JP2001005516A - Method for retrieving time-sequential data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make quickly retrieable data collected by a plant monitoring device even when a file capacity for storing the data is large. SOLUTION: In this method for retrieving time-sequential data, at the time of retrieving time-sequential plant data collected and stored by a plant monitoring device 1, a time-sequential data file 13 which can store L pieces of data is divided into M blocks with N pieces of data each, and the oldest time data in each block are successively extracted and stored in a file 14, and the time-sequential data are retrieved by setting up a rough standard in the file 14. Thus, the data retrieval can be quickly attained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of searching for plant data in a plant monitoring device for monitoring various industrial plant control devices.

[0002]

2. Description of the Related Art FIG. 2 shows a conventional system. In the figure, 1 is a plant monitoring device, 21 and 22 are plant control devices, and 3 is a transmission line. Also, 11 of the monitoring device 1 indicates a reception area, 12 indicates a time-series data collection program, 13 indicates a time-series data file, and 15 indicates a data read program. That is, the control devices 21 and 22 and the monitoring device 1 that performs the monitoring and operation thereof are connected to each other via the transmission line 3. Although the number of control devices is two here, it is needless to say that the number is not limited to this.

The data of the control devices 21 and 22 are stored in the monitoring device 1
To display data on the monitoring device 1,
Further, the data is stored in a time-series manner in a storage device such as a hard disk, which constitutes the time-series data file 13 in the monitoring device 1 at a certain fixed cycle. That is, the time-series data file 13 cyclically stores the time-series data together with the time data at which the data is stored by the time-series data collection program 12.

[0004]

In the above configuration, when time series data before a certain time is to be displayed, the data read program 15 uses the time data in the time series data file 13 to display the data. Data is read and displayed by searching for the time. Therefore, when the capacity of the time-series data file 13 is large, there is a problem that it takes time to read and display the data. Therefore, an object of the present invention is to reduce the time required for reading and displaying data even when the time-series data file is large.

[0005]

According to the present invention, when searching for the time-series plant data collected and stored by the plant monitoring apparatus, the collected and stored time-series plant data is divided into blocks. By extracting one reference time data for each block to create a time search file, and referring to the time search file, plant data can be searched at high speed.

[0006]

FIG. 1 is a block diagram showing an embodiment of the present invention. Although only the monitoring device 1 is shown here, it goes without saying that the system configuration is the same as that of FIG. As is clear from FIG. 1, a feature is that a time search file 14 is provided for the one shown in FIG. Hereinafter, the difference will be mainly described.

Now, assuming that the total data storage capacity of the time-series data file 13 is L, the data is stored in order from the first, and when the data is stored up to the L-th, the data returns to the first again, and the operation is repeated cyclically thereafter. Here, the time-series data file 13 is divided into M blocks (one block: N). When the time-series data collection program 12 stores, for example, the first data of each block, the time data is It is stored in the time search file 14 as the oldest time data in the block. The time data is not limited to the oldest time data in the block, but may be the latest time data in the block.

As described above, the time search file 14
Is stored in the data read program 1
5 is read. Now, assuming that data is to be displayed by reading N pieces of data before the time Ta, first, the oldest time of the time search file 14 is searched, and a block Ma closest to the time data Ta is obtained. Next, a search is performed within the block Ma of the time-series data file 13 to find a position La closest to the time data Ta, and by reading N pieces of data that go back in the past from this point, the data before the time Ta is read. N pieces of data can be displayed. As described above, the time data stored in the time search file 14 at regular time intervals serves as an index (reference) for the search, so that it is possible to speed up the search.

[0009]

According to the present invention, there is an advantage that the time required to read and display data can be shortened even if the time-series data file is large, by merely providing the time search file 14.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram showing a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Monitoring device, 21, 22 ... Control device, 3 ... Transmission line,
4 analog device, 4A analog device interface, 5 multiplexer, 6 level converter, 7 communication cable (RS232C), 8 communication cable (GP
-IB), 9 ... Personal computer (personal computer).

Claims (1)

[Claims] When searching for time-series plant data collected and stored by a plant monitoring apparatus, the collected and stored time-series plant data is divided into blocks, and one block serving as a reference is provided for each block. A time-series data search method characterized in that a time search file is created by extracting time data, and a high-speed search of plant data is enabled by referring to the time search file.