JPH1042380A - Information transmission system for supervisory and control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To securely transmit supervisory and control information between stations through a network at high speed by transmitting operation situation information by means of a communication protocol UDP/IP and control information and slip data by means of a communication protocol TCP/IP between the stations. SOLUTION: The hierarchical information network where information is transmitted through the network between the highest station 11 and the general stations 131 and 132 through a host station 12 and between the and the respective general stations and control stations 141 -14J and information is transmitted between the control station and stations to be controlled 151 -15N is provided. Operation situation data is transmitted by the communication protocol UDP/IP to the host station 12 from the slave station by using a datagram socket and control data by the communication protocol TCP/IP to the controlled slave station from the controlling host station 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information transmission method between stations in a monitoring and control system hierarchized from a lower station to an upper station via a network, and more particularly to information transmission in which monitoring information and control information are distinguished. The present invention relates to an information transmission method between stations having different methods and communication protocols.

[0002]

2. Description of the Related Art When a plant is large in scale, a hierarchical information network is constructed for the purpose of sophistication and efficiency based on basic functions such as multipurpose use of resources and facilities and maintenance of an information communication network.

For example, a monitoring control information network in a sewage treatment system transmits operation status (real-time data such as the status of equipment, form data such as a daily report) from a treatment plant or a pump station to an upper station using an optical fiber cable. In order to transmit information for controlling a lower-level unmanned pumping station from a manned pumping station in real time, a plurality of hierarchies are constructed from the lowest station (child pumping station or the like) to the highest station.

[0004]

[Problems to be solved by the invention]

(First Problem) For information transmission between stations through a network, for example, a communication protocol TCP / IP can be used. This TCP / IP enables reliable information transmission by performing transmission confirmation, order control, and flow control when transmitting information.

For example, the control station 1 shown in FIG.
TCP / IP is used for information transmission through a network between the _1A to 1 _NA and Administration station 1 _1C, 1 _2C.

However, since the information transmission speed of TCP / IP is relatively low, it becomes difficult to transmit a large amount of real-time information required for monitoring and control as the size of a plant increases.

[0007] It is an object of the present invention to provide an information transmission system for reliably and quickly transmitting supervisory control information between stations through a network.

(Second Problem) In a plant such as a sewage treatment system, control stations and the like are added or renewed over a long period of time. When this control station or the like is added or rebuilt, systems of different manufacturers are installed, and the monitoring control devices provided in the individual systems perform different characteristic information processing on the operation management and the like even for different manufacturers or for the same manufacturer.

For this reason, in order to construct an information network, it becomes necessary to transmit information between supervisory control devices of different communication protocols.

[0010] For example, as shown in FIG. 8, when the control station 1 _1A to 1 _NA and of the control station 1 _1B to 1 _NB to different manufacturers system is provided, the information transmission between the control station and a controlled station Cannot be connected between monitoring and control devices having different communication protocols, and can only be connected between the same monitoring and control devices.

[0011] In order to construct such a system, a connection corresponding to each model and communication protocol is required as a network, which complicates the network configuration and communication processing.

Another object of the present invention is to provide an information transmission system which enables unified connection between devices having different models and communication protocols.

[0013]

SUMMARY OF THE INVENTION According to the present invention, from an upper station to a lower station, hierarchies are formed via a network. Operating status information and form data are transmitted from the lower station to the upper station, and the upper station is transmitted from the upper station to the lower station. Is a monitoring and control system for transmitting control information, wherein the operation status information is transmitted between stations by a communication protocol UDP / IP, and the control information and the form data are transmitted by a communication protocol TCP / IP.
Is transmitted between stations.

Further, the transmission of the operation status information is characterized in that a serial number is provided in a common control unit of the transmission format, and data drop is recognized from the serial number.

Further, the control information is transmitted as setting / operation data from an upper station, the lower station transmits response data indicating that the setting / operation data has been received, and transmits a status corresponding to the setting / operation data. The change is transmitted as the driving situation data.

Further, the transmission of the control information is characterized in that the presence or absence of an abnormality is checked for the line state, transmission / reception time and reception data length.

Further, the upper station transmits time data to the lower station when receiving a fixed period or a rise notification of the lower station, and the lower station receives the time data and adjusts the internal time. Features.

Further, between the stations having different communication protocols, a common format and data are exchanged with the upper station, and a front end processor is exchanged with the lower station in a format and data unique to the device. It is characterized by having.

