JP6478714B2 - Monitoring control system, server, client terminal, and monitoring control method - Google Patents

Description

  The present invention relates to a monitoring control system, a server, a client terminal, and a monitoring control method for performing time equivalence between devices via a network.

2. Description of the Related Art Conventionally, SNTP (Simple Network Time Protocol) is known as a method for performing time synchronization between a plurality of devices via a TCP / IP (Transmission Control Protocol / Internet Protocol) network such as the Internet.
Since time equivalence by SNTP is performed via a network, it may be affected by a temporary increase in the load on the network.
For this reason, in order not to unnecessarily increase the load on the network, a method is disclosed in which the timing for performing the next equivalent process is determined based on the magnitude of the time error when the equivalent process is performed. (See Patent Document 1)

JP 2007-214670 A (pages 5 to 7, FIG. 2)

  Since the conventional time equivalence method is configured as described above, it is not sufficient to control the timing of time equivalence processing. For this reason, in the supervisory control system, processing that must be performed at regular intervals or on a regular basis (hereinafter referred to as steady processing) competes with equivalent processing, and the above processing may not be performed or may be performed in duplicate. There was a risk of being unable to monitor and control.

  The present invention has been made in order to solve the above-described problems, and includes a monitoring control system, a server, a client terminal, and a time-equivalent process for performing a time equivalent process so as to suppress a network load and prevent a conflict with a steady process. The purpose is to obtain a monitoring control method.

The monitoring control system according to the present invention is a monitoring control system for performing time information equalization processing between a server and a client terminal connected to the server via a network. According to the error calculation unit for calculating the error with the time information of the timer of the terminal, the statistical data table for storing the time error statistical information for each time zone, and the magnitude of the error of the time information calculated by this error calculation unit In addition, the server includes an equivalent processing interval determination unit that determines the next equivalent processing timing so as not to compete with the regular processing of the monitoring control system, and the server has a timer that generates time information. The client terminal is configured to transmit a time information from a server and a server that generates time information. Based on the time information signal, and a time correcting unit for correcting the time of the own timer, when equivalent processing is configured to transmit the time information before the correction of the own server, equivalent processing interval determiner Uses the time error statistical information to determine the equivalent processing timing .

According to the present invention, there is provided a supervisory control system for performing time information equalization processing between a server and a client terminal connected to the server via a network, wherein the time information of the server timer and the timer of the client terminal An error calculation unit that calculates an error from time information, a statistical data table that stores time error statistical information for each time zone, and a monitoring control system according to the magnitude of the time information error calculated by the error calculation unit The equivalent processing interval determination unit that determines the next equivalent processing timing is provided so that the server does not compete with the regular processing, and the server has a timer that generates time information, and transmits the time information to the client terminal in the equivalent processing. The client terminal is configured based on a timer that generates time information and time information transmitted from the server. And a time correcting unit for correcting the time of the own timer, when equivalent processing is configured to transmit the time information before the correction of the own server, equivalent processing interval determination unit, using the time error statistics Thus, since the equivalent process timing is determined , the steady process of the monitoring control system can be normally executed while suppressing the network load for the equivalent process of the time information.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram which shows the monitoring control system by Embodiment 1 of this invention. It is a flowchart which shows the flow after determining the timing which issues the request | requirement of the next equivalent process after the request | requirement of an equivalent process is transmitted from the server of the monitoring control system by Embodiment 1 of this invention. It is a block diagram which shows the monitoring control system by Embodiment 2 of this invention. It is a flowchart which shows the flow after determining the timing which issues the request | requirement of the internal time of the next server after the request | requirement of the internal time of the server is transmitted from the client terminal of the monitoring control system by Embodiment 2 of this invention. It is a block diagram which shows the monitoring control system by Embodiment 3 of this invention. It is a flowchart which shows the flow after determining the timing which issues the request | requirement of the internal time of the next server after the request | requirement of the internal time of the server is transmitted from the client terminal of the monitoring control system by Embodiment 3 of this invention. It is a block diagram which shows the monitoring control system by Embodiment 4 of this invention. It is a flowchart which shows the flow after determining the timing which issues the request | requirement of the next equivalent process after the request | requirement of an equivalent process is transmitted from the server of the monitoring control system by Embodiment 4 of this invention. It is a flowchart which shows the flow after determining the timing which issues the request | requirement of the internal time of the next server after the request | requirement of the internal time of the server is transmitted from the client terminal of the monitoring control system by Embodiment 4 of this invention. It is a block diagram which shows the monitoring control system by Embodiment 5 of this invention. It is a flowchart which shows the flow until it determines the timing which issues the request | requirement of the next equivalent process after the request | requirement of an equivalent process is transmitted from the server of the monitoring control system by Embodiment 5 of this invention.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing a monitoring control system according to Embodiment 1 of the present invention.
In FIG. 1, the monitoring control system includes a server 100 and a client terminal 200 connected to the server 100 via a network.
The server 100 is configured as follows.
The timer 110 is an internal clock that generates time information. The request transmission unit 120 transmits an equivalent process request to the client terminal 200. The response receiving unit 130 receives a time response from the client terminal 200. The error calculator 140 calculates the timer error between the server 100 and the client terminal 200. The transmission interval determining unit 150 (equivalent processing interval determining unit) determines the timing for performing the next equivalent processing. The equivalent processing timing table 160 holds list information of timing candidates for performing equivalent processing. For example, timing candidates for equivalent time processing are set in advance so as not to compete with steady processing of the monitoring control system over a predetermined period of 24 hours. The timing for performing the next equivalent process is determined by selecting this timing candidate.

