is written into the system A object database  605 . 
     The mapping executing section  608  searches the mapping database  607  for object of the system B  602  which corresponds to the system A object database  605  into which the control data has been written. Then, the mapping executing section  608  writes the control data of the system B  602  corresponding to the control data of the system A  601  obtained with reference to the mapping database  607  into the system B object database  606 . 
     The system B communicating section  610  creates a communication command of the system B  602  corresponding to the system B object database  606  into which the data has been written, and outputs it to the system B  602 . 
     Thus, the communication for control is performed from the system A  601  to the system B  602 . 
     Note that a communication performed from the system B  602  to the system A  601  is carried out through the route in a reverse way to that discussed above. 
     Next, a method for setting up the system A object database  605 , the system B object database  606 , and the mapping database  607  which are used for such a communication will be discussed with reverence to  FIG. 7  and  FIG. 8 . 
     With the gateway setup tool  611 , the data of various devices connected to the system A  601 , the data of various objects to be monitored and controlled by the system A  601  and the like are inputted to the system A object setup database  617  through the setup data inputting section  613 . Also, through the same inputting section, the data of various devices connected to the system B  602 , the data of various objects to be monitored and controlled by the system B  602  and the like are inputted to the system B object setup database  620 . Furthermore, through the same inputting section, information on correspondence between those databases is inputted to the mapping setup database  624 . 
     Alternatively, however, information on the all system A object database  615  and the all system B object database  618  which are provided in the gateway setup tool  611  in advance, like the one shown in  FIG. 7  for example, may be used. Specifically, the all system A object database  615  is a database for the model data of various objects which are available in the system A  601 , and the information of the all system B object data base  618  is a database for the model data of various objects which are available in the system B  602 . 
     Similarly, information on the all mapping database  621  which is model data for mapping between the system A  601 -the system B  602 , like one shown in  FIG. 8  for example, may be used. 
     Still alternatively, when these pieces of data is inputted, setup information of the system A object setup database  617 , the system B object setup database  620 , and the mapping setup database  624 , the information of the input status thereof or the like may be provided by means of the setup data displaying section  614  so as to help a setter input those items of data. 
     Data thus inputted to the system A object setup database  617 , the system B setup database  620 , and the mapping setup database  624  is usually complied to be intelligible to the setter. Or, all correspondence elements are held in the form as they are. For that reason, it is in many cases redundant as data to be held in the execution environment on the gateway apparatus  603 . 
     A real system includes many devices, and therefore information on correspondence which is provided individually for each device such as the Logical Value object  804  and a Lighting Device object  805  shown in  FIG. 8  is required. Specifically, information for identifying the individual of each device, such as a Logical Value Object  5002  and a Lighting Device Object  2001 , and a Logical Value Object  5004  and a Lighting Device Object  2002 , is required at the same time. That means information to be held may be indicated as (a Logical Value,  5002 , a Current Value) v. (a Lighting Device,  2001 , Light-On/Light-Off), (a Logical Value,  5004 , a Current Value) v. (a Lighting Device,  2002 , Light-On/Light-Off) and so on. However, a relationship (a Logical Value, a Current Value) v. (a Lighting Device, Light-On/Light-Off) is common through all the devices and therefore it is redundant to hold the information including repetitions of these through all the devices. 
     As a solution, the relationship (a Logical Value, a Current Value) v. (a Lighting Device, Light-On/Light-Off) is held only once, and then the correspondence of individual identification information, that is, ( 5002 ,  2001 ), ( 5004 ,  2002 ) and so on may be held separately. This allows a total amount of information to be compressed. 
     Thus, the system A object processing section  616 , the system B object processing section  619 , the mapping data processing section  623  normalize the inputted system A object setup database  617 , system B object setup database  620 , and mapping setup database  624  in order to minimize the redundancy of data to be held on the gateway apparatus  603 , and transform them into the form of minimum required data in order to operate in an execution environment. 
