JPH1188384A - Data collection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain a quick and appropriate sending back of a response text to a request text from host equipment by having subordinate equipment prepare the response text corresponding to the request text transmitted from the host equipment in advance, store this in a memory, read the response text matched to the request text at the time of reception of the request text, and transmit it to the host equipment immediately. SOLUTION: Host equipment 1 such as a data display device or the like is connected to a communication line 2 a LAN or the like and so on and to the communication line 2 is connected plural subordinate equipment 3a controller, sequencer or the like. Thus, it is possible for the host equipment 1 and the subordinate equipment 3 to mutually communicate by way of the communication line 2 and data from the subordinate equipment 3 is made possible to be collected into the host equipment 1. The subordinate equipment 3 always uses the latest data, prepares a response text and accumulates it in a memory so that it can quickly send back the response text. Also the subordinate equipment 3 provides plural response text accumulation area with a memory.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to communication between a higher-level device such as a data display device and a data transmission device and a lower-level device such as a controller or a sequencer via a communication line, and data from the lower-level device. A data collection method for collecting data in a host device.

[0002]

2. Description of the Related Art In a data collection operation by a higher-level device in this type of data collection method, when a higher-level device transmits a data collection request text to a lower-level device, the lower-level device that has received the request text interprets the content, and Necessary data is collected from sensors and memories connected to the lower device, and a response text is assembled using the transmission buffer.
The assembled response text is sent back to the requesting host device. Further, there is another system in which a memory area for assembling a transmission text and a transmission buffer are different. In such a system, a response text is assembled in a memory and then transferred to a transmission buffer for transmission.

[0003]

In the above-described conventional data collection method, the lower-level device receives a request text, interprets the content, and in some cases collects necessary data from a sensor or the like to arrange necessary data. Since the response text is assembled from the response text and sent back to the upper device of the request source, there is a problem that it takes time to return the response text.

[0004] Further, since the length of the response text varies depending on the type of the request text, the size of the transmission buffer may be erroneously managed, and the response text may become invalid.

[0005] Further, when the response text becomes invalid as described above, the data requesting upper device detecting that the response text is invalid re-creates the request text and makes a retransmission request. Therefore, there is a problem that much more time is required until necessary data is collected.

Further, as described above, even if the response text becomes invalid or an abnormal situation occurs in a plant or the like while a retransmission request is made, it cannot be displayed on a higher-level device. However, there is also a problem that the plant may fall into a dangerous state.

[0007] The present invention has been made in view of the above,
An object of the present invention is to provide a data collection method capable of quickly and accurately returning a response text to a request text from a higher-level device.

[0008]

In order to achieve the above object, according to the present invention, in a high-order device and a low-order device connected to each other via a communication line, data from the low-order device is collected by the high-order device. Data collection method,
A response text corresponding to the request text transmitted from the higher-level device is always created in advance by using the latest data in the lower-level device and stored in the memory, and when the request text is received from the higher-level device, the response text matches the request text. The gist is to read the response text from the memory and immediately return the response text to the host device.

According to the first aspect of the present invention, a response text is always prepared in advance in the lower device using the latest data and stored in the memory, and when the request text is received from the upper device, the response text is received. Since the response text that matches the request text is read from the memory and immediately returned to the host device, the response text can be returned to the host device quickly and accurately.

The present invention described in claim 2 is the same as the claim 1.
In the invention described in the claims, the step of preparing the response text in advance and storing the response text in a memory includes the following steps:
A plurality of response text storage areas each having first and second two memory areas for storing two response texts for one request text are provided, and the previously completed response text is stored using the latest data. An area management information storage area for storing area management information indicating which of the two memory areas is stored is provided corresponding to each response text storage area, and a response created in advance using the latest data in a lower device. A text is stored in one of the two memory areas of the response text storage area, and area management information indicating that the response text is completed in the one memory area is stored in the area management information storage area. After the storage, when a response text is created using the latest data and stored in the other memory area, And repeating the same process sequentially for each of the plurality of response text storage areas, reading the response text from the memory, and immediately returning the response text to the host device. The point is that the response text stored in the memory area indicated by the area management information is read out and the response text is returned to the host device.

According to the second aspect of the present invention, the response text prepared in advance using the latest data in the lower device is stored in one memory area of the response text storage area, and the response text is completed. Is stored in the area management information storage area,
After the storage, a process of creating a response text using the latest data and storing the response text in the other memory area is sequentially repeated for each of the plurality of response text storage areas. The response text stored in the memory area indicated by the information is read out and sent back to the higher-level device, so that the lower-level device receives the request text and then creates the response text quickly and accurately without having to create the response text. Can be returned to equipment.

Further, the present invention according to claim 3 provides the invention according to claim 2.
In the invention described above, the gist is that the response text stored in the memory area is formatted and stored.