The client terminal 200 is configured as follows.
The timer 210 is an internal clock that generates time information. The request reception unit 220 receives a request for time equivalence processing from the server 100. The response transmission unit 230 responds to the server 100 with the internal time of the client terminal 200 before performing the equivalent process. The time correction unit 240 corrects the time of the timer 210 based on the time received from the server 100.

Next, the operation will be described.
A flow from when the request for equivalent processing is transmitted from the server 100 to when the timing for issuing the next request for equivalent processing is determined will be described with reference to the flowchart of FIG.
The request transmission unit 120 of the server 100 transmits a request for time equivalence processing and the internal time of the server 100 to the client terminal 200 (ST1001, first step).
The request reception unit 220 of the client terminal 200 receives the equivalence processing request and the internal time of the server 100, and transmits the internal time of the server 100 to the time correction unit 240 (ST1002).
Time correction section 240 transmits the internal time of client terminal 200 to response transmission section 230, and corrects the internal time of timer 210 with the internal time of server 100 (ST1003, third step).

Response transmitting section 230 transmits the internal time of client terminal 200 to server 100 (ST1004, second step).
The response reception unit 130 of the server 100 receives the internal time of the client terminal 200 and transmits the internal time of the client terminal 200 to the error calculation unit 140 (ST1005).
Error calculation section 140 compares the internal times of server 100 and client terminal 200 (fourth step), and transmits error magnitude Δt to transmission interval determination section 150 (ST1006).
Transmission interval determination section 150 compares error thresholds t1 and t2 (t1> t2) with the magnitude of Δt (ST1007).
When Δt> t1, transmission interval determination section 150 halves the time until the next request for equivalent processing is issued (ST1008).
When Δt <t2, transmission interval determination section 150 multiplies the time until the next request for equivalent processing is issued by 1.5 times (ST1009).
When t2 ≦ Δt ≦ t1, transmission interval determination section 150 does not change the time until the next equivalent process is issued (ST1010).
The transmission interval determination unit 150 selects, from the equivalent processing timing table 160, a timing candidate immediately after the time until the next equivalent processing request is issued (the time calculated as described above from the previous equivalent processing timing). (5th step), it transmits to the request | requirement transmission part 120 as a next equivalent process timing (ST1011).
In subsequent operations, ST1001 to ST1011 are repeated.

