JPH09319770A - Data collector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent increase of the communication time and cost due to transmission of the redundant data by placing a secondary storage means at a remote place and storing the data also at the remote place. SOLUTION: When a data demander 5' inputs a fact that it does not change the data extracting condition, a primary storage means 3 asks a secondary storage means 9 to supply the short process value data to a primary extraction means 10 based on the extracting condition CS4 (t3 :t4 ) and waits for a report to be sent from the means 10 to show the end of supply of the data (S4: combination of value data 2 and data 3). Receiving the report from the means 10 via the means 3, a secondary extraction means 11 extracts the necessary process value data PS3 (t2 :t4 ) from the means 9 which stores all requested process value data. Then the data PS3 (t2 :t4 ) is sent to the requester demander 5'. Thus, the necessary process value data can be obtained even at a remote place in the least necessary extraction time of the data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data collection device, and in particular, collects a large amount of process value data such as dynamic characteristic data of a large-scale plant from a facility located at a remote place via a low-speed communication line. The present invention relates to a suitable data collection device.

[0002]

2. Description of the Related Art Construction of large-scale plants such as thermal power plants,
At the time of remodeling and periodic inspection, a trial run is indispensable for plant adjustment and performance confirmation. At that time, a large amount of process value data is required to evaluate the test operation results and record the results. Particularly in recent thermal power plants, the behavior of process values such as temperature and pressure of each part (hereinafter referred to as "dynamic characteristics") is emphasized in the process of large changes in the plant state such as start, stop, and immutable. It became so. To evaluate the dynamic characteristics, process value data sampled continuously during the target test period at intervals of the time constant of the plant is required. For this reason, the amount of data required for the evaluation has increased dramatically compared to the case where the evaluation of the static characteristics is the main focus.

In the meantime, the means for collecting process value data is
Most of them were recorded on paper, such as records of temporary data recorders during the test run, screen hard copy of the plant control device, and process value list output to the printer for recording. Therefore, when preparing samples such as evaluation and reporting of collected process value data, all processes were done manually, such as list, reading process values from hard copy, making summary table, cutting hard copy, etc. It took a lot of trouble and time.

In recent years, the performance of inexpensive computers such as personal computers has been remarkably improved. By using data processing software available on such computers, evaluation of test data is multifaceted and efficient. It became possible to do it. However, the data obtained from the plant is still data recorded on paper, and in order to be processed by data processing software, it must be manually read and
It was necessary to input again into the data processing software. For this reason, the use of data processing software is mainly used to evaluate static characteristics where the number of data is relatively small, and in the evaluation of dynamic characteristics that requires the input of enormous amounts of data, manual graph tracing and cutting processing are still required. It was done.

Therefore, a plant data collecting apparatus has been devised and used for the purpose of collecting the process value data as a file that can be directly input to the data processing software, instead of outputting it on paper.

FIG. 4 is a block diagram showing the configuration of an example of such a conventional plant data collecting apparatus. Time t
The process value group Pa (t) in (1) is sampled at every sampling period determined by the data sampling means 2, and is added with a time stamp (time information) and then stored in the primary storage means 3. As shown in the figure, the primary storage means 3 forms a ring buffer in the time direction, and can hold the process values sampled in time series for a period determined by the capacity of the ring buffer.

The period for sampling the process value group is usually fixed to the shortest time constant of the plant regardless of the purpose of the test. This is to make it possible to retroactively obtain the maximum value of the process value data necessary for the cause investigation when an unexpected phenomenon occurs during the trial run. In addition, depending on the purpose of the test being conducted at that time, the sampling period may be changed as appropriate to stop collecting the minimum necessary process value data.

As described above, the process value data for a certain period from the past to the present are accumulated in the primary storage means 3 every moment, but when the evaluation / analysis of the test is performed, all the accumulated process value data are stored. It is extremely rare to use, and usually a part of it is used. Required process value data is evaluated
Since there are various combinations and sample periods depending on the purpose of analysis, it is necessary to be able to extract a necessary and sufficient process value group from the process value data accumulated in the primary storage means 3 at an appropriate sample period. Taking a thermal power plant as an example, the data collection means 2 collects thousands of process values, whereas most evaluation and analysis process values are hundreds at most.

Therefore, in this conventional example, the data extracting means 4
Is the extraction condition Cs ₁ (t ₁ : t ₂ ) given by the data demand destination 5.
(It means from the time t ₁ to the time t _{2 in the} process value combination s _{1. The same} applies to the following.) Based on the process value data stored in the primary storage means 3, the extraction condition Cs ₁ (t ₁ : t ₂ ). The process value data Ps ₁ (t ₁ : t ₂ ) matching the above is extracted and sent to the data demand destination 5.

