JP2000324567A - Remote monitor system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a remote monitor system which guarantees maximum throughput of a plant monitor device by limiting the maximum quantity of a data acquisition request to the plant monitor device. SOLUTION: The remote monitor system is equipped with the plant monitor device 1 which monitors an object plant to be monitored, a data distribution device 3 which is provided on the monitored object side and sends a data acquisition request to the plant monitor device in response to the reception of the data acquisition request to acquire and distribute data of the plant complying with the data acquisition request from the plant monitor device, and multiple remote monitor devices 2 which are installed at remote places and send data acquisition requests to the data distribution device 3 through a data transmission line and receive data of the plant complying with the data acquisition requests. In this case, the data distribution device 3 limits the maximum number of the remote monitor devices to which data are distributed by checking the number of the remote monitor devices having made the data acquisition requests.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote monitoring system for monitoring the status of a plant at a remote place remote from the plant in real time.

[0002]

2. Description of the Related Art FIG. 8 is a block diagram showing the configuration of a conventional remote monitoring system disclosed in, for example, Japanese Patent Application Laid-Open No. 10-41861. In FIG. 8, reference numeral 1 denotes a plant monitoring device which is placed near a plant to be monitored and monitors the plant in a central control room or the like, and collects plant data from the controllers 4A and 4B via the plant network 100. Data collection processing unit 10
And display processing unit 11 for displaying collected data on a CRT or the like
And a data transmission processing unit 12 for transmitting the current value data of the plant via the data distribution device 3 described later.

The remote control 2 is installed in a remote place such as an office or home away from the plant, and is used to monitor the plant in a remote place using a general PC (personal computer) or workstation. It is a monitoring device and includes a data acquisition processing unit 20 that acquires current value data of a plant, and a display processing unit 21 that displays the current value of a plant. A plurality of the remote monitoring devices 2 are installed.

[0004] Further, reference numeral 3 denotes a data distribution device for acquiring the current value data of the plant from the plant monitoring device 1 and transmitting the data to the remote monitoring device 2, and a data acquisition processing unit 30 for acquiring data from the plant monitoring device 1. And a data transmission processing unit 31 for transmitting data acquired from the plant monitoring device 1 to the remote monitoring device 2. The data distribution device 3 is connected to the plant monitoring device 1 via the LAN 300 and is connected to the remote monitoring device 2 via a data transmission line 200 such as a LAN, a WAN, or a public line.

Next, the operation will be described. The display processing unit 21 of the remote monitoring device 2 transmits the plant current value data to the CRT.
A request for data acquisition is made to the data acquisition processing unit 20 to display the data. The data acquisition processing unit 20 transmits a request from the data acquisition processing unit 20 to the data transmission processing unit 31 of the data distribution device 3.

The data transmission processing unit 31 of the data distribution device 3
Receives the data acquisition from the remote monitoring device 2 and makes a data acquisition request to the data acquisition processing unit 30. Next, the data acquisition processing unit 30 of the data distribution device 3 issues a data acquisition request to the data transmission processing unit 12 of the plant monitoring device 1.

[0007] Data transmission processing unit 1 of plant monitoring device 1
2 acquires the current value data of the plant collected by the data collection processing unit 10 according to the content of the data acquisition request. The current value data acquired by the data transmission processing unit 12 is transmitted to the data acquisition processing unit 30, the data transmission processing unit 31, and the data acquisition processing unit 2 of the remote monitoring device 2 of the data distribution device 3.
0, the data is sent to the display processing unit 21 of the remote monitoring device 2 and is displayed on the CRT by the display processing unit 21. Or later,
The same process is periodically repeated, and the remote monitoring device 2 displays the current value data of the latest plant.

[0008]

Since the conventional remote monitoring system is configured as described above, as the number of remote monitoring devices 2 increases, the amount of data transmission increases. However, there is a problem that the processing amount increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and a remote processing system capable of guaranteeing the maximum processing amount of a plant monitoring device by limiting the maximum amount of a data acquisition request to the plant monitoring device. The purpose is to obtain a monitoring system.

[0010]

A remote monitoring system according to the present invention includes a plant monitoring device for monitoring a plant to be monitored and a plant monitoring device provided on the monitoring target side based on reception of a data acquisition request. A data distribution device that issues a data acquisition request and acquires and distributes data of a plant corresponding to the data acquisition request from the plant monitoring device; and a data acquisition request that is installed in a remote location and transmitted to the data distribution device via a data transmission path. And a plurality of remote monitoring devices for receiving the data of the plant in response to the data acquisition request, wherein the data distribution device checks the number of the remote monitoring devices that have requested the data acquisition and sets the maximum number of the remote monitoring devices for data distribution. It is characterized by limiting the number.

