JP7034681B2 - Communication control device - Google Patents

Description

The present invention relates to a communication control device that realizes data transfer between a higher-level device and a lower-level device.

When reading and writing data by communication to an instrument such as a programmable logic controller (hereinafter, PLC) or a temperature controller (hereinafter, controller), via the communication control device disclosed in Patent Document 1, There is a communication protocol that reads and writes the value of a parameter in command response communication by specifying the data address associated with the parameter (or register) in the device. Examples of such a communication protocol include MODBUS (registered trademark), MC protocol, and CPL (Controller Peripheral Link) disclosed in Patent Document 2.

FIG. 15 is a diagram illustrating the operation of the communication control device disclosed in Patent Document 1. In the example of FIG. 15, the communication control device 1 reads data from the controller 3 using CPL and writes the read data to PLC 2 using MODBUS.

In a system in which PLC 2 exists as a master device and each controller 3 controls according to the instruction, the data of each controller 3 (data of operation amount MV and control amount PV) is read out by communication as described above. It is aggregated in PLC2.
Conventionally, serial communication has been used in the communication between the PLC 2 and the controller 3 via the communication control device 1. In the case of serial communication, as shown in FIG. 16, the number of regulators 3 capable of reading data by command response for one physical port (COM port) was one.

In the case of IP (Internet protocol) communication using LAN (Local Area Network) such as Ethernet (registered trademark), which has been increasing in recent years, as shown in FIG. 17, parallel from a plurality of regulators 3 on the same LAN 4. It has become possible to read a large amount of data at high speed with a command response. The amount of data per unit time for the communication control device 1 to transfer data to the PLC 2 is proportional to the number of connected controllers 3. There is a limit to the number of data that can be sent and received by the command response between the communication control device 1 and PLC2, and if the number of data that can be exchanged at one time is exceeded, it is divided into multiple communication frames 5-1, 5-2, ... It is necessary to send and receive data, and if parallel processing is not possible, it is necessary to process in order while waiting for a command response for each communication frame.

Regarding the amount of communication between the communication control device 1 and PLC2 per unit time, in the case of serial communication, even if the number of connected controllers 3 increased, there was no significant change due to the limitation of the number of physical communication ports, but IP In the case of communication, the amount of communication between the communication control device 1 and the PLC 2 increases in proportion to the number of connected controllers 3. As a result, in a system in which many regulators 3 are used, there is a problem that communication between the communication control device 1 and the PLC 2 becomes a bottleneck.

As one solution to such a problem, in the communication between the communication control device 1 and the PLC 2, there is a method of transmitting commands in parallel without waiting for a response in the command response processing. For example, if it is a communication protocol having a frame number (frame identification ID) function such as MODBUS / TCP (Transmission Control Protocol), a plurality of commands can be transmitted at one time.

However, the number that can be executed in parallel is limited by the communication protocol and device-specific specifications. If a command is transmitted beyond the processing capacity of PLC2, TCP retransmission processing may occur frequently, leading to a decrease in overall performance.
There are also communication protocols that do not have a frame number function. When such a communication protocol is used, the order of frames may be changed due to retransmission processing or the like, so that it is not possible to execute a plurality of command response processes in parallel.

Japanese Unexamined Patent Publication No. 2017-344333 Japanese Unexamined Patent Publication No. 2011-234171

The present invention has been made to solve the above problems, and even when the number of connections of lower-level devices such as a controller increases, the efficiency between the higher-level device and the lower-level device is not restricted by the communication protocol. It is an object of the present invention to provide a communication control device capable of realizing good data transfer.

The communication control device of the present invention is provided for each of the plurality of lower-level devices, and is set between the plurality of first communication processing units configured to communicate with the corresponding lower-level devices and the higher-level device. A plurality of second communication processing units provided for each of the plurality of connections and configured to communicate with the higher-level device via the corresponding connections, and a plurality of second communication processing units configured to store data transfer definition information in advance. When read request information is created for the data transfer definition unit and the lower-level device of the transfer source defined in the data transfer definition information, and the data requested by this read request information is received from the transfer source, the received data is received. A data transfer processing unit configured to create write request information for writing to a higher-level device of the transfer destination defined in the data transfer definition information, and a first unit that reads data from the transfer source in response to the read request information. Command frame is created and passed to the first communication processing unit corresponding to the transfer source, and when the first communication processing unit receives the first response frame from the transfer source, the read request is made. There is a first communication request processing unit configured to take out the data requested by information from the first response frame and pass it to the data transfer processing unit, and a usable connection among the plurality of connections. In this case, a second command frame for writing data to the transfer destination is created according to the write request information, and the second command frame is sent to the second communication processing unit corresponding to the available connection. Is passed, and when the second communication processing unit receives the second response frame from the transfer destination, the result indicated by the second response frame is notified to the data transfer processing unit. It is characterized by having a communication request processing unit of 2.