[0019]

FIG. 1 is an example of a system configuration showing an embodiment of the present invention. The supervising station 13 ₁ from the top station 11 via the top station 12,
Between 13 ₂ and performs information transmission through the network by each Administration station control station 14 ₁ to 14 _J, and each control station and a controlled station 1
5 ₁ construct an information network that is layered to the information transmitted between the to 15 _N.

In this system configuration, macro monitoring is performed from a lower station to a higher station. Therefore, the information is aggregated and transmitted to the higher stations, so that the monitoring control purpose, the level, the network load, and the data processing amount of the computer are obtained. To be appropriate.

In the transmission of information, operation status data (e.g., device status) is transmitted from the lower station to the upper station in the monitoring information. In addition, the control information includes the setting and the setting to the lower station controlled by the higher station that controls.
Operation data (such as turning on / off the device) is transmitted, and response data indicating that this data has been received reliably is transmitted from the lower station to the upper station.

[0022] Here, the control station 14 ₁ to 14 _J and the control station 15 ₁ to 15 _N are each made treatment with its own monitoring and control system, each of supervisory control devices of the system is to have its own communication protocol . For example, the control station 14 ₁ and the controlled station 15 ₁
And a and 15 ₂ are installed supervisory control system of different manufacturers.

In the information transmission between the control station and the controlled station, the control station, which becomes the upper station, transmits and receives a common format and data with the upper station, and exchanges the format and data unique to each device with the lower station. Is provided.

[0024] By providing the front-end processor, to absorb the difference of the communication protocol and data control station 14 ₁ and the control station 15 _1, 15 ₂ to allow communication unified therebetween.

If there is a difference between the communication protocols and data between the control stations 13 ₁ and 13 ₂ and the control stations 14 _{1 to} 14 _J , a front-end processor for absorbing the difference is provided in each control station. When the communication protocols and data between the supervising stations 13 ₁ and 13 ₂ and the uppermost station 11 are different from each other, a front-end processor is provided on the uppermost station side to enable unified communication.

Therefore, the monitoring and control data transmitted between the stations is integrated by the front-end processor, the communication protocol and data unique to each manufacturer are absorbed, and the network of the device having different models and communication protocols is absorbed. Enable connection.

Next, the supervising station 13 _1, 13 ₂ and the control station 14 ₁ to 14 _J communicates with two communication protocols TCP / IP and UDP / IP. Similarly, the uppermost station 11, the upper station 12, and the control stations 13 ₁ and 13 ₂ communicate using two communication protocols TCP / IP and UDP / IP.

These communication protocols TCP / IP and UD
The data transmission processing between stations using P / IP will be described in detail.

(1) Operation status data transmission (monitoring data transmission) The operation status data is transmitted from the lower station to the upper station at regular intervals by a communication protocol UDP / IP using a datagram socket.

The operation status data includes digital data DI, an analog instantaneous value AI, an integrated counter value PI, and the like. Each of the data DI, AI, and PI has an individual format, and each format has a common format. The control section is composed of a data section defined for each data type (DI, AI, PI) so that the processing can be shared.

The level to be monitored in real time (for example, when an unmanned controlled station is monitored from a manned supervising station) has a DI of 1 second cycle, AI
Is transmitted at high speed at a period of 10 seconds and PI at a period of 1 minute.
In addition, the monitoring level for grasping the operation status (for example, in the case of monitoring from the highest station) is transmitted in a 5-minute cycle.

Therefore, the operation status data is expressed by UDP /
It can be transmitted at high speed by IP, and can be applied to a large-scale processing system or a system whose scale increases over time, and can transmit a large amount of real-time information required for monitoring and control.

Here, the communication protocol UDP / IP is
Compared with the communication protocol TCP / IP, since it does not require the trouble of opening and releasing a connection, it is convenient to transmit relatively short data in a short time. However, transmission confirmation, sequence control, and flow control are performed. Communication protocol TC
There is a possibility of data drop compared to P / IP.

Therefore, in addition to the transmission destination, transmission source, data length, and the like, a serial number necessary for data processing is provided in the common control section of the format. The state is recognized, and if necessary, the defect of data loss is compensated by retransmission of data.

FIG. 2 shows a communication processing flow based on UDP / IP. A server / client system is used in which the upper station is a server and the lower station is a client.