The data distribution device includes a data transmission processing unit for requesting communication permission of a corresponding remote monitoring device based on a data acquisition request from the remote monitoring device, and an ID number of the remote monitoring device that has requested the data acquisition. And a management table for registering the number, and a communication permission request from the data transmission processing unit is received, and the number of remote monitoring devices registered in the management table is checked. The ID number of the device is registered in the management table and the data transmission processing unit is notified of the communication permission. If the number of registrations is equal to or greater than the set number, the data transmission is performed without registering the ID number of the remote monitoring device. And a management unit for notifying the processing unit of the communication rejection, wherein the data transmission processing unit transmits a communication permission notification from the management unit to the remote monitoring device. Performed only data delivery, the remote monitoring device that received the communication rejection notification is characterized in that to return the response data acquisition failure.

According to another aspect of the present invention, there is provided a remote monitoring system for monitoring a plant to be monitored, and a data acquisition request provided to the plant monitoring device based on the reception of the data acquisition request. And a data distribution device for acquiring and distributing plant data in response to the data acquisition request from the plant monitoring device, and a data acquisition request to the data distribution device installed at a remote location via a data transmission path, and A plurality of remote monitoring devices that receive distribution of plant data in response to the data acquisition request, wherein the data distribution device counts data acquisition requests from the remote monitoring devices and limits the maximum number thereof. Is what you do.

Further, the data distribution device is characterized in that the totalized data acquisition requests are collectively requested to the plant monitoring device to acquire the current value data of the plant.

Further, the data distribution device is characterized in that data acquisition requests from a plurality of remote monitoring devices are counted without duplication.

Further, the data distribution device notifies the plant monitoring device of the counting result, and the plant monitoring device periodically transmits the current value data of the plant to the data distribution device based on the notified counting result. It is characterized by transmitting.

Further, the data distribution device stores a previous value of the data obtained from the plant monitoring device, compares the previous value with the current value, and transmits updated data to the remote monitoring device only when the value is different. It is characterized by the following.

The data distribution device includes a data transmission processing unit that receives a data acquisition request from the remote monitoring device, and a tally table that stores data acquisition requests from a plurality of remote monitoring devices for a predetermined number of records. And a current value table for storing current value data from the plant monitoring device, and storing the data acquisition request received from the data transmission processing unit in the aggregation table, and setting the data acquisition request in the aggregation table in advance. And a counting unit that notifies the data transmission processing unit of communication rejection when the number of records exceeds the number of records.
Acquire current value data from the plant monitoring device based on the data acquisition request saved in the aggregation table, and save the acquired data in the current value table,
Reading the current value data stored in the current value table, distributing the data to the remote monitoring device that issued the request, and returning a data acquisition failure response to the remote monitoring device that received the communication rejection notification from the counting unit. It is characterized by the following.

The totaling table has a request counter for counting the number of requests for each data acquisition request. If the data acquisition request has already been stored, only the request counter for the corresponding record position is counted up,
When a data acquisition request for only the end index is received, the request counter of the corresponding record position is counted down,
It is characterized in that a data acquisition request whose count number has become zero is deleted.

Further, the data distribution device further includes a data acquisition processing unit for transmitting the contents of the tally table to the plant monitoring device when the contents of the tally table are changed. And a data transmission process for periodically transmitting the current value data of the plant to the data distribution device in response to a data acquisition request stored in the plant monitoring side total table storing the received contents. And a device.

Further, the data distribution device further includes a current value table for storing current value data of the plant, and a previous value table for storing previous value data of the plant. The data stored in the current value table is transmitted to the remote monitoring device only when the data values stored in the table and the previous value table are changed, and the data in the current value table are stored in the previous value table. It is characterized by copying.

[0021]

Embodiments of the present invention will be described below. Embodiment 1. FIG. 1 is a block diagram showing a configuration of a remote monitoring system according to Embodiment 1. In the figure, 1
Is a plant monitoring device that is placed near the plant to be monitored and monitors the plant in a central control room or the like, and includes a data collection processing unit 10 that collects data from the controllers 4A and 4B through the plant network 100. , A display processing unit 11 that displays collected data on a CRT or the like, and a data transmission processing unit 12 that transmits the current value data of the plant to the data distribution device 3 described below.