     The system A object setup database  617 , the system B object setup database  620 , and the mapping setup database  624  transformed into data ideal for the execution environment on the gateway apparatus  603  through those components are transmitted to the gateway apparatus  603  by the setup data transmitting and receiving section  625 , and received by the setup data transmitting and receiving section  604  on the gateway apparatus  603 . 
     The system A object setup database  617 , the system B object setup database  620 , and the mapping setup database  624  received are held on the gateway apparatus  603  as the system A object database  605 , the system B object database  606 , and the mapping database  607 , respectively, to be used for a mutual communication between the system A  601  and the system B  602 . 
     Note that, if the above mentioned procedure is reversed, the system A object database  605 , the system B object database  606 , the mapping database  607  on the gateway apparatus  603  are transmitted to the gateway setup tool  611  by the setup data transmitting and receiving section  604 . Then, the setup data transmitting and receiving section  625  of the gateway setup tool  611  places received data in the system A object setup database  617 , the system B object setup database  620 , the system B object setup database  620 , and the mapping setup database  624 , respectively. Then, they are presented to the setter by the setup data displaying section  614 . This allows the current setup status of the gateway apparatus  603  to be acquired and displayed. 
     Note that by further repeating the set up operation in this current setup status, it is possible to change and update the setup. 
     Still more, the mapping setup database  624  may be generated automatically by the mapping generating section  622  by using the information of the all mapping database  621  which is the model of mapping, the information of such as the system A object setup database  617  and the system B object setup database  620  which have been set up in agreement with the current system, and the like. 
     Next,  FIG. 9  is a simplified diagram illustrating connection types between the gateway apparatus  603  and the gateway setup tool  611  according to the fourth embodiment of the present invention. 
     Specifically,  FIG. 9(   a ), ( b ) show simplified views, respectively, of a connection type using a physical medium which is different from the respective systems and a connection type using the same physical medium. Portions which are the same as or equivalent to those of  FIGS. 6 through 8  are assigned the same numerals as those, and will not be discussed here. 
     The figure shows building management systems  901 ,  911 , building management devices  902 ,  912 , LANs (short for Local Area Network)  903 ,  913 , gateway setup tools  904 ,  914 , gateway apparatuses  906 ,  915 , an interface  905  for connecting the gateway apparatus and the gateway setup tool, equipment systems  907 ,  916 , equipment network systems  908 ,  917 , air conditioners  909 ,  918 , lighting devices  910 ,  919 . The figure also shows a first protocol  920  and a second protocol  921  which are different from each other. 
     Note that the connection type shown in  FIG. 9(   b ) may be configured, as one example, by using Ethernet (registered trade name) as the LAN  913 , BACnet (short for A Data Communication Protocol for Building Automation and Control Networks) as the first protocol  920  connecting the building management system  911  and the gateway apparatus  915 , and HTTP (short for Hyper Text Transfer Protocol) as the second protocol  921  for connecting the gateway setup tool  914  and the gateway apparatus  915 . 
     Note also that, with the connection type of  FIG. 9(   b ), it is also possible that the gateway setup tool  914  obtains the system information of the building management system  911 , that is, information corresponding to the system A object data  605  or the system A object setup data  617  in  FIG. 6 , directly from the building management system  911  with no involvement of the gateway apparatus  915 . 
     With either one of the connection forms of  FIG. 9(   a ), ( b ), in the case where a protocol on which the building management system  911  is built is differ from that on which the gateway setup tool  914  is built, an original protocol for direct transfer may be used for data transfer. Then, if it is the same protocol, of the protocol is the same, that protocol or the original protocol may be used. 
     Thus, with the gateway apparatus according to the fourth embodiment of the present invention, it is allowed that the data of a system to be connected is created by the gateway setup tool  611  which is provided outside of the gateway apparatus  603  and exchanged. As a result, it becomes possible to provide the gateway apparatus which may be flexible in handling a change in a system to be connected, a change in mapping specification or a change in mapping algorithm with no involvement of updating software in the gateway apparatus. 
