JP2009118298A - Control system and communication control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve transmission efficiency in a serial-communication-connected one-to-many communication system. <P>SOLUTION: In a control system 1 where a plurality of terminals 20 as slave units are serial-communication-connected to a control device 10 that is a master unit, the control device 10 first simultaneously transmits setting information, control information and common polling to all the terminals 20. Each of the terminals 20 then transmits response information to the control device 10 after the lapse of delay D of the relevant terminal 20 contained in received control information 200 from the reception of common polling 300, wherein the delay D is determined by the control device 10 so that the response information transmission timing of each of the terminals 20 does not overlap one on another. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a control system or the like in which a master device and a plurality of slave devices are serially connected, and the master device monitors the operating state of each slave device.

  In a communication system having a one-to-many master-slave relationship in which a plurality of slave devices are connected to one master device by serial communication, a polling method is used as one of the methods for preventing collision of transmitted and received data. . In the polling method, individual polling is sequentially transmitted from the master device to each slave device, and data transmission is performed from the slave device only when individual polling is received from the slave device.

  FIG. 10 is a diagram illustrating a communication procedure according to a conventional polling method, and shows a case of a communication system in which all slave devices transmit response information to control information transmitted from the master device to the master device. In the figure, the horizontal axis represents time t, and the data transmission timings of the master device and the n slave devices are shown. According to the figure, first, control information for all the slave devices is collectively transmitted from the master device to all the slave devices. Next, the individual polling P1 for the slave device 1 is transmitted from the master device. Then, response information for the control information is transmitted from the slave device 1 to the master device. Then, after receiving the response information from the slave device 1, the master device transmits the individual polling P <b> 2 for the slave device 2. Then, the response information for the control information is transmitted from the slave device 2 to the master device. In this manner, the master device receives the response information from all the slave devices by repeatedly transmitting the individual polling P to each slave device and transmitting the response information from the slave device.

By the way, a pre-polling method is known as a method for improving the transmission efficiency by applying the polling method. In this pre-polling method, first, a pre-polling message is transmitted collectively from a master device (master station) to a slave device (slave station). Then, in response to the pre-polling message, the slave device transmits a pre-polling response message including the presence / absence of a data transmission request. Then, after receiving the pre-polling response message, the main apparatus performs individual polling only for the slave station having a data transmission request. As a result, the master device can grasp in advance a slave device that does not require data transmission, and transmission efficiency can be improved by not transmitting individual polling to a slave device that does not require data transmission (see, for example, Patent Document 1).
JP-A 63-279636

  However, for example, in a system that always needs to receive data from all the slave devices, transmission efficiency cannot be improved even if the above-described pre-polling method is applied. Conversely, transmission / reception of pre-polling messages and pre-polling response messages is not possible. As a result, the total time required for data transmission / reception increases, and transmission efficiency decreases. Further, in the conventional polling method, in order to prevent data collision, it is necessary to provide a predetermined pause time during which data transmission / reception is not performed between transmission of individual polling from the master device and data transmission from the slave device. As a result, the transmission efficiency was reduced. In particular, as the number of slave devices increases, the sum of the pause times becomes longer, and the reduction in transmission efficiency is further increased.

  The present invention has been made in view of the above circumstances, and aims to improve transmission efficiency in a one-to-many communication system connected through serial communication.

The first invention for solving the above-described problems is
A master device (for example, the control device 10 in FIG. 1) and a plurality of slave devices (for example, the terminal 20 in FIG. 1) are connected by serial communication, and the master device receives command information including control information for each of the slave devices. A control system (for example, the control system 1 in FIG. 1) that transmits and periodically receives response information including operation state information from each of the slave devices and monitors the operation state of each slave device;
The main unit is
The command information includes setting information in which the transmission timing of each slave device is set so that the transmission timing of the response information of each slave device does not overlap, and is necessary for receiving the response information from all the slave devices Transmission means (for example, the communication control unit 11 in FIG. 1) that periodically transmits to all the slave devices at a predetermined time interval of time or more;
Receiving means (for example, the communication control unit 11 in FIG. 1) that sequentially receives the response information transmitted from each of the slave devices between the current transmission and the next transmission by the transmission means;
An operation state determination unit that determines an operation state of the slave device based on operation state information included in response information sequentially received by the reception unit;
Have
Each of the slave devices is
Command information receiving means for receiving the command information from the main unit;
Response information transmitting means for varying the transmission timing of the response information according to the setting information included in the received command information, and transmitting the response information to the main device;
Having
Control system.