Reference numeral 2 denotes a remote server which is installed at a remote place away from the plant, such as an office or a home, and sends a data acquisition request to a data distribution device 3 described later using a general PC (personal computer) or workstation. A remote monitoring device for monitoring the plant at a remote location so as to receive the distribution of the plant data in response to the data acquisition request, and a data acquisition processing unit 20 for acquiring the current value data of the plant; Has a display processing unit 21 for displaying the current value of. A plurality of remote monitoring devices 2 are installed, and an individual ID number is assigned to each remote monitoring device.

Reference numeral 3 denotes a data distribution device for acquiring the current value data of the plant from the plant monitoring device 1 based on the data acquisition request from the remote monitoring device 2 and transmitting the data to the remote monitoring device 2. A data acquisition processing unit 30 for acquiring data from the device 1, a data transmission processing unit 31 for transmitting data acquired from the plant monitoring device 1 to the remote monitoring device 2, and managing a data acquisition request from the remote monitoring device 2 And a management table 33 for storing the ID numbers and the numbers of the remote monitoring devices in use. The data distribution device 3 is connected to the plant monitoring device 1 via the LAN 300 and is connected to the remote monitoring device 2 via a data transmission line 200 such as a LAN, a WAN, or a public line.

Next, the operation will be described. The display processing unit 21 of the remote monitoring device 2 transmits the plant current value data to the CRT.
A request for data acquisition is made to the data acquisition processing unit 20 to display the data. This acquisition request includes a list of point numbers of plant data to be displayed and the ID number of the remote monitoring device 2. The data acquisition processing unit 20 transmits a request from the data acquisition processing unit 20 to the data transmission processing unit 31 of the data distribution device 3.

FIG. 2 is a flowchart for explaining the operation contents of the data transmission processing unit 31 and the management unit 32 of the data distribution device 3. Data transmission processing unit 31 of data distribution device 3
Receives a data acquisition request from the remote monitoring device 2 (step ST11), and issues a communication permission request to the management unit 32 (step ST12). The management unit 32 receives the communication permission request from the data transmission processing unit 31 (Step S
T21), the number of remote monitoring devices registered in the management table 33 is checked (step ST22).

If the number of registrations is smaller than the predetermined maximum number, the ID number of the remote monitoring device is registered in the management table 33 (step ST23), and the data transmission processing unit 3
1 is notified of communication permission (step ST24).
If the number of registrations is equal to or larger than the maximum number, the ID number is not registered, and the data transmission processing unit 31 is notified of the refusal of communication (step ST25). When receiving the communication permission notification from the management unit 32, the data transmission processing unit 31 issues a data acquisition request to the data acquisition processing unit 30 (step ST1).
5). When the communication rejection notification is received, a response of data acquisition failure is returned to the data acquisition processing unit 20 of the remote monitoring device 2 (step ST16).

Next, the data acquisition processing unit 30 of the data distribution device 3
2 is issued a data acquisition request. Plant monitoring device 1
The data transmission processing unit 12 acquires the current value data of the plant collected by the data collection processing unit 10 according to the content of the data acquisition request. The current value data acquired by the data transmission processing unit 12 is transmitted to the display processing unit of the remote monitoring device 2 through the data acquisition processing unit 30, the data transmission processing unit 31, and the data acquisition processing unit 20 of the remote monitoring device 2 of the data distribution device 3. The display processing unit 21 performs display on the CRT. Thereafter, the same processing is periodically repeated, and the current value data of the latest plant is displayed on the remote monitoring device.

As described above, according to the first embodiment, since the maximum number of remote monitoring devices 2 used simultaneously by the data distribution devices 3, that is, the maximum number of remote monitoring devices 2 that distribute data, is limited. The maximum amount of data acquisition requests to the monitoring device 1 can be limited, and the maximum processing amount of the plant monitoring device 1 can be guaranteed. This makes it possible to construct a remote monitoring system that does not affect the processing of the original plant monitoring device 1.

Embodiment 2 FIG. 3 is a block diagram showing a configuration of a remote monitoring system according to Embodiment 2. In FIG. 2, the same parts as those in FIG. 1 are denoted by the same reference numerals, and redundant description will be omitted. As a new code, 32 'is a counting unit that counts data acquisition requests from the remote monitoring device 2, 33'
Is a tabulation table that stores a list of point numbers that are request tabulation results, and 34 is a current value table that stores current value data of each point number corresponding to the tabulation table 33 ″.