Further, the data extracting means 4 stores the extracted process value data in the storing / transporting means 6 in accordance with an instruction from the data demand destination 5, and the stored process value data is later stored in the data demand destination 5. It is also possible to use.

When a portable medium such as a floppy disk, a magneto-optical disk, or a magnetic tape is used as the storage / transport means 6, the storage / transport means 6 is transported,
It is also possible to send to a remote place by mail or other means and use the process value data at the remote data demand destination 5 ′.

Even when the data collection means 2, the primary storage means 3, the data extraction means 4, and the data demand destination 5 are all built in the same computer, when they are realized by a plurality of computers connected by the communication means. There is also.

FIG. 5 shows the configuration of another conventional example. This conventional example is an improvement of the conventional example of FIG. 4 in order to realize a quick process value data reference from a remote location. Data extraction means 4'installed in a remote location communicates with a network such as a local network described later. Means 7 and communication means 7 and primary storage means 3
Alternatively, connecting means 8, 8'for connecting with the data extracting means 4 '
The data stored in the primary storage means 3 is collected via the. Further, as a modification of the conventional example of FIG. 5, the data demand destination 5 ′ on the remote side requests the process value data extraction to the data extraction means 4 on the plant side through the communication means 7 and the connection means 8 ′, and the extraction is performed. The processed process value data is sent to the data demand destination 5 ′ through the communication means 7 and the connection means 8.
Some are configured to be sent to. Both of these conventional configurations have advantages in terms of ease of system construction, convenience during system operation, and cost.
It is selected according to the operational status. Further, similarly to the conventional example of FIG. 4, also in the conventional example of FIG. 5, the method of collecting the process value data at a remote location by transporting the storage / conveyance means 6 to a remote location is used together, and the urgency, convenience, and cost are increased. It is also possible to operate in consideration of.

[0014]

SUMMARY OF THE INVENTION The above-mentioned conventional technique is basically developed in consideration of local use. In the conventional example of FIG. 5, it is possible to obtain desired process value data from a remote place, but in reality, the primary storage means 3 and the data extracting means 4 or the data extracting means 4 of the conventional example of FIG. Only the extension was made between the data demand destination 5 via the communication means 7 and the connection means 8, and there was essentially no change in the handling of the process value data, and there were the following problems.

That is, the conventional example of FIG. 5 does not provide means for preventing the same process value data from being transmitted a plurality of times via the communication means 7. The necessary extraction conditions (combination of process values, data period, cycle) of process value data differ depending on the contents of evaluation and analysis. Therefore, the data demand destination 5 ′ sets different extraction conditions for each evaluation / analysis and repeats the data extraction. In many cases, the process value data to be extracted includes a process value that serves as an index of the plant state (for example, plant output, main part temperature / pressure, main manipulated variable, etc.). Therefore, while data extraction is repeated for various purposes, a large amount of overlapping data is included, and the same data is transmitted many times via the communication means 7.

Although it is possible to plan the process value data used in advance in the data demand destination 5'in detail and extract it without duplication, it is not convenient.

In addition, the Xerox Corporation, which has become popular recently,
Local network (L
ocal Area Netwrok (LAN) is laid in a remote place, and a plurality of geographically dispersed data demand destinations 5'are connected to the data extraction means 4 via the LAN or a plurality of scattered data demand destinations 5 '. There is also seen an example in which the data extraction means 4'and the data extraction means 4'are connected to the connection means 8 via a LAN.

In such a conventional example, since the plurality of data demand destinations 5'are geographically distant from each other, it is difficult to perceive each other's extraction operation, and the process value data to be extracted may overlap. Especially often occurs.

If the transmission speed of the communication means 7 is sufficiently high and the cost of the communication means 7 is a fixed amount (constant regardless of the communication time and the transmission data amount), the same data is transmitted through the communication means 7 in plurals. Even if it is done, no particular problem occurs. However, in many cases, from the viewpoint of cost, a relatively low-speed and pay-as-you-go communication means is often used. In this case, the same data is redundantly transmitted via the communication means 7, and the total transmission amount increases, so that the following problems occur.

First, due to the duplicated data, the entire transmission time is extended and the responsiveness as seen from the remote customer 5'is degraded. For example, process value data of 200 points, 1 second cycle, 1 hour (single precision floating point format: 4 bytes / sample point) is 64.
When the data is transmitted through the communication means 7 having the transmission rate of Kbps, theoretically 360 seconds are required (actually, the data required for the transmission control is also added, so that more time is required). For a start-up test of a thermal power plant, a plant for 300 points, a period of 1 second, and 6 hours is required. If 20% of the process value data is duplicated, the transmission time is extended by 648 seconds, which is a cause of a significant decrease in responsiveness.

Secondly, communication costs for duplicate data that are essentially unnecessary occur. In the pay-as-you-go communication means, an increase in the amount of transmission data or a communication time means an increase in communication cost, resulting in an unnecessary communication cost.

The present invention has been made for the purpose of solving the above problems by preventing the transmission of duplicate data through the communication means 7.

[0023]

The data collecting apparatus of the present invention comprises second data extracting means for extracting necessary data from the first storing means via a communication means to a remote place, and the second data extracting means. Second for storing the data extracted by the data extracting means
And a third data extracting means also provided in a remote place store data necessary for satisfying a data extraction request from a data demand destination located in a remote place in the second storing means. It is determined whether or not there is insufficient data, and the second data extraction means is instructed to transfer the insufficient data from the first storage means to the second storage means. After being stored in the second storage means, the data satisfying the data extraction request is extracted from the second storage means and supplied to the data demand destination. With such a configuration, in a remote place, in principle, the data is extracted from the second storage unit to meet the request of the data demand destination, and the data stored in the second storage unit is requested from the data demand destination. If the extracted request is not satisfied (the data is insufficient), only the insufficient data is extracted from the first storage means via the communication means and replenished in the second storage means. You can Therefore, the same data is transmitted to the same data demand destination via the communication means only once, and the time required for data extraction without duplication of the data transmitted via the communication means and Communication costs are not unnecessarily increased by duplicate data transmission. On the contrary, when trying to extract the data already stored in the second storage means (that is, the duplicated data), the processing is completed on the remote side and does not go through the low-speed communication means. Responsiveness comparable to that obtained is obtained.

When the data stored in the second storage means is insufficient to satisfy the data extraction request from the data demand destination, the insufficient data is displayed to the data demand destination. Then, the material to be reconsidered is provided to the data demand destination, and when the data demand request is received again from the data demand destination, the insufficient data which is insufficient to satisfy the second data extraction request is first From the storage means of the second
The second data extracting means is instructed to transfer the data to the second storing means, and the data satisfying the data extraction request is extracted from the second storing means after the insufficient data is stored in the second storing means to obtain the data demand destination. It is intended to be supplied to. As a result, the data demand destination is given an opportunity to reexamine the extraction of the data, and it is possible to avoid unnecessary and urgent data collection.

Further, the data to be stored in the first or second or both storage means is process value data obtained by sampling the process value of the plant in a predetermined cycle.

Further, the table further stores a combination of process values and a sampling period of each process value. Thereby, the data processing can be made more efficient.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.

FIG. 1 is a block diagram showing the configuration of the first embodiment of the present invention. In the figure, FIG. 4 and FIG.
The components having the same functions as those of the conventional example disclosed in 1 are given the same symbols, and the description thereof will be omitted.

In this embodiment, on the remote side,
Primary extraction means 10 for extracting the data stored in the primary storage means 3 via the communication means 7 and the connection means 8, 8 '.
And a secondary storage means 9 for storing the data extracted by the primary extraction means 10. Secondary storage means 9
Is usually realized as an area on a mass storage device such as a hard disk that can be accessed at high speed. As for the format of the secondary storage means 9, when the expected total transmission amount is sufficiently smaller than the capacity of the secondary storage means 9 due to the operation of the plant system, a normal file is used. When a transmission amount exceeding the capacity is expected, a ring buffer is used as shown in FIG.

This embodiment is further provided with secondary extraction means 11 for extracting data from the secondary storage means 9 in response to a data extraction request from a remote data demand destination 5 '. Only one secondary storage means 11 is provided in each remote place, and even if there are a plurality of demand destinations 5 ′ in that remote place, the data extraction requests from all the demand destinations are uniformly accepted and the data extraction is performed. Perform processing. The secondary storage means 11 confirms the presence or absence of the process value data requested by the data demand destination 5 ', requests the supplemental process value data to the primary extraction means 10, extracts the process value data from the secondary storage means 9, and requests the data. The extracted process value data is sent to the destination 5 '. The operation of the secondary extraction means 11 will be described in detail later.

The primary extraction means 10 which has received the supplement request from the secondary extraction means 11 extracts the requested process value data from the primary storage means 3 via the communication means 7 and the connection device 8 and then the secondary storage means. 9 and notifies the secondary extraction means 11 that the replenishment is completed.

