JP2001251318A - Gateway system and information terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication unit that can absorb differences among devices so as to unifiedly read/write data. SOLUTION: The communication unit of this invention is provided with application programs 11, an operating system 12, and a communication middle ware section 13 that is interposed between them to control data transmission reception. The communication middle ware section has a device 1 connected to a network, a device access section 13b for data communication, and a virtual memory data management section 13a that instructs the device access section to transmit/receive data to/from the device. The virtual memory data management section provides a common communication procedure with respect to the applications and the applications make communication with the virtual memory data management section to attain transmission reception of data to/from the device. The device access section absorbs differences among communication protocols of respective devices.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gateway system and an information terminal.

[0002]

2. Description of the Related Art For example, in an FA system or the like,
As shown in FIG. 1, a network system in which a plurality of devices 1 are connected to a computer 2 via a network line, a serial line, or the like may be constructed. The computer 2 has an internal storage device 3 such as a main memory,
An external storage device 4 such as a hard disk is connected via each interface, and data is read and written. The device 1 includes a temperature control device, a PLC, and the like, and there is a demand to collect data such as a state of each device and a detection signal and to collectively manage the data.

Conventionally, therefore, an application program having a data collection function is incorporated in the computer 2 to collect data from the devices 1 and the storage devices 3 and 4, and if necessary, a predetermined storage device 3 or 4. To store data. At this time, the application program that performs data collection creates a communication program for each device and performs data collection.

FIG. 2 shows a relationship between an application program and a memory for storing collected data.
become that way. That is, the application program 5 incorporated in the computer 2 stores the event memory 6
The shared memory 7 is accessed to read data. The event memory 6 is installed in the communication middleware.

[0005] Further, the computer 2 often has a plurality of application programs 5.
In this case, in order for the data collected by one application program 5 to be used by another application program 5, that is, for the collected data to be shared by a plurality of application programs 5, inter-process communication and shared memory provided by the OS are required. Data is exchanged using functions.

[0006]

However, the conventional system has the following problems. First, when an access method such as a network or a communication procedure is different for each communication partner (device 1 or storage devices 3 and 4), a communication program corresponding to each system or the like is mounted, and an application program is set according to the communication partner. It is necessary to switch the communication program to be used, and the processing becomes complicated.

When sharing data, there is no means for guaranteeing the validity of the collected data.
However, there is a problem that it is not possible to know whether or not the data stored in the data is reliable data or at what point in time.

According to the present invention, when collecting and managing data with respect to a plurality of devices and storage devices, it is possible to absorb differences between the devices, read and write data in a unified manner, and share data. It is an object of the present invention to provide a gateway system and an information terminal capable of ensuring the reliability of the information.

[0009]

A gateway system according to the present invention is a gateway system mounted on a device connectable to a network. And a device access unit for performing data communication with a device that can be connected to the network, and a data management unit that instructs the device access unit to transmit and receive data to and from the device, wherein the data management unit includes: Has a function of providing a common communication procedure to the embedded application when the application is incorporated in the apparatus, and the application communicates with the data management means to transmit and receive data to and from the device. It was configured to enable.

Communication protocols and the like that differ for each device are individually handled by device access means. The application sends and receives data to and from the data management means according to a common communication procedure provided by the data management means. Since the data management means and the device access means communicate according to a predetermined procedure, the data management means transmits (writes) data to, for example, a predetermined device, In order to acquire (read) data from a device, an instruction is issued to device access means for that device.

In other words, when an application sends and receives data to and from a certain device, the application simply sends and receives data according to a common communication procedure with the data management means without being aware of the existence of the actual device. Can be transmitted and received. Further, when developing an application, it is sufficient to consider a communication procedure with the data management means, and the application can be created without being conscious of a communication protocol with various devices.

[0012] Further, an access means is provided for enabling access to the storage means provided in the apparatus in accordance with an instruction from the data management means, and the application communicates with the data management means to provide the storage means. You may comprise so that reading and writing of data with respect to a means are possible. Here, the storage unit corresponds to the shared memory 15 in the embodiment, but may be another internal storage device or an external storage device.

This configuration is preferable because data can be read from and written to the storage means provided not only in the device but also in the apparatus in accordance with a common communication procedure. Of course, such a function is not necessarily required.

In the case where such storage means is provided, additional information storage means for storing additional information relating to data to be stored in the storage means is provided, and the data management means is provided for the additional information storage means. It is more preferable to provide a function that allows access by the user.

With this configuration, by setting the additional information appropriately, it is possible to judge the reliability of the data stored in the storage means from the acquired additional information. Therefore, for example, when the same data is shared by a plurality of applications, the reliability of the data is improved.