The server receives the start-up when the station is started up, performs an initial process of generating a socket (socket-bind) (S1), starts a reception timer for periodic reception (S2), and waits for data reception. State (S
3). At the time of data reception, a timer check is performed (S4), and a header of the received data is further checked (S4).
5) If any of these are abnormal, the abnormality is notified (S6, S
7) Waiting for reception again.

The client receives the start-up when the station is started up, and performs initial processing for generating a socket (S1).
1) After that, the system waits for the start time of the periodic transmission (S12), and when the transmission time comes, the transmission data block is edited (S1)
3) Data is transmitted in block units (S14). When data transmission of all blocks is checked (S1
5) Wait for the next fixed-cycle transmission activation.

(2) Setting / Response Data Transmission (Data Transmission for Control) Setting / operation data, such as an on / off operation of a device, is transmitted from a higher-level station for control to a lower-level station controlled by a communication protocol TCP / TCP. It is transmitted by IP, and can be transmitted reliably by transmission confirmation, order control, and the like.

The response data is transmitted to the upper station to notify that the lower station that has received the setting data has surely received the setting data. However, a change in the state of the device with respect to the setting is transmitted to the upper station as operation status data of a fixed period by UDP / IP.

The format of these setting / response data is a common control section and a setting / response data section. The common control unit is common to the operation status data, and the setting / response data unit is in an optimal format for each data type.

In order to transmit and receive the setting data and the response data, the connection between the stations is made one by one for each use (a large classification unit of the format) by a stream socket (full-duplex connection). In addition, the socket connection is performed at the time of starting the upper station, and the connection is maintained except for disconnection due to abnormal processing, thereby preventing time waiting when setting is continuously performed.

Therefore, the setting / operation data used for control becomes important information on the monitoring and control system such as control of equipment, so that it is transmitted by TCP / IP, and response data indicating that the data has been received is returned. As a result, reliable control can be obtained.

FIG. 3 shows a communication processing flow based on TCP / IP. A server-client system is used in which the lower station is a server and the upper station is a client.

The parent process on the server side receives the activation at the time of starting the station, generates a socket (S21),
An address is assigned to this socket (S22), and acceptance of the connection starts (S23). And
The client waits for a connection connection request from the client side, and upon receiving the request, establishes a connection (S24), generates a child process to wait for the next connection connection request (S25), and newly creates a child process used by the child process. The closed socket is closed (S26).

On the client side, the created child process is started when the station is started or by an abnormality monitoring process described later, generates a socket (S31), requests a connection connection to the server (S32), and checks the connection. If (S33) is abnormal, a specified number of retries is performed every fixed time (several seconds).

When a connection is established between the server side and the client side, a child process generated on the server side and the client side transmit data request and response data. Processing of the child process for this transmission (S2
7) and the processing of the client (S34) are shown in FIGS.
Shown in

In the processing of the child process shown in FIG. 4, after the parent process closes the socket waiting for connection connection, the header portion (fixed length) of the data requested from the client (data corresponding to the service provided by the server) ) Is received in the blocking mode (S27 ₁ ).

[0048] Thereafter, it is checked whether or not there is an abnormality of the return code abnormal and receive data length discrepancies from the socket (S27 _2), abnormality sets the reception timer for otherwise if reception time monitoring (S27 ₃ ), The data section (variable length) is received in the non-blocking mode (S2).
7 _4).

[0049] Thereafter, it is checked whether or not there is a return code to check whether there is an abnormality (S27 _5), the timeout of the reception timer of the socket again (S2
7 ₆ ), it is checked whether the received data length is exceeded (S2).
7 _7), an application to edit the transmit data according to the received data when the received data length matches the set value of the header portion (S27 _8).

[0050] Then, performs transmission timer set for transmission time monitoring (S27 _9), transmits a response data of a fixed length (S27 _10), the line abnormality check (S27 ₁₁₎ and the transmission timer according to the return code abnormal again Is performed (S27 ₁₂ ), and the process returns to the next data reception.

When a line error, a timer timeout, or an error in the received data length occurs, the socket is closed (FIG. 3).
S28), and the process ends.

[0052] processing of the client shown in FIG. 5, waits for a linkage message of the transmission data upon successful connection connection (S34 _1), performs transmission timer set to monitor the response headers from the child process for data transmission (S34 _2), transmits the transmission data (S3
4: _3).

[0053] Thereafter, checked (S34 ₅₎ of the return code abnormal reception of the check (S34 ₄₎ and timeout transmission timer from the socket, for receiving the header portion of the response data from the child process in blocking mode (S34 ₆ ).