     In addition, it becomes unnecessary to perform a complicated operation on the gateway apparatus such as the process of generating and updating mapping information based on setup data. For that reason, an MPU (short for Micro Processor Unit) or memory which is built in the gateway apparatus is not necessarily highly efficient. Hence, it becomes possible to provide the gateway apparatus whose development cost, engineering cost, and hardware cost are held down low. 
     In addition, by thus separating the gateway setup tool  611  from the gateway apparatus  603  which performs communication between the system A  601  and the system B  602 , the design flexibility of the gateway setup tool  611  is enhanced. As a result, a sophisticated user interface is allowed to be provided privately. Hence, it becomes possible to provide the gateway setup tool  611  whose setting efficiency is enhanced and engineering cost is held down low. 
     In addition, by thus using the mapping generating section  622  for generating mapping data, it becomes possible to carry out a setup operation easily with no need of full knowledge about the systems on both sides to be connected including correspondence. Hence, it becomes possible to provide the gateway setup tool  611  whose engineering cost is reduced. 
     Note that although the interface  905  is separated from the gateway apparatus  906  in  FIG. 9 , it may alternatively be built in the gateway apparatus  906 . 
     As mentioned above, it is allowed that the data of a system to be connected is created by the gateway setup tool which is provided outside of the gateway apparatus and exchanged. As a result, it becomes possible to provide the gateway apparatus which can be flexible in handling a change in a system to be connected, a change in mapping specification or a change in mapping algorithm with no involvement of updating software in the gateway apparatus. 
     In addition, it becomes unnecessary to perform a complicated operation on the gateway apparatus such as the process of generating and updating mapping information based on setup data. For that reason, an MPU or memory which is built in the gateway apparatus is not necessarily highly efficient. Hence, it becomes possible to provide the gateway apparatus whose development cost, engineering cost, and hardware cost are held down low. 
     In addition, by thus separating the gateway setup tool from the gateway apparatus, the design flexibility of the gateway setup tool is enhanced. Accordingly, with a sophisticated user interface provided privately, it becomes possible to provide the gateway setup tool whose engineering cost is held down low. 
     Embodiment 5. 
     A fifth embodiment of the present invention relates to mapping generation performed by the gateway setup tool. 
       FIG. 10  shows an example of automatic mapping generation in which supplemental information for mapping is added to the setup data of each object according to the fifth embodiment of the present invention. Portions which are the same as or equivalent to those of the fourth embodiment are assigned the same numerals as those, and will not be discussed here. 
     With referring to the figure, the system is composed of a system A object setup database  1001 , a mapping setup database  1002  and a system B object setup database  1003 . It further includes Logical Value objects  1004 ˜ 1007 , Integer Value objects  1008 ,  1009 , Air Conditioner objects  1010 ,  1011 , and Lighting Device objects  1012 ,  1013 . 
     With the system A object setup database  1001 , the Logical Value objects with object numbers= 5001 ,  5002 ,  5003 ,  5004  and the Integer Value objects with object numbers= 5101 ,  5102  are defined. With the system B object setup database  1003 , the Air Conditioner objects with unit numbers= 1401 ,  1402 , and the Lighting Device objects with unit numbers= 2001 ,  2002  are defined. 
     Note that a black circle ● is marked, in the figure, at the front of the property of minimum required information as an object representing a device or a object to be monitored and controlled. 
     Besides that, a black square ▪ is marked at the front of the Installation Location property as the supplemental information of each object. The value of this property is to include information identifying where in the article a device or an object to be monitored and controlled which is represented by each object is installed. 
     Specifically, with the Air Conditioner object  1010  having the unit number  1401 , for example, information identifying that it is an object representing a device which is installed in “J201” is to be added. With the Logical Value object  1006  having the object number  5003 , information identifying that it is an object representing an object to be monitored and controlled which is installed in “J202” is to be added. 
     Next, a procedure for generating mapping will be discussed based on groups of the objects of both the system A and the system B which are provided with supplemental information. 