An information terminal according to the present invention is an information terminal connectable to a network, comprising the gateway system according to any one of claims 1 to 3, wherein the information terminal is connected to the network. , So that information on devices connected to the network through the gateway system can be collected.

An information terminal is an apparatus that can be connected to a network and has a function of collecting at least information from devices and the like connected to the connected network.

The above-described components of the present invention can be combined as much as possible. Each means constituting the gateway system according to the present invention can be realized by a dedicated hardware circuit, or can be realized by a programmed computer.

[0019]

FIG. 3 shows a preferred embodiment of an information terminal according to the present invention. This information terminal 10
Corresponds to the computer 2 shown in FIG. As shown in FIG. 3, the information terminal 10 includes a plurality of application programs 11 and an operating system (OS) 1.
2 and a communication middleware unit 13 interposed between the two to control data transmission and reception.

The operating system 12 manages (reads and writes data) various control units, that is, a communication control unit (gateware) 12a for communicating with external devices and the like, and internal and external storage devices and shared memories. It has a storage device controller 12b and the like. Further, data shared by a plurality of application programs 11 is stored in a shared memory 15 in the operating system 12.

In this embodiment, the communication middleware unit 1
3 is provided with a virtual memory data management unit 13a, each device access unit 13b, and a shared memory access unit 13c.

The virtual memory data management section 13a has a function of managing memory data as interface means for the application program 11 to handle a real memory on the device 1 as a virtual memory space.

Specifically, in response to a data read / write request from the application program 11,
Via the corresponding device access unit 13b or shared memory access unit 13c, the desired device 1 or shared memory 15
(Corresponding to the internal storage device 3 and the like shown in FIG. 1).

That is, the application program 11
In response to the request, the OPEN request which is an effective instruction requesting the initial processing, the CLOSE request which is an effective instruction requesting the end processing, and the READ request which instructs the data reading are sent to the access units 13b and 13c. , Which outputs a WRITE request to instruct data writing.

In the case of a READ request, information indicating which data is to be read is also sent out, and if the data returned from each of the access units 13b and 13c (data corresponding to the read request) is obtained, A process for transferring the program to the application program 11 is executed. Also, WR
In the case of the ITE request, information on a position to be written is transmitted together with data to be written.

The device access unit 13b transmits and receives data to and from various devices 1 connected to the information terminal 10 via a network or a serial line as shown in FIG. As described in the related art, the communication protocol differs for each device 1, and the communication protocol differs depending on the type of network to be connected. In order to cope with such a difference, a communication function corresponding to the device 1 to be connected is provided, and data can be transmitted to and received from the device 1.

Further, the device access unit 13b is also connected to the virtual memory data management unit 13a, and transmits and receives information (data). The data communication procedure between the virtual memory data management unit 13a and each device access unit 13b is shared.

The specific processing functions are as shown in FIG. That is, in accordance with the OPEN request received from the virtual memory data management unit 13a, predetermined initial processing is executed (ST1), a communication endpoint with a connected device is created, and communication with the device 1 is enabled ( ST2).

Further, it is determined what the actual operation request is, and R
In the case of an EAD request, data read processing is performed (S
T3, ST4). That is, a communication command is created from the read position and data size of the data received together with the READ request, and the created communication command (read request command) is transmitted to the connected device 1 managed by itself (ST5, ST5). ST6).

The device 1 returns the data at the corresponding read position as a response according to the received read request command, and receives the response (ST7). Then, the received response (read data) is returned to the virtual memory data management unit 13a.

Thereafter, a CLOSE request is issued from the virtual memory data management unit 13a that has received the read data, and the termination processing is performed after waiting for the request (ST1).
2). That is, the communication end point with the device created in step 2 is released, and the process ends.

If the request sent after the OPEN request is a WRITE request, the process jumps from step 3 to step 8 to execute a data write process (ST).
8). That is, a communication command is created from the write position and the data size of the data received together with the WRITE request, and the created communication command (write request command:
(With write data) (ST9, ST1)
0).

According to the received write request command, the device 1 writes the received data at the corresponding write position and, at the same time, returns a response, and receives the response (ST11). Then, the received response is returned to the virtual memory data management unit 13a. As a result, the virtual memory data management unit 13a knows that the data has been successfully written to the device. Therefore, the virtual memory data management unit 13a issues a CLOSE request. I do.

Similarly to the device access unit 13b, the shared memory access unit 13c is connected to the shared memory 15 and sends and receives (reads / writes) data according to a predetermined communication procedure. Then, it is also connected to the virtual memory data management unit 13a, and sends and receives data according to the same communication procedure as that of the device access unit 13b. The specific processing functions are as shown in FIG. FIG.
4 and FIG. 4, the basic processing flow is the same.