Next, the operation will be described. The data transmission processing unit 31 of the data distribution device 3 receives a data acquisition request from the remote monitoring device 2 and transmits the data acquisition request to the counting unit 32 '. The tallying unit 32 'stores the data acquisition request received from the data transmission processing unit 31 in the tallying table 33'. The data acquisition processing unit 30 periodically acquires the current value data from the plant monitoring device 1 based on the data acquisition request stored in the aggregation table 33 ', and stores the acquired data in the current value table 34. . The data transmission processing unit 31 periodically reads the current value data stored in the current value table 34 and transmits the data to the remote monitoring device 2 that has issued the request.

FIG. 4 is an explanatory diagram showing the structure of the aggregation table 33 'and changes in registered contents. In FIG. 4, the aggregation table 33 'is composed of a list for storing point numbers, and can store data acquisition requests for a predetermined number of records. A0001 to A0005 represent point numbers of plant data, and END represents an end index.

In the tallying table 33 ', an end index is written in the first record in the initial state like T1. When receiving the data acquisition request such as Y11 from the remote monitoring device 2 whose ID number is ID1, the counting unit 32 '
The request content similar to that of No. 1 is stored in the aggregation table 33 '.
At this time, the total table 33 'is as shown in T2. Next, when receiving a data acquisition request such as Y21 from the remote monitoring device 2 whose ID number is ID2, the counting unit 32 'adds the same request content as Y21 to the counting table 33'. At this time, the total table 33 'is as shown in T3.

Next, the counting section 32 'determines that the ID number is
When a data acquisition request including only an end index such as Y12 is received from the remote monitoring device 2 that is No. 1 as a data acquisition end request, the previous data acquisition request from the remote monitoring device 2 whose ID number is ID1 is received. Delete from the aggregation table 33 '. At this time, the total table 33 'is as shown in T4. If the data acquisition request exceeds the number of records in the tallying table 33 ', the tallying unit 32' notifies the data transmission processing unit 31 of the refusal of communication.

As described above, according to the second embodiment, the data distribution device 3 counts data acquisition requests from a plurality of remote monitoring devices 2 and limits the maximum number of data acquisition requests. , The maximum amount of data acquisition requests can be accurately limited.

Also, by summing up data acquisition requests from a plurality of remote monitoring devices 2 and collectively making a data acquisition request to the plant monitoring device 1, the overhead associated with the data acquisition request can be reduced, 3 and the plant monitoring device 1 can reduce the amount of data transmission in the LAN 300.

Embodiment 3 Embodiment 3 has the configuration of a remote monitoring system configured as in Embodiment 2, and its block diagram is the same as that of FIG. FIG.
FIG. 14 is an explanatory diagram showing a configuration of a tallying table 33 ′ and changes in registered contents according to the third embodiment. In FIG. 5, the totaling table 33 'includes a list for storing point numbers and a counter for the number of requests for each point number, and can store data acquisition requests for a predetermined number of records. A0001 to A0005 represent point numbers of plant data, and END represents an end index.

Next, the operation will be described. In the tallying table 33 ', the end index is written in the first record in the initial state like T1, and the number-of-requests counter is all zero. When receiving a data acquisition request such as Y11 from the remote monitoring device 2 whose ID number is ID1, the counting unit 32 'stores the same request content as Y11 in the counting table 33', and counts the number of requests for each point number. Add 1 to the counter. At this time, the total table 33 'is as shown in T2. Then
When receiving a data acquisition request such as Y21 from the remote monitoring device 2 whose ID number is ID2, the counting unit 32 'sets the data to A0001 if the same data acquisition request such as the point number A0001 already exists in the counting table 33'. One is added to the corresponding request number counter, and point numbers A0004, A00
Only requests that are not in the tallying table 33 'as in 05 are added to the tallying table 33', and 1 is added to the request number counter of each point number. At this time, the total table 33 'is as shown in T3.

Next, the counting section 32 'determines that the ID number is
When a data acquisition request of only the end index such as Y12 of the remote monitoring device 2 which is the ID 1 is received, it is regarded as a data acquisition end request, and the last data acquisition request from the remote monitoring device 2 whose ID number is ID1. Is subtracted from the request counter. Point numbers such as point numbers A0004 and A0005 for which the number-of-requests counter becomes 0 are deleted from the aggregation table 33 '. At this time, the total table 33 'is as shown in T4. If the data acquisition request exceeds the number of records in the tally table 33 ', the tally unit 32'
Notifies the data transmission processing unit 31 of the refusal of communication.

As described above, according to the third embodiment, data acquisition requests from a plurality of remote monitoring apparatuses 2 are totaled without duplication, and data acquisition requests are collectively sent to the plant monitoring apparatus 1. By doing so, the data transmission amount in the LAN 300 between the data distribution device 3 and the plant monitoring device 1 can be reduced. Also, if there are many duplicate data acquisition requests, more remote monitoring devices 2 can be used simultaneously.

Fourth Embodiment FIG. 6 is a block diagram showing a configuration of a remote monitoring system according to a fourth embodiment. 6, the same components as those in the second embodiment shown in FIG. 3 are denoted by the same reference numerals, and the description thereof will not be repeated. As a new code, reference numeral 13 denotes a copy of the tally table having the same contents as the tally table 33 'of the data acquisition request tallyed by the data distribution device 3.

Next, the operation will be described. The tallying unit 32 'of the data distribution device 3 tallyes the data acquisition requests from the plurality of remote monitoring devices 2, and stores them in the tallying table 33'. When the tally table 33 'is changed, the data acquisition processing unit 30 transmits the contents of the tally table 33' to the data transmission processing unit 12 of the plant monitoring device 1.
The data transmission processing unit 12 of the plant monitoring device 1 receives the contents of the tally table, and stores a copy in the tally table 13 of the plant monitoring device 1. Thereafter, the data transmission processing unit 12 periodically transmits the current value data of the plant to the data distribution device 3 based on the content of the request of the tally table 13. Data acquisition processing unit 3 of data distribution device 3
0 stores the data periodically transmitted from the plant monitoring device 1 in the current value table 34. The data transmission processing unit 31 periodically reads the current value data stored in the current value table 34, and transmits the data to the remote monitoring device that issued the request.

As described above, according to the fourth embodiment, the data distribution device 3 does not make a data acquisition request to the plant monitoring device 1 every period, and the plant monitoring device 1 actively and periodically Data distribution device 3 for present value data of the plant
, The overhead associated with the data acquisition request can be reduced, and the data transmission amount in the LAN 300 between the data distribution device 3 and the plant monitoring device 1 can be reduced.

Fifth Embodiment FIG. 7 is a block diagram showing a configuration of a remote monitoring system according to a fifth embodiment. In FIG. 7, the same parts as those in the third embodiment shown in FIG. As a new code, 35 is a previous value table in which the data acquisition processing unit 30 stores the current value data of the plant received last time,
Compared to the previous value table 35, the current value table 34
Saves the current value data of the plant received by the data acquisition processing unit 30 of the data distribution device 3.

Next, the operation will be described. The data transmission processing unit 12 of the plant monitoring device 1 periodically transmits the current value data of the plant to the data distribution device 3. When receiving the data from the plant monitoring device 1, the data acquisition unit 30 of the data distribution device 3 stores the received data in the current value table. The data transmission processing unit 31 reads the data stored in the current value table 34, transmits the data to the remote monitoring device 2,
4 is copied to the previous value table 35. Or later,
The data transmission processing unit 31 periodically updates the current value table 34
The current value data stored in the previous value table and the previous value data stored in the previous value table 35 are read, and it is checked whether the value has changed. Only when the current value and the previous value are changed, the data stored in the current value table 34 is transmitted to the remote monitoring device 2, and the data in the current value table 34 is copied to the previous value table 35. .

As described above, according to the fifth embodiment, the data transmission processing unit 31 of the data distribution device 3 transmits the current value to the remote monitoring device 2 only when the current value of the plant changes. By transmitting the data, the amount of data transmission in the data transmission line 200 between the remote monitoring device 2 and the data distribution device 3 can be suppressed to a low level. Also, the remote monitoring device 2 can display the current value data of the plant in real time.

[0046]

As described above, according to the present invention, a plant monitoring apparatus for monitoring a plant to be monitored and a data acquisition request provided to the plant monitoring apparatus based on the reception of a data acquisition request provided on the monitoring target side. A data distribution device that makes a request and obtains and distributes data of a plant according to the data acquisition request from the plant monitoring device, and makes a data acquisition request to the data distribution device installed at a remote location via a data transmission path. A plurality of remote monitoring devices that receive distribution of plant data in response to the data acquisition request, wherein the data distribution device checks the number of remote monitoring devices that have requested data acquisition and determines the maximum number of remote monitoring devices that distribute data. The maximum number of remote monitoring devices that the data distribution device uses at the same time is limited, and the data collection for the plant monitoring device is restricted. Because it can limit the maximum amount of requests, it is possible to ensure maximum throughput of the plant monitoring apparatus. Thereby, there is an effect that it is possible to construct a remote monitoring system without affecting the processing of the original plant monitoring device.