       FIG. 11  is a flow chart illustrating an example of a procedure for mapping generation performed by the gateway setup tool. The procedure will be discussed with reference to the figure. 
     It is assumed here that objects of the system A are objects to be monitored and controlled and objects of the system B are device objects. Then, a description will be given in the case where the former is mapped sequentially to the latter. Note that even if they are in opposite relation or they map to each other, the result is the same. 
     First, when the operation starts (step  1101 ), unmapped objects are retrieved sequentially among system B objects (step  1102 ). If all the mapping has already been completed, then the process jumps to the end (step  1110 ). 
     In the case where an unmapped object exists, then the unmapped object is retrieved (step  1103 ), and the supplemental information of the retrieved object is obtained (step  1104 ). 
     A series of those steps correspond to retrieving the Air Conditioner object with the unit number= 1401  and obtaining the information of “Installation Location=J201” in  FIG. 10 . 
     Then, unmapped system A objects whose supplemental information is in agreement with it are retrieved in numerical order (step  1105 ). This step corresponds to retrieving the Logical Value objects with the object numbers= 5001 ,  5002 , and the Integer Value objects with the object number= 5101 , both having “Installation Location=J201” in  FIG. 10 . 
     Now, a search is made to check whether mapping database information corresponding to a currently processed system B object exists or not (step  1106 ). In the case where the mapping database information exists, then the class/property information of the system A corresponding to each property is obtained from the mapping database (step  1107 ). 
     Those steps correspond to obtaining the information identifying that the Start/Stop property of the air conditioner  803  corresponds to the Current Value property of the Logical Value object  801 , and also obtaining information identifying that the Operation Mode property corresponds to the Current Value property of the Integer Value object  802  in  FIG. 8 . 
     Next, objects which are in agreement with the condition of the obtained class/property of the system A are retrieved in numerical order, and mapping setup data is generated (step  1108 ). This step corresponds to starting to search retrieved objects in agreement with the installation location in numerical order, with respect to the Start/Stop property of the Air Conditioner object with the unit number= 1401 , for an object which is in agreement with the correspondence information of (an air conditioner, Start/Stop) v. (a logical value, a current value) which is obtained from the mapping database in  FIG. 10 . The Current Value property of the Logical Value object with the object number= 5001  is mapped thereto. 
     Continuously, it is found from the correspondence information of (an air conditioner, Operation Mode) v. (an integer value, a current value) obtained from the mapping database that the Current Value property of the Integer Value object with the object number= 5101  is mapped to the Operation Mode property. 
     When a mapping generation of mapping setup data is completed for one of the system B objects in this manner, the same is repeated for a next object of the system B objects until no unmapped object exists. 
     In the case where no mapping database information exists as a result of searching for mapping database information corresponding to a currently processed system B object (step  1106 ), a comparison is drawn between the data type information of each property of the system B object and the data type information of each property of a system A objet which has been retrieved under the condition that the supplemental information is in agreement with it. Then, they are mapped to each other in order of agreement to generate mapping setup data (step  1109 ). 
     Thereafter, the same is performed as that in the case where mapping database information exists. When all the mapping setup data is generated in this manner, such a correspondence as that shown in  FIG. 10  is to be established. 
     Thus, according to the gateway setup tool of the fifth embodiment of the present invention, the supplemental information for mapping objects between the system A and the system B to be connected is defined, and the supplemental information is assigned, respectively, to the object setup data of the system A and the system B so as to generate mapping data between objects. As a result, if the supplemental information is system independent on such as installation location, for example, then it is allowed to perform a setup operation easily with no need of full knowledge of the systems A and B on both sides including correspondence. Hence, it becomes possible to provide the gateway setup tool whose engineering cost is reduced. 
     Note that it is possible to handle objects which are not available for mapping through error detection caused by indecency in setup information or the like. Alternatively, however, there is another possible method applicable to that case as well. Specifically, a default correspondence between objects on both sides is held in advance like the mapping database, and when the object of one system is set up, the corresponding object of the other system is automatically generated. 