That is, predetermined processing is set in accordance with the OPEN request, and a shared memory (file) is opened (ST21, ST22). Then, in the case of a READ request, data read processing is performed (ST23, S
T24). That is, the read pointer is moved based on the read position of the data received with the READ request (ST25), the data of the requested size is read from the head of the pointer, and the read data is transferred to the virtual memory data management unit 13a. It is sent back (ST26).

Thereafter, a CLOSE request is issued from the virtual memory data management unit 13a that has received the read data, and a termination process is performed after waiting for the request (ST3).
0). That is, the communication end point with the device created in step 12 is released, and the process ends.

If the request sent after the OPEN request is a WRITE request, the process jumps from step 23 to step 27 to execute data write processing. That is, the write pointer is moved according to the write position of the data received with the WRITE request, and data of a predetermined size is written from the position of the moved write pointer (ST28, ST29).

As described above, the virtual memory data management unit 1
When the device 1 and the shared memory 15 are viewed from the device 3a, the direct communication partner is each device access unit 13b and the shared memory access unit 13c, and sends various instructions and other information according to a common communication procedure, and transmits necessary data. Can be obtained. In other words, the device access unit 13b and the shared memory access unit 13c can absorb differences in network / communication means and the like for each of the connected devices 1 and the storage devices 3 and 4, and the device access unit 13b and the shared memory The access unit 13c is a functional module for absorbing the above.

Further, the application program 11
Can read and write data in a common procedure for the virtual memory data management unit 13a, and can execute processing without being aware of the existence of the device 1 or the shared memory 15, which is the actual data read / write destination.

An example of the operation will be described with reference to FIG. FIG. 6 shows an example of collecting data from the device 1. As shown in the figure, first, the application program 11 executes the virtual memory data management unit 1
A read request is issued to 3a (). Then
The virtual memory data management unit 13a determines a device 1 desired by the application program 11, determines a device access unit 13b connected to the device 1,
A read request is made to the determined device access unit 13b ().

The device access unit 13b issues a read request to the real device 1 (), and acquires data from the device 1 returned according to the request (). Accordingly, the device access unit 13b stores the returned read data in the virtual memory data management unit 13b.
a) (), and further, the virtual memory data management unit 13a
Transfers the acquired read data to the application program 11 (). By doing so, the application program 11 can collect and manage the usage information of the real device only by transmitting and receiving data to and from the virtual memory data management unit 13a. In the illustrated example, data collection is described with focus on data collection. However, the present invention is not limited to this, and data can be written. Further, the procedure for the shared memory 15 can be the same as that shown in FIG.

In the above example, when the application program 11 writes data collected from the device 1 to the shared memory 15, a read process is executed once, and the application program 11
Acquires the data, and then executes the writing process to the shared memory 15 to store the acquired data in the shared memory 15 so that the data can be shared.

Further, the present invention is not limited to such a procedure.
When writing previously collected data to shared memory,
The instruction command is given to the virtual memory data management unit 13a, and the virtual memory data management unit 13a supplies the acquired data to the application program 11,
Writing to the shared memory 15 can also be performed.

FIG. 7 shows a main part of the second embodiment of the present invention. As shown in the figure, an additional information management table 17 is provided, and when writing data to the shared memory 15, additional information such as validity and time of the written data is stored. Thereby, for example, when the application program 11 reads the corresponding data from the shared memory 15 to update the already acquired data, the application program 11 considers the additional information and, for example, reads the time information (write If the time information of the currently acquired data is later than (time) and is valid, the application program updates the data. Conversely, if the data is not valid, or even if it is valid, if the time information (write time) of the data held by itself is the same as the time information of the currently acquired data,
If it is determined that there is no need to update, and if the time information of the acquired data is older, it is known that some error has occurred. Therefore, in any case, the data cannot be updated. By doing so, the reliability of the shared data can be ensured.

The internal structure of the additional information management table 17 for executing the above processing and the data access management method are as shown in FIG. 8, for example. That is, the virtual memory data management unit 13a (event memory)
The virtual memory data 18 for managing and searching the additional information management table 17 is provided in the virtual memory data 1.
The access is made based on the information stored in 8. The virtual memory data 18 is managed as an array in units of WORD (channel: 2 bytes). Then, an additional information management table 17 corresponding to each channel (maximum n) may exist. However, if all the tables are secured in advance, the memory use efficiency is deteriorated. The virtual memory data management unit 13a (virtual memory data 18) prepares an additional information management table 17 for registering the additional information of the virtual memory. Detect and read / write data.