In addition, the fifth invention,
The master device and a plurality of slave devices are connected by serial communication, and the master device transmits command information including control information to each of the slave devices, and response information including operation state information is periodically transmitted from each of the slave devices. A communication control method (for example, communication control processing of FIG. 9) in a control system that receives the data and monitors the operating state of each slave device,
The command information includes setting information in which the master device sets the transmission timing of each slave device so that the transmission timings of the response information of the slave devices do not overlap, and the response information from all the slave devices A transmission step (for example, steps S5 to S9 in FIG. 9) for periodically transmitting to all the slave devices at a predetermined time interval equal to or longer than the time required for reception of
A response in which each of the slave devices changes the transmission timing of the response information according to the setting information included in the command information received from the main device, and transmits the response information in response to the reception to the main device An information transmission step (for example, step S11 in FIG. 9);
The master device sequentially receives the response information transmitted from each of the slave devices during the period from the current transmission to the next transmission in the transmission step, and based on the operation state information included in the received response information An operation state determination step for determining the operation state of the slave device,
Is a communication control method.

  According to the first or fifth aspect, in the control system in which the master device and the plurality of slave devices are connected by serial communication, the master device includes the setting information that sets the transmission timing of the response information of each slave device. The command information is periodically transmitted to all the slave devices at once, and the response information including the operation status information is received from each slave device, and the operation status of each slave device is monitored. Each slave device transmits response information to the master device at a transmission timing according to the setting information included in the command information received from the master device. Here, the transmission timing is set so that the transmission timings of the response information of the slave devices do not overlap. That is, since the transmission timing of response information of all the slave devices can be arbitrarily set by the command information transmitted from the master device, it is not necessary to set the transmission timing of response information in each slave device in advance. As a result, it is easy to change the configuration of the control system, such as changing the number and type of slave devices connected to the master device as the monitoring target.

  In addition, since the transmission timing of response information of each slave device is set by command information transmitted to all slave devices at once, conventional polling that transmits individual polling that specifies the transmission timing for each slave device Compared with the system, the time required for data transmission / reception between the master device and each slave device can be shortened, and the transmission efficiency is improved. Furthermore, this improvement in transmission efficiency is more effective as the number of slave devices increases.

The second invention is the control system of the first invention,
The main unit is
Transmission timing setting for setting the transmission timing of each slave device based on the number of slave devices connected to the serial communication, the data length of the response information, and the order of the slave devices transmitting the response information Means (for example, communication control unit 11 in FIG. 1; step S1 in FIG. 9),
Control system.

  According to the second aspect of the present invention, in the master device, the transmission of each slave device is based on the number of slave devices serially connected, the data length of the response information, and the order of the slave devices transmitting the response information. Timing is set. Thus, for example, when it is desired to change the number of slave devices connected in serial communication, or when it is desired to change the transmission order of response information from each slave device, even if the data length of the response information differs for each slave device. The transmission timing of response information from each slave device can be set appropriately and easily.

The third invention is the control system of the second invention,
The transmission timing setting means defines the transmission timing by an elapsed time from the time when the slave device receives the command information,
The response information transmitting means transmits the response information when an elapsed time from reception of the command information by the command information receiving means has reached a transmission timing set in setting information included in the received command information. Send,
Control system.

  According to the third aspect, the transmission timing of the response information is defined by the elapsed time from the time when the slave device receives the command information, and the time elapsed since the reception of the command information is received from each slave device. The response information is transmitted when the transmission timing set in the setting information included in the command information is reached.

A fourth invention is a control system according to any one of the first to third inventions,
This is a control system consisting of a signal security system for railway facilities.

  According to the fourth aspect of the invention, the control system described above can be applied to a signal security system for railway facilities. Here, as the signal security system, for example, a system constituted by connecting an electronic interlocking device as a main device and a terminal device for controlling a turning machine, a signal, and a track circuit installed as a slave device as a slave device. There is.

