JP2022132862A - Communication method, communication system, and network controller - Google Patents

Abstract

To provide a mechanism for ensuring a necessary band according to a situation in a network obtained by combining TSN and OPC UA.SOLUTION: There is provided a communication method in a network conforming to TSN (time-sensitive networking). At least part of devices connected with the network is configured to perform data communication according to a communication protocol conforming to OPC UA (OPC unified architecture). The communication method includes the steps of: in response to a request, instructing stop of data communication to part or all of the devices connected with the network; transmitting setting parameters to part or all of the devices connected with the network; and after the transmission of the setting parameters, instructing resumption of the data communication to part or all of the devices connected with the network.SELECTED DRAWING: Figure 1

Description

The present technology relates to a communication method, a communication system, and a network controller related to a network conforming to TSN (Time Sensitive Networking).

Efforts are underway to expand standard networks (for example, Ethernet (registered trademark)) used in general information networks so that they can also be used in networks in the industrial field. More specifically, IEEE (Institute of Electrical and Electronic Engineers) 802.1 TSN (Time Sensitive Networking) (hereinafter referred to as Time Sensitive Networking), which is based on Ethernet (registered trademark) and improved so that the network behaves deterministically. Also simply referred to as “TSN”) is known. According to TSN, for example, real-time communication can be realized more easily using general-purpose hardware such as Ethernet (registered trademark).

Also, OPC UA (OPC Unified Architecture), which is internationally standardized as IEC62541, is attracting attention as a communication stack for performing data communication between devices.

A combination of TSN and OPC UA is also referred to as “OPC UA over TSN”. For example, Patent Document 1 (European Patent No. 03357218) discloses data communication between a client device and a server device according to the OPC-UA protocol in a network by a stream according to the TSN standard according to IEEE 802.1. .

EP 03357218

In TSN, traffic is scheduled in consideration of streams corresponding to frame transfer paths, traffic classes that are the priority of each stream, and available bands. On the other hand, in OPC UA, data transfer requirements are defined for each traffic.

This technology provides a mechanism for securing necessary bandwidth according to the situation in a network that combines TSN and OPC UA.

According to one embodiment of the present technology, a communication method in a TSN compliant network is provided. At least some of the devices connected to the network are configured to perform data communication using a communication protocol conforming to OPC UA. The communication method includes the step of instructing some or all of the devices connected to the network to stop data communication in response to the request; It includes the steps of: transmitting setting parameters; and, after transmitting the setting parameters, instructing some or all of the devices connected to the network to resume data communication.

According to this configuration, the data communication of the target device connected to the network can be stopped when it is necessary to transmit the setting parameters, so that the band required for transmitting the setting parameters can be secured.

The step of instructing suspension of data communication may include the step of instructing suspension of scheduling of traffic according to the TSN. According to this configuration, the frames to be preferentially transferred can be reduced by scheduling the traffic according to the TSN, so that the required bandwidth can be secured.

The step of instructing to stop data communication may include instructing the switch to stop scheduling traffic according to the TSN only for a specific port. According to this configuration, only the transfer of frames passing through a specific port can be stopped, so data communication can be continued through a path that does not require securing a band. Therefore, it is possible to localize the impact on the network due to the transfer of parameter settings.

The step of instructing to stop data communication may include a step of instructing to stop OPC UA Publish/Subscriber communication. According to this configuration, it is possible to stop the data periodically transmitted by the Publish/Subscriber communication of OPC UA, so it is possible to more easily secure the band.

The step of instructing to stop the OPC UA Publish/Subscriber communication may include the step of instructing to change the state of the OPC UA. According to this configuration, the entire Publish/Subscriber communication of OPC UA can be stopped only by changing the state of OPC UA, so that the processing can be simplified.

The request may be sent from an external support device. According to this configuration, it is possible to secure a necessary band according to a request from outside the network.

Sending the configuration parameters may comprise sending a schedule of traffic according to the TSN from the network controller to the end device of interest. According to this configuration, after transmission of the setting parameters, frames can be transferred according to a new traffic schedule.

According to another embodiment of the present technology, a communication system is provided that includes a TSN compliant network. A communication system includes a network controller and one or more devices connected to a network. At least part of the one or more devices are configured to perform data communication in a communication protocol according to OPC UA. In response to a request, the communication system instructs some or all of the devices connected to the network to stop data communication; It includes means for transmitting setting parameters, and means for instructing some or all devices connected to the network to resume data communication after transmitting the setting parameters.