     As discussed above, the supplemental information for mapping objects between the systems A and B to be connected is defined, and then assigned, respectively, to the object setup data of the systems A and B so as to generate mapping data between the objects. In addition, it is designed that the supplemental information is system independent. As a result, it is allowed to perform a setup operation easily without the need of full knowledge of the systems A and B on both sides including correspondence. Hence, it becomes possible to provide the gateway setup tool whose engineering cost is held down low. 
     Embodiment 6. 
       FIGS. 12 and 13  show examples of object setup data and mapping setup data, respectively, written in a structured data description language in the gateway setup tool according to a sixth embodiment of the present invention. 
     In both cases of  FIGS. 12 and 13 , the description is give in XML (short for extensible Markup Language) as a structured data description language. Then, it is expressed in the form of “a property name=a property value” with each tag having an object name such as a logical value, an integer value, an air conditioner and a lighting device, and each attribute having a property name and a property value of each object. 
     The figures each show system A object setup data  1201  written in XML, a structured data description language, system B objet setup data  1202  written in XML in a structured data description language, a Logical Value object  1203  written in XML, a structured data description language, an Integer Value object  1204  written in XML, a structured data description language, an Air Conditioner object  1205  written in XML, a structured data description language, mapping setup data  1301  written in XML, a structured data description language, and mapping data  1302  written in XML, a structured data description language. 
     For example, the Logical Value object  1203  written in XML, a structured data description language, of  FIG. 12  represents that “the value of the Current Value property of the Logical Value object for object number= 5001  is 1, and the value of the Installation Location property is J201”. The Air Conditioner object  1205  written in XML, a structured data description language, represents that “the value of the Start/Stop property of the Air Conditioner object for the unit number= 1401  is Start, and the value of the Operation Mode property is Cooling, and the value of the Installation Location property is J201”. These are shown in the form which specifies the property values and correspond to the Logical Value object  1004  and the Air Conditioner object  1010  of  FIG. 10 , respectively. 
     Similarly, the example of the mapping setup data written in a structured data description language of  FIG. 13  is equivalent to the mapping setup data which illustrates the mapping status of  FIG. 10 . 
     For example, the mapping data  1302  written in XML, a structured data description language, represents such a correspondence as (Air Conditioner,  1401 , Start/Stop) v. (Logical Value,  5001 , Current Value). 
     By thus describing the system A object setup data, the system B objet setup data, and the mapping setup data in a structured data description language, an interface or data communications between the gateway apparatus and the gateway setup tool, can be depend on the structured data description language. As a result, it becomes possible to handle various changes in data structure in a flexible manner. 
     Note that descriptions have been given specifically with XML employed so far, but that is not a must. Alternatively, however, any structured data description language may be employed other than XML, such as SGML (short for Standard Generalized Markup Language) and XHTML (short for eXtensible HyperText Markup Language). In particular, if the structured data description language which is available even for a general WEB browser or the like, it is become possible to produce the gateway apparatus and the gateway setup tool by using a generally and widely used general-purpose application program. Hence, it becomes possible to provide a gateway apparatus and a gateway setup tool whose development cost and engineering cost are reduced. 
     In addition, since the structured data description language is used for the interface between the gateway apparatus and the gateway setup tool, it is become possible to produce the gateway apparatus and the gateway setup tool by using a generally and widely used general-purpose application program such as a WEB browser. Hence, it becomes possible to provide a gateway apparatus and a gateway setup tool whose development cost and engineering cost are held down low. 
     INDUSTRIAL APPLICABILITY 
     As discussed above, according to the present invention, it is provided with the intermediate model to be accessed by the other systems, and the intermediate model is provided with the intermediate object which corresponds to a component. Then, each of the systems maps a component of itself to the intermediate object and then transmits the data thereto. In addition, each system is allowed to obtain another system&#39;s component data from the intermediate object. Hence, it is effective in making the use of another system&#39;s component data easy and minimizing a possible influence of a change occurred in an item of each system on other systems.