JP7294391B2 - Controller, control method and program - Google Patents

Description

The present disclosure relates to a controller such as a programmable logic controller (PLC: Programmable Logic Controller), a control method, and a program, and more particularly to a controller, a control method, and a program having multiplexed communication units that perform communication between the controller and an external device. .

Controllers such as PLCs are used to control automatic machines in factories and the like, have a plurality of input/output functions, and for example, sequentially read values output from sensors and the like and store data. In recent years, a PLC is connected to an external device such as a database system, and stores data held in the PLC in the database system. This makes it possible to easily share data between information processing apparatuses connected to the database, collect various data, and facilitate aggregation and analysis of the data.

For example, in Japanese Unexamined Patent Application Publication No. 2014-194592 (Patent Document 1), a device monitoring terminal connects to a setting information management device that connects a plurality of communication mediating devices. Each communication mediating device connects a plurality of communication-enabled devices. The equipment monitoring terminal manages the communication mediation equipment via the setting information management device.

Japanese Patent Laying-Open No. 2014-078253 (Patent Document 2) configures a field device using configuration tool software that runs on a host computer. The host computer uses the configuration tool to send messages and transfer settings to multiple field devices.

JP 2014-194592 A JP 2014-078253 A

When a controller such as a PLC communicates with an external device such as a database system and aggregates data, it is desired that the data be aggregated without data loss in order to maintain the reliability of the controller. Patent Document 1 has a configuration in which communication devices are redundant or multiplexed by providing a plurality of communication mediating devices. Replacement of equipment including PLC is required.

An object of the present disclosure is to provide an environment in which communication functions with external devices are multiplexed within a controller while utilizing existing equipment.

A controller according to this disclosure includes a communication program execution unit that executes a plurality of communication programs, and a user program for controlling a controlled object, the user program including instructions for communicating with an external device. a user program execution unit; a communication interface configured to be connectable to any of a plurality of communication programs and controlling communication between the plurality of communication programs and an external device; a determination unit that receives data to be communicated with the external device from the execution unit, and determines a communication program for transmitting the data to the external device from among a plurality of communication programs based on the destination of the data.

According to this disclosure, the controller includes a plurality of programs that communicate with an external device while sharing the communication interface of the controller. This provides a multiplexed communication environment for communicating with external devices within the controller.

In the above disclosure, a communication stack may be provided for each communication program.

According to this disclosure, a separate communication stack is provided for each communication program, thereby enabling the above-described multiplexing at the communication stack level.

In the above disclosure, the determination unit may determine a communication program for transmitting data to the external device from among the plurality of communication programs based on the execution status of each communication program and the destination.

According to this disclosure, a communication program for transmitting the data to the external device can be determined from among a plurality of communication programs based on the destination of the data.

In the above disclosure, the determination unit may determine the communication program as the communication program for transmitting data to the external device when the execution state of the destination-based communication program satisfies a predetermined condition.

According to this disclosure, a communication program for transmitting data to an external device can be determined based on the destination of the data and the execution status of the communication program.

In the above disclosure, the execution state of the communication program may be indicated by the communication response performance of the communication program during execution.

According to this disclosure, the response performance of the communication program can be indicated by the execution state of the communication program.

In the above disclosure, the predetermined condition includes a response performance threshold, and the threshold may be determined by machine learning using communication feature values related to response performance.

According to this disclosure, a threshold for evaluating response performance can be determined by machine learning using communication feature values related to response performance.

In the above disclosure, the determination unit may determine another communication program as the communication program for transmitting data to the external device when the execution state of the communication program based on the destination does not satisfy a predetermined condition.

According to this disclosure, if the execution state of the communication program determined based on the destination does not satisfy a predetermined condition, data can be transmitted to the external device by another communication program.

In the above disclosure, the determination unit may output data to the storage unit when the execution status of the destination-based communication program does not satisfy a predetermined condition.

According to this disclosure, when the execution state of the destination-based communication program does not satisfy a predetermined condition, data can be saved by storing it.

In the above disclosure, unlike the destination-based communication program type and the predetermined communication program type described above, the communication program type corresponds to the communication protocol type for the communication program to transmit data. good too.

This disclosure allows data to be sent to an external device using a different type of communication program, ie, according to a different transmission protocol, than the type of communication program based on the destination of the data.

In the above disclosure, the external device may include a database server or a communication unit that controls communication between the database server and the controller, and the type of communication protocol may include a communication protocol for connecting to the database server.

According to this disclosure, the controller has, as the multiplexed communication environment, a communication environment for accessing the database using data from the user program, or a communication unit that controls communication between the database server and the controller. It is possible to provide a communication environment for accessing the database by relaying.

According to one example of the present disclosure, a control method is provided by a controller having a communication interface for connecting with an external device. A control method includes a step of executing a user program for controlling a control target, the user program including instructions for communicating with an external device, and a plurality of processes for controlling communication with the external device via a communication interface. a step of executing a communication program; receiving data to be communicated with a user program or an external device when executing an instruction; and determining, from among a plurality of communication programs, a communication program for transmitting data to the external device based on the destination of the data. step.

According to this disclosure, a plurality of programs for communicating with an external device are provided within the controller, thereby providing a multiplexed communication environment for communicating with the external device within the controller.

According to an example of the present disclosure, there is provided a program for causing a computer to execute the control method described above.

According to an example of the present disclosure, a plurality of programs for communicating with external devices are provided within the controller to provide a multiplexed communication environment for communicating with the external devices within the controller.

FIG. 3 is a schematic diagram showing an example of application of the controller according to the present embodiment; It is a figure showing the whole example of composition of the control system concerning this embodiment. It is a schematic diagram which shows an example of the hardware configuration which shows the principal part of PLC which concerns on this Embodiment. It is a schematic diagram which shows an example of the software configuration of PLC which concerns on this Embodiment. 1 is a schematic diagram showing an example of a configuration of a server according to an embodiment; FIG. FIG. 2 is a schematic diagram showing an example of the configuration of a PLC together with data flow according to the present embodiment; FIG. 4 is a schematic diagram showing an example of allocation rules and state information according to the present embodiment; 4 is a schematic diagram showing an example of an address conversion table according to the embodiment; FIG. FIG. 6 is a diagram schematically showing an example of a flowchart of allocation processing according to the present embodiment; FIG. 4 is a diagram schematically showing an example of communication monitoring processing according to the present embodiment; FIG. 4 is a schematic diagram showing another example of the configuration of the PLC together with the flow of data according to the present embodiment; FIG. 9 is a schematic diagram showing another example of allocation rules according to the present embodiment; FIG. 10 is a diagram schematically showing an example of threshold change patterns by machine learning according to the present embodiment; FIG. 10 is a schematic diagram showing still another example of the configuration of the PLC together with the flow of data according to the present embodiment; FIG. 10 is a diagram schematically showing yet another example of allocation rules according to the present embodiment; 9 is a flowchart showing another example of allocation processing according to the present embodiment; 9 is a flow chart showing another example of communication monitoring processing according to the present embodiment; FIG. 4 is a diagram schematically showing an example of changes in memory size used in the communication stack according to the present embodiment; FIG. 4 is a diagram schematically showing an example of switching modes of communication clients according to the present embodiment; FIG. 10 is a diagram schematically showing another example of switching of communication clients according to the present embodiment;

Embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated.