  According to the present invention, in a control system in which a master device and a plurality of slave devices are connected by serial communication, the transmission timing of response information of all slave devices can be arbitrarily set by command information transmitted from the master device. It is not necessary to set the transmission timing of the response information in each slave device in advance. As a result, it is easy to change the configuration of the control system, such as changing the number and type of slave devices connected to the master device as the monitoring target. In addition, since the transmission timing of response information of each slave device is set by command information transmitted to all slave devices at once, conventional polling that transmits individual polling that specifies the transmission timing for each slave device Compared with the system, the time required for data transmission / reception between the master device and each slave device can be shortened, and the transmission efficiency is improved. Furthermore, this improvement in transmission efficiency is more effective as the number of slave devices increases.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[Constitution]
FIG. 1 is a diagram illustrating a configuration of a control system 1 of the present embodiment. As shown in the figure, the control system 1 includes a control device 10 that is a main device and a plurality of terminals 20 that are slave devices, and the control device 10 and the plurality of terminals 20 are connected by serial communication via a communication line 30. Configured.

  The control device 10 performs one-to-many communication with the terminals 20 connected via serial communication, and monitors the operating state of each of the terminals 20. That is, the control device 10 periodically transmits command information including control information to each terminal 20 and periodically receives response information including operation state information transmitted from each terminal 20. 20 operation states are monitored. In the figure, the control device 10 is provided with a plurality of communication lines 30, and a plurality of terminals 20 are connected to the respective communication lines 30, whereby the control device 10 and the terminals 20 are connected by serial communication. Data transmission / reception between the control device 10 and the terminal 20 is controlled on a communication line 30 basis.

  FIG. 2 is an example in which the control system 1 is applied to a signal security system for a railway facility. In this case, the control device 10 corresponds to an interlocking logic unit of the electronic interlocking device. The terminal 20 is an electronic terminal (for example, “switch control terminal”, “DC control terminal”, “AC control terminal”, “ Signal control terminal "," orbit input terminal "," general-purpose input / output terminal ", etc.). The communication line 30 is a dedicated LAN configured by, for example, an optical cable. And these control apparatuses 10 and the terminal 20 are accommodated in the logical installation installed, for example in a handling office.

  Returning to FIG. 1, the control device 10 includes a plurality of communication control units 11 that control communication with the terminal 20 in units of communication lines 30, and a storage unit 13.

  The communication control unit 11 controls communication with each terminal 20 connected to the corresponding communication line 30. FIG. 3 is a diagram illustrating a communication procedure between the control device 10 and each terminal 20 by the communication control unit 11. In the figure, the horizontal axis represents time t, and the transmission timing of data transmitted from the control device 10 and each of the n terminals 20 connected to the control device 10 via the corresponding communication line 30 through serial communication. Is shown. Although a time difference occurs in data transmission / reception between the control device 10 and each terminal 20, since this time difference is slight, it is considered that the timing is the same.

  According to the figure, first, command information is sent from the control device 10 to the communication line 30 and is sent to all the terminals 20 at once. The command information includes setting information 100, control information 200, and common polling 300, and is transmitted in the order of setting information 100, control information 200, and then common polling 300. Then, the response information 400 in response to this command information is transmitted from each terminal 20 to the control device 10 in order. That is, after a predetermined delay D has elapsed from the reception of the common polling 300 from each of the terminals 20, the response information 400 is transmitted to the control device 10.

The delay D is data that specifies the transmission timing of the response information 400 from the terminal 20, and is determined as the elapsed time from the reception of the common polling 300 for each terminal 20. In addition, the delay D is set so that the transmission timing of the response information 400 transmitted from each terminal 20 does not overlap, that is, the response information 400 is not transmitted from a plurality of terminals 20 at the same time. Of the response information 400, the data length of the response information 400, the communication speed of the communication line 30, and the like. Specifically, assuming that the response information 400 is fixed-length data, the time required to transmit the response information 400 is td, and the margin time for preventing the response information 400 from colliding is Δt, the transmission order is the x-th terminal. The 20 delays Dx are given by the following equation (1).
Dx = Δt × x + td × (x−1) (1)

  The delay information D for each of all the terminals 20 is included in the control information 200. That is, each terminal 20 acquires the delay D of the terminal 20 included in the command information received from the control device 10, and transmits the response information 400 to the command information after the delay D has elapsed since the reception of the common polling 300. To do.

  Further, the control device 10 periodically transmits the command information at intervals of a predetermined reception standby time T. The reception waiting time T is a time for receiving the response information 400 transmitted from the terminal 20 in accordance with the transmitted command information, and is determined as a time during which the response information 400 from all the terminals 20 can be received. That is, the reception standby time T is a time longer than the time “(Δt + td) × n” required to receive the response information 400 from all the terminals 20 when the number of terminals 20 connected by serial communication is “n”. Become.