According to the third aspect of the present invention, the response text stored in the memory area is formatted and stored, so that the response text corresponding to the request text from the higher-level device is simply read from the memory area. The read response text can be quickly returned to the host device without the need for a formatting process.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a system configuration diagram for implementing a data collection method according to an embodiment of the present invention. In FIG. 1, a host device 1 such as a data display device is connected to a LAN.
(Local area network) or the like, and a plurality of lower devices 3 such as a controller and a sequencer are connected to the communication line 2 so that the upper device 1 and the lower device 3 are connected to the communication line 2. , And can collect data from the lower-level device 3 in the higher-level device 1. The data collection method of this embodiment is particularly useful for collecting data by calling a lower device at a predetermined cycle by a polling operation from a higher device.
The lower-level device 3, such as a controller or a sequencer, has a variety of raw data therein, such as data read from a plant or the like, and parameters associated with the data, such as instrument range data and alarm limit values. Is what it is.

In the lower device 3, a response text is always created using the latest data and stored in a memory so that the response text can be promptly returned to the request text from the higher device 1. In case a plurality of request texts are continuously transmitted from the host device 1,
A plurality of response text storage areas, each of which can store a plurality of response texts, are provided in a memory, and the response texts are quickly transmitted even if the request text is transmitted while the response texts are being created using the latest data. Each response text storage area is provided with two memory areas so that it can be returned, and while the response text for one memory area is being created with the latest data, it is already created and stored in the other memory area first. The response text is returned to the host device 1.

FIG. 2A shows a memory configuration for performing such processing. The memory 11 of the lower device 3 has a plurality of response text storage areas 13a and 13a.
b to 13n are provided, and each of the response text storage areas is capable of storing two response texts.
Are provided. One of the two memory areas stores a completed text, that is, a response text created using the latest data, and the other memory area is created using the latest data. This is for accumulating the response text that is about to be started, and is displayed in FIG.

A plurality of response text storage areas 13
Area management information storage areas 15a, 15b to 15n are provided corresponding to a, 13b to 13n, respectively, and these area management information storage areas 15a, 15b to 15n constitute response text storage areas 13a, 13b to 13n. Response text area management information indicating in which of the two memory areas the completed text is stored is stored. For example, when the completed text of the response text is stored in the first memory area as in the first response text storage area 13a and the second memory area is for the text being created, the corresponding first area is used. The response information area management information indicating the first memory area in which the completed text is stored is stored in the management information storage area 15a.

FIG. 2B shows the response text storage area 13.
a, and 13b to 13n, the format of completed response texts stored in the first and second memory areas is shown.
V (data), SV (data), an error check sequence, and the like. That is, in the first and second memory areas of the response text storage areas 13a, 13b to 13n, as shown in FIG. 2B, formatted response texts which can be transmitted as they are to the higher-level device are stored. Has been accumulated. Accordingly, when the request text is transmitted from the higher-level device to the lower-level device, the lower-level device transmits the response text storage areas 13a and 13b to
By reading out the completed response text from 13n, the response text can be transmitted to the host device as it is without any need for formatting, and the speed can be further improved.

Next, the operation of the above embodiment will be described with reference to the flowcharts shown in FIGS. FIG.
4 is a flowchart showing creation and transmission of a request text in the upper device 1 and reception of a response text from the lower device 3, and FIG. 4 is a flowchart showing reception of the request text, reading and transmission of the response text in the lower device 3. FIG. 5 is a flowchart showing the creation and update of the response text.

First, the host device 1 creates a request text corresponding to the type of data to be collected (step 11 in FIG. 3).
0), and transmits the created request text to the lower-level device 3 via the communication line 2 (step 120).

When the lower device 3 receives the request text from the upper device 1 (step 210 in FIG. 4), it determines the type of the received request text (step 22).
0). Then, the first or second area management information indicated by the area management information stored in the area management information storage areas 15a, 15b to 15n of the response text storage areas 13a, 13b to 13n of the memory 11 corresponding to the type of the request text. The response text in the memory area is quickly read (step 230), and the read response text is read by the host device 1.
(Step 240).

When the response text is received from the lower device 3, the upper device 1 performs data processing on the response text (step 130 in FIG. 3), and stores the response text corresponding to the lower device 3 that has returned the response text. It is stored as processed data in the area (step 140). The above processing is performed for all the lower devices 3, and all the lower devices 3
Collect data from

On the other hand, in the lower-level device 3, a response text for the request text is always prepared in advance using the latest data and stored in the memory 11, thereby coping with the processing in step 230 in FIG. This processing will be described with reference to the flowchart shown in FIG.

As shown in FIG. 2A, the lower device 3
A plurality of response text storage areas 13a, 13b to 13n corresponding to the number of response texts or request texts and corresponding area management information storage areas 15a, 15b to 15n are secured in the memory 11, and each response text storage area 13a, 1
3b to 13n are divided into first and second memory areas (step 310 in FIG. 5). Then, the area management information indicating the first and second memory areas of the response text storage area 13i storing the response text created using the latest data is stored in the area management information storage area 15i (step 320). . For example, when the completed text of the response text is stored in the first memory area of the response text storage area 13a as shown in FIG. 2A, the first text is stored in the corresponding area management information storage area 15a. Area management information indicating a memory area is stored.