The internal data structure of the additional information management table 17 includes a “next index” which is an index to the next management table, and a “time data area” for storing the time at which the data was written or designated to be written. , A "history data area" for storing history information such as data update, and a "user data area" for storing any additional data specified by the user. Note that the other configurations, functions, and effects are the same as those of the above-described first embodiment.

As a specific example of reading and writing data in the above embodiment, as shown in FIG. 7, when writing data from the application program A to the shared memory, the application program A
Performs data write processing on the virtual memory data management unit 13a (). Then, the virtual memory data management unit 13a that has received the write issues a WRITE request to the shared memory access unit 13c together with the data to write the received data to the shared memory (). At the same time, the virtual memory data management unit 13a registers, in the additional information management table 17, additional information on the data requested to be written ().
Then, upon receiving the WRITE request, the shared memory access unit 13c writes data to a predetermined position of the shared memory 15 (). Thus, a series of data write processing ends.

On the other hand, when the application program B reads data stored in the shared memory, the application program B shown in FIG.
As shown in FIG.
Performs data read processing on the virtual memory data management unit 13a ('). Then, the virtual memory data management unit 13a that has received this readout transmits the designated data to the shared memory access unit 13c.
Then, a READ request is issued to read data from No. 5 (').
At the same time, the virtual memory data management unit 13a acquires additional information for the specified data from the additional information management table 17 (').

The shared memory access unit 13c
In response to the request, data stored in a predetermined position of the shared memory 15 is obtained ('), and the obtained data is passed to the virtual memory data management unit 13a ('). Then, the virtual memory data management unit 13a associates the acquired data with the additional information and returns it to the application program B. Thus, a series of data reading processing is completed (').

In the usage mode shown in FIG.
Is a computer for data collection to which various devices such as a PLC and a temperature control device are connected, and is a conventional computer for information collection and management. However, the present invention is not limited to this. May be used in a system structure in which a computer is connected to a higher level. That is, the system structure is briefly described. The network communication is relayed between the control system network and the information system network, and the control system (to which various devices such as a PLC and a temperature control device are connected) and the higher-level information are connected. A controller (open controller) that communicates data with a system (a conventional computer that ultimately obtains information). Although an open network controller is referred to as an open controller in the sense of a controller that can be freely connected to various types of networks, it goes without saying that the name is not restricted to that name.

Further, for example, in a PLC, various I / Os
O, sensors and other devices will be connected and control them. A digital display also collects and displays information from connected devices. Therefore, a PLC or a digital display having such an information collecting function is also the information terminal 10 according to the present invention.

[0052]

As described above, according to the present invention, the device access means for each device and the data management means for managing the device are provided, and the data management means and the application transmit and receive data in a common communication procedure. Thus, when collecting and managing data, differences between devices can be absorbed and data can be transmitted and received in a unified manner.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a system for collecting information from devices connected via a network.

FIG. 2 is a diagram illustrating a management structure of collected data.

FIG. 3 is a diagram showing a first embodiment of the present invention.

FIG. 4 is a flowchart illustrating functions of a device access unit.

FIG. 5 is a flowchart illustrating functions of a shared memory access unit.

FIG. 6 is a diagram illustrating an operation of reading data from a device.

FIG. 7 is a diagram illustrating an operation of writing data to a shared memory.

FIG. 8 is a diagram showing a second embodiment of the present invention.

FIG. 9 is a diagram illustrating an operation of reading data from a shared memory.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Device 10 Information terminal 11 Application program 12 Operating system 13 Communication middleware 13a Virtual memory data management unit 13b Device access unit 13c Shared memory access unit 15 Shared memory 17 Additional information management table 18 Virtual memory data 19 Additional information management index

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5B089 GA21 GB03 JA36 KA10 KF05 KF06 5K033 BA04 CB02 DB04 DB12 DB18

Claims (4)

[Claims] 1. A gateway system mounted on a device connectable to a network, comprising: a device access unit for performing data communication with a device connectable to the network; Data management means for instructing transmission and reception of data, the data management means has a function of providing a common communication procedure for the installed application when the application is installed in the device, A gateway system that enables an application to transmit and receive data to and from the device by communicating with the data management unit. 2. A storage device provided in the device,
2. The gateway according to claim 1, further comprising an access unit that enables access according to an instruction from the data management unit, wherein the application communicates with the data management unit so that data can be read from and written to the storage unit. system. 3. An additional information storage means for storing additional information on data stored in the storage means, wherein the data management means has a function of making the additional information storage means accessible. The gateway system according to claim 2, wherein: 4. An information terminal connectable to a network, comprising: the gateway system according to any one of claims 1 to 3, wherein the terminal is connected to the network via the gateway system. An information terminal that can collect information on devices connected to the network.