  FIG. 4 is a data configuration example of the setting information 100 sent from the control device 10. According to the figure, the setting information 100 includes terminal setting information 110 and terminal transmission definition information 120. The terminal setting information 110 is setting data for setting the function of the terminal 20, and includes individual setting data for all the terminals 20 connected by serial communication. Note that the terminal setting information 110 does not necessarily include individual data for all the terminals 20. For example, the terminal 20 that does not need to be set may not include the individual setting data. The terminal transmission definition information 120 is data defining data communication between the control device 10 and each terminal 20, and includes individual data for all terminals 20 connected by serial communication. This includes data for designating which part of the delay D and the control information 200 to be subsequently transmitted is to be referred to.

  FIG. 5 is a data configuration example of the control information 200 sent from the control device 10. According to the figure, the control information 200 includes common control information 210 and individual control information 220. The common control information 210 is control data common to all terminals 20. The individual control information 220 is control data for each terminal 20, and is composed of individual control data for all terminals 20 connected by serial communication.

  FIG. 6 is a data configuration example of the response information 400 sent from the terminal 20. According to the figure, the response information 400 includes a terminal ID 410 that is identification information of the terminal 20, system state information 420, and operation state information 430. The system state information 420 is system state data indicating whether the terminal 20 is normal / abnormal. Further, the operation state information 430 is data of the current operation state of the terminal 20, and for example, if the terminal 20 is a control terminal, data such as localization / inversion of the control target switch It is.

  Returning to FIG. 1, the storage unit 13 stores a system program of the control device 10, a program and data for the communication control unit 11 to realize communication control for the terminal 20, and serves as a work area of the communication control unit 11. Used. In the present embodiment, the storage unit 13 stores connection terminal data 14 and reception data 15.

  The connection terminal data 14 is data regarding the terminal 20 connected in serial communication with the control device 10. FIG. 7 shows an example of the data configuration of the connection terminal data 14. According to the figure, the connection terminal data 14 includes, for each communication line 30, the terminal ID 14 a of the terminal 20 connected to the communication line 30, the type 14 b, the data length 14 c of the response information 400, and the response information 400. 14d and the delay 14e are stored in association with each other. Note that the response information data lengths 14c are all equal because the response information 400 is fixed-length data.

  The reception data 15 is data received from the terminal 20 connected via serial communication. FIG. 8 shows an example of the data configuration of the reception data 15. According to the figure, the reception data 15 accumulates and stores response information 400 received from the terminal 20 connected to the communication line 30 in the order of reception for each communication line 30. In the reception data 15, a storage area for at least the number of terminals 20 connected to the communication line 30 is secured for each communication line 30.

[Process flow]
FIG. 9 is a flowchart for explaining a communication control process by the communication control unit 11. According to the figure, the communication control unit 11 first determines the delay D of each terminal 20 connected to the corresponding communication line 30. Specifically, the connection terminal data 14 of the corresponding communication line 30 is referred to, and the delay D of each terminal 20 is set according to the equation (1) based on the transmission order and data length of the response information 400 for each terminal 20. calculate. The determined delay D of each terminal 20 is stored in the connection terminal data 14 (step S1).

  Next, setting information 100 and control information 200 are generated (step S3). Then, the command information is collectively transmitted to each terminal 20. That is, the generated setting information 100 is collectively transmitted to each terminal 20 (step S5), and then the generated control information 200 is collectively transmitted to each terminal 20 (step S7). Thereafter, the common polling 300 is collectively transmitted to each terminal 20 (step S9).

  When the common polling 300 is transmitted, the communication control unit 11 receives the response information 400 transmitted from the terminal 20 until the reception standby time T elapses (step S13: NO). The received response information 400 is accumulated and stored in the received data 15 in the order of reception (step S11). If the predetermined reception waiting time T has elapsed (step S13: YES), it is subsequently determined whether or not to end communication with the terminal 20. If the communication is not terminated (step S15: NO), the process returns to step S3. If the communication is terminated (step S15: YES), the communication control process is terminated.

[Action / Effect]
According to this embodiment, in the control system 1 in which a plurality of slave devices 20 are serially connected to the control device 10 that is the main device, first, the setting information 100, the control information 200, and then the control device 10. The common polling 300 is transmitted to all terminals 20 at once. Then, each terminal 20 transmits the response information 400 to the control device 10 after the delay D of the terminal 20 included in the received control information 200 has elapsed since the reception of the common polling 300. Here, the delay D is determined by the control device 10 so that the transmission timings of the response information 400 of the terminals 20 do not overlap. Thereby, compared with the conventional polling system, the time required for data reception from each terminal 20 can be shortened, and the transmission efficiency is improved. Further, the transmission efficiency is expected to be further improved as the number of terminals 20 increases.