Next, for the other memory area not specified in the area management information, in the above example, the latest data is used for the second memory area of the response text storage area 13a in FIG. A response text in a format as shown in FIG. 3B is created (step 330), and the created response text is stored in the other memory area of the response text storage area 13i, in the above example, in the second memory area. The area management information corresponding to the memory area is stored in the corresponding area management information storage area 15i to update the area management information storage area 15i (step 340).

The above processing is performed successively and sequentially on each of the response text storage areas 13a, 13b to 13n of the memory 11 so that the response text corresponding to the request text from the higher-level device 1 is prepared in advance using the latest data. It is always created and stored in the memory 11. As a result, when the request text is transmitted from the host device 1, the response text corresponding to the request text is read from the memory 11, and the read response text is returned to the host device 1 as in the related art. The response text can be quickly returned to the host device 1 without requiring much time for receiving the request text and then preparing the response text. In addition, since the response text created in advance is formatted as shown in FIG. 2B and stored in the memory 11, no formatting process is required after the response text is read from the memory 11, thereby further speeding up. Can be achieved.

That is, in the lower device 3, if the response text is completed in one memory area of the response text storage area 13i of the memory 11, when the response text is transmitted from the higher device 1, the response text is transmitted. Returns the response text of the memory area. Even during such processing, the latest response text is created in the other memory area using the latest data. And when the response text in the other memory area is completed and stored,
The area management information storage area 15i is updated from one memory area to the other memory area. Then, when the request text is received from the higher-level device, the operation of returning the response text of the other memory area designated by the area management information storage area 15i to the higher-level device is always repeated, so that the memory area can be rewritten. In either case, the response text with the latest data is always completed, and in the other memory area, the response text can be created using the further latest data.

[0029]

As described above, according to the first aspect of the present invention, a response text is created in advance in a lower-level device by using the latest data at all times and stored in a memory. When a text is received, a response text that matches the request text is read from the memory and immediately sent back to the host device. Therefore, it is not necessary to create a response text each time the request text is received as in the related art. Texts can be returned to the host device quickly and accurately.

According to the second aspect of the present invention, the response text prepared in advance using the latest data in the lower device is stored in one memory area of the response text storage area, and the response text is completed. Is stored in the area management information storage area, and after storing the area management information, a response text is created using the latest data and stored in the other memory area. When the lower device receives the request text, the lower device reads the response text stored in the memory area indicated by the area management information and returns it to the upper device. Quickly and simply read the response text from memory without creating the response text from You can be sure to return to the host device.

Further, according to the third aspect of the present invention, the response text stored in the memory area is formatted and stored, so that only the request text from the host device is read out from the memory area. The read response text can be promptly returned to the host device without the need for formatting, and the response text can be invalidated due to a format error or the like and the response text retransmission process can be reduced. Thus, efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram that implements a data collection method according to an embodiment of the present invention.

FIG. 2 is a diagram showing a memory configuration and a data format of a response text used in the embodiment shown in FIG. 1;

FIG. 3 is a flowchart showing creation and transmission of a request text in a higher-level device and reception of a response text from a lower-level device in the embodiment shown in FIG. 1;

FIG. 4 is a flowchart showing reception of a request text, reading and transmission of a response text in a lower device in the embodiment shown in FIG. 1;

FIG. 5 is a flowchart showing creation and update of a response text in the embodiment shown in FIG. 1;

[Explanation of symbols]

 Reference Signs List 1 upper device 2 communication line 3 lower device 11 memory 13a, 13b to 13n response text storage area 15a, 15b to 15n area management information storage area

Claims (3)

[Claims] 1. A data collection method for collecting data from a lower-level device in a higher-level device and a lower-level device connected to each other via a communication line, wherein the lower-level device includes a request text transmitted from the higher-level device. A response text corresponding to the request text is always created in advance using the latest data and stored in a memory. When a request text is received from a host device, a response text corresponding to the request text is read from the memory, and the response text is read. A data collection method characterized by immediate return to the host device. 2. The method according to claim 1, wherein said response text is created in advance and stored in a memory. The first and second memory areas for storing two response texts for one request text in a lower-level device are provided. Area management information storage for providing a plurality of response text storage areas each having therein and storing area management information indicating in which of the two memory areas the response text completed in advance using the latest data is stored. An area is provided corresponding to each response text storage area, and the response text created in advance using the latest data in the lower device is stored in one of two memory areas of the response text storage area, and the one memory Area management information indicating that the response text is completed in the area is stored in the area management information storage area. Along with the accumulation, a process of creating a response text using the latest data and accumulating the response text in the other memory area is sequentially repeated for each of the plurality of response text accumulation regions, and the response text is read from the memory. The step of immediately returning the response text to the higher-level device includes reading the response text stored in the memory area indicated by the area management information stored in the area management information storage area, and transmitting the response text to the higher-level device. 2. The data collection method according to claim 1, wherein the data is returned. 3. The data collection method according to claim 2, wherein the response text stored in the memory area is formatted and stored.