<A. Application example>
First, with reference to FIG. 1, an example of a scene to which the present invention is applied will be described. FIG. 1 is a schematic diagram showing an example of an application scene of a controller according to this embodiment. PLC 100 is an example of a controller of the control system according to this embodiment. The controller (e.g., PLC 100) is a communication interface (e.g., host communication controller 160) for connecting to one or more external devices (e.g., server 400), and a user program 186 for controlling the control target. , a user program execution unit (e.g., CPU unit 104) for executing the user program 186 containing instructions for communicating with an external device, and a plurality of communication programs for controlling communication with the external device via a communication interface. It comprises a communication program executing section (for example, the CPU unit 104) that executes (for example, a communication client (X) program 181 and a communication client (Y) program 182), and an allocation section 188.

The communication client (X) program 181 and the communication client (Y) program 182 provide the same communication function by being executed. For example, communication client (Y) program 182 is created by copying communication client (X) program 181 .

In the control system of FIG. 1, for example, a server-client system can be applied. The PLC 100 as a client, while executing an application layer user program 186, communicates, for example, TCP/IP (Transmission Control protocol/Internet protocol) to communicate with the server 400 of the external device.

In the PLC 100, in a layer between the application layer and the physical layer, for example, in the session layer, an allocation unit 188, a communication client (X) 181, and a communication client (Y) 182 are provided. Within PLC 100, this hierarchy is employed to separate the programs or modules (including circuits) of each layer from other layers.

A general-purpose computer, for example, may be applied to the PLC 100 . The user program 186 is executed under an OS (Operating System) (more typically a real-time OS) of a general-purpose computer, and exchanges data with various field devices. These field devices include actuators for performing some processing on the controlled object, sensors for acquiring information from the controlled object, and the like.

The allocation unit 188 receives data to be communicated with the server 400 from the user program execution unit when an instruction is executed by the user program execution unit, and transmits data from among a plurality of communication programs to the server 400 based on the destination of the data. 1 is an embodiment of a "determining unit" that determines a communication program for the . The allocation unit 188 is typically provided by software (program).

As described above, in the present embodiment, it is possible to provide a plurality of communication programs that provide the same communication function by being executed inside the PLC 100 . Accordingly, communication means with the server 400 can be multiplexed (or redundant) within the PLC 100 without connecting a plurality of communication devices to the PLC 100 . In addition, by installing a plurality of communication programs and a program of the determination unit (allocation unit 188) in the existing PLC 100, the above multiplexing can be performed in the PLC 100 while utilizing the existing equipment without replacing equipment such as the PLC 100. Realization is possible.

The PLC 100 of FIG. 1 is configured so that a plurality of communication programs (communication client (X) 181, communication client (Y) 182) share one communication interface. That is, one communication interface is configured to be connectable to any of a plurality of communication programs, and controls communication between the plurality of communication programs and server 400 . As a result, the configuration of multiplexing communication means within the PLC 100 can be realized without increasing the number of circuits such as the communication interface 160 of the PLC 100 .

In addition, in this embodiment, the PLC 100 can use a plurality of communication programs while switching according to the destination of the data, and the load applied to the communication between the PLC 100 and the server 400 can be reduced between the plurality of communication programs. A distributed environment can also be provided.

The server 400 described above may include, for example, various servers. Server 400 may include a database server. Data from user programs 186 may include database manipulation instructions (such as SQL statements) for accessing this database server. The data may also include a protocol (eg, File Transfer Protocol (FTP), etc.) specified by user program 186 for transmitting the data. This SQL statement or transmission protocol may indicate the type of data.

Also, the allocation unit 188 determines a communication program for transmitting data to the server 400 from among a plurality of communication programs based on the execution status of each communication program. This execution state can be indicated by the communication response performance measured for each communication program, and this response performance can be measured during the execution of the communication program, ie when transmitting data.

The response performance of the communication program may include, for example, the response time of the communication program. The response time can be obtained, for example, by measuring the time required from sending a request for data communication to the communication program until receiving a response (Ack) to the request. Alternatively, it can be obtained by measuring the time required to send data to a communication program and receive a response (for example, a response to the effect that the data has been sent to the server 400). In this embodiment, for example, the monitoring unit 189 of the allocation unit 188 can measure this response performance (response time) for each communication program.

In the PLC 100, communication stacks (communication stacks 191 and 192 in FIG. 4) are individually provided for each communication program. A communication stack is a type of memory area and corresponds to a part of the non-volatile memory of the PLC 100, for example. By providing a communication stack for each communication program in this way, multiplexing at the communication stack level becomes possible.

The communication stack is used as an area for storing objects created when the communication program is executed. When the size of the used area of the communication stack increases, processing for releasing the used area to a usable area, ie, garbage collection, is performed. Therefore, while garbage collection is being performed in one communication stack, the other communication stack can be used as an area for storing objects generated during this period. As a result, in the multiplexing described above, it is possible to continue communication between the PLC 100 and the server 400 while distributing the communication load among a plurality of communication programs (that is, among a plurality of communication stacks).

Hereinafter, more detailed configuration and processing of controller 100 according to the present embodiment will be described as a more specific application example of the present invention.

<B. System configuration>
A system configuration of a control system according to this embodiment will be described. In the present embodiment, a PLC that controls a controlled object such as a machine or facility will be described as a typical example of a controller. However, the controller according to the present invention is applicable to various controllers without being limited to PLC.

FIG. 2 is a diagram showing an example of the overall configuration of a control system according to this embodiment. Referring to FIG. 2 , control system 1 includes PLC 100 , support device 300 connected to PLC 100 , and server 400 having DB (database) 430 that receives access from PLC 100 . In this embodiment, the control system 1 includes a plurality of servers 400, but at least one or more may be provided. The server 400 includes a DB 430 and a later-described DBMS (Database Management System) that controls writing and reading of data to and from the DB 430 .

PLC 100 executes user program 186 periodically or on an event basis. This user program 186 can include an access instruction to the DB 430, and the PLC 100 can access the server 400 according to this access. That is, PLC 100 and server 400 are configured to be able to exchange data with each other via network 112 such as Ethernet (registered trademark).

Support device 300 is a typical example of an information processing device connectable to PLC 100 . The support device 300 is connected to the PLC 100 via the connection cable 114 and provides functions such as setting of various parameters, programming, monitoring and debugging with the PLC 100 . PLC 100 and support device 300 are typically configured to be communicable according to the USB (Universal Serial Bus) standard.

The PLC 100 includes a CPU unit 104 that performs control calculations and one or more IO (Input/Output) units 106 . These units are configured to exchange data with each other via the PLC system bus 108 . These units are also supplied with power of appropriate voltage by the power supply unit 102 .

In control system 1, PLC 100 exchanges data with various field devices via IO unit 106 (connected via PLC system bus 108) and/or via field bus 110. . These field devices include actuators for performing some processing on the controlled object, sensors for acquiring various information from the controlled object, and the like. In FIG. 2, an example of such a field device includes a detection switch 10, a relay 20, and a servo motor driver 30 that drives a motor 32. FIG. PLC 100 is also connected to remote IO terminal 200 via field bus 110 . The remote IO terminal 200 basically performs processing related to general input/output processing similarly to the IO unit 106 . More specifically, remote IO terminal 200 includes a communication coupler 202 and one or more IO units 204 for handling data transmission over fieldbus 110 . These units are configured to exchange data with each other via remote IO terminal bus 208 .