As described above, according to the first embodiment, it is possible to prevent a situation in which the steady process and the equivalent process of the monitoring control system compete with each other, and the steady process can be executed normally.
In the first embodiment, a case where there is one client terminal has been described. However, a similar effect can be obtained even in a monitoring control system having a plurality of client terminals.
In the first embodiment, the interval until the next request for equivalent processing to be set is made half or 1.5 times depending on the magnitude relationship between the error threshold value and the error magnitude. Even if the value is arbitrary, the same effect can be obtained.

Embodiment 2. FIG.
FIG. 3 is a block diagram showing a monitoring control system according to Embodiment 2 of the present invention.
In FIG. 3, reference numerals 100, 110, 200, 210, and 240 are the same as those in FIG. In FIG. 3, the server 100 receives a timer 110 that is an internal clock for generating time information, a response transmission unit 121 that responds to the client terminal 200 with the internal time of the server 100, and an internal time request from the client terminal 200. A request receiving unit 131 is provided.
In addition, the client terminal 200 receives a response reception unit 221 that receives the internal time from the server 100, the request transmission unit 231 that requests the server 100 for the internal time of the server 100, and a time correction unit 240 that corrects the time of the timer 210. An error calculation unit 250 that calculates the timer error between the server 100 and the client terminal 200, a transmission interval determination unit 260 (equivalent processing interval determination unit) that determines the timing for performing the next equivalent process, and a timing candidate for performing the equivalent process The equivalent processing timing table 270 that holds the list information is provided.

In the second embodiment, the error calculation unit, the transmission interval determination unit, and the equivalent processing timing table are moved from the server 100 to the client terminal 200 with respect to the first embodiment. A request for transmission of the internal time is issued.
As a result, it is possible to obtain a supervisory control system having a highly functional time equivalent method.

The operation will be described below.
A flow from when a request for the internal time of the server 100 is transmitted from the client terminal 200 to the server 100 until a timing for issuing a request for the internal time of the next server 100 is determined will be described with reference to FIG.
The request transmission unit 231 of the client terminal 200 transmits a request for the internal time of the server 100 to the server 100 (ST1012). That is, an equivalent process is requested from the client terminal 200.
The request receiving unit 131 of the server 100 receives the request from the client terminal 200, and transmits the internal time of the server 100 to the response transmitting unit 121 (ST1013).
Response transmission section 121 transmits the internal time of server 100 to client terminal 200 (ST1014).
The response reception unit 221 of the client terminal 200 receives the internal time of the server 100 and transmits the internal time of the server 100 to the time correction unit 240 (ST1015).

Time correction section 240 transmits the internal time of server 100 to error calculation section 250 and corrects the internal time of timer 210 based on the internal time of server 100 (ST1016).
The time from when the error calculation unit 250 compares the internal time of the server 100 and the internal time of the client terminal 200 until the transmission interval determination unit 260 issues a request for the next equivalent process according to the size of the error. The flow until determining is the same as ST1006 to ST1010 of the first embodiment.
Transmission interval determining section 260 selects a timing candidate immediately after the time until the next equivalent process request is issued from equivalent process timing table 270, and transmits it to request transmitter 231 as the next equivalent process timing (ST1017).
Subsequent operations repeat steps ST1012 to ST1017.

  In this way, according to the second embodiment, by issuing a request for equivalent processing from a client terminal, in the case of a monitoring control system having a plurality of client terminals, equivalent processing can be performed at a timing suitable for each client terminal. Therefore, there is an effect that the network load of the supervisory control system is reduced.

Embodiment 3 FIG.
FIG. 5 is a block diagram showing a monitoring control system according to Embodiment 3 of the present invention.
In FIG. 5, reference numerals 100, 110, 121, l31, 200, 210, 221, 231, 240, 250, and 260 are the same as those in FIG. In FIG. 5, the client terminal 200 is provided with a client processing timing table 290 that stores a list of information on processing performed by the client terminal 200 and a client terminal processing management unit 280 that manages the client processing timing table 290.

  The third embodiment is different from the second embodiment in that a client processing timing table 290 that stores a list of information on processing performed in the client terminal 200 and a client that manages the client processing timing table 290 instead of the equivalent processing timing table 270. A terminal processing management unit 280 is provided. As a result, it is possible to obtain a supervisory control system having a highly functional time equivalent method.