Further, the communication control device of the present invention is provided for each of a plurality of connections set between the host device and the host device, and is configured to communicate with the host device via the corresponding connection. Communication processing unit, a plurality of second communication processing units provided for each of the plurality of lower-level devices and configured to communicate with the corresponding lower-level devices, and a configuration for storing data transfer definition information in advance. When the read request information for the data transfer definition unit and the higher-level device of the transfer source defined in the data transfer definition information is created and the data requested by the read request information is received from the transfer source, this reception is performed. There is a data transfer processing unit configured to create write request information for writing the data to the lower-level device of the transfer destination defined in the data transfer definition information, and a connection that can be used among the plurality of connections. In this case, a first command frame for reading data from the transfer source according to the read request information is created and passed to the first communication processing unit corresponding to the available connection , and the first communication is performed. When the processing unit receives the first response frame from the transfer source, the data requested by the read request information is taken out from the first response frame and passed to the data transfer processing unit. A communication request processing unit of 1 and a second command frame for writing data to the transfer destination according to the write request information are created and passed to the second communication processing unit corresponding to the transfer destination, and the second command frame is created. When the communication processing unit 2 receives the second response frame from the transfer destination, the second communication request processing configured to notify the data transfer processing unit of the result indicated by the second response frame. It is characterized by having a part.

Further, in one configuration example of the communication control device of the present invention, the data transfer definition information includes the data transfer start condition together with the transfer source information and the transfer destination information, and the data transfer start condition is used as the start condition. It is characterized in that a cycle is set.
Further, in one configuration example of the communication control device of the present invention, the data transfer definition information includes the data transfer start condition together with the transfer source information and the transfer destination information, and the trigger information is used as the start condition. It is characterized by being set.
Further, one configuration example of the communication control device of the present invention is characterized in that the plurality of connections are set in one communication port of the higher-level device.
Further, one configuration example of the communication control device of the present invention is characterized in that one connection is set for each of a plurality of communication ports of the higher-level device.

According to the present invention, by setting a plurality of connections between the communication control device and the host device and performing communication, a plurality of command frames can be transmitted to the host device in parallel via the plurality of connections. Therefore, even if the number of connections of the lower-level device increases, efficient data transfer between the higher-level device and the lower-level device can be realized without being restricted by the communication protocol.

FIG. 1 is a diagram illustrating the principle of the present invention. FIG. 2 is a block diagram showing a configuration of a communication control device according to the first embodiment of the present invention. FIG. 3 is a diagram illustrating an example in which a plurality of connections are set in one TCP communication port of a PLC in the first embodiment of the present invention. FIG. 4 is a diagram showing data transfer definition information stored in the data transfer definition unit of the communication control device according to the first embodiment of the present invention. FIG. 5 is a flowchart illustrating the operation of the data transfer processing unit of the communication control device according to the first embodiment of the present invention. FIG. 6 is a flowchart illustrating the operation of the communication request processing unit and the communication processing unit for the controller of the communication control device according to the first embodiment of the present invention. FIG. 7 is a flowchart illustrating the operation of the communication request processing unit and the communication processing unit for PLC of the communication control device according to the first embodiment of the present invention. FIG. 8 is a sequence diagram illustrating the operation of the communication control device according to the first embodiment of the present invention. FIG. 9 is a sequence diagram illustrating the operation of the conventional communication control device. FIG. 10 is a diagram illustrating an example in which a connection is set for each of a plurality of TCP communication ports of a PLC in a second embodiment of the present invention. FIG. 11 is a diagram showing data transfer definition information stored in the data transfer definition unit of the communication control device according to the third embodiment of the present invention. FIG. 12 is a flowchart illustrating the operation of the communication request processing unit and the communication processing unit for PLC of the communication control device according to the third embodiment of the present invention. FIG. 13 is a flowchart illustrating the operation of the communication request processing unit and the communication processing unit for the controller of the communication control device according to the third embodiment of the present invention. FIG. 14 is a block diagram showing a configuration example of a computer that realizes the communication control device according to the first to third embodiments of the present invention. FIG. 15 is a diagram illustrating the operation of the conventional communication control device. FIG. 16 is a diagram illustrating communication between the PLC and the controller using serial communication. FIG. 17 is a diagram illustrating communication between the PLC and the controller using a LAN.