Further, the data distribution device includes a data transmission processing unit for requesting communication permission of the corresponding remote monitoring device based on the data acquisition request from the remote monitoring device, and an ID number of the remote monitoring device that has requested the data acquisition. And a management table for registering the number, and a communication permission request from the data transmission processing unit is received, and the number of remote monitoring devices registered in the management table is checked. The ID number of the device is registered in the management table and the data transmission processing unit is notified of the communication permission. If the number of registrations is equal to or greater than the set number, the data transmission is performed without registering the ID number of the remote monitoring device. And a management unit for notifying the processing unit of the communication rejection, wherein the data transmission processing unit transmits a communication permission notification from the management unit to the remote monitoring device. Data transmission, and a data acquisition failure response is sent back to the remote monitoring device that received the communication rejection notification.This limits the maximum number of remote monitoring devices that the data distribution device can use at the same time, Since the maximum amount of data acquisition requests to the monitoring device can be limited, it is possible to guarantee the maximum processing amount of the plant monitoring device. Thereby, there is an effect that it is possible to construct a remote monitoring system without affecting the processing of the original plant monitoring device.

Further, according to the remote monitoring system of another invention, a plant monitoring device for monitoring a plant to be monitored and a data provided to the plant monitoring device on the monitoring target side based on reception of a data acquisition request. A data distribution device for performing an acquisition request and acquiring and distributing plant data corresponding to the data acquisition request from the plant monitoring device, and a data acquisition request to the data distribution device installed at a remote location via a data transmission path. And a plurality of remote monitoring devices that receive the distribution of the plant data in response to the data acquisition request, wherein the data distribution device counts the data acquisition requests from the remote monitoring devices and limits the maximum number thereof. Therefore, the data distribution device aggregates data acquisition requests from multiple remote monitoring devices and limits the maximum number of data acquisition requests. Can be more accurately limit the maximum amount of data acquisition request to the monitoring device, it is possible to ensure maximum throughput of the plant monitoring apparatus.

Further, the data distribution device requests the plant monitoring device to collectively collect the data acquisition requests and obtains the current value data of the plant.
This has the effect of reducing the overhead associated with the data acquisition request and reducing the amount of data transmission on the LAN between the data distribution device and the plant monitoring device.

Further, the data distribution device counts data acquisition requests from a plurality of remote monitoring devices without duplication, so that data collection requests from a plurality of remote monitoring devices are counted without duplication. , It is possible to collectively make a data acquisition request to the plant monitoring device,
This has the effect of reducing the amount of data transmission on the LAN between the data distribution device and the plant monitoring device. Further, if there are many duplicate data acquisition requests, there is an effect that more remote monitoring devices can be used at the same time.

Further, the data distribution device notifies the plant monitoring device of the counting result, and the plant monitoring device periodically sends the current value data of the plant to the data distribution device based on the notified counting result. Since the data is transmitted, the data distribution device does not make a data acquisition request to the plant monitoring device every period, and the plant monitoring device actively and periodically transmits the current value data of the plant to the data distribution device. By transmitting, there is an effect that the overhead related to the data acquisition request can be reduced, and the amount of data transmission in the LAN between the data distribution device and the plant monitoring device can be reduced.

The data distribution device stores the previous value of the data acquired from the plant monitoring device, compares the previous value with the current value, and transmits the updated data to the remote monitoring device only when the value is different. Therefore, the data transmission processing unit of the data distribution device sends the current value to the remote monitoring device only when there is a change in the current value of the plant. This has the effect of reducing the amount of data transmission on the data transmission path.For example, even when connected via a transmission path with a small transmission point such as a public telephone line, the current value data of the plant is displayed on a remote monitoring device in real time. There is an effect that can be.

The data distribution device includes a data transmission processing unit that receives a data acquisition request from the remote monitoring device, and a totaling table that stores data acquisition requests from a plurality of remote monitoring devices for a predetermined number of records. And a current value table for storing current value data from the plant monitoring device, and storing the data acquisition request received from the data transmission processing unit in the aggregation table, and setting the data acquisition request in the aggregation table in advance. And a counting unit that notifies the data transmission processing unit of communication rejection when the number of records exceeds the number of records.
Acquire current value data from the plant monitoring device based on the data acquisition request saved in the aggregation table, and save the acquired data in the current value table,
The current value data stored in the current value table is read, data is distributed to the remote monitoring device that has made the request, and a data acquisition failure response is returned to the remote monitoring device that has received the communication rejection notification from the counting unit. By limiting the maximum number of data acquisition requests from multiple remote monitoring devices by the data distribution device and limiting the maximum number, the maximum amount of data acquisition requests to the plant monitoring device can be more accurately limited. It is possible to guarantee the maximum throughput of the plant monitoring device.

The totaling table has a request counter for counting the number of requests for each data acquisition request. If the data acquisition request has already been stored, only the request counter for the corresponding record position is counted up.
When a data acquisition request for only the end index is received, the request counter of the corresponding record position is counted down,
Since the data acquisition request whose count number becomes zero is deleted, the overhead related to the data acquisition request is reduced, and the LA between the data distribution device and the plant monitoring device is reduced.
This has the effect of reducing the amount of data transmission in N.

Further, the data distribution device further includes a data acquisition processing unit for transmitting the contents of the tally table to the plant monitoring device when the contents of the tally table are changed. And a data transmission process for periodically transmitting the current value data of the plant to the data distribution device in response to a data acquisition request stored in the plant monitoring side total table storing the received contents. Device, the overhead required for the data acquisition request is reduced, and the LA between the data distribution device and the plant monitoring device is reduced.
This has the effect of reducing the amount of data transmission in N.

Further, the data distribution device further includes a current value table for storing current value data of the plant, and a previous value table for storing previous value data of the plant. The data stored in the current value table is transmitted to the remote monitoring device only when the data values stored in the table and the previous value table are changed, and the data in the current value table are stored in the previous value table. I decided to copy it,
The data transmission processing unit of the data distribution device sends the current value to the remote monitoring device only when there is a change in the current value of the plant, so that the data transmission path between the remote monitoring device and the data distribution device can be reduced. There is an effect that the amount of data transmission can be kept low. For example, even when connected through a transmission line with a small transmission point such as a public telephone line, the current value data of the plant can be displayed on the remote monitoring device in real time. effective.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a remote monitoring system according to Embodiment 1 of the present invention.

FIG. 2 is a flowchart illustrating operations of a data transmission processing unit and a management unit of the data distribution device according to the first embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a remote monitoring system according to a second embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a configuration of a tally table and changes in registered contents according to a second embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a configuration of a tallying table and changes in registered contents according to a third embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of a remote monitoring system according to a fourth embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration of a remote monitoring system according to a fifth embodiment of the present invention.

FIG. 8 is a block diagram showing a configuration of a conventional remote monitoring system.

[Explanation of symbols]

1 plant monitoring device, 10 data collection processing unit, 11
Display processing unit, 12 data transmission processing unit, 13 count table, 2 remote monitoring device, 20 data acquisition processing unit, 2
REFERENCE SIGNS LIST 1 display processing unit, 3 data distribution device, 30 data acquisition processing unit, 31 data transmission processing unit, 32 management unit, 3
2 'totaling unit, 33' totaling table, 34 current value table, 35 previous value table, 4A, 4B controller, 100 plant network, 200 data transmission path, 300 LAN.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G08B 25/00 520 G08B 25/00 520C G08C 15/00 G08C 15/00 EF term (Reference) 2F073 AA19 AB01 AB05 BB09 BC01 CC11 CC14 DD05 DE11 GG01 5C087 AA24 BB03 BB12 BB74 BB76 BB77 DD08 DD21 EE07 FF01 FF02 FF19 FF20 GG08 GG18 GG23 GG29 GG31 GG36 GG70 5H223 AA01 DD07 EE06 5A048

Claims (11)