According to yet another embodiment of the present technology, a network controller is provided for configuring a TSN compliant network. At least some of the one or more devices connected to the network are configured to perform data communication using a communication protocol conforming to OPC UA. In response to the request, the network controller instructs some or all of the devices connected to the network to stop data communication; It includes means for transmitting setting parameters, and means for instructing some or all devices connected to the network to resume data communication after transmitting the setting parameters.

According to the present technology, in a network that combines TSN and OPC UA, it is possible to provide a mechanism for securing a necessary band depending on the situation.

1 is a schematic diagram showing an example of the overall configuration of a control system according to an embodiment; FIG. It is a figure which shows an example of the communication model which the control system which concerns on this Embodiment employ|adopts. 2 is a block diagram showing an example hardware configuration of an end device that constitutes the control system according to the present embodiment; FIG. 3 is a block diagram showing an example hardware configuration of a switch that constitutes the control system according to the present embodiment; FIG. 2 is a block diagram showing an example hardware configuration of a network controller that configures the control system according to the present embodiment; FIG. FIG. 3 is a schematic diagram showing a more detailed configuration of one port of a switch that configures the control system according to the present embodiment; FIG. 4 is a diagram showing an example of QoS definition in OPU UA; 1 is a schematic diagram showing an outline of a component configuration for realizing Pub/Sub communication defined in OPU UA; FIG. FIG. 4 is a diagram showing an example of a state machine related to Pub/Sub communication defined in OPU UA; It is a figure which shows the processing procedure in the control system which concerns on this Embodiment. It is a figure which shows another processing procedure in the control system which concerns on this Embodiment. FIG. 12 is a schematic diagram showing an example of a frame structure in the process shown in FIG. 11; FIG. 3 is a diagram showing a processing procedure in a network controller of the control system according to this embodiment;

Embodiments of the present technology 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, an example of the overall configuration of the control system 1 according to this embodiment will be described.

FIG. 1 is a schematic diagram showing an example of the overall configuration of a control system 1 according to this embodiment. A control system 1 shown in FIG. 1 is an example of a communication system including a network conforming to IEEE 802.1 TSN.

In this specification, unless otherwise specified, the term simply "TSN" generically refers to networks conforming to IEEE 802.1 TSN. Note that IEEE 802.1 TSN mainly defines the data link layer, and protocols such as TCP/IP or UDP/IP can be used for the network layer and transport layer. As described below, the IEEE 802.1 TSN standard includes several sub-standards.

As used herein, "device" encompasses any device connected to a network that conforms to IEEE 802.1 TSN. "Devices" may typically include end devices, switches, and network controllers.

As used herein, "configuration parameters" include configuration information required to operate the network. "Setting parameters" include, for example, various setting values and traffic schedules.

A control device such as a PLC (programmable controller) is connected to the TSN of the control system 1 shown in FIG. A control device connected to a network corresponds to an end device, so the control device is referred to as an "end device" in the following description. However, the "end device" is not limited to the control device, and may include any device.

As an example, the control system 1 includes end devices 100 - 1 and 100 - 2 (also collectively referred to as “end devices 100 ”), a switch 200 and a network controller 300 . A network to which one or more of these devices are connected corresponds to the TSN.

FIG. 2 is a diagram showing an example of a communication model adopted by the control system 1 according to this embodiment. FIG. 2 shows a communication model adopted by the control system 1 according to the OSI hierarchical model.

Referring to FIG. 2, the control system 1 is implemented with Ethernet (registered trademark) extended according to IEEE 802.1 TSN as a data link layer on any physical layer. Furthermore, the IP protocol is implemented as the network layer and the TCP or UDP protocol as the transport layer. Furthermore, OPC UA is adopted as the session layer, presentation layer, and application layer. OPC UA consists of multiple layers such as an information model and a communication model.

It should be noted that OPC UA need not be implemented in the switch, and OPC UA is mainly implemented in the end device 100 . Therefore, at least some of the devices connected to the TSN are configured to perform data communication with a communication protocol conforming to OPC UA.

Referring to FIG. 1 again, the end device 100-1 is connected to the switch 200 via the link 20. End device 100 - 2 is connected to switch 200 via link 22 . Furthermore, the network controller 300 is connected to the switch 200 via the link 24 .

Note that the end device 100, the switch 200, and the network controller 300 that configure the control system 1 are time-synchronized with each other by a time synchronization subject (not shown). Note that time synchronization is implemented according to IEEE 802.1 AS-2020, which is a lower standard of IEEE 802.1 TSN, IEEE 1588, which is a precision time protocol (PTP), and the like.