[Principle of invention]
FIG. 1 is a diagram illustrating the principle of the present invention. In communication with PLC, even if the available communication protocol is a protocol that cannot execute commands in parallel, it may be possible to establish multiple connections on one TCP communication port as a PLC specification. be. Also, even if only a single connection is allowed, multiple TCP communication ports may be available at the same time. The specifications of these PLCs assume that a plurality of devices (touch panel, computer, etc.) are connected to the PLC.

In the present invention, the communication control device 1a executes command response processing in parallel for a plurality of connections by utilizing the fact that a plurality of connections can be established with the PLC at the same time. Reduce wasted time due to waiting for a response from PLC.

[First Example]
Hereinafter, examples of the present invention will be described with reference to the drawings. FIG. 2 is a block diagram showing a configuration of the communication control device 1a according to the first embodiment of the present invention. The communication control device 1a is connected to the PLC2 via a network such as Ethernet, is provided for each of a plurality of connections set between the PLC2 and the PLC2, and communicates with the PLC2 via the corresponding connection. Communication processing units 10-1 to 10-n (n is an integer of 2 or more) and a command frame that writes data to the transfer destination according to the write request information from the data transfer processing unit described later can be created and used. The result shown by this response frame when the command frame is passed to the communication processing units 10-1 to 10-n for PLC corresponding to the connection and the communication processing units 10-1 to 10-n for PLC receive the response frame. Is provided to the communication request processing unit 11 for notifying the data transfer processing unit, and the regulators 3-1 to 3-m, which are connected to the regulators 3-1 to 3-m via a network such as Ethernet. Create a command frame to read data from the transfer source according to the communication processing unit 12-1 to 12-m (m is an integer of 2 or more) for each controller and the read request information from the data transfer processing unit. It is passed to the communication processing units 12-1 to 12-m for the controller corresponding to the transfer source, and when the communication processing units 12-1 to 12-m for the controller receive the response frame, it is requested by the read request information. The communication request processing unit 13 that extracts data from the response frame and passes it to the data transfer processing unit and the read request information for the transfer source defined in the data transfer definition information are created, and the data requested by this read request information is transmitted from the transfer source. The data transfer processing unit 14 that creates write request information that writes the received data to the transfer destination defined in the data transfer definition information when it is received, the transfer source information, the transfer destination information, and the data transfer start condition. It is composed of a data transfer definition unit 15 that stores data transfer definition information including and in advance.

In this embodiment, as shown in FIG. 3, a case where a plurality of connections Pcon-1 to Pcon-n are permitted to be established in one TCP communication port 200 will be described as a specification of PLC2. In FIG. 3, 100-1 to 100-n are TCP communication ports set in the PLC communication processing units 10-1 to 10-n of the communication control device 1a, respectively, and 101-1 to 101-m are communication control devices 1a, respectively. TCP communication ports set in the controller communication processing unit 12-1 to 12-m, 300-1 to 300-m are TCP communication ports of the controller 3-1 to 3-m, respectively, Concon-1 to Ccon. -M is a connection set between the TCP communication ports 101-1 to 101-m and the TCP communication ports 300-1 to 300-m.

The data transfer definition unit 15 stores data transfer definition information as shown in FIG. 4 in advance. The data transfer definition information includes the data transfer start condition, the data transfer source address information (in this embodiment, the monitoring point of the regulators 3-1 to 3-m and the address that specifies the data), and the data transfer destination address. It consists of information (in this embodiment, the address of the register of PLC2).

In the example of FIG. 4, it can be seen that the data transfer cycle is defined as the data transfer start condition, and the data transfer is performed every 200 msec. Such data transfer definition information is registered in advance by the user of the communication control device 1a.

FIG. 5 is a flowchart illustrating the operation of the data transfer processing unit 14 of the communication control device 1a of the present embodiment, and FIG. 6 is an operation of the communication request processing unit 13 and the communication processing units 12-1 to 12-m for the controller. FIG. 7 is a flowchart illustrating the operation of the communication request processing unit 11 and the PLC communication processing units 10-1 to 10-n.

The data transfer processing unit 14 waits until the start condition defined in the data transfer definition information of the data transfer definition unit 15 is satisfied.
When the data transfer processing unit 14 reaches the timing to execute the data transfer and the activation condition is satisfied (YES in step S100 in FIG. 5), the data transfer source 14 is based on the transfer source address information defined in the data transfer definition information. Create read request information for reading data from (FIG. 5, step S101). The read request information includes transfer source address information.

Then, the data transfer processing unit 14 transmits the created read request information to the communication request processing unit (communication request processing unit 13 in this embodiment) corresponding to the data transfer source defined in the data transfer definition information (FIG. FIG. 5 steps S102).
The data transfer processing unit 14 of steps S101 and S102 until the transmission of read request information for all the sets of the data transfer source and the data transfer destination defined in the data transfer definition information is completed (YES in step S103 of FIG. 5). Repeat the process.