<C. Hardware configuration of PLC 100>
Next, a hardware configuration of the PLC 100 according to this embodiment will be described. FIG. 3 is a schematic diagram showing an example of a hardware configuration showing main parts of the PLC 100 according to this embodiment.

The hardware configuration of the CPU unit 104 of the PLC 100 will be described with reference to FIG. The CPU unit 104 includes a processor 120, a chipset 122, a system clock 124, a main memory 126, a nonvolatile memory 128, a USB connector 130, a PLC system bus controller 140, a fieldbus controller 150, and host communication. It includes a controller 160 and a memory card interface 170 . Chipset 122 and other components are each coupled via various buses.

Processor 120 and chipset 122 are typically configured according to general computer architectures. That is, the processor 120 interprets and executes instruction codes sequentially supplied from the chipset 122 according to the internal clock. The chipset 122 exchanges internal data with various connected components and generates instruction codes necessary for the processor 120 . The system clock 124 generates a system clock with a predetermined period and provides it to the processor 120 . The chipset 122 has a function of caching data obtained as a result of arithmetic processing executed by the processor 120 .

The CPU unit 104 has a main memory 126 and a nonvolatile memory 128 as storage means. The main memory 126 is a volatile storage area, holds various programs to be executed by the processor 120, and is also used as a working memory when executing various programs. The nonvolatile memory 128 nonvolatilely holds various programs and data such as the OS, system programs, user programs, data definition information, and log information.

The USB connector 130 is an interface for connecting the support device 300 and the CPU unit 104 . Typically, executable programs and the like transferred from support device 300 are loaded into CPU unit 104 via USB connector 130 .

The CPU unit 104 has a PLC system bus controller 140, a fieldbus controller 150, and an upper communication controller 160 as communication means. These communication circuits transmit and receive data.

PLC system bus controller 140 controls the exchange of data via PLC system bus 108 . More specifically, PLC system bus controller 140 includes buffer memory 142 , PLC system bus control circuit 144 , and DMA (Dynamic Memory Access) control circuit 146 . PLC system bus controller 140 is connected to PLC system bus 108 via PLC system bus connector 148 .

Fieldbus controller 150 includes buffer memory 152 , fieldbus control circuitry 154 and DMA control circuitry 156 . Fieldbus controller 150 is connected to fieldbus 110 via fieldbus connector 158 . The upper communication controller 160 includes a buffer memory 162 , a higher communication control circuit 164 and a DMA control circuit 166 . Upper communication controller 160 is connected to network 112 via communication port 168 . The communication port 168 corresponds to a physical port for connecting with a host system. For example, the host communication controller 160 connecting the communication port 168 is an example of a "communication interface."

Memory card interface 170 connects processor 120 and memory card 172 detachable from CPU unit 104 .

<D. Software configuration of PLC 100>
FIG. 4 is a schematic diagram showing an example of the software configuration of the PLC 100 according to this embodiment. Next, a software configuration for realizing various functions provided by the PLC 100 according to the present embodiment will be described with reference to FIG. Instruction codes contained in these software are read out at appropriate timings and executed by the processor 120 of the CPU unit 104 .

PLC 100 has a scheduler for periodically executing each program including user program 186, communication client (X) program 181 and communication client (Y) program 182 which are executed under OS 180. FIG. When executing the user program 186 , the PLC 100 reads and writes information in a memory area within the PLC 100 and sequentially executes instructions indicated by the user program 186 . The PLC 100 has an input/output function, receives data from the outside of the PLC 100 such as sensor output, and accumulates the data. PLC 100 communicates with server 400 to store accumulated data in DB 430 . The PLC 100 can read data from the DB 430 from the server 400 and pass it to the user program 186 or the like.

With reference to FIG. 4, each function of PLC100 is demonstrated by operating OS180, the system program 187, the user program 186 grade|etc.,.

The OS 180 is an operating system that manages the hardware resources 190 including the memory and the like of the PLC 100, and causes the PLC 100 to exhibit functions such as task scheduling and access processing to the server 400. FIG. The OS 180 is, for example, a real-time OS and provides a basic execution environment for executing system programs 187 and user programs 186 .

The system program 187 is a software group for providing basic functions of the PLC 100 . In this embodiment, system program 187 includes a group of programs for PLC 100 to access server 400 . This program group includes, for example, a communication client (X) program 181 and a communication client (Y) program 182 realized by Java (registered trademark) programs, and a JVM (Java virtual machine) implemented as a virtual machine for executing these Java programs. 183 , 184 , and a hypervisor 185 implemented for virtual machines to utilize hardware resources 190 via the OS 180 .

For example, the communication client (X) program 181 and the communication client (Y) program 182 each provide a common communication environment for communicating with the server 400 to the PLC 100 by being executed. Hereinafter, the communication client (X) program 181 is also referred to as communication client (X) 181 and the communication client (Y) program 182 is also referred to as communication client (Y) 182 . Moreover, when collectively referring to the communication client (X) 181 and the communication client (Y) 182, they will be referred to as communication clients.

Communication client (X) 181 is executed by JVM 183 and communication client (Y) 182 is executed by JVM 184, so that communication client (X) 181 and communication client (Y) 182 can be executed in parallel. While communication client (X) 181 and communication client (Y) 182 are running, JVM 183 and JVM 184 utilize resources such as hardware resource 190 via hypervisor 185 and OS 180 .

Thus, within the PLC 100, communication clients for communicating with the server 400 can be multiplexed (or redundant). Here, the programs executed on the JVMs 183 and 184 are two, the communication client (X) 181 and the communication client (Y) 182, but are not limited to these two, and include other Java programs. may be

In a storage area such as the non-volatile memory 128 of the hardware resource 190, a communication stack 191 and a communication stack 192 limited to a predetermined size are stored for each of the communication client (X) 181 and the communication client (Y) 18. Be prepared. Although communication stack 191 and communication stack 192 are shown as separate areas in FIG. 4, both may be continuous areas.

In this embodiment, the user program 186 is created according to the user's control purpose (for example, target line or process). A communication client program is also created according to the purpose of communication between the PLC 100 and the server 400 of the user. User program 186 is typically in the form of an object program executable by processor 120 of CPU unit 104 . Communication client (X) 181 and communication client (Y) 182 are in a format executable by JVMs 183 and 184 . The user program 186 or the communication client (X) 181 and the communication client (Y) 182 are created and compiled in the support device 300 or the like. These generated programs are transferred from the support device 300 to the CPU unit 104 and stored in the nonvolatile memory 128 or the like.

In this embodiment, communication client programs such as the communication client (X) 181 and the communication client (Y) 182 are assumed to be executed by a virtual computer, but the execution environment of the communication client program is a virtual computer. not limited to For example, similar to the user program 186, it may be executed by the OS 180 provided in the CPU unit 104. FIG.

<E. Configuration of Server 400>
Next, the configuration of server 400 according to this embodiment will be described. FIG. 5 is a schematic diagram showing an example of the configuration of server 400 according to this embodiment. Server 400 is typically composed of a general-purpose computer.

Referring to FIG. 5, server 400 includes a CPU 402 that executes various programs including an OS, a ROM (Read Only Memory) 404 that stores BIOS and various data, and data necessary for CPU 402 to execute programs. and a hard disk (HDD) 408 for nonvolatilely storing programs to be executed by the CPU 402 . More specifically, the hard disk 408 stores various programs and data including programs of the DB 430 and DBMS 431 .

Server 400 further includes a keyboard 310 and mouse 312 for receiving operations from the user, and a monitor 314 for presenting information to the user. Further, server 400 includes communication interface (IF) 418 for communicating with PLC 100 (CPU unit 104) and the like.

Server 400 has a known configuration for providing DB 430 . As the DB 430, any configuration such as a relational data type or an object data type can be adopted. Server 400 is configured according to a general-purpose computer architecture, so detailed description thereof will not be repeated here.

The server 400 receives a connection request or an access request (a SQL statement in relational data type) from the PLC 100, executes necessary processing, and responds to the PLC 100 with the processing results and the like. Here, for example, the DB 430 is a relational data type, and the DBMS 431 reads and writes data to and from the DB 430 according to SQL statements, but the type of the DB 430 and the operation language of the DB 430 are not limited to SQL.

<F. Data flow and setting data>
FIG. 6 is a schematic diagram showing an example of the configuration of the PLC along with the flow of data according to this embodiment. FIG. 7 is a schematic diagram showing an example of allocation rules and status information according to this embodiment. Referring to FIG. 7A, allocation rule 90 has a plurality of different records. Each record includes a destination 91, a client identifier 92 for identifying a communication client, and a condition 93 in association. Conditions 93 include thresholds 96 for determining the responsiveness of the corresponding communication client. Condition 93 indicates, for example, response time<Tms (where T>0). In this embodiment, the response performance of the communication client is represented by, for example, response time, but is not limited to response time.

Referring to FIG. 7B, state information 95 has client identifier 92 and state 94 of the communication client corresponding to each of communication client (X) 181 and communication client (Y) 182 . State 94 is indicated by the communication response performance of the communication program during execution. In other words, if the program execution speed is slow (including program errors), the response performance will decrease (for example, the response time will be long), and if the program execution speed is fast, the response performance will be high (for example, shorter response times). Against this background, for example, a state 94 indicates that a response time, which is an example of response performance, does not satisfy a condition 93 including a threshold value 96 (for example, response time <Tms) (where T>0). Either "Time Out Occurred" or "Good" indicating that the response time satisfies the condition 93 (for example, response time<Tms) is set. State 94 switches from "Time Out" to "Good" or from "Good" to "Time Out" in accordance with changes in response performance. Note that the threshold value 96 is determined in advance, for example, by experiments or the like.

FIG. 8 is a schematic diagram showing an example of the address conversion table 80 according to this embodiment. The address translation table 80 has destinations 91 and IP addresses 82 corresponding to each destination 91 . The allocation rule 90, status information 95 and address conversion table 80 are stored in the non-volatile memory 128 or the like.

The flow of data addressed to server 400 within PLC 100 will be described with reference to FIG. In FIG. 6, the plurality of servers 400 connected to the PLC 100 are classified into three types, server A, server B and server C, for example. First, when an instruction in the user program 186 for communicating with the server 400 is executed and the data 70 is output, the user program 186 outputs the data 70 to one of the multiple ports 68 provided in the allocation unit 188. Output to port. At this time, the user program 186 selects one of the plurality of ports 68 based on the type of data 70 and outputs the data 70 to the selected port 68 .

The monitoring unit 189 measures the response time of the communication client (X) 181 and the communication client (Y) 182, outputs allocation commands based on the measurement results, and changes the status information 95. FIG. Details of the output of the allocation command by the monitoring unit 189 and the change of the status information 95 will be described later.

The allocation unit 188 performs allocation processing. In the allocation process, the allocation unit 188 converts the number (corresponding to the identifier) of the port 68 that received the data 70 to the destination 91 according to a predetermined conversion rule. As a result, the destination 91 is determined for each type of data 70 . The allocating unit 188 determines a communication client (either one of the communication client (X) 181 and the communication client (Y) 182) to which the data 70 is to be allocated based on an allocation command from the monitoring unit 189, which will be described later. The data 70 with the destination 91 added is delivered to the communication client.

Upon receiving the data 70 from the allocation unit 188, the communication client retrieves the IP address 82 associated with the destination 91 from the address conversion table 80 of FIG. The communication client adds the searched IP address 82 to the data 70 and outputs the data 70 to the upper communication controller 160 . The upper communication controller 160 receives the data 70 from the communication controller and transmits it to the server 400 according to TCP/IP.

In this embodiment, as described above, it is possible to transmit data 70 to server 400 corresponding to the type of data 70 .

Retrieval according to the priority of allocation rule 90 will be described. Referring to FIG. 7A, allocation rule 90 has, for example, a table format. In the allocation rule 90, for example, a record containing the client identifier 92 of the communication client (X) 181 is registered at the top of the table, and a record containing the client identifier 92 of the communication client (Y) 182 is registered after that. Registered. When searching for the allocation rule 90, the allocating unit 188 sequentially searches downward from the top record of the table of the allocation rule 90. FIG. In this way, the priority with which records are retrieved by the allocation rule 90 can be set differently for each communication client. can be set differently in In this embodiment, as shown in FIG. 7A, the priority of communication client (X) 181 is higher than that of communication client (Y) 182 .

In the present embodiment, considering the above priority, the threshold 96 of the communication client (X) 181 with a high priority is set to "Tms", and the condition 93 of the communication client (Y) 182 with a low priority is set to "Tms". threshold 96 is set to "none".

Specifically, the threshold 96 can be changed according to the communication load of the communication client in this embodiment. In other words, the communication client (X) 181 has a high priority assigned as a communication client to which data 70 should be transmitted, so the load of transmitting the data 70 is reduced to the communication load of the communication client (Y) 182, which has a low priority. tend to be relatively large.

Considering such variations in communication load, in the present embodiment, the threshold 96 of the communication client (X) 181 with a high priority is set to the threshold of the communication client (Y) 182 with a low priority as described above. A stricter value than 96 is set. As a result, before the communication load on the communication client (X) 181 becomes excessive and communication becomes impossible, it is possible to switch to "time out occurrence", allocate the communication client (Y) 182, and realize distribution of the communication load. becomes.

<G. Flowchart>
FIG. 9 is a diagram schematically showing an example of a flowchart of allocation processing according to the present embodiment. FIG. 10 is a diagram schematically showing an example of communication monitoring processing according to this embodiment. First, the communication monitoring process will be described with reference to FIG. When the assigning unit 188 receives the data 70 from the user program 186, the monitoring unit 189 transmits a request for communication to a plurality of communication clients according to the order of priority from high to low as described above. In FIG. 10, a request for transmission of data 70 is transmitted to the communication client (X) 181 with a higher priority, and the time required to receive a response (Ack) to the request, that is, the response time is measured (step S11 ).

When the monitoring unit 189 determines that the response time does not satisfy the condition 93 corresponding to the communication client (X) 181, that is, determines that the response time exceeds the threshold value 96 of the condition 93 (NO in step S13), the monitoring unit 189 When it is determined that the current value of the state 94 corresponding to the communication client (X) 181 of the state information 95 indicates "time out occurred" (YES in step S15), an allocation specifying the communication client (Y) 182 is performed. A command is generated and output to the allocation unit 188 (step S19). On the other hand, when the monitoring unit 189 determines that the current value of the status 94 corresponding to the communication client (X) 181 does not indicate "Time Out" (NO in step S15), the monitoring unit 189 monitors the communication client ( X) The state 94 corresponding to 181 is set to "time out occurred" (step S17), and the process proceeds to step S19. As a result, when the PLC 100 transmits the data 70, if the response time of the communication client (X) 181 having a high priority does not satisfy the condition 93, the communication client for transmitting the data 70 is given the next priority. communication client (Y) 182 with the highest priority (ie, low priority).

When the monitoring unit 189 determines that the response time satisfies the condition 93 corresponding to the communication client (X) 181, that is, determines that the response time does not exceed the threshold value 96 of the condition 93 (YES in step S13), the monitoring unit 189 , when it is determined that the current value of the state 94 corresponding to the communication client (X) 181 indicates "time out occurred" (YES in step S19), the monitoring unit 189 The state 94 is set to "Good" (step S21), an allocation instruction specifying the communication client (X) 181 is generated, and output to the allocation unit 188 (step S23). On the other hand, when the monitoring unit 189 determines that the current value of the status 94 corresponding to the communication client (X) 181 does not indicate "Time Out" (NO in step S19), the process proceeds to step S23. As a result, in the PLC 100, when the response time of the communication client (X) 181 with a high priority satisfies the condition 93 when transmitting the data 70, the communication client for transmitting the data 70 with a high priority Communication client (X) 181 is allocated.

The processing of the allocation unit 188 will be described with reference to FIG. When the user program 186 is executed (step R1), it outputs the data 70 to the allocation section 188 (step R3). Thereafter, when it is determined that the execution of the program is to be terminated (YES at step R5), the execution is terminated, but when it is determined not to be terminated (NO at step R5), the process returns to step R1.

The allocation unit 188 determines whether or not to accept the data 70 from the user program 186 via the port 68 (step S1). If it is determined that the data 70 is not accepted (NO in step S1), the process of step S1 is repeated. A monitoring process is performed, and an allocation command is output to the allocation unit 188 (step S3). The allocating unit 188 uses the allocation command from the monitoring unit 189 to perform the above-described allocation processing (step S5).

During program execution (step R7), communication client (X) 181 or communication client (Y) 182 receives data 70 from allocation unit 188, adds IP address 82 to received data 70, and sends data to host communication controller 160. output to After that, when the communication controller determines to end the execution of the program (YES in step R8), it ends the execution, but when it determines not to end the execution (NO in step R8), it returns to step R7.

(Modified example of response time)
In the allocation process described above, the response time is detected by measuring the time required for the monitoring unit 189 to transmit a request to the communication client and receive a response (Ack) before the data 70 is transmitted. The method of measuring time is not limited to this method. For example, the allocation unit 188 transmits the data 70 to the communication client (X) 181 with a higher priority, and the communication client (X) 181 responds (for example, a response indicating that the data 70 has been transmitted to the server 400). The response time may be obtained by measuring the time it takes to receive the In this case, the allocating unit 188 determines whether the response time satisfies the condition 93 corresponding to the communication client (X) 181, and if it determines that the response time does not satisfy, the allocation unit 188 selects the communication client with the next highest priority, that is, the communication client ( Y) send data 70 to 182; Also in this modified example, the allocation unit 188 sets (changes) the state 94 of the communication client in the same manner as described above.

As described above, the allocation unit 188 preferentially allocates the communication client (X) 181 as the communication client that transmits the data 70. However, if the response time of the communication client (X) 181 no longer satisfies the condition 93, , the allocation destination is switched to the communication client (Y) 182 . After that, when the response time of the communication client (X) 181 satisfies the condition 93, the allocation destination returns to the communication client (X) 181. FIG. As a result, when the PLC 100 communicates the data 70 to the server 400 , the communication can be continued while distributing the communication load among multiplexed communication clients in the PLC 100 .

<H. Change of allocation rule>
In this embodiment, the condition 93 of the allocation rule 90 can be variably set. FIG. 11 is a schematic diagram showing another example of the configuration of the PLC along with the flow of data according to this embodiment. FIG. 12 is a schematic diagram showing another example of allocation rules according to this embodiment. FIG. 13 is a diagram schematically showing an example of threshold change patterns by machine learning according to the present embodiment. Referring to FIG. 11, PLC 500 includes learning section 1872 and allocation rule 901 of FIG. 12 in addition to the configuration of PLC 100 shown in FIG. Other parts of PLC 500 are the same as those of PLC 100 shown in FIG. 6, so the description will not be repeated.

Referring to FIG. 12, each record of allocation rule 901 includes destination 91 , client identifier 92 and condition 931 . A condition 931 indicates, for example, (response time<learning threshold 97). The learning unit 1872 sets (or changes) the learning threshold 97 of the allocation rule 901 . The learning unit 1872 detects a threshold change pattern for guaranteeing the response performance to a predetermined value by machine learning using various communication feature amounts in communication with the communication client. The learning unit 1872 sets the learning threshold 97 of the allocation rule 901 according to the detected change pattern.

Referring to FIG. 13, change patterns P1 and P2 detected by learning unit 1872 are shown in a graph. In this graph, the horizontal axis represents the interval of "Time Out occurrence" (that is, the time from the detection of "Time Out occurrence" to the next "Time Out occurrence") or the amount of data transmitted to the server 400. The learning threshold 97 is plotted on the vertical axis. Patterns P1 and P2 in FIG. 13 are examples of optimal threshold change patterns for ensuring response performance. The pattern P1 corresponds to, for example, the interval of "Time Out Occurrence", and the pattern P2 corresponds to, for example, the amount of transmission data. The learning unit 1872 stores the generated threshold change pattern in FIG. 13 in the nonvolatile memory 128 . Note that FIG. 13 illustrates two types of change in response performance, namely, the interval of "Time Out occurrence" and the amount of transmission data, but the present invention is not limited to these, and the change in response performance may be, for example, the duration of "Good".

For example, when setting the learning threshold value 97 based on the pattern P1, the learning unit 1872 sets the representative value (predetermined Measure the mean, mode, etc.) RP in the period. The learning unit 1872 acquires (determines) the threshold TH corresponding to the representative value RP from the pattern P1 and sets the acquired threshold TH as the learning threshold 97 of the allocation rule 901 .

As a result, for example, when a software error occurs in the communication client or when the communication load becomes excessive, the interval of "Time Out occurrence" changes (increases). It becomes possible to change the learning threshold value 97 so as to guarantee the response performance in conjunction with the change in the interval.

Also, the learning unit 1872 may change the learning threshold value 97 so as to cope with a situation where the communication load of the communication client becomes excessive due to congestion of the network 112 between the PLC 500 and the server 400 or the like. In this case, the learning unit 1872 may learn time-series/time period patterns in which congestion of the network 112 occurs, and change the threshold before congestion occurs based on the learning result.

<I. Allocation according to communication client type>
Although communication client (X) 181 and communication client (Y) 182 described above provide the same type of communication functionality when executed, the communication functionality provided may be of different types. FIG. 14 is a schematic diagram showing still another example of the configuration of the PLC together with the flow of data according to this embodiment. FIG. 15 is a diagram schematically showing yet another example of allocation rules according to this embodiment. FIG. 16 is a flowchart showing another example of allocation processing according to this embodiment. FIG. 17 is a flowchart showing another example of communication monitoring processing according to this embodiment.

Referring to FIG. 14, PLC 600 includes a DB connection communication client (X) 1811 and FTP ( File Transfer Protocol) communication client (Y) 1821 includes two types. Note that the types of data transmission protocols applied to the communication client are not limited to these. Also, when the PLC 600 connects to the database server, a communication unit that controls communication between the database server and the PLC 600 (more specifically, the DB connection communication client (X) 1811) according to the DB connection protocol. may intervene. Such a communication unit may include, for example, a communication device (for example, a repeater) or software that relays communication between the two. The PLC 600 of FIG. 14 also includes an allocation unit 188 having a monitoring unit 1891 and a storage unit 1875 that stores data 70 received from the user program 186 in a data buffer 1874 . The allocation unit 188 retrieves the allocation rule 902 and the state information 95 . Other parts of PLC 600 are similar to those shown in FIG. 6 or FIG. 11, and description thereof will not be repeated.

Referring to FIG. 15, each record of allocation rule 902 includes an action identifier 98 in addition to the contents of the record of allocation rule 901 of FIG. The action identifier 98 indicates an action (processing) to be taken by the allocation section 188 when the data 70 is received from the user program 186 . In this embodiment, this action identifier 98 indicates either "send to communication client" or "buffer send".

In the PLC 600, the monitoring unit 1891 monitors the response performance (for example, response time) of the DB connection communication client (X) 1811, and uses the DB connection communication client (X) 1811 during the period when the response performance is determined to be good. The data 70 received during the period when the response performance is degraded is stored in the data buffer 1874 by the storage unit 1875 . As a result, the data 70 received from the user program 186 is stored (saved) in the data buffer 1874 while the response performance of the high-priority DB connection communication client (X) 1811 is degraded. The allocation unit 188 collectively sends the data 70 stored in the data buffer 1874 to the FTP communication client (Y) 1821 . The FTP communication client (Y) 1821 transfers the data stored in the data buffer 1874 to the server 400 as a file.

As a result, even if the server 400 of the server A or the server B goes down, the data 70 stored in the server 400 of the server C can be collectively transferred. Server C can send data 70 received from PLC 600 by file transfer to server A or server B. FIG. The DBMS 431 of Server A or Server B uses the data 70 from Server C as traceability information to restore the DB 430 to a state reflecting the updates during the down period. This makes it possible to guarantee the accuracy of the DB 430 of server A or server B. FIG. Specific processing will be described with reference to FIGS. 16 and 17. FIG.

First, communication monitoring processing by the monitoring unit 1891 will be described with reference to FIG. When the assigning unit 1881 receives the data 70 from the user program 186, the monitoring unit 1891 transmits a communication request to the communication client according to the order of priority from high to low as described above. In FIG. 14, a request is sent to the DB connection communication client (X) 181 with a higher priority, and the time required to receive a response (Ack) to the request, that is, the response time is measured (step S11).

When the monitoring unit 1891 determines that the response time does not satisfy the condition 931 corresponding to the DB connection communication client (X) 1811, that is, determines that the response time exceeds the learning threshold value 97 of the condition 931 (NO in step S13), When the monitoring unit 1891 determines that the current value of the state 94 corresponding to the DB communication client (X) 181 in the state information 95 indicates "time out occurred" (YES in step S15), the storage unit 1875 is assigned as an allocation destination. is generated and output to the allocation unit 188 (step S22). Monitoring unit 1891 includes in this allocation command the corresponding action identifier 98 (“transmit buffer”) read from allocation rule 902 .

On the other hand, when the monitoring unit 1891 determines that the current value of the state 94 corresponding to the DB connection communication client (X) 1811 does not indicate "Time Out" (NO in step S15), the monitoring unit 1891 The state 94 corresponding to the connection communication client (X) 181 is set to "time out occurred" (step S17), and the process proceeds to step S22. As a result, in the PLC 100, if the response time of the DB connection communication client (X) 1811 with high priority does not satisfy the condition 93 when transmitting the data 70, the data 70 is stored in the data buffer 1874 for transmission. Section 1875 is allocated.

When the monitoring unit 1891 determines that the response time satisfies the condition 931 corresponding to the communication client (X) 181, that is, determines that the response time does not exceed the learning threshold value 97 of the condition 931 (YES in step S13), the monitoring unit When the 1891 determines that the current value of the status 94 corresponding to the DB connection communication client (X) 1811 indicates "Time Out" (YES in step S19), the monitoring unit 1891 monitors the DB connection communication client (X) 1811. ) 1811 is set to “Good” (step S 21 ), an allocation command designating a communication client with a high priority, that is, the DB connection communication client (X) 1811 is generated and output to the allocation unit 188 . (Step S25). The monitoring unit 1891 includes an action identifier 98 (“communication client transmission”) corresponding to the allocation rule 902 in this allocation command.

On the other hand, when the monitoring unit 189 determines that the current value of the state 94 corresponding to the communication client (X) 181 does not indicate "Time Out" (NO in step S19), the process proceeds to step S25. As a result, when the PLC 100 transmits the data 70, if the response time of the DB connection communication client (X) 1811 having a high priority satisfies the condition 931, the communication client for transmitting the data 70 is given priority DB connection communication client (X) 181 with a high value is allocated.

Next, referring to FIG. 16, processing of the allocation unit 1881 will be described. The allocation unit 1881 determines whether or not to accept the data 70 from the user program 186 via the port 68 (step S1). If it is determined that the data 70 is not accepted (NO in step S1), the process of step S1 is repeated, but if it is determined that the data 70 is accepted (YES in step S1), the monitoring unit 1891 executes the communication monitoring process of FIG. Then, an allocation command including the action identifier 98 is output to the allocation unit 1881 (step S2).

The allocation unit 1881 performs allocation processing using the allocation command from the monitoring unit 1891 (step S4). Specifically, when the allocation command indicates the DB connection communication client 1811, the allocation unit 188 adds the destination 91 to the data 70 according to the action command (“communication client transmission”), and transfers the data 70 based on the allocation command. It is passed to the DB connection communication client 1811 . On the other hand, when the allocation command indicates the storage unit 1875, the allocation unit 188 passes the data 70 to the allocation destination storage unit 1875 indicated by the allocation command in accordance with the action command ("buffer transmission").

When receiving the data 70 from the allocation unit 188 , the DB connection communication client 1811 adds the IP address 82 to the received data 70 and outputs the data 70 to the upper communication controller 160 .

Further, when the storage unit 1875 receives the data 70 from the allocating unit 188, the storage unit 1875 stores the data 70 in the data buffer 1874 according to the order of reception, for example.

The allocation unit 188 determines whether or not to transfer the file (step S7). For example, when the size of the unsent data 70 out of the data 70 stored in the data buffer 1874 exceeds a predetermined threshold value, the allocating unit 1881 determines to perform file transfer (YES in step S7). If it is determined not to transfer the file (NO in step S7), the process ends.

When it is determined that file transfer is to be performed (YES in step S7), allocation unit 188 reads unsent data 70 from data buffer 1874 and passes it to FTP communication client 1821 (step S9). The FTP communication client 1821 transmits the data 70 received from the allocation unit 188 to the server C in a file format with the IP address of the server C according to FTP.

In this way, the DB connection communication client (X) 1811 is preferentially allocated as the communication client that transmits the data 70. After that, when the response time of the communication client (X) 1811 satisfies the condition 93, the allocation Return to the DB connection communication client (X) 1811 first. During this period, that is, while the response time of the DB connection communication client (X) 1811 does not satisfy the condition 93, the data 70 received from the user program 186 is not sent to the storage unit 1875 to the server, but is stored in the data buffer 1874. and save it. This can prevent the data 70 output from the user program 186 from disappearing during this period.

The data in the data buffer 1874 can be file-transferred to server C as a batch and used to recover the DB 430 of server A or server B. FIG.

16 and 17, the method of measuring the response time according to the modification of the response time described above can also be applied.

<J. Program>
A program showing the processing of each flowchart shown in the present embodiment or at least one program shown in FIG. CPU 110 can implement the communication control described in the present embodiment by reading and executing the program from the storage unit.

Such a program is recorded on a computer-readable recording medium such as a flexible disk attached to the PLC 100, a CD-ROM (Compact Disk-Read Only Memory), a ROM, a RAM, and a memory card 172, and provided as a program product. You can also Alternatively, the program can be provided by recording it in a recording medium such as a hard disk built in the PLC 100 . The program can also be provided by downloading from a network (not shown) via a communication interface (higher level communication controller 160, communication port 168, etc.).

<K. Advantages of Embodiment>
FIG. 18 is a diagram schematically showing an example of changes in memory size used in the communication stack according to this embodiment. With reference to FIG. 18, the advantages of considering garbage collection will be described.

In this embodiment, if the size of an object stored in the communication stack by the JVM exceeds the size limit of the communication stack while the communication client is running, the execution speed of the communication client drops. FIG. 18 exemplifies the change in memory size due to the storage of such objects. The memory size variations of FIG. 18 are equally applicable to both communication stacks 191 and 192 .

A predetermined limit size of the communication stack corresponds to the size of the heap area. The heap area consists of the new generation for storing short-lived objects that are no longer needed as soon as they are created, and the old generation for storing long-lived objects that are required for a relatively long time. FIG. 18 shows changes in the used size 214 of the heap area and the used size 211 of the old generation over time.

The JVM performs full garbage collection targeting substantially the entire heap area including the old generation and garbage collection targeting only the new area. FIG. 18 shows times 212, 213, and 215 at which full garbage collection is performed, and a required time 210 for garbage collection. In the period between full garbage collections, garbage collection targeting only the New area may be performed.

As shown in FIG. 18, when a full garbage collection is performed, the time 210 required for garbage collection increases, and accordingly the execution speed of the communication client by the JVM decreases. In this embodiment, it is possible to detect (estimate) when the full garbage collection is to be performed by detecting that the response time of the communication client no longer satisfies the condition 93 (931). As a result, it is possible to prevent loss of data due to continued communication of data 70 between the PLC and the server and storage in the data buffer 1874 even during the execution of full garbage collection.

<L. Other advantages of the embodiment>
FIG. 19 is a diagram schematically showing an example of switching modes of communication clients according to the present embodiment. With reference to FIG. 19, a case will be described in which communication can be continued by switching to the communication client (Y) 182 when, for example, the communication client (X) 181 encounters an abnormality during communication.

First, of the communication client (X) 181 and the communication client (Y) 182, assume that the communication client (X) 181 is in the running state ST3 and the communication client (Y) 182 is in the stopped state ST1. . When the communication client (X) 181 is executing communication, for example, a program error occurs in the communication client (X) 181 and the response time does not satisfy the condition 93 (state ST4), the communication client (X) 181 stops communication. It stops and shifts to the execution state (state ST5) of abnormality confirmation or automatic recovery processing. At this time, the allocation destination of the data 70 is switched to the communication client (Y) 182, and a switch notification is sent to the communication client (Y) 182 (state ST2). Upon receiving the switching notification, the JVM 184 switches the communication client (Y) 182 from the stop state to the communication execution state (state ST6). As a result, the communication client (Y) 182 executes communication and transmits the data 70 to the server 400 .

In this way, when an abnormality occurs in the communication client (X) 181, the communication client (Y) 182 in the stopped state is switched from the stopped state to the communication execution state, and the communication client (Y) 182 sends the server 400 Data 70 can be reached. Further, since the communication client (Y) 182 is in a halted state until receiving the switching notification, the load on program execution in the PLC 100 can be reduced during this halted state.

<M. Other advantages of the embodiment>
FIG. 20 is a diagram schematically showing another example of switching of communication clients according to the present embodiment. A case where communication by the communication client (X) 181 and communication by the communication client (Y) 182 are performed at the same time will be described with reference to FIG.

Referring to FIG. 20, in the communication execution state (state ST3) of data 70 by communication client (X) 181, when the response time does not satisfy condition 93 (state ST4), assigning unit 188 next accepts The obtained data 70 is transferred to the communication client (Y) 182 (state ST7). The communication client (Y) 182 shifts from the communication stop state (state ST1) to the communication execution state (state ST6). As a result, the load on the communication client (X) 181 can be reduced. If the allocating unit 188 receives the next data 70 before the communication of the data 70 of the communication client (Y) 182 is completed, the communication whose response time satisfies the condition 93 at this time The data 70 can be passed to the client (X) side. As a result, in the PLC 100, the communication execution state (state ST3) of the communication client (X) 181 and the communication execution state (state ST6) of the communication client (Y) 182 can be continued in parallel. X) 181 and communication client (Y) 182 can perform multiplex communication (for example, time-division multiplex communication) of data 70 by the host communication controller 160 .

<N. Still Other Advantages of Embodiment>
Advantages considering the usage environment of the PLC will be explained. In recent years, a PLC is connected to an external device such as a database system, and stores data held in the PLC in the database system. This facilitates sharing of data between information processing apparatuses connected to the database, and facilitates collection and analysis of data by collecting various data.

For communication functions built into the PLC that connect to such external devices, for example, a communication function built into the PLC that uses Common Industrial Protocol (CIP) supports two communication ports. offer.

By using two communication ports in this way, compared to the case of multiplexing the communication units within the PLC, the PLC according to the present embodiment multiplexes the communication units that share the physical communication port 168. is realized, the number of parts can be reduced. Further, even if the communication units in the PLC are multiplexed, no special change corresponding to the multiplexing is required on the server 400 side. Therefore, this embodiment can be implemented using an existing control system.

<O. Note>
The present embodiment as described above includes the following technical ideas.
[Configuration 1]
a controller (100),
a communication program execution unit (104) that executes a plurality of communication programs (181, 182);
a user program execution unit (104) for executing a user program (186) for controlling a controlled object, the user program including instructions for communicating with an external device (400);
a communication interface (160) configured to be connectable to any of the plurality of communication programs and controlling communication between the plurality of communication programs and the external device;
receiving data (70) to be communicated with the external device from the user program execution unit when the instruction is executed by the user program execution unit, and selecting the data from among the plurality of communication programs based on the destination of the data; and a determination unit (188) for determining a communication program to be transmitted to an external device.
[Configuration 2]
The controller of arrangement 1, wherein the controller comprises a communication stack (191, 192) for each communication program.
[Configuration 3]
The decision unit
3. The controller according to configuration 1 or 2, wherein a communication program for transmitting the data to the external device is determined from among a plurality of communication programs based on the execution status and destination (91) of each communication program.
[Configuration 4]
The decision unit
The controller according to configuration 3, wherein when the execution state of the communication program based on the destination satisfies a predetermined condition (93), the communication program is determined as the communication program for transmitting the data to the external device. .
[Configuration 5]
The controller according to configuration 4, wherein the execution state of the communication program is indicated by communication response performance of the communication program during execution.
[Configuration 6]
The predetermined condition includes the response performance threshold (96),
The controller according to configuration 4 or 5, wherein the threshold is determined by machine learning using a communication feature quantity related to response performance.
[Composition 7]
The decision unit
7. Any one of configurations 4 to 6, wherein when the execution state of the communication program based on the destination does not satisfy a predetermined condition, another of the communication programs is determined as a communication program for transmitting the data to the external device. or 1. The controller according to 1.
[Configuration 8]
The decision unit
7. The controller according to any one of configurations 4 to 6, outputting said data to a storage unit (1875) when said execution state of said communication program based on said destination does not satisfy a predetermined condition.
[Composition 9]
The controller is
9. The controller according to configuration 8, wherein the data in the storage unit is transmitted to the external device via a predetermined communication program (1821) of the communication programs.
[Configuration 10]
Different from the type of the communication program based on the destination and the type of the predetermined communication program,
10. The controller of configuration 9, wherein the communication program type corresponds to a communication protocol type for transmitting data by the communication program.
[Configuration 11]
the external device includes a database server;
11. The controller according to configuration 10, wherein the type of communication protocol includes a communication protocol for connecting to the database server or a communication unit that controls communication between the database server and the controller.
[Configuration 12]
A control method by a controller (100), comprising:
a step (R7) of executing a plurality of communication programs (181, 182);
a step (R1) of executing a user program (186) for controlling a controlled object, the user program comprising instructions for communicating with an external device (400);
The controller is
A communication interface (160) configured to be connectable to any of the plurality of communication programs and controlling communication between the plurality of communication programs and the external device,
The control method further comprises:
receiving data (70) to be communicated with the external device from the user program when the instruction of the user program is executed, and transmitting the data from among the plurality of communication programs to the external device based on the destination of the data; A control method comprising steps (S3, S5) of determining a communication program to be transmitted to the device.
[Composition 13]
A program for causing a computer to execute the control method according to configuration 12.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.

1 control system, 68 ports, 70 data, 80 address conversion table, 90, 901, 902 allocation rule, 95 state information, 96, TH threshold, 97 learning threshold, 100 controller, 112 network, 120 processor, 128 non-volatile memory, 160 host communication controller, 168 communication port, 181 communication client (X), 182 communication client (Y), 185 hypervisor, 186 user program, 187 system program, 188, 1881 allocation section, 189, 1891 monitoring section, 190 hardware Resources 191, 192 communication stack 1811 DB connection communication client 1821 FTP communication client 1872 learning unit 1874 data buffer 1875 storage unit P1, P2 patterns RP representative value.

Claims (13)

is a controller,
a fieldbus connector that connects the controller to an external fieldbus;
a communication port that connects the controller to an external network;
a communication program execution unit that executes a plurality of communication programs;
A user program for communicating with a controlled object provided outside the controller via the fieldbus and controlling the controlled object, the external device provided outside the controller via the network. a user program execution unit for executing the user program containing instructions for communicating with
a communication interface configured to be shared by the plurality of communication programs and controlling communication between the plurality of communication programs and the external device via the network;
receiving data transmitted from the user program execution unit to the external device when the instruction is executed by the user program execution unit, and transmitting the data from among the plurality of communication programs to the external device based on the destination of the data; a determination unit that determines a communication program to be transmitted to
each of the plurality of communication programs includes a communication client program for the controller to communicate with the external device as a server;
A controller, wherein the data transmitted to the external device includes data for the user program to communicate with the controlled object, and a database operation instruction for accumulating the data for communicating with the controlled object in a database. 2. The controller of claim 1, comprising a communication stack for each said communication program. The decision unit
3. The controller according to claim 1, wherein a communication program for transmitting said data to said external device is determined from among said plurality of communication programs based on the execution status and said destination of each of said communication programs. The decision unit
4. The controller according to claim 3, wherein when said execution state of said communication program based on said destination satisfies a predetermined condition, said communication program is determined as a communication program for transmitting said data to said external device. 5. The controller according to claim 4, wherein the execution state of said communication program is indicated by the communication response performance of said communication program during execution. The predetermined condition includes the response performance threshold,
6. The controller according to claim 5, wherein said threshold is determined by machine learning using communication feature quantities related to response performance. The decision unit
7. The method according to claim 4, wherein when said execution state of said communication program based on said destination does not satisfy a predetermined condition, another said communication program is determined as a communication program for transmitting said data to said external device. A controller according to any one of the preceding claims. The decision unit
7. The controller according to any one of claims 4 to 6, wherein said data is output to a storage unit when said execution state of said communication program based on said destination does not satisfy a predetermined condition. The controller is
9. The controller according to claim 8, wherein the data in said storage unit is transmitted to said external device via a predetermined communication program among said communication programs. Different from the type of the communication program based on the destination and the type of the predetermined communication program,
10. The controller according to claim 9, wherein the communication program type corresponds to a communication protocol type for transmitting data by the communication program. The external device includes a database server or a communication unit that controls communication between the database server and the controller,
11. The controller of claim 10, wherein the communication protocol type includes a communication protocol for connecting to the database server. A control method by a controller,
The controller is
A fieldbus connector that connects the controller to an external fieldbus, and a communication port that connects the controller to an external network,
The control method is
executing a plurality of communication programs;
A user program for communicating with a controlled object provided outside the controller via the fieldbus and controlling the controlled object, the external device provided outside the controller via the network. executing the user program comprising instructions for communicating with
each of the plurality of communication programs includes a communication client program for the controller to communicate with the external device as a server;
The controller is
a communication interface configured to be shared by the plurality of communication programs and controlling communication between the plurality of communication programs and the external device via the network;
The control method further comprises:
receiving data transmitted from the user program to the external device when the instruction of the user program is executed, and transmitting the data from among the plurality of communication programs to the external device based on the destination of the data comprising a step of determining a communication program to be transmitted;
The control method according to claim 1, wherein the data transmitted to the external device includes data for the user program to communicate with the controlled object and a database operation instruction for accumulating the data for communicating with the controlled object in a database. A program for causing a computer to execute the control method according to claim 12.

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