The operation will be described below.
The flow from when the request for the internal time of the server 100 is transmitted from the client terminal 200 to when the timing for issuing the internal time request for the next server 100 is determined will be described with reference to FIG.
From when the request transmission unit 231 of the client terminal 200 transmits a request for the internal time of the server 100 to the server 100, until the transmission interval determination unit 260 issues a request for the next equivalent processing according to the magnitude of the error. The flow until the time is determined is the same as ST1012 to ST1010 of the second embodiment.

The transmission interval determination unit 260 of the client terminal 200 transmits time for issuing a request for the next equivalent processing to the client terminal processing management unit 280 (ST1018).
The client terminal processing management unit 280 refers to the client processing timing table 290, selects the timing immediately after the time until the next equivalent processing request is issued so as not to conflict with the processing of the client terminal 200, and It transmits to the request transmission part 231 as an equivalent process timing (ST1019).
Subsequent operations repeat steps ST1012 to ST1019.

  As described above, according to the third embodiment, since the equivalent process can be performed without competing with the dynamic process of the client terminal, there is an effect that the dynamic process can be normally executed.

Embodiment 4 FIG.
FIG. 7 is a block diagram showing a monitoring control system according to Embodiment 4 of the present invention.
7, 100, 110, 140, 150, 160, 200, 210, and 240 are the same as those in FIG. 1, and 250, 260, and 270 are the same as those in FIG. In FIG. 7, a request / response transmission unit 122 that transmits an internal time request to the client terminal 200 and transmits a response to the internal time request from the client terminal 200 to the server 100, and an internal time from the client terminal 200. A request / response receiving unit 132 for receiving a request and receiving a response of the internal time from the client terminal 200 is provided.
In addition, the client terminal 200 transmits a request for internal time to the server 100 and transmits a response to the request for internal time from the server 100, and receives a request for internal time from the server 100. In addition, a request / response receiving unit 222 that receives a response of the internal time from the server 100 is provided.

The fourth embodiment is different from the first embodiment in that an error calculation unit 250, a transmission interval determination unit 260, and an equivalent processing timing table 270 are provided in the client terminal 200, and time equivalent processing is performed from both the server 100 and the client terminal 200. A request is issued. As a result, it is possible to obtain a supervisory control system having a highly functional time equivalent method.

The operation will be described below.
First, the flow from when a request for equivalent processing is transmitted from the server 100 to when the timing for issuing the next request for equivalent processing is determined will be described with reference to FIG.
The request / response transmission unit 122 of the server 100 transmits a request for equivalent processing and the internal time of the server 100 to each client terminal 200 (ST1020).
The request / response receiving unit 222 of each client terminal 200 receives the equivalence processing request and the internal time of the server 100, and transmits the internal time of the server 100 to the time correction unit 240 (ST1021).
The time correction unit 240 transmits the internal time of the client terminal 200 to the request / response transmission unit 232, transmits the internal time of the server 100 to the error calculation unit 250, and sets the internal time of the timer 210 according to the internal time of the server 100. Correction is performed (ST1022).
Request / response transmission section 232 transmits the internal time of client terminal 200 to server 100 (ST1023).

Error calculation section 250 compares the internal times of server 100 and client terminal 200, and transmits error magnitude Δt to transmission interval determination section 260 (ST1006).
Transmission interval determination section 260 deletes the schedule of time until the next request for equivalent processing is issued (ST1024).
The flow from when the transmission interval determining unit 260 determines the time until the request for the next equivalent processing is issued after comparing the error thresholds t1 and t2 (t1> t2) with the magnitude of Δt is described in the embodiment. 1 is the same as ST1007 to ST1010.

Request / response receiving section 132 of server 100 receives the internal time of client terminal 200 and transmits the internal time of client terminal 200 to error calculation section 140 (ST1025).
Error calculation section 140 calculates the average value of the time error magnitude of each client terminal, and transmits error magnitude Δt to transmission interval determination section 150 (ST1026).
The flow from when the transmission interval determining unit 150 compares the error thresholds t1 and t2 (t1> t2) and the magnitude of Δt until determining the time until the next request for equivalent processing is issued is described in the first embodiment. This is the same as ST1007 to ST1010.
Transmission interval determination section 150 selects a timing candidate immediately after the time until a request for the next equivalent process is issued from equivalent process timing table 160, and transmits it to request / response transmission section 122 as the next equivalent process timing (ST1027). ).
In subsequent operations, ST1020 to ST1027 are repeated.

Next, the flow from when a request for the internal time of the server 100 is transmitted from the client terminal 200 to when the timing for issuing the internal time request of the next server 100 is determined will be described with reference to FIG.
Request / response transmission section 232 of client terminal 200 transmits a request for the internal time of server 100 to server 100 (ST1028).
The request / response receiving unit 132 of the server 100 receives the request from the client terminal 200 and transmits the internal time of the server to the request / response transmitting unit 122 (ST1029).
Request / response transmission section 122 transmits the internal time of the server to client terminal 200 (ST1030).

The request / response receiving unit 222 of the client terminal 200 receives the internal time of the server 100, and transmits the internal time of the server 100 to the time correction unit 240 (ST1031).
The time from when the time correction unit 240 transmits the internal time of the server 100 to the error calculation unit 250 until the transmission interval determination unit 260 determines the time until the next request for equivalent processing is issued according to the magnitude of the error. The flow is the same as ST1016 to ST1010 of the second embodiment.
Transmission interval determining section 260 selects a timing candidate immediately after the time for issuing the next equivalent process request from equivalent process timing table 270, and transmits it to request / response transmitter 232 as the next equivalent process timing (ST1032). .
In subsequent operations, ST1028 to ST1032 are repeated.

  As described above, according to the fourth embodiment, it is possible to perform equivalent processing at a timing suitable for each client terminal while collectively transmitting requests for equivalent processing from the server to each client terminal. This has the effect of reducing the load on the network.

Embodiment 5. FIG.
FIG. 10 is a block diagram showing a monitoring control system according to Embodiment 5 of the present invention.
10, reference numerals 100, 110, 120, 130, 140, 150, 160, 200, 210, 220, 230, and 240 are the same as those in FIG. In FIG. 10, the server 100 is provided with a statistical data table 180 that stores time error statistical information for each time zone and a statistical data management unit 170 that manages the statistical data table 180. The statistical data table 180 stores, as time error statistical information, an average value of time errors for each time zone and the number of time errors (number of data) from which the average value is calculated.

  The fifth embodiment is different from the first embodiment in that a statistical data table 180 that stores time error statistical information for each time zone and a statistical data management unit 170 that manages the statistical data table 180 are provided. is there. As a result, it is possible to obtain a supervisory control system having a highly functional time equivalent method.

Next, the operation will be described.
The flow from when the request for equivalent processing is transmitted from the server 100 to when the timing for issuing the next request for equivalent processing is determined will be described with reference to FIG.
After the request transmission unit 120 of the server 100 transmits the request for equivalent processing and the internal time of the server 100 to the client terminal 200, the response reception unit 130 receives the internal time of the client terminal 200, and the error calculation unit 140 The flow until the internal time of terminal 200 is transmitted is the same as ST 1001 to ST 1005 of the first embodiment.
Error calculation section 140 compares the internal times of server 100 and client terminal 200, and transmits error magnitude Δt to transmission interval determination section 150 and statistical data management section 170 (ST1033).
Transmission interval determination section 150 requests statistical data management section 170 for time error statistical information for the current time zone (ST1034).

Statistical data management section 170 acquires time error statistical information for the requested time zone from statistical data table 180 and transmits it to transmission interval determination section 150 (ST1035).
Transmission interval determination section 150 compares value Δt ′ obtained by subtracting time error statistical information from Δt with error threshold values t1 and t2 (t1> t2) (ST1036).
When Δt ′> t1, transmission interval determination section 150 halves the time until the next request for equivalent processing is issued (ST1037).
When Δt ′ <t2, transmission interval determination section 150 multiplies the time until the next request for equivalent processing is issued by 1.5 times (ST1038).
When t2 ≦ Δt ′ ≦ t1, transmission interval determining section 150 does not change the time until the next equivalent process is performed (ST1039).

Statistical data management section 170 calculates an average value to which the current time error is added, adds 1 to the number of time errors for which the average value has been calculated, and updates statistical data table 180 (ST1040).
Transmission interval determination section 150 selects a timing candidate immediately after the time until the next equivalent processing request is issued from equivalent processing timing table 160, and transmits it to request transmission section 120 as the next equivalent processing timing (ST1011). .
In subsequent operations, ST1001 to ST1011 are repeated.

  As described above, according to the fifth embodiment, the interval until the next equivalent process is determined according to the past trend, and the timing of the equivalent process can be optimized in a shorter time, and the load on the network is reduced. It has the effect of decreasing.

  In the fifth embodiment, the time error statistical information of the current time zone is used, but date and day of week statistics and a combination of these parameters may be used. Even in that case, the same effect can be obtained.

  It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

100 server, 110 timer, 120 request transmission unit, 121 response transmission unit,
122 request / response transmission unit, 130 response reception unit, 131 request reception unit,
132 request / response receiver, 140 error calculator, 150 transmission interval determiner,
160 equivalent processing timing table, 170 statistical data management unit,
180 statistical data table, 200 client terminal, 210 timer,
220 request receiver, 221 response receiver, 222 request / response receiver,
230 response transmitter, 231 request transmitter, 232 request / response transmitter,
240 time correction unit, 250 error calculation unit, 260 transmission interval determination unit,
270 equivalent processing timing table, 280 client terminal processing management unit,
290 Client processing timing table

Claims (12)