Next, when the communication request processing unit 13 receives the read request information from the data transfer processing unit 14 (YES in step S200 of FIG. 6), the communication request processing unit 13 stores the received read request information in the internal communication request queue (not shown). Communication request queue processing is performed (step S201 in FIG. 6).

Subsequently, when the unprocessed read request information is stored in the communication request queue (YES in step S202 of FIG. 6), the communication request processing unit 13 sets the unprocessed read request information as a processing target, and sets the unprocessed read request information as the processing target. It is determined whether or not communication processing is in progress with the data transfer source regulators 3 (3-1 to 3-m) specified by the transfer source address information included in (FIG. 6, step S203).

When the communication request processing unit 13 is not in the process of communicating with the data transfer source (NO in step S203), the communication request processing unit 13 creates a command frame for reading data from the data transfer source based on the read request information to be processed. (FIG. 6 step S204). The command frame contains the forwarding address information.

Then, the communication request processing unit 13 passes the created command frame to the communication processing unit 12 (12-1 to 12-m) for the controller corresponding to the data transfer source (regulator in this embodiment). The communication processing unit 12 (12-1 to 12-m) for the controller transfers the received command frame to the data transfer source via the connection Con (Conon-1 to Con-m) set. It is transmitted to the original controller 3 (3-1 to 3-m) (FIG. 6, step S205).

When the controller 3 (3-1 to 3-m) receives a command frame, it acquires the data specified by the transfer source address information included in the received command frame from the internal memory, and responds including this data. Create a frame. Then, the regulators 3 (3-1 to 3-m) connect the created response frame to the communication control device 1a that is the source of the command frame, and the connection Concon (Conon-1 to Conon-m) is set. Is transmitted to the communication control device 1a via.

When the communication processing unit 12 (12-1 to 12-m) for the controller of the communication control device 1a that has transmitted the command frame receives the response frame for this command frame from the controller 3 (3-1 to 3-m). (YES in step S206 of FIG. 6), the received response frame is passed to the communication request processing unit 13.

The communication request processing unit 13 analyzes the response frame and extracts the data transmitted from the data transfer source controller 3 (3-1 to 3-m) from the response frame (step S207 in FIG. 6). The communication request processing unit 13 transmits the data extracted from the response frame to the data transfer processing unit 14 as a result requested by the read request information to be processed (step S208 in FIG. 6).

Then, the communication request processing unit 13 sends the result requested by the read request information to be processed to the data transfer processing unit 14, and then deletes the read request information from the internal communication request queue (step S209 of FIG. 6). ), Return to step S200.

Next, when the data transfer processing unit 14 receives the result requested by the read request information from the communication request processing unit 13 (YES in step S104 of FIG. 5), the data transfer definition information from which the read request information is created is created. Create write request information for writing data to the data transfer destination based on the transfer destination address information defined in (FIG. 5, step S105). The write request information includes the transfer destination address information and the data transmitted from the data transfer source controller 3 (3-1 to 3-m).

Then, the data transfer processing unit 14 transmits the created write request information to the communication request processing unit (communication request processing unit 11 in this embodiment) corresponding to the data transfer destination defined in the data transfer definition information (FIG. 5 steps S106).

Next, when the communication request processing unit 11 receives the write request information from the data transfer processing unit 14 (YES in step S300 of FIG. 7), the communication request processing unit 11 stores the received write request information in the internal communication request queue (not shown). Communication request queue processing is performed (step S301 in FIG. 7).

Subsequently, when the communication request processing unit 11 stores the unprocessed write request information in the communication request queue (YES in step S302 of FIG. 7), the communication request processing unit 11 sets the unprocessed write request information as a processing target, and sets the unprocessed write request information as the processing target. It is determined whether or not communication processing is in progress with the data transfer destination (PLC2 in this embodiment) specified by the transfer destination address information included in (FIG. 7 step S303).

In this embodiment, since a plurality of connections Pcon-1 to Pcon-n are set between the communication control device 1a and the PLC2, when all the connections Pcon-1 to Pcon-n are used. The determination result is that communication processing is in progress, and if at least one of the connections Pcon-1 to Pcon-n is unused, the determination result is that communication processing is not in progress.

The communication request processing unit 11 processes when communication processing is not in progress with the data transfer destination, that is, when there is a usable connection among a plurality of connections Pcon-1 to Pcon-n (NO in step S303). A command frame for writing data to the data transfer destination is created based on the target write request information (step S304 in FIG. 7). The command frame includes transfer destination address information and data transmitted from the data transfer source controller 3 (3-1 to 3-m).