Each of the end devices 100-1 and 100-2 has a fieldbus 30 independent of TSN. One or more field devices 40 are connected to the fieldbus 30 . One or more field devices 40 include input devices that obtain field signals and output devices or actuators that perform some action on the field according to instructions from the end device 100 .

The network controller 300 is the entity that manages frame transfer in the TSN and schedules traffic (streams) by calculating resource allocation and availability. Typically, network controller 300 schedules traffic according to IEEE 802.1 Qcc, a substandard of IEEE 802.1 TSN.

In the control system 1 according to the present embodiment, by dynamically changing the priority of frame transfer in TSN according to the state of OPC UA, data communication that satisfies the request of OPC UA is realized. .

<B. Hardware configuration example>
Next, an example of the hardware configuration of each device included in the control system 1 will be described.

(b1: End device 100 (control device))
FIG. 3 is a block diagram showing a hardware configuration example of the end device 100 configuring the control system 1 according to this embodiment. Referring to FIG. 3, end device 100 includes processor 102 , main memory 104 , network interface 110 , storage 120 , internal bus interface 130 , fieldbus interface 132 and memory card interface 134 . Each component is electrically connected via bus 138 .

The processor 102 is composed of a CPU (Central Processing Unit), an MPU (Micro-Processing Unit), a GPU (Graphical Processing Unit), etc., reads out various programs stored in the storage 120, develops them in the main memory 104, and executes them. By doing so, processing as a control device is realized.

Network interface 110 is responsible for frame transfer over TSN. More specifically, network interface 110 includes transmission/reception control circuitry 112 , transmission circuitry 114 , and reception circuitry 116 . The transmission/reception control circuit 112 controls the transmission circuit 114 and the reception circuit 116 according to a traffic schedule given in advance by the network controller 300 . The transmission circuit 114 transmits frames on the TSN according to instructions from the transmission/reception control circuit 112 . Receive circuit 116 receives incoming frames via TSN.

The storage 120 typically stores a system program 122 for realizing functions as a control device and a user program 124 that defines control logic executed by the control device.

The internal bus interface 130 exchanges data with the I/O unit 140 mounted on the end device 100 .

Fieldbus interface 132 exchanges data with field devices via fieldbus 30 .

The memory card interface 134 is configured such that a memory card 136 can be attached/detached, and data can be written to the memory card 136, and various data (user program, trace data, etc.) can be read from the memory card 136. ing.

FIG. 3 shows a configuration example in which necessary functions are provided by the processor 102 executing a program. (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), etc.). Alternatively, the main part of the end device 100 may be implemented using hardware following a general-purpose architecture (for example, an industrial personal computer based on a general-purpose personal computer). As such, the processing performed and functions provided by end device 100 may be implemented in processing circuitry including processors, ASICs, FPGAs, and the like.

(b2: switch 200)
FIG. 4 is a block diagram showing a hardware configuration example of the switch 200 configuring the control system 1 according to this embodiment. Referring to FIG. 4, switch 200 includes transmission/reception control circuit 212 and transmission circuits 214-1, 214-2, 214-3, and 214-4 (hereinafter collectively referred to as "transmission circuit 214"). , and receiving circuits 216-1, 216-2, 216-3, and 216-4 (hereinafter also collectively referred to as “receiving circuits 216”). A set of the transmission circuit 214 and the reception circuit 216 forms one port. Note that FIG. 4 illustrates the switch 200 having four ports, but the number of ports is not particularly limited.

The transmission/reception control circuit 212 controls the transmission circuit 114 and the reception circuit 116 according to a traffic schedule given in advance by the network controller 300 . More specifically, the transmit/receive control circuit 212 includes a transfer engine 218 and a queue 220 .

The transmission/reception control circuit 212 may be implemented by a processor executing firmware, or may be implemented using a hardwired circuit such as an ASIC or FPGA. Also, not only the transmission/reception control circuit 212 but also the entirety including the transmission circuit 114 and the reception circuit 116 may be implemented in a single chip. As such, the processing performed and functions provided by switch 200 may be implemented in processing circuitry including processors, ASICs, FPGAs, and the like.

(b3: network controller 300)
FIG. 5 is a block diagram showing a hardware configuration example of the network controller 300 that configures the control system 1 according to this embodiment. Referring to FIG. 5, network controller 300 includes processor 302 , main memory 304 , network interface 310 and storage 320 . Each component is electrically connected via bus 338 .

The processor 302 is composed of a CPU, an MPU, a GPU, etc., reads various programs stored in the storage 320, develops them in the main memory 304, and executes them, thereby realizing processing as a network controller.