  Further, since the delay D (transmission timing of the response information 400) of each terminal 20 is set by the control information 200 transmitted collectively to all the terminals 20, it is necessary to set the delay D in the terminal 20 in advance. In addition, it is easy to change the configuration of the control system 1 such as changing the number or type of terminals 20 connected to the communication line 30.

[Modification]
It should be noted that embodiments to which the present invention can be applied are not limited to the above-described embodiments, and can of course be changed as appropriate without departing from the spirit of the present invention.

(A) Common polling 300
For example, the common polling 300 may not be included in the command information. In this case, the control information 200 also serves as the common polling 300. That is, the control device 10 collectively transmits the setting information 100 and the control information 200 as command information to each terminal 20. Then, the terminal 20 transmits the response information 400 to the control device 10 after a predetermined delay D has elapsed since the reception of the control information 200.

(B) Response information 400
In the above-described embodiment, the response information 400 is fixed length data, but may be variable length data. In this case, the control device 10 needs to determine the delay D every time the command information is transmitted.

(C) Control system Moreover, although the above-mentioned embodiment demonstrated the case where the control system of this invention was applied to the signal security system of a railroad facility, several subordinate apparatus is connected to the main apparatus by serial communication, and is regularly Needless to say, the present invention is applicable to any system in which the master device receives data from all slave devices.

The block diagram of a control system. Application example of control system. Communication procedure between the control device and each terminal. The data structural example of setting information. The data structural example of control information. The example of a data structure of response information. The data structural example of connection terminal data. Data configuration example of received data. The flowchart of a communication control process. A communication procedure between a conventional master device and a plurality of slave devices.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control system 10 Control apparatus 11 Communication control part 13 Storage part, 14 Connection terminal data, 15 Received data 20 Terminal 30 Communication line 100 Setting information, 200 Control information 300 Common polling, 400 Response information

Claims (5)

The master device and a plurality of slave devices are connected by serial communication, and the master device transmits command information including control information to each of the slave devices, and response information including operation state information is periodically transmitted from each of the slave devices. And a monitoring system that monitors the operating state of each slave device.
The main unit is
The command information includes setting information in which the transmission timing of each slave device is set so that the transmission timing of the response information of each slave device does not overlap, and is necessary for receiving the response information from all the slave devices Transmitting means for periodically transmitting to all the slave devices at a predetermined time interval of time or more;
Receiving means for sequentially receiving the response information transmitted from each of the slave devices between the current transmission and the next transmission by the transmission means;
An operation state determination unit that determines an operation state of the slave device based on operation state information included in response information sequentially received by the reception unit;
Have
Each of the slave devices is
Command information receiving means for receiving the command information from the main unit;
Response information transmitting means for varying the transmission timing of the response information according to the setting information included in the received command information, and transmitting the response information to the main device;
Having
Control system. The main unit is
Transmission timing setting for setting the transmission timing of each slave device based on the number of slave devices connected to the serial communication, the data length of the response information, and the order of the slave devices transmitting the response information Having means,
The control system according to claim 1. The transmission timing setting means defines the transmission timing by an elapsed time from the time when the slave device receives the command information,
The response information transmitting means transmits the response information when an elapsed time from reception of the command information by the command information receiving means has reached a transmission timing set in setting information included in the received command information. Send,
The control system according to claim 2.   The control system according to any one of claims 1 to 3, comprising a signal security system for a railway facility. The master device and a plurality of slave devices are connected by serial communication, and the master device transmits command information including control information to each of the slave devices, and response information including operation state information is periodically transmitted from each of the slave devices. And a communication control method in a control system that monitors the operating state of each slave device.
The command information includes setting information in which the master device sets the transmission timing of each slave device so that the transmission timings of the response information of the slave devices do not overlap, and the response information from all the slave devices A transmission step of periodically transmitting to all the slave devices at a predetermined time interval equal to or longer than a time required for reception of
A response in which each of the slave devices changes the transmission timing of the response information according to the setting information included in the command information received from the main device, and transmits the response information in response to the reception to the main device An information transmission step;
The master device sequentially receives the response information transmitted from each of the slave devices during the period from the current transmission to the next transmission in the transmission step, and based on the operation state information included in the received response information An operation state determination step for determining the operation state of the slave device,
Including a communication control method.

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