A monitoring control system for performing time information equalization processing between a server and a client terminal connected to the server via a network,
An error calculator for calculating an error between the time information of the timer of the server and the time information of the timer of the client terminal;
Statistical data table that stores time error statistical information for each time zone,
And according to the magnitude of the error of the time information calculated by the error calculation unit, an equivalent processing interval determination unit that determines the next equivalent processing timing so as not to compete with the steady processing of the monitoring control system,
The server
It has a timer that generates time information,
In the equivalent process, the time information is configured to be transmitted to the client terminal,
The client terminal
A timer for generating time information;
A time correction unit that corrects the time of its own timer based on the time information transmitted from the server,
In the equivalent process, it is configured to transmit its time information before correction to the server ,
The monitoring control system, wherein the equivalent processing interval determination unit determines the equivalent processing timing using the time error statistical information . A monitoring control system for performing time information equalization processing between a server and a client terminal connected to the server via a network,
The server
An error calculator for calculating an error between the time information of the timer of the server and the time information of the timer of the client terminal;
And an equivalent processing interval determination unit that determines the next equivalent processing timing so as not to compete with the steady processing of the monitoring control system, according to the magnitude of the error of the time information calculated by the error calculation unit,
It has a timer that generates time information,
In the equivalent process, the time information is configured to be transmitted to the client terminal,
The client terminal
A timer for generating time information;
A time correction unit that corrects the time of its own timer based on the time information transmitted from the server,
In the equivalent process, it is configured to transmit its time information before correction to the server,
When there are a plurality of the client terminals, the error calculation unit calculates an average value of errors between the server and each of the different client terminals,
The monitoring control system, wherein the equivalent processing interval determination unit determines the next equivalent processing timing in accordance with the calculated average value of errors . An equivalent process timing table storing a plurality of equivalent process timing candidates created in advance so as not to compete with the steady process of the monitoring control system over a predetermined period of time,
3. The supervisory control system according to claim 1, wherein the equivalent processing interval determination unit determines the next equivalent processing timing with reference to the equivalent processing timing table. The error calculation unit and the equivalent processing interval determination unit are arranged in the server,
Claim 1 Symbol placement of the supervisory control system, characterized in that to request the equivalent process in the client terminal from the server. When there are a plurality of the client terminals, the error calculation unit calculates an average value of errors between the server and each of the different client terminals,
The monitoring control system according to claim 4, wherein the equivalent processing interval determination unit determines the next equivalent processing timing in accordance with the calculated average value of errors. The error calculation unit and the equivalent processing interval determination unit are arranged in the client terminal,
The client terminal
A client processing timing table storing the processing timing of the client terminal for a predetermined period;
The monitoring control system according to claim 1, wherein the equivalent processing interval determination unit determines the next equivalent processing timing so as to avoid the processing timing of the client processing timing table. The error calculation unit and the equivalent processing interval determination unit are arranged in the client terminal,
Claim 1 Symbol placement of the supervisory control system, characterized in that to request the equivalent process in the server from the client terminal. The error calculation unit and the equivalent processing interval determination unit are arranged in the server and the client terminal, respectively.
Said server and said client terminal, according to claim 1 Symbol placement of the supervisory control system, respectively, characterized in that to be able to request the equivalent process to the other. A server that constitutes a monitoring control system together with a client terminal connected via a network, and performs an equivalent process of time information with the client terminal,
A timer that generates time information,
An error calculator for calculating an error between the time information of the timer and the time information transmitted from the client terminal;
An equivalent process timing table storing a plurality of candidates for equivalent process timings created in advance so as not to compete with the steady process of the monitoring control system over a predetermined period;
And according to the magnitude of the error of the time information calculated by the error calculation unit, with reference to the equivalent processing timing table, an equivalent processing interval determination unit that determines the next equivalent processing timing,
In performing the equivalent process, the time information of the timer is configured to be transmitted to the client terminal,
When there are a plurality of the client terminals, the error calculation unit calculates an average value of errors between the server and each of the different client terminals,
The server according to claim 1, wherein the equivalent processing interval determination unit determines a next equivalent processing timing in accordance with the calculated average value of errors . A server that constitutes a monitoring control system together with a client terminal connected via a network, and performs an equivalent process of time information with the client terminal,
A timer that generates time information,
An error calculator for calculating an error between the time information of the timer and the time information transmitted from the client terminal;
An equivalent process timing table storing a plurality of candidates for equivalent process timings created in advance so as not to compete with the steady process of the monitoring control system over a predetermined period;
Statistical data table that stores time error statistical information for each time zone,
And an equivalent processing interval determining unit that determines the next equivalent processing timing with reference to the equivalent processing timing table and the statistical data table in accordance with the magnitude of the error of the time information calculated by the error calculating unit. ,
A server configured to transmit time information of the timer to the client terminal in performing the equivalent process. A client terminal that configures a monitoring control system together with a server connected via a network and performs an equivalent process of time information with the server,
A timer that generates time information,
An error calculator for calculating an error between the time information of the timer and the time information transmitted from the server;
A client processing timing table storing the processing timing of the client terminal for a predetermined period;
An equivalent processing interval determination unit that determines the next equivalent processing timing so as to avoid the processing timing of the client processing timing table according to the magnitude of the error of the time information calculated by the error calculation unit,
A client terminal comprising a time correction unit that corrects the time of its own timer based on time information received from the server. A first step of configuring a monitoring control system together with a client terminal connected via a network, and performing a time information equivalent process with the client terminal, transmitting timer time information to the client terminal,
A second step in which the client terminal transmits time information before correction of its timer to the server;
A third step in which the time correction unit of the client terminal corrects the time of its own timer based on the time information from the server;
A fourth step in which the error calculation unit of the server calculates an error between the time information of the timer of the server and the time information received from the client terminal;
And the equivalent processing interval determination unit of the server refers to an equivalent processing timing table storing a plurality of equivalent processing timing candidates created in advance so as not to compete with the steady processing of the monitoring control system. depending on the magnitude of the error of the calculated the time information, a fifth step of determining a next equivalent processing timing seen including,
The fifth step is a monitoring control method, wherein the equivalent processing timing is determined using time error statistical information for each time zone stored in a statistical data table .

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