The point of the operation of this embodiment is to check whether or not the process value data to be extracted by the secondary extraction means 11 has been stored in the secondary storage means 9 without any shortage. is there.

The primary storage means 3 stores the process value data of a fixed combination at equal intervals. For this reason,
In extracting the process value data from the primary storage means 3, the desired location of the process value data is confirmed after the desired extraction start time is later than the sample time of the oldest process value data existing in the primary storage means 3. All you have to do is confirm. This is because the primary storage means 3 continuously stores all process value data at a constant sampling period, so that if there is data at the extraction start time, then data up to a desired time thereafter may exist. Because it is clear.

On the other hand, in the secondary storage means 9, the process value data is randomly stored according to the extraction request from the data demand destination 5 '. If all sample value data requested from the data demand destination 5'is individually searched for each sample point and sample time, all process value data stored in the secondary storage means 9 will be accessed, and a large amount of data will be accessed. It is obvious that the processing takes a long time when the process value data of is stored. In some cases, the processing time may be longer than in the case of collecting the process value data of the conventional example via the communication means 7. Therefore, it cannot be put to practical use unless some efficient searching means is provided.

In this embodiment, it is predicted that most of the data used in the data demand destination 5'will be used for the evaluation / analysis of the dynamic characteristics of the plant if the data amount is compared. Employs a search method.

In the evaluation and analysis of the dynamic characteristics, in many cases, the same process value combination and process value data for a relatively long time (tens of minutes to tens of hours) at a constant cycle are required. Therefore, the process value data accumulated in the secondary storage means 9 has the same recording state (presence or absence of each process value data, recording cycle) in the sampling time direction as shown in FIG. Repeating another recording state with t ₁ to t ₄ in the figure as a boundary.

Needless to say, the recording state changes at the start or end time of any past data extraction.
Therefore, a state change table 12 as shown in FIG. 2B is provided on the same storage device where the secondary storage means 9 is provided,
The time at which the state of the process value data stored in the secondary storage unit 9 changes, the presence or absence of each changed process value, and the sampling period are recorded.

Each cell of the state change table 12 of FIG. 2 (2) shows the storage status of each process value after the time, and "0" is not stored. Indicates the storage cycle. The cycle in which the state of the process value data changes is considered to be several tens to several hundred times the sample cycle of the process value data on average. Therefore, the secondary extraction means 11
By referring to the state change table 12, it becomes possible to confirm at a high speed whether or not there is a shortage in the secondary storage means 9 of the process value data to be extracted.

By the way, in actual work, when the extraction condition is set in the data demand destination 5 ', process values which are not necessary for the immediate purpose but may be related are often included in the extraction condition. It is desirable to avoid unnecessary processing time and communication cost due to an increase in the amount of data transmitted through the communication means 7 due to careless addition of such process value data that is strictly unnecessary. Therefore, if the process value data to be extracted is insufficient in the secondary storage unit 9, the insufficient data is presented to the data demand destination 5 ′ that requested extraction, and the continuation of the process is confirmed. As a result, the data demand destination 5 ′ presented with the lacking data reconsiders whether or not the lacking data is truly necessary, and if unnecessary data is removed, the extraction processing time is reduced. Can be suppressed to the necessary minimum.

After all, the operation of the secondary extraction means 11 becomes like the flowchart shown in FIG. Hereinafter, FIGS. 1, 2, and 3
The operation of the secondary extraction means 11 will be described in detail using.

Upon receiving the extraction request from the data demand destination 5 ', the secondary extraction means 11 extracts the requested process value data according to the following procedure.

First, it is checked whether or not all the process value data included in the extraction condition Cs ₃ (t ₂ : t ₄ ) presented by the data demand destination 5'is already stored in the secondary storage means 9 ( Step S1). If the process value data included in the extraction condition Cs ₃ (t ₂ : t ₄ ) is already stored in the secondary storage means 9, this process value data is extracted (step S8), and the extracted process value is extracted. The data is sent to the requesting data demand destination 5 '(step S9), and the work is completed.

The current state change table 12 is shown in FIG.
In such a state, it can be seen that the secondary storage means 9 currently stores data of five sample points of data1 to data5 only for the period shown by the hatching in FIG. 2 (1) ( Differences in shaded patterns indicate differences in sample period). For simplification of explanation, it is assumed that S ₃ indicates a combination of process values data1, data2, data3, data4, and in this case, the secondary extraction means 11 referring to the state change table 12 requests the requested process. Da in the value data
ta2 and data3 is determined to be insufficient period t ₄ from t ₃ (step S2).

Since the data shortage is detected, the secondary extraction means 11 notifies the data demand destination 5'requesting the extraction that the above data is insufficient, and whether or not to change the extraction condition. Is inquired (step S3). Then, it waits for a response from the data demand destination 5 '(step S4).

When the data demand destination 5'changes the extraction condition, the process returns to step S1 and the data search is repeated again (steps S5 and S1).

When the data demand destination 5'inputs that the data extraction conditions are not changed (step S5), the extraction conditions are supplied to the primary extraction means 10 in order to supplement the shortage of process value data. A request for replenishment from the primary storage means 3 to the secondary storage means 9 by Cs ₄ (t ₃ : t ₄ ) is requested, and the completion report from the primary extraction means 10 is awaited (steps S6 and S7). Here, S ₄ is a combination of the process values data2 and data3.

The secondary extraction means 11 which has received the report of the completion of the supplement of the insufficient data from the primary storage means 3 by the primary extraction means 10 is required by the secondary storage means 9 having all the requested process value data. Process value data Ps ₃ (t ₂ : t ₄ )
Is extracted (step S8). The extracted process value data Ps ₃ (t ₂ : t ₄ ) is sent to the requesting data demand destination 5 ′ (step S9), and the work is completed.

[0048]

According to the present invention, the secondary storage means is provided on the remote side so that the data can be stored on the remote side as well. Therefore, in the plant data collecting apparatus via the low-speed or meter-based communication means. In addition, it is possible to obtain the necessary process value data from a remote place in the minimum required data extraction time, and it is possible to prevent increase in communication time and cost due to transmission of duplicated data.

Further, in the case of extracting only the plant data already existing in the secondary storage means, it is possible to perform the extraction in the same short time as in the case of directly extracting from the primary storage means without going through the communication means. , Operability is greatly improved.

Further, by notifying the data demand destination of the lacking process value data in the secondary storage means and prompting for re-examination, careless extraction of data is suppressed, and only the minimum necessary process value data is stored in a remote location. Therefore, the communication cost of the communication line can be minimized.

[Brief description of drawings]

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

2A and 2B are a perspective view and a state change table of a secondary storage unit according to the embodiment of FIG.

FIG. 3 is a flowchart showing an operation of the secondary extraction means of the exemplary embodiment of FIG.

FIG. 4 is a block diagram showing a configuration of an example of a conventional data collection device.

FIG. 5 is a block diagram showing the configuration of another example of the conventional data collection device.

[Explanation of symbols]

 1 Plant 2 Data Collection Means 3 Primary Storage Means 4 Data Extraction Means 5, 5'Data Demand 7 Communication Means 9 Secondary Storage Means 10 Primary Extraction Means 11 Secondary Extraction Means 12 State Change Table

Claims (4)

[Claims] 1. A data collection means for collecting data from a collection target, a first storage means for storing the data collected by the data collection means, and the collection for extracting necessary data from the first storage means. First data extraction means located in the vicinity of the object, communication means for transferring data of the first storage means to a remote place distant from the collection target, and the first storage means via the communication means Second data extraction means located at the remote location for extracting necessary data from the remote storage; second storage means located at the remote location for storing the data extracted by the second data extraction means; It is determined whether or not the data necessary for satisfying the data extraction request from the data demander located on the ground is stored in the second storage means. The first From the storage means of the second
Instructing the second data extracting means to transfer the data to the second storing means, and storing the data satisfying the data extracting request after the insufficient data is stored in the second storing means.
And a third data extraction means for extracting the data from the storage means and supplying the data to the data demand destination. 2. A data collection means for collecting data from a collection target, a first storage means for storing the data collected by the data collection means, and the collection for extracting necessary data from the first storage means. First data extraction means located in the vicinity of the object, communication means for transferring data of the first storage means to a remote place distant from the collection target, and the first storage means via the communication means Second data extraction means located at the remote location for extracting necessary data from the remote storage; second storage means located at the remote location for storing the data extracted by the second data extraction means; It is determined whether or not the data necessary for satisfying the data extraction request from the data demander located on the ground is stored in the second storage means. The day The data is displayed to the demand destination and the insufficient data which is insufficient to satisfy the request for re-extracting the data from the data demand destination is transferred from the first storage means to the second storage means. The second data extracting means is instructed, and after the insufficient data is stored in the second storing means, data satisfying the data extracting request is extracted from the second storing means and supplied to the data demand destination. A data collection device comprising a third data extraction means. 3. The method according to claim 1, wherein the data stored in the first or second or both storage means is process value data obtained by sampling a process value of a plant at a predetermined cycle. The described data collection device. 4. The data collecting apparatus according to claim 3, further comprising a table storing a combination of the process values and a sampling period of each process value.