[0054] Setting this after the reception timer for the return code abnormal and performs a line abnormality check (S34 ₇₎ and timeout check (S34 ₈₎ of the transmission timer for the received data length discrepancy, the reception time monitoring if successful and (34 _9), receives the response data in non-blocking mode (S34 _10).

Thereafter, a line abnormality check based on a return code (S34 ₁₁ ), a timeout check of a reception timer (S34 ₁₂ ) and a reception data length check (S3)
4 ₁₃ ), the application links the received data (S 34 ₁₄ ), and returns to the next transmission request.

When a line error, a timer timeout, or an error in the received data length occurs, the socket is closed (FIG. 3).
S35), and the process ends.

Therefore, the setting / response data (control data) can be transmitted while performing various abnormality checks, and reliable control by reliable data transmission can be performed.

(3) File transmission (form data transmission) Form data such as daily reports and monthly reports are large in size,
Since it is only necessary to be transmitted when necessary, a file transfer function is used. The file is always transmitted from the lower station to the upper station. However, the transfer method is different when the file transfer is requested from the upper station and when the file is sent to the upper station because the data has been stored in the lower station.

When performing file transfer in response to a request from a higher-level station, the requesting station requests TCP / IP to request required data from the requesting station using file transfer request data. The lower station prepares a file according to the request and transfers the file. The request data includes a common control unit and a request data unit similar to other data. After the data transfer, the transfer completion data is transmitted to the upper station.

When a file transfer request is made from a lower station to an upper station, file reception data is sent from the lower station by TCP / IP, and when the upper station is ready for reception, response data is sent to the TCP.
Send by / IP. After that, the file is transferred from the lower station, and after the transfer is completed, the completion data is transmitted. The request data section is defined for each data type of file transfer.

FIG. 6 shows a file communication process.
Is the case where the upper station requests the lower station to transfer the file, and the procedure B is the case where the file transfer is performed by the request from the lower station.

In file transfer, connection connection and data transmission / reception are performed in the same manner as in the communication processing of FIG. 3, and data transmission / reception is performed while performing an abnormality check such as a line abnormality.

Therefore, the form data is based on TCP / IP
To transmit a file, thereby enabling reliable information transmission.

(4) Time Adjustment If the time does not match at each station, data inconsistency may occur. For this purpose, the time adjustment between the stations is performed by transmitting the data consisting of the common control unit and the time setting data from the reference station to the TCP / I.
Send by P and return the response data from the receiving station.

FIG. 7 shows a time communication process. The process is the same as that in FIG. 3 until the upper station and the lower station are connected by a line connection request. Further, the line abnormality and its recovery processing are performed according to the TCP / IP specifications.

After the line connection has been made, the upper station transmits time data to the lower station when it receives a rising notification of the lower station by a fixed period or UDP / IP (S41).

When the lower station receives the time data (S51), it transmits the time response data to the upper station (S52), and adjusts the internal time (S53).
This time adjustment is performed only when there is a time difference within the correction range, thereby preventing the time from being erroneously corrected due to a lack of a gator or the like. Thereafter, a message is output when the time adjustment is normally performed and when the time is out of the correction range (S5).
4).

The upper station receives the time response data from the lower station (S42), and receives the data and outputs the contents of the response data as a message (S43).

Therefore, by adjusting the internal clock of the lower station based on the time information of the upper station, it is possible to eliminate the occurrence of data inconsistency due to the difference in time between the stations.

[0070]

As described above, according to the present invention, the operation status information is transmitted between the stations by the communication protocol UDP / IP, and the control information and the form data are transmitted between the stations by the communication protocol TCP / IP. Thus, there is an effect that the control information and the form data, which require certainty, can be reliably transmitted while the operating condition information, which requires real-time property, is transmitted at high speed.

In the transmission of the operation status information, a serial number is provided in a common control unit of the transmission format, and data drop is recognized from this serial number.
Erroneous data transmission can be eliminated while high-speed transmission by P is performed.

The control information is transmitted from the upper station as setting / operation data, the lower station transmits response data indicating that the setting / operation data has been received, and checks the state change with respect to the setting / operation data. Since the data is transmitted as the operation status data, the state change data can be transmitted at a high speed by UDP / IP while the control information is reliably transmitted by setting and transmitting and receiving the response data.

In the transmission of the control information, the presence or absence of an abnormality is checked for the line state, the transmission / reception time, and the reception data length, respectively, so that the transmission of the control information is more reliably performed.

