KR100959100B1 - Method and Apparatus for arranging BACnet objects - Google Patents

Abstract

The present invention relates to an apparatus for managing a BACnet object. A first memory area having a fixed size corresponding to the BACnet objects of the fixed structure attribute and a second memory area having an adaptive size corresponding to the BACnet objects of the variable structure attribute are set, and the BACnet object is managed using an index.

BACnet objects, objects, mutable structures

Description

Device and method for managing objects {Method and Apparatus for arranging BACnet objects}

The present invention relates to a method for managing a BACnet object having a variable structure in an embedded BACnet device.

BACnet objects defined in BACnet have various types of attribute information. The attribute information may be a simple form such as one numerical information or a complex form having a variable structure in size and structure. In some cases, this may be in the form of a list of these.

Since the BACnet devices used in the building automatic control system are embedded systems, a systematic and efficient method for managing objects having various attribute information suitable for the characteristics of the embedded system is required.

BACnet objects defined in BACnet have various types of attribute information. The attribute information may be a simple form such as one numerical information or a complex form having a variable structure in size and structure. In some cases, this may be in the form of a list of these.

Since the BACnet devices used in the building automatic control system are embedded systems, a systematic and efficient method for managing objects having various attribute information suitable for the characteristics of the embedded system is required.

Conventional BACnet object implementation methods include a fixed structure object implementation method and a variable structure object implementation method. However, this conventional implementation method involves the problems of dynamic allocation and indirect reference.

Therefore, in the present invention, an efficient method of managing a BACnet object in a BACnet device while solving the problems of the prior art will be presented.

The present invention is to solve the problem that the conventional fixed structure object can not include unnecessary memory usage and attribute information over a predetermined size. In addition, a memory fragmentation problem caused by frequent dynamic allocation in a conventional variable structure object and a memory leak caused by not releasing a memory area when deleting an object are solved.

The present invention solves the above problems by implementing a variable size object that secures and manages a memory for variable size attribute information in a memory area.

The method for managing a BACnet object proposed in the present invention can effectively handle BACnet objects having a large amount of variable structure by using memory in a built-in BACnet device having a limited memory capacity.

In addition, the BACnet device can be implemented more stably if the object management method using the proposed index is used instead of the memory dynamic allocation of the indirect reference method.

In a preferred embodiment of the present invention, an apparatus for managing a BACnet object of a fixed structure attribute and a variable structure attribute includes a first memory area of a fixed size corresponding to the BACnet objects of the fixed structure attribute and a BACnet object of the variable structure attribute. A memory unit including a second memory area of an adaptive size corresponding to the memory units; An index unit including an identifier of each of the BACnet objects and memory location information and size information of a BACnet object corresponding to each identifier; It includes.

According to another preferred embodiment of the present invention, a method for managing a BACnet object of a fixed structure attribute and a variable structure attribute includes a first memory area having a fixed size corresponding to the BACnet objects of the fixed structure attribute and the variable structure attribute. A memory setting step of setting a second memory area of an adaptive size corresponding to BACnet objects; Generating an index table matching the identifier of each BACnet object and memory location information and size information of the BACnet object corresponding to each identifier; It includes.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the same elements among the drawings are denoted by the same reference numerals and symbols as much as possible even though they are shown in different drawings.

In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

In addition, in order to be more faithful to the present invention, it is noted that changes or modifications can be made by those skilled in the art without departing from the spirit of the present invention.

1 (a) and (b) illustrate an existing method of implementing a BACnet object.

Conventional BACnet object implementation methods include a fixed structure object implementation method as shown in Figure 1 (a) and a variable structure object implementation method as shown in Figure 1 (b).

In the method of implementing a fixed structure object as shown in FIG. 1A, all the attribute information is contained in the object structure variable region, and no indirect reference is made. Therefore, in the fixed structure object implementation method, the structure and size of the BACnet object must be fixed in advance.

However, in this case, the memory may be unnecessarily used by fixing the structure or size of the object in advance, and there is a problem that the attribute information cannot be included beyond the fixed size.

In the method of implementing a variable structure object as illustrated in FIG. 1A, attribute information may be included in an object structure variable region, and some attribute information exists outside the object structure variable region. Thus, object structure variables contain references to externally existing attributes, and indirect references are made.

In the case of the variable structure object implementation method, some attribute information exists outside the object structure variable area so that memory is dynamically allocated and used. However, frequent memory dynamic allocation can cause memory fragmentation problems.

In addition, when the object is deleted, the memory area in which the referenced attribute value exists must be released. Otherwise, the memory leaks.

BACnet objects defined in BACnet have various types of attribute information. The attribute information may be in a simple form or in a list form that is variable in size and structure. Since the BACnet devices used in the building automatic control system are embedded systems, a systematic and efficient method for managing objects having various attribute information suitable for the characteristics of the embedded system is required.

FIG. 2 is a diagram illustrating an internal configuration of an apparatus for managing a BACnet object as a preferred embodiment of the present invention.

The apparatus for managing the BACnet object includes an index unit 200 and a memory unit 210, and the memory unit 210 includes a first memory area 220 and a second memory area 230.

The index unit 200 includes an identifier of each BACnet object and memory location information and size information of a BACnet object corresponding to each identifier. See FIG. 3 for an example of the BACnet object index unit.

The first memory area 220 includes attribute information on BACnet objects of fixed structure attributes and has a fixed size. In addition, the first memory area 220 includes a header having attribute information of the fixed structure attribute and the variable structure attribute of the BACnet object. As a specific example, the header for the configuration attribute of the schedule object is described with reference to FIG. 5 (c).

The second memory area 230 includes a header having attribute information of the variable structure attribute of the BACnet object.

3 illustrates an index table that is an example of an index unit.

The index table of the BACnet object easily indicates where the individual object information exists, and includes the identifier of each BACnet object and the memory location information and size information of the BACnet object corresponding to each identifier.

The index unit shown in FIG. 3 uses an index that classifies attributes from two viewpoints. First of all, the setting attribute refers to a property defined in advance by the user, and the real-time property refers to a property determined in the system or device. Next, they are classified according to whether the size of the attribute is fixed or variable.

4 illustrates a concept of using a memory according to the index table of FIG. 3.

The index table shown in FIG. 4 has index information on individual objects of the BACnet device. The index information of one object has setting information of the corresponding object, a start address of the real-time information area, and size information of each object. Since the BACnet device illustrated in FIG. 4 has three objects, it has three index information.

5 through 10 illustrate the concept of the present invention using a schedule object.

5 illustrates the definition of a schedule object in a BACnet object.

6 illustrates a memory area of a schedule object constructed in accordance with the present invention.

The memory area is divided into a setting property area 610 and a real time property area 620, and each of the setting property area 610 and the real time property area 620 includes a first memory area and a second memory area.

The first memory area includes header information and a fixed size attribute as a fixed size, and the second memory area includes a variable size attribute as an adaptive variable size.

7 shows header information for the setting attribute area 610 of the schedule object. The header information includes attribute information of the variable structure attribute of the BACnet object (730).

8 illustrates an example of setting a memory unit of a schedule object according to the present invention.

The memory unit is largely composed of a first memory region 810 having a fixed size attribute and a second memory region 820 having a variable size attribute. Since the schedule object has five variable size attributes, the first memory area 810 includes header information including information about an offset for each variable size attribute, a fixed size common attribute, and other fixed attributes.

The second memory area is accessed using a relative offset, and the size of the memory is adaptively set to correspond to the number of variable size attributes.

9 illustrates a method of managing variable attribute information according to the present invention.

The basic unit that handles information in BACnet is an attribute belonging to an object. In order to obtain or change a specific attribute value of an object, the following operations and corresponding information to be transmitted are required.

First, if you want to get the property value of an object when it is not an array property, the object identifier and property identifier are passed. When changing an attribute value of an object, an object identifier, an attribute identifier, and an object attribute value are transmitted.

Next, in the case of an array attribute, when an object attribute value is to be obtained, an object identifier, an attribute identifier, and an array index are transmitted. If you want to change the property value of an object, the object identifier, property identifier, object property value, and array index are delivered.

In the present invention, the variable structure attribute is structured as an array attribute.

That is, as shown in FIG. 8, the second memory area is set in a contiguous memory space in the memory unit and structured as an array attribute, and does not perform indirect reference.

The variable attribute information designated by the offset has a form as shown in FIG. 9.

First, the header portion of the attribute information for all the variable structure attributes is set to a fixed size (910). Next, in one embodiment of the present invention, the size information tagged using the method of noting the data size in BACnet as it is is composed of 6 bytes (920).

6 bytes is a value defined to hold a data size that can be represented by up to 4 bytes. If only part of the 6 bytes can be used to represent the data size, the remaining bytes are filled with specific data. In the present invention, it is filled with 0xaa as an example. In this case, the array element may have various data structures according to the type of attribute information.

10 (a) and 10 (b) show an example of managing Exception_Schedule, which is a variable size attribute of a schedule object, according to the present invention.

FIG. 10 (a) is an example of how Exception_Schedule attribute information of a representative schedule object among the variable attributes of a BACnet object is configured when located in a memory.

In FIG. 10 (a), Exception_Schedule is a list type attribute having three elements. Each element is variable in size and structure.

As can be seen in FIG. 10 (b), the three elements are all different in size, 16, 30, and 20 bytes, but the front of the attribute information is configured to sufficiently consider these things.

The invention can also be embodied as computer readable code on a computer readable recording medium. Computer-readable recording media include all kinds of recording devices that store data that can be read by a computer system. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage, and the like, which are also implemented in the form of carrier waves (for example, transmission over the Internet). It also includes. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

The best embodiments have been disclosed in the drawings and specification above. Although specific terms have been used herein, they are used only for the purpose of describing the present invention and are not used to limit the scope of the present invention as defined in the meaning or claims.

Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

1 (a) and (b) illustrate an existing method of implementing a BACnet object.

FIG. 2 is a diagram illustrating an internal configuration of an apparatus for managing a BACnet object as a preferred embodiment of the present invention.

3 illustrates an index table that is an example of an index unit.

4 illustrates a concept of using a memory according to the index table of FIG. 3.

5 illustrates the definition of a schedule object in a BACnet object.

6 illustrates a memory area of a schedule object constructed in accordance with the present invention.

7 shows header information of a schedule object.

8 illustrates an example of setting a memory unit of a schedule object according to the present invention.

9 illustrates a method of managing variable attribute information according to the present invention.

10 (a) and 10 (b) show an example of managing Exception_Schedule, which is a variable size attribute of a schedule object, according to the present invention.

Claims (14)

As a device that manages BACnet objects of fixed and variable structure attributes, A memory unit including a fixed sized first memory area corresponding to the BACnet objects of the fixed structure attribute and an adaptive sized second memory area corresponding to the BACnet objects of the variable structure attribute; An index unit including an identifier of each of the BACnet objects of the fixed structure attribute and the BACnet objects of the variable structure attribute, and memory location information and size information of a BACnet object corresponding to each identifier; Apparatus for managing a BACnet object comprising a. The memory device of claim 1, wherein the first memory area comprises: And a header having attribute information of the fixed structure attribute and the variable structure attribute of the BACnet object. The method of claim 1, wherein the second memory area is And a header having attribute information on the variable structure attribute of the BACnet object. The method of claim 1, wherein the index unit And offset information indicating a start address of a memory in which the respective BACnet objects having the variable structure attribute exist. The method of claim 4, wherein the second memory area is BACnet object management, characterized by adaptively setting the memory size corresponding to each BACnet object of the variable structure attribute based on the information in the header and the offset information of the BACnet object of the variable structure attribute Device. The method of claim 5, wherein the second memory area is And a BACnet object set in a contiguous memory space in the memory unit. The method of claim 2, wherein the attribute information is The number of BACnet objects, identification information of BACnet objects, size information on whether the size of BACnet objects is fixed or variable, and type information indicating whether the BACnet objects are designated by the user or the system. Device that manages BACnet objects. As a way to manage BACnet objects of fixed and variable structure attributes, Setting a first memory area having a fixed size corresponding to the BACnet objects of the fixed structure attribute and a second memory area having an adaptive size corresponding to the BACnet objects of the variable structure attribute; Generating an index table matching the identifiers of the BACnet objects of the fixed structure attribute and the BACnet objects of the variable structure attribute and memory location information and size information of the BACnet object corresponding to each identifier; How to manage the BACnet object, characterized in that it comprises a. The method of claim 8, wherein the first memory area is And a header having attribute information of the fixed structure attribute and the variable structure attribute of the BACnet object. The method of claim 8, wherein the second memory area is A method for managing a BACnet object, comprising a header having attribute information of the variable structure attribute of a BACnet object. The method of claim 8, wherein the index table And offset information indicating a start address of a memory in which the respective BACnet objects having the variable structure attribute exist. 12. The method of claim 11, wherein the second memory area is BACnet object management, characterized by adaptively setting the memory size corresponding to each BACnet object of the variable structure attribute based on the information in the header and the offset information of the BACnet object of the variable structure attribute How to. The method of claim 12, wherein the second memory area is The method of managing a BACnet object, characterized in that set in the contiguous memory space in the memory setting step. The method of claim 9, wherein the attribute information is The number of BACnet objects, identification information of BACnet objects, size information on whether the size of BACnet objects is fixed or variable, and type information indicating whether the BACnet objects are designated by the user or the system. To manage BACnet objects.

Images