Then, the communication request processing unit 11 transfers the created command frame to a usable connection among a plurality of connections Pcon-1 to Pcon-n set between the created command frame and the data transfer destination (PLC2 in this embodiment). It is passed to the corresponding PLC communication processing unit 10 (10-1 to 10-n). The PLC communication processing unit 10 (10-1 to 10-n) transmits a command frame to the data transfer destination PLC2 via the corresponding connection Pcon (Pcon-1 to Pcon-n) (step S305 in FIG. 7). ..

When the PLC2 receives a command frame, it returns a response frame indicating that the command frame has been received to the communication control device 1a by using the connection Pcon (Pcon-1 to Pcon-n) that has received the command frame. Further, PLC2 writes the data included in this command frame to the register specified by the forwarding address information included in the received command frame.
In this way, the data of the controller 3 (3-1 to 3-m) can be transferred to the PLC 2.

When the PLC communication processing unit 10 (10-1 to 10-n) of the communication control device 1a that has transmitted the command frame receives the response frame for this command frame from the PLC 2 (YES in step S306 of FIG. 7), the received response. The frame is passed to the communication request processing unit 11.

When the communication request processing unit 11 analyzes the response frame (step S307 in FIG. 7) and confirms that the PLC2 of the data transfer destination has received the command frame, the processing requested by the write request information to be processed is completed. Information indicating that is transmitted to the data transfer processing unit 14 as a result requested by the write request information to be processed (step S308 in FIG. 7).

Then, the communication request processing unit 11 sends the result requested by the write request information to be processed to the data transfer processing unit 14, and then deletes the write request information from the internal communication request queue (step S309 of FIG. 7). ), Return to step S300.

When the data transfer processing unit 14 receives the result requested by the write request information from the communication request processing unit 11 (YES in step S107 of FIG. 5), all the data transfer sources and data transfer destinations defined in the data transfer definition information. It is determined whether or not the data transfer is completed for the set (step S108 in FIG. 5).

If the data transfer is not completed for all the sets of the data transfer source and the data transfer destination defined in the data transfer definition information (NO in step S108), the data transfer processing unit 14 returns to step S104. Further, when the data transfer is completed for all the sets of the data transfer source and the data transfer destination defined in the data transfer definition information (YES in step S108), the data transfer processing unit 14 returns to step S100 and next. Wait until the start condition of is satisfied.

FIG. 8 is a sequence diagram illustrating the operation of the communication control device 1a of this embodiment. In the example of FIG. 8, a case where three connections Pcon-1 to Pcon-3 are set between the communication control device 1a and the PLC2 will be described.

By the operation described with reference to FIGS. 5 and 6, the communication control device 1a transmits command frames Cc-1 to Cc-3 for reading data to the controllers 3-1 to 3-3. With respect to the command frames Cc-1 to Cc-3, the regulators 3-1 to 3-3 return the response frames Cr-1 to Cr-3 including the requested data to the communication control device 1a.

Then, the communication control device 1a uses the command frames Pc-1 to Pc-3 for writing the data contained in the received response frames Cr-1 to Cr-3 to the PLC2, and the three connections Pcon-1 to Pcon-3. It is transmitted to PLC2 in parallel via. The PLC2 returns the response frames Pr-1 to Pr-3 indicating that the command frames Pc-1 to Pc-3 have been received to the communication control device 1a via the connections Pcon-1 to Pcon-3, respectively.

FIG. 9 is a sequence diagram illustrating the operation of the conventional communication control device 1. Conventionally, the command response processing between the communication control device 1 and the controllers 3-1 to 3-3 is the same as in this embodiment.

On the other hand, since only one connection Pcon-1 is set between the communication control device 1 and the PLC2, the communication control device 1 continues until the response frame Pr-1 for the command frame Pc-1 is received. Command frame Pc-2 cannot be transmitted to PLC2. Similarly, the communication control device 1 cannot transmit the next command frame Pc-3 to the PLC 2 until the response frame Pr-2 for the command frame Pc-2 is received. As described above, it can be seen that the conventional communication control device 1 cannot execute a plurality of command response processes in parallel.

As described above, in the present embodiment, by setting a plurality of connections between the communication control device 1a and the PLC2 and performing communication, the PLC2 and the controller 3 (3-1 to 3) via the communication control device 1a are communicated. Efficient data transfer with 3-m) can be realized. The communication protocol of the PLC 2 and the communication protocol of the controller 3 (3-1 to 3-m) may be any communication protocol that can use TCP / IP communication, and the present invention may be applied regardless of the type of communication protocol. can. Therefore, efficient data transfer can be realized without being restricted by the communication protocol.

[Second Example]
In the first embodiment, a case where a plurality of connections Pcon-1 to Pcon-n are permitted to be established in one TCP communication port 200 has been described as a specification of PLC2. On the other hand, as shown in FIG. 10, as the specification of PLC2, only one connection is allowed to be established for one TCP communication port, but a plurality of TCP communication ports 200-1 to 200-n are set. The present invention is also applicable when it is possible to establish connections Pcon-1 to Pcon-n for each TCP communication port 200-1 to 200-n.
Also in the example shown in FIG. 10, the configuration and operation of the communication control device 1a are as described in the first embodiment.

Further, as the specification of PLC2, the present invention can be applied even when a plurality of TCP communication ports can be set and a plurality of connections are permitted to be established in each TCP communication port.

[Third Example]
In the first and second embodiments, the case where the data transfer cycle is defined as the start condition of the data transfer has been described, but as shown in FIG. 11, even if the trigger information is defined as the start condition. good. In the example of FIG. 11, when the register specified by the address M001 of PLC2 is turned ON, the start condition is satisfied and the data transfer is started. Further, in the first and second embodiments, the case where the regulators 3-1 to 3-m are the transfer source and the PLC2 is the transfer destination has been described, but as shown in FIG. 11, the PLC2 is the transfer source. The controller 3-1 to 3-m may be the transfer destination.

Also in this embodiment, since the configuration of the communication control device 1a is the same as that of the first and second embodiments, the communication control when the data transfer definition information as shown in FIG. 11 is stored in the data transfer definition unit 15. The operation of the device 1a will be described with reference to the reference numerals in FIG.
Since the processing flow of the data transfer processing unit 14 is the same as that of the first embodiment, the reference numerals in FIG. 5 will be used for description. FIG. 12 is a flowchart illustrating the operation of the communication request processing unit 11 and the communication processing units 10-1 to 10-n for PLC, and FIG. 13 shows the communication request processing unit 13 and the communication processing units 12-1 to 12-m for the controller. It is a flowchart explaining the operation of.

When the register specified by the address M001 of the PLC2 is turned on and the start condition is satisfied (YES in step S100 in FIG. 5), the data transfer processing unit 14 is based on the transfer source address information defined in the data transfer definition information. To create read request information (step S101 in FIG. 5). The state of the register of the PLC 2 can be periodically monitored via the communication request processing unit 11 and the PLC communication processing unit 10 (10-1 to 10-n).

Then, the data transfer processing unit 14 transmits the created read request information to the communication request processing unit (communication request processing unit 11 in this embodiment) corresponding to the data transfer source defined in the data transfer definition information (FIG. FIG. 5 steps S102).

Next, when the communication request processing unit 11 receives the read request information from the data transfer processing unit 14 (YES in step S400 in FIG. 12), the communication request queue process stores the received read request information in the internal communication request queue. (FIG. 12, step S401).

Subsequently, when the unprocessed read request information is stored in the communication request queue (YES in step S402 of FIG. 12), the communication request processing unit 11 sets the unprocessed read request information as a processing target, and sets the unprocessed read request information as the processing target. It is determined whether or not communication processing is being performed with the data transfer source specified by the transfer source address information included in (FIG. 12, step S403).

The communication request processing unit 11 is not in the process of communicating with the data transfer source PLC2, that is, when there is a usable connection among a plurality of connections Pcon-1 to Pcon-n (NO in step S403). , Create a command frame for reading data from the data transfer source based on the read request information to be processed (step S404 in FIG. 12).

Then, the communication request processing unit 11 transfers the created command frame to a usable connection among a plurality of connections Pcon-1 to Pcon-n set between the created command frame and the data transfer source (PLC2 in this embodiment). It is passed to the corresponding PLC communication processing unit 10 (10-1 to 10-n). The PLC communication processing unit 10 (10-1 to 10-n) transmits a command frame to the data transfer source PLC2 via the corresponding connection Pcon (Pcon-1 to Pcon-n) (step S405 of FIG. 12). ..

When the PLC2 receives a command frame, it acquires the data specified by the transfer source address information included in the received command frame from the internal memory and creates a response frame including this data. Then, the PLC 2 returns the response frame to the communication control device 1a by using the connection Pcon (Pcon-1 to Pcon-n) that has received the command frame.

When the PLC communication processing unit 10 (10-1 to 10-n) of the communication control device 1a that has transmitted the command frame receives the response frame for this command frame from the PLC 2 (YES in step S406 of FIG. 12), the received response. The frame is passed to the communication request processing unit 11.

The communication request processing unit 11 analyzes the response frame and extracts the data transmitted from the data transfer source PLC2 from the response frame (step S407 in FIG. 12). The communication request processing unit 11 transmits the data extracted from the response frame to the data transfer processing unit 14 as a result requested by the read request information to be processed (step S408 in FIG. 12).

Then, the communication request processing unit 11 sends the result requested by the read request information to be processed to the data transfer processing unit 14, and then deletes the read request information from the internal communication request queue (step S409 of FIG. 12). ), Return to step S400.

Next, when the data transfer processing unit 14 receives the result requested by the read request information from the communication request processing unit 11 (YES in step S104 of FIG. 5), the data transfer definition information from which the read request information is created is created. Create write request information for writing data to the data transfer destination based on the transfer destination address information defined in (FIG. 5, step S105). The write request information includes transfer destination address information and data transmitted from the data transfer source PLC2.

Then, the data transfer processing unit 14 transmits the created write request information to the communication request processing unit (communication request processing unit 13 in this embodiment) corresponding to the data transfer destination defined in the data transfer definition information (FIG. FIG. 5 steps S106).

Next, when the communication request processing unit 13 receives the write request information from the data transfer processing unit 14 (YES in step S500 in FIG. 13), the communication request queue process stores the received write request information in the internal communication request queue. (Step S501 in FIG. 13).

Subsequently, when the communication request processing unit 13 stores the unprocessed write request information in the communication request queue (YES in step S502 of FIG. 13), the communication request processing unit 13 sets the unprocessed write request information as a processing target, and sets the unprocessed write request information as the processing target. It is determined whether or not communication processing is being performed with the data transfer destination (regulators 3-1 to 3-m in this embodiment) specified by the transfer destination address information included in (FIG. 13, step S503).

When the communication request processing unit 13 is not in the process of communicating with the data transfer destination (NO in step S503), the communication request processing unit 13 creates a command frame for writing data to the data transfer destination based on the write request information to be processed. (FIG. 13 step S504). The command frame includes the transfer destination address information and the data transmitted from the data transfer source PLC2.

Then, the communication request processing unit 13 passes the created command frame to the communication processing unit 12 (12-1 to 12-m) for the controller corresponding to the data transfer destination (regulator in this embodiment). The communication processing unit 12 (12-1 to 12-m) for the controller transfers the received command frame to the data transfer source via the connection Con (Conon-1 to Con-m) set. It is transmitted to the original controller 3 (3-1 to 3-m) (FIG. 13, step S505).

When the controller 3 (3-1 to 3-m) receives the command frame, it returns a response frame indicating that the command frame has been received to the communication control device 1a. Further, the regulator 3 (3-1 to 3-m) writes the data included in the command frame to the register specified by the transfer destination address information included in the received command frame.

When the communication processing unit 12 (12-1 to 12-m) for the controller of the communication control device 1a that has transmitted the command frame receives the response frame for this command frame from the controller 3 (3-1 to 3-m). (YES in step S506 of FIG. 13), the received response frame is passed to the communication request processing unit 13.

When the communication request processing unit 13 analyzes the response frame (step S507 in FIG. 13) and confirms that the data transfer destination controller 3 (3-1 to 3-m) has received the command frame, the processing target is processed. Information indicating that the processing requested by the write request information has been completed is transmitted to the data transfer processing unit 14 as a result requested by the write request information to be processed (step S508 in FIG. 13).

Then, the communication request processing unit 13 sends the result requested by the write request information to be processed to the data transfer processing unit 14, and then deletes the write request information from the internal communication request queue (step S509 of FIG. 13). ), Return to step S500.

When the data transfer processing unit 14 receives the result requested by the write request information from the communication request processing unit 13 (YES in step S107 of FIG. 5), all the data transfer sources and data transfer destinations defined in the data transfer definition information. It is determined whether or not the data transfer is completed for the set (step S108 in FIG. 5).

If the data transfer is not completed for all the sets of the data transfer source and the data transfer destination defined in the data transfer definition information (NO in step S108), the data transfer processing unit 14 returns to step S104. Further, when the data transfer is completed for all the sets of the data transfer source and the data transfer destination defined in the data transfer definition information (YES in step S108), the data transfer processing unit 14 returns to step S100 and next. Wait until the start condition of is satisfied.

Thus, in this embodiment, the data of PLC2 can be transferred to the regulator 3 (3-1 to 3-m).
In this embodiment, the information specifying the event occurrence on the PLC2 side has been described as the example in which the information specifying the event occurrence on the PLC2 side is registered in the data transfer definition unit 15 as the trigger information. Alternatively, the information specifying the occurrence of the event may be registered in the data transfer definition unit 15 as the trigger information. The status of the controller 3 (3-1 to 3-m) can be periodically monitored via the communication request processing unit 13 and the controller communication processing unit 12 (12-1 to 12-m). be.

In the first to third embodiments, the PLC 2 is used as a higher-level device, and the plurality of regulators 3 (3-1 to 3-m) are used as lower-level devices, but the present invention is not limited to this. For example, each of the higher-level device and the plurality of lower-level devices may be a PLC.

Further, in the first to third embodiments, the operation after the connection has already been established is described, but it goes without saying that the establishment of the connection is a well-known technique in TCP / IP communication.
Further, it goes without saying that if the response frame does not return within a predetermined time with respect to the transmission of the command frame, the command frame is retransmitted as is well known.

The communication control device 1a described in the first to third embodiments can be realized by a computer including a CPU (Central Processing Unit), a storage device, and an interface, and a program for controlling these hardware resources. An example of the configuration of this computer is shown in FIG. The computer includes a CPU 400, a storage device 401, and an interface device (hereinafter, abbreviated as I / F) 402. The PLC2 and the regulators 3-1 to 3-3 are connected to the I / F 402. In such a computer, the program for realizing the present invention is stored in the storage device 401. The CPU 400 executes the processes described in the first to third embodiments according to the program stored in the storage device 401.

The present invention can be applied to a technique for transferring data between a higher-level device and a lower-level device.

1a ... Communication control device, 2 ... PLC, 3-1 to 3-m ... Controller, 10-1 to 10-n ... PLC communication processing unit, 11, 13 ... Communication request processing unit, 12-1 to 12- m ... Communication processing unit for controller, 14 ... Data transfer processing unit, 15 ... Data transfer definition unit.

Claims (6)

A plurality of first communication processing units provided for each of the plurality of subordinate devices and configured to communicate with the corresponding subordinate devices, and a plurality of first communication processing units.
A plurality of second communication processing units provided for each of the plurality of connections set between the host device and the host device and configured to communicate with the host device via the corresponding connection, and a plurality of second communication processing units.
A data transfer definition unit configured to store data transfer definition information in advance,
When the read request information for the lower device of the transfer source defined by the data transfer definition information is created and the data requested by the read request information is received from the transfer source, the received data is used as the data transfer definition information. A data transfer processing unit configured to create write request information to be written to the higher-level device of the transfer destination defined in
A first command frame for reading data from the transfer source is created in response to the read request information and passed to the first communication processing unit corresponding to the transfer source, and the first communication processing unit is the first. When the response frame of is received from the transfer source, the data requested by the read request information is taken out from the first response frame and passed to the data transfer processing unit. Department and
When there is a usable connection among the plurality of connections, a second command frame for writing data to the transfer destination is created according to the write request information, and the usable connection is supported. When the second command frame is passed to the second communication processing unit and the second communication processing unit receives the second response frame from the transfer destination, the result indicated by the second response frame is described. A communication control device including a second communication request processing unit configured to notify the data transfer processing unit. A plurality of first communication processing units provided for each of the plurality of connections set between the host device and the host device and configured to communicate with the host device via the corresponding connections.
A plurality of second communication processing units provided for each of the plurality of subordinate devices and configured to communicate with the corresponding subordinate devices, and a plurality of second communication processing units.
A data transfer definition unit configured to store data transfer definition information in advance,
When the read request information for the higher-level device of the transfer source defined by the data transfer definition information is created and the data requested by the read request information is received from the transfer source, the received data is used as the data transfer definition information. A data transfer processing unit configured to create write request information to be written to the lower device of the transfer destination defined in.
When there is a usable connection among the plurality of connections, a first command frame for reading data from the transfer source is created according to the read request information, and the usable connection is supported. When the data is passed to the first communication processing unit and the first communication processing unit receives the first response frame from the transfer source, the data requested by the read request information is taken out from the first response frame. A first communication request processing unit configured to be passed to the data transfer processing unit, and
A second command frame for writing data to the transfer destination is created in response to the write request information and passed to the second communication processing unit corresponding to the transfer destination, and the second communication processing unit is the second. It is characterized by including a second communication request processing unit configured to notify the data transfer processing unit of the result indicated by the second response frame when the response frame of the above is received from the transfer destination. Communication control device. In the communication control device according to claim 1 or 2.
The data transfer definition information includes information on the transfer source and information on the transfer destination, as well as data transfer activation conditions.
A communication control device characterized in that a data transfer cycle is set as the activation condition. In the communication control device according to claim 1 or 2.
The data transfer definition information includes information on the transfer source and information on the transfer destination, as well as data transfer activation conditions.
A communication control device characterized in that trigger information is set as the activation condition. The communication control device according to any one of claims 1 to 4.
A communication control device, characterized in that the plurality of connections are set in one communication port of the host device. The communication control device according to any one of claims 1 to 4.
A communication control device, characterized in that one connection is set for each of a plurality of communication ports of the host device.

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