Further, the upper station transmits the time data to the lower station when it receives the notification of the fixed period or the rising of the lower station, and the lower station receives the time data and adjusts the internal time. It is possible to prevent inconsistency in monitoring and control due to a difference in time between stations.

Further, between stations having different communication protocols, a front-end processor for transmitting and receiving a common format and data to and from the upper station and transmitting and receiving a format and data unique to the device to and from the lower station is interposed. Even when monitoring and control equipment from different manufacturers is installed in the system, data can be exchanged using a common protocol using a common network, and information transmission can be unified even when equipment is added or changed over time. it can.

[Brief description of the drawings]

FIG. 1 is a system configuration example showing an embodiment of the present invention.

FIG. 2 is a communication processing flow of UDP / IP in the embodiment.

FIG. 3 is a communication processing flow of TCP / IP in the embodiment.

FIG. 4 is a processing flow of a child process in the embodiment.

FIG. 5 is a processing flow of a client in the embodiment.

FIG. 6 is a flowchart of a file transfer process according to the embodiment.

FIG. 7 is a time communication processing flow in the embodiment.

FIG. 8 is a time communication processing flow in the embodiment.

[Explanation of symbols]

11 top-level station 12 top-level station 13 ₁ , 13 ₂ control station 14 ₁ , 14 ₂ , 14 _J control station 15 ₁ to 15 _N controlled station

Continuation of the front page (71) Applicant 000003078 Toshiba Corporation 72 Horikawa-cho, Saiwai-ku, Kawasaki-shi, Kanagawa (71) Applicant 000006013 Mitsubishi Electric Corporation 2-3-2 Marunouchi, Chiyoda-ku, Tokyo (71) Applicant 000005234 Fuji Electric Co., Ltd. 1-1-1, Tanabe-Nitta, Kawasaki-ku, Kawasaki-ku, Kanagawa Prefecture (71) Applicant 000006105 Meidensha Co., Ltd. 2-1-1-17 Osaki, Shinagawa-ku, Tokyo (72) Inventor Toshiro Harada Konan-ku, Yokohama-shi, Kanagawa Konandai 6-1-23-305 (72) Inventor Yoji Shimizu 2-6-1, Otemachi, Chiyoda-ku, Tokyo Inside Tokyo Sewerage Service Co., Ltd. (72) Naota Miura 5-chome Omikacho, Hitachi City, Ibaraki Prefecture No. 1 Hitachi, Ltd. Omika Plant (72) Inventor Sugino Sugino 1 Toshiba-cho, Fuchu-shi, Tokyo Inside the Fuchu Plant, Toshiba Corporation (72) Inventor Saburo Tanaka 2-3-2 Marunouchi, Chiyoda-ku, Tokyo (72) Inventor Kazunobu Yatsushiro Kawaken Kawasaki-ku, Tanabeshinden No. 1 No. 1 Fuji Electric Co., Ltd. in the (72) inventor Masayuki Tatsuta Shinagawa-ku, Tokyo Osaki 2-chome No. 17 stock companies in Meidensha

Claims (6)

[Claims] 1. Supervisory control for hierarchizing from an upper station to a lower station via a network, transmitting operation status information and form data from the lower station to the upper station, and transmitting control information from the upper station to the lower station. In the system, the operation status information is transmitted between stations by a communication protocol UDP / IP, and the control information and the form data are transmitted between stations by a communication protocol TCP / IP. Transmission method. 2. The information transmission method of a supervisory control system according to claim 1, wherein the transmission of the operation status information is provided with a serial number in a common control unit of a transmission format and recognizes a data drop from the serial number. . 3. The transmission of the control information is performed as setting / operation data from an upper station, the lower station transmits response data indicating that the setting / operation data has been received, and a state of the state corresponding to the setting / operation data. 2. The information transmission method according to claim 1, wherein the change is transmitted as the operation status data. 4. The information transmission method according to claim 1, wherein the transmission of the control information is performed by checking whether there is any abnormality in the line state, the transmission / reception time, and the reception data length. 5. The high-order station transmits time data to the low-order station when receiving a fixed period or a low-level station rise notification, and the low-order station receives the time data and adjusts the internal time. The information transmission method for a supervisory control system according to claim 1, wherein: 6. A station which exchanges a common format and data with an upper station, and a front end processor which exchanges a lower station with a format and data unique to the apparatus, between the stations having different communication protocols. 2. The information transmission method for a supervisory control system according to claim 1, wherein: