JP5516020B2 - Data storage device and data storage method - Google Patents

Description

  The present invention relates to a data storage device that collects plant data and stores it as history data.

  When high reliability is required for the system, a duplex configuration (redundant configuration) using two servers having the same function can be employed. In this case, one server is operated as the active side and the other server is operated as the standby side. When the active server is down due to a failure, the standby server is promoted to the active side. Can be maintained.

JP 2001-042928 A

  However, when a failure occurs on the operating side, a certain amount of time is required until the standby side detects it, starts operation as a server on the operating side, and shifts to a steady state. For this reason, for example, when the server is provided with a function of collecting and storing data, the data during the transition period cannot be collected, and the history data is lost.

  An object of the present invention is to provide a data storage device or the like that can prevent loss of history data.

The data storage device of the present invention is a data storage device for collecting plant data and storing it as history data. Main storage means for collecting plant data and storing it as history data in a main storage unit; and the main storage means Collecting the data to be collected in parallel with the main storage means and storing it as history data in the sub-storage unit, thereby converting the history data stored in the sub-storage unit into a certain amount of the most recent data Sub-storage means for sequentially updating, detection means for detecting that data storage by the main storage means is stopped, and when the stop is detected by the detection means, stored in the main storage unit and a writing means for writing the read said main storage unit from the sub-storage unit without the historical data, a time stamp is attached to the history data, the write The stage acquires the time when the history data was last stored in the main storage unit by the main storage unit based on the time stamp, and the history data stored in the sub-storage unit after the time is obtained. It writes to the said main storage part, It is characterized by the above-mentioned .
According to this data storage device, when it is detected that data storage is stopped, history data that is not stored in the main storage unit is written into the main storage unit, so that loss of history data can be prevented.

The main storage means may be duplicated between an operation side and a standby side, and the detection means may detect an interruption of an operation that occurs when the main storage means is switched from the operation side to the standby side as the stop.

  The plant data may be process data.

  The plant data may be event data.

The data storage method of the present invention is a data storage method for collecting plant data and storing it as history data. Main storage step for collecting plant data and storing it as history data in a main storage unit; The data to be collected by is collected in parallel with the main storage step, and is stored as history data in the secondary storage unit, so that the history data stored in the secondary storage unit is converted into a certain amount of recent data. A sub-storage step for sequentially updating; a detection step for detecting that data storage by the main storage step is stopped; and a storage step stored in the main storage unit when the stop is detected by the detection step. and a write step of writing to reading said main storage unit from the sub-storage unit without the history data, data on the history data And the write step obtains the time when the history data was last stored in the main storage unit by the main storage step based on the time stamp, and after that time, The stored history data is written into the main storage unit .
According to this data storage method, when it is detected that data storage is stopped, history data that is not stored in the main storage unit is written into the main storage unit, so that loss of history data can be prevented.

  According to the data storage device of the present invention, when data storage is detected to be stopped, history data that is not stored in the main storage unit is written to the main storage unit, thereby preventing loss of history data. it can.

  According to the data storage method of the present invention, when data storage is detected to be stopped, history data that is not stored in the main storage unit is written to the main storage unit, thereby preventing loss of history data. it can.

The block diagram which shows the structure of the data storage apparatus of one Embodiment functionally. The flowchart which shows the operation | movement at the time of switching of an operation side and a standby side. The timing chart which shows the operation | movement at the time of switching. The block diagram which shows the operation | movement at the time of switching.

  Hereinafter, an embodiment of a data storage device according to the present invention will be described.

  FIG. 1 is a block diagram functionally showing the configuration of the data storage device of this embodiment.

  As shown in FIG. 1, the data storage device of the present embodiment is provided with field controllers 3, 3,... (Only one field controller 3 is shown in FIG. 1) distributed in the plant. A data server 1A and a data server 1B that collect plant data, and a large-capacity shared storage 2 that stores data collected by the data server 1A and the data server 1B as history data. The shared storage 2 functions as a main storage unit.

  Field controllers 3, 3,... Are connected to field devices such as sensors and valves, respectively. The field controllers 3, 3,... Execute control calculations based on input data from the sensors, It has a function of transmitting instructions to field devices.

  As shown in FIG. 1, the field controllers 3, 3,... And the data server 1 </ b> A and the data server 1 </ b> B are connected to each other via the control network 4. Further, the data server 1A and the data server 1B are connected to the operation monitoring device 5 via the intranet 6, and sensor values and operations exchanged between the field monitoring devices 3, 3,. Process data such as values and various event data transmitted to the control network 4 can be widely collected and stored in the shared storage 2. For example, the data server 1A and the data server 1B can acquire and store data from an arbitrary field controller 3 at an arbitrary timing.

  The operation monitoring device 5 can display the latest data held by the field controllers 3, 3,... And the history data stored in the shared storage 2. The data server 1 </ b> A and the data server 1 </ b> B provide the latest data and the history data of the shared storage 2 in response to a request from the operation monitoring device 5.

  The data server 1A and the data server 1B have the same function, and constitute a redundant apparatus (redundant apparatus) in which one functions as an active server and the other functions as a standby server.

  As shown in FIG. 1, the data server 1A includes a monitor unit 11A serving as a detection unit that notifies the state with the data server 1B, a main storage unit that collects plant data via the control network 4, and a secondary storage unit. A data collection unit 12A as a storage unit, a local storage 13A corresponding to a secondary storage unit that stores data collected by the data collection unit 12A as history data, and history data stored in the local storage 13A in the shared storage 2 And a transfer unit 14A corresponding to writing means for transferring.

  Similarly, the data server 1B includes a monitor unit 11B serving as a detection unit that notifies the state with the data server 1A, and a main storage unit and a sub storage unit that collect plant data via the control network 4. A data collection unit 12B, a local storage 13B corresponding to a sub-storage unit that stores data collected by the data collection unit 12B as history data, and a history data stored in the local storage 13B is transferred to the shared storage 2 And a transfer unit 14B corresponding to the means.

  The monitor unit 11A and the monitor unit 11B notify the other party of the operating state of the own data server periodically or at an arbitrary timing, and monitor the notification from the other party using a watch dock timer. Also, when it is determined by the watch dock timer that a failure has occurred in the data server of the other party, a notification that the own data server is in operation is output.

  The storage capacities of the local storage 13A and the local storage 13B are small compared to the shared storage 2, and when the limit of the recording capacity is reached, every time the latest data is stored, the oldest data is deleted in order. Accordingly, the local storage 13A or the local storage 13B always stores the most recent history data.

  Next, the operation of the data storage device of this embodiment will be described.

  FIG. 1 shows a case where the data server 1A is in an operating state and the data server 1B is in a standby state. In this case, the data collection unit 12A of the data server 1A sequentially acquires plant data (process data, event data, etc.) preset as collection targets via the control network 4 and stores it as history data in the shared storage 2. To do.

  In addition, the data collection unit 12B of the data server 1B sequentially acquires plant data (process data, event data, etc.) preset as collection targets via the control network 4, and stores the data in the local storage 13B as history data. .

  The contents of the data to be collected in the data server 1A and the data server 1B are the same, and the data collection unit 12A and the data collection unit 12B acquire the same data and store them in the shared storage 2 and the local storage 13B, respectively. .

  Each history data collected by the data server 1A and the data server 1B is given a time stamp.

  As described above, the monitor unit 11A of the data server 1A and the monitor unit 11A of the data server 1B mutually notify the states of the data server 1A and the data server 1B. When the status notification from the data server on the operating side cannot be recognized for a certain period of time, the data server on the standby side is switched to the operating side. Hereinafter, the operation at the time of switching will be described.

  2 is a flowchart showing the operation at the time of switching between the active side and the standby side, FIG. 3 is a timing chart showing the operation at the time of switching, and FIG. 4 is a block diagram showing the operation at the time of switching.

  The flowchart of FIG. 2 shows a procedure when the data server 1B is switched from the standby side (state of FIG. 1) to the operating side.

  In step S1 of FIG. 2, the monitor unit 11B determines whether or not the status notification from the monitor unit 11A of the data server 1A cannot be recognized for a certain time (Δt), and waits for a positive determination to proceed to step S2. move on.

  In step S2, the monitor unit 11B notifies the data collection unit 12B and the transfer unit 14B of switching to the operation side (FIG. 4). Further, the data collection unit 12B that has received the notification of switching to the operation side switches the storage destination of the collected data from the local storage 13B to the shared storage 2 (FIG. 4).

  Next, in step S3, the transfer unit 14B stores the history data last by the data server 1A, that is, the last update time before switching to the operating side, based on the time stamp of the history data stored in the shared storage 2. The acquired time is acquired (FIG. 4).

  Next, in step S4, the transfer unit 14B copies from the local storage 13B history data stored in the local storage 13B after the last update time obtained in step S3, that is, history data not saved in the shared storage 2. (FIG. 4). Here, the history data to be copied is identified based on the time stamp of the history data stored in the local storage 13B.

  Next, in step S5, the transfer unit 14B writes the history data copied in step S4 to the shared storage 2 (FIG. 4), and ends the process.

  In the data storage device of the present embodiment, it is possible to eliminate data storage deficiencies that occur when switching between the active and standby servers. For example, as shown in FIG. 3, when a failure occurs at time t1 and data cannot be stored by the data server 1A on the operating side, a certain time (Δt) until time t2 when the failure is detected in the data server 1B. )Is required. For this reason, a temporary loss occurs in the history data of the shared storage 2. However, since the history data during this time is stored in the local storage 13B, the history data of the shared storage 2 is complemented by writing this data to the shared storage 2. Therefore, in the data storage device of the present embodiment, even if data cannot be stored in the shared storage 2 due to a failure of the data server on the operation side, the history data is not lost.

  After the server on the operating side and the standby side are switched, both data servers execute the same operation symmetrical to the above-described operation, so that it is possible to prevent the loss of history data when the next operation is switched.

  In the above embodiment, the sub storage means or the sub storage unit is configured as a part of the data server functioning as the main storage means. However, the sub storage means or the sub storage unit is separated from the main storage means. It can also be configured as a server.

  The history data handled in the data storage device of the present invention includes event data such as alarms and messages that are notified asynchronously or unexpectedly, in addition to data such as process data collected periodically. Further, the method for specifying the data to be written to the main storage unit is not limited, and the data can be specified based on information other than the time stamp.

  Moreover, although the said embodiment showed the example applied to a duplication apparatus, this invention is applicable also when the main storage part is not duplication. In this case, loss of history data can be prevented by storing history data during a period when the function of the main storage unit is stopped in the secondary storage unit.

  The scope of application of the present invention is not limited to the above embodiment. The present invention can be widely applied to a data storage device that collects plant data and stores it as history data.

11A Monitor unit (detection means)
12A Data collection unit (main storage means and secondary storage means)
13A local storage (secondary storage)
14A Transfer section (writing means)

Claims (5)

In a data storage device that collects plant data and stores it as historical data,
Main storage means for collecting plant data and storing it in the main storage as historical data;
Collecting the data to be collected by the main storage means in parallel with the main storage means and storing the data as history data in the secondary storage section so that the history data stored in the secondary storage section is the latest constant Secondary storage means for sequentially updating the amount of data;
Detecting means for detecting that data storage by the main storage means is stopped;
A writing unit that reads the history data that is not stored in the main storage unit from the sub storage unit and writes the history data to the main storage unit when the stop is detected by the detection unit;
Equipped with a,
The history data is time stamped,
The writing means acquires the time when the history data was last stored in the main storage by the main storage based on the time stamp, and the history stored in the sub-storage after that time. A data storage device for writing data in the main storage unit . The main storage means is duplicated between an operation side and a standby side, and the detection means detects an interruption of an operation that occurs when the main storage means is switched from the operation side to the standby side as the stop. The data storage device according to claim 1.   The data storage device according to claim 1, wherein the plant data is process data.   The data storage device according to claim 1, wherein the plant data is event data. In a data storage method for collecting plant data and storing it as historical data,
A main storage step of collecting plant data and storing it in the main storage as historical data;
Collecting the data to be collected by the main storage step in parallel with the main storage step and storing the data as history data in the sub storage unit so that the history data stored in the sub storage unit is the latest constant A sub-storage step that sequentially updates the amount of data;
A detection step of detecting that data storage by the main storage step is stopped;
A writing step of reading the history data not stored in the main storage unit from the secondary storage unit and writing it to the main storage unit when the stop is detected by the detection step;
Equipped with a,
The history data is time stamped,
In the writing step, based on the time stamp, the time when the history data was last stored in the main storage unit by the main storage step is acquired, and the history stored in the sub storage unit after the time is acquired. A data storage method , wherein data is written to the main storage unit .

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