[Claims] 1. A plant monitoring device for monitoring a plant to be monitored, and a data acquisition request provided to the plant monitoring device on the monitoring target side based on the reception of the data acquisition request, the data acquisition request being issued from the plant monitoring device. A data distribution device that acquires and distributes data of a plant according to the data transmission request, and sends a data acquisition request to the data distribution device via a data transmission path that is installed at a remote location, and transmits the data of the plant according to the data acquisition request. A remote monitoring system comprising: a plurality of remote monitoring devices receiving distribution; wherein the data distribution device checks the number of remote monitoring devices that have requested data acquisition and limits the maximum number of remote monitoring devices that distribute data. 2. The remote monitoring system according to claim 1, wherein the data distribution device is configured to request a communication permission of the corresponding remote monitoring device based on a data acquisition request from the remote monitoring device. A management table for registering the ID number and the number of the remote monitoring device that has requested data acquisition, a communication permission request from the data transmission processing unit is received, and the number of remote monitoring devices registered in the management table is checked and registered. If the number is smaller than the set number, the ID number of the remote monitoring device is registered in the management table and communication permission is notified to the data transmission processing unit. A management unit for notifying the data transmission processing unit of communication refusal without registering an ID number, wherein the data transmission processing unit includes:
A remote monitoring system, wherein data is distributed only to a remote monitoring device that has received a communication permission notification from the management unit, and a data acquisition failure response is returned to the remote monitoring device that has received the communication rejection notification. 3. A plant monitoring device for monitoring a plant to be monitored, and a data acquisition request provided to the plant monitoring device on the monitoring target side based on the reception of the data acquisition request, and a data acquisition request from the plant monitoring device. A data distribution device that acquires and distributes data of a plant according to the data transmission request, and sends a data acquisition request to the data distribution device via a data transmission path that is installed at a remote location, and transmits the data of the plant according to the data acquisition request. A remote monitoring system comprising: a plurality of remote monitoring devices that receive distribution; wherein the data distribution device counts data acquisition requests from the remote monitoring devices and limits the maximum number of data acquisition requests. 4. The remote monitoring system according to claim 3, wherein the data distribution device requests the plant monitoring device to collectively collect the data acquisition requests and obtains the current value data of the plant. And remote monitoring system. 5. The remote monitoring system according to claim 3, wherein said data distribution device counts data acquisition requests from a plurality of remote monitoring devices without duplication. 6. The remote monitoring system according to claim 3, wherein the data distribution device notifies the plant monitoring device of a counting result, and the plant monitoring device transmits the counting result to the notified counting result. A remote monitoring system for periodically transmitting current value data of a plant to the data distribution device based on the data. 7. The remote monitoring system according to claim 6, wherein the data distribution device stores a previous value of the data acquired from the plant monitoring device, compares the previous value with the current value, and sets the remote value only when different. A remote monitoring system for transmitting updated data to a monitoring device. 8. The remote monitoring system according to claim 3, wherein the data distribution device includes a data transmission processing unit that receives a data acquisition request from the remote monitoring device, and a plurality of remote monitoring devices. Tabulation table for storing a predetermined number of records of data acquisition requests, a current value table for storing current value data from the plant monitoring device, and a data acquisition request received from the data transmission processing unit. And a counting unit that notifies the data transmission processing unit of a communication rejection when the data acquisition request exceeds a preset number of records in the counting table. The current value data is acquired from the plant monitoring device based on the data acquisition request stored in the table, and the acquired data is acquired. Is stored in the current value table, the current value data stored in the current value table is read, and the data is distributed to the remote monitoring device of the request source.
A remote monitoring system characterized by returning a data acquisition failure response to the remote monitoring device that has received the communication rejection notification from the counting unit. 9. The remote monitoring system according to claim 8, wherein the totaling table has a request number counter for counting the number of requests for each data acquisition request, and corresponds to a case where the data acquisition request has already been saved. Count up only the request count counter of the record position, and if a data acquisition request of only the end index is received, count down the request count counter of the corresponding record position and delete the data acquisition request with the count number of zero. Characterized remote monitoring system. 10. The remote monitoring system according to claim 8, wherein the data distribution device transmits the contents of the tally table to the plant monitoring device when the contents of the tally table are changed. While further comprising an acquisition processing unit, the plant monitoring device, the plant monitoring side aggregation table that stores the received content,
A remote monitoring system comprising: a data transmission processing device that periodically transmits current value data of a plant to the data distribution device in response to a data acquisition request stored in the plant monitoring-side aggregation table. 11. The remote monitoring system according to claim 10, wherein the data distribution device further includes a current value table storing current value data of the plant, and a previous value table storing previous value data of the plant. The data transmission processing unit transmits the data stored in the current value table to the remote monitoring device only when the data values stored in the current value table and the previous value table are changed. A remote monitoring system for copying data of a current value table to a previous value table.