Network interface 310 is responsible for frame transfer over TSN. More specifically, network interface 310 includes transmit/receive control circuitry 312 , transmit circuitry 314 , and receive circuitry 316 .

The storage 320 typically stores an OS 322 for implementing basic processing and a network setting program 324 for implementing processing as described later.

FIG. 5 shows a configuration example in which necessary functions are provided by the processor 302 executing a program. As such, the processing performed and functions provided by network controller 300 may be implemented in processing circuitry including processors, ASICs, FPGAs, and the like.

<C. Realization of traffic scheduling according to the TSN standard>
In TSN, a stream ID is assigned (a stream is reserved) for each data path according to IEEE 802.1 Qcc, and traffic is scheduled according to IEEE 802.1 Qbv. To control traffic according to scheduling, the following queue and gate configurations are employed.

FIG. 6 is a schematic diagram showing a more detailed configuration of one port of switch 200 that configures control system 1 according to the present embodiment. With reference to FIG. 6, each port consists of a set of a transmitter circuit 214 and a receiver circuit 216 . Transfer engine 218 and queue 220 are provided between transmit circuit 214 and receive circuit 216 .

More specifically, transfer engine 218 includes distribution circuit 224 and timing control circuit 226 . Queue 220 also includes a plurality of queues 220-1 to 220-M associated with each traffic class value.

Distribution circuit 224 stores the frame in one of queues 220-1 to 220-M according to the header information of the frame received via reception circuit 216, or distributes the frame to distribution circuit 224 of another port. transfer to Also, the sorting circuit 224 performs similar determination and processing for frames received from the sorting circuit 224 of another port.

When the distribution circuit 224 receives a frame to be sent from the transmission circuit 214 of its own port, the distribution circuit 224 stores the frame in the queue 220 corresponding to the traffic class of the frame. By such processing in the distribution circuit 224, the queues 220-1 to 220-M sequentially store frames classified by traffic class. For example, if the traffic class is 8, then 8 queues 220 are provided.

Gates 222-1 to 222-M are provided on the output sides of the queues 220-1 to 220-M, respectively. Each of gates 222 - 1 to 222 -M (hereinafter collectively referred to as “gates 222 ”) opens and closes according to instructions from timing control circuit 226 . When the gate 222 is opened, the frame stored in the associated queue 220 is sent from the transmission circuit 214 . Timing control circuit 226 does not give open commands to a plurality of gates 222 at the same time. That is, timing control circuit 226 sequentially opens and closes gates 222 according to traffic schedule 228 . This allows traffic to be controlled according to scheduling.

The port of the end device 100 (network interface 110) and the port of the network controller 300 (network interface 310) also have the same configuration as in FIG.

Thus, each of the end device 100 and the switch 200 opens and closes the gate 222 of the queue 220 provided according to the traffic class (priority) according to IEEE 802.1 Qbv at pre-calculated timing. This makes it possible to guarantee the required arrival time (Deadline, Latency, etc.) for each frame.

<D. OPU UA>
Next, some explanations regarding OPU UA are provided.
(d1: QoS (Quality of Service))
FIG. 7 is a diagram showing an example of QoS definition in OPU UA. Referring to FIG. 7, in OPU UA, a plurality of traffic types are defined as indicated by traffic type names 50 . For each traffic type, Periodicity 52, Data delivery requirements 54, Synchronized to network cycle 56, Criticality 58 and is defined.

For example, in isochronous communication, data is transmitted at predetermined intervals (cyclic communication), and an upper limit of time required for data transmission (that is, transmission interval) is provided (deadline mode). Similarly, in Cyclic-Synchronous communication, data is periodically transmitted (cyclic communication), and an upper limit of delay time (Latency) is provided (Latency mode).

In this way, highly strict data communications such as isochronous communications and cyclic-synchronous communications use more bands.

On the other hand, configuration & diagnosis communication requires securing a certain data transmission band (Bandwidth mode). However, when there are relatively many isochronous communications and cyclic-synchronous communications, the usable data transmission band is limited.
(d2: Relationship between Pub/Sub communication and TSN)
Publish/Subscriber communication (hereinafter also abbreviated as “Pub/Sub communication”) is defined as one form for realizing data communication between devices in OPC UA. In Pub/Sub communication, the receiving side becomes the Subscriber, and the transmitting side publishes data.

FIG. 8 is a schematic diagram showing an outline of a component configuration for realizing Pub/Sub communication defined in OPU UA. Referring to FIG. 8, Pub/Sub communication component 60 includes root component 61 and connection component 63 . Connection component 63 includes write group component 64 and read group component 66 .

The write group component 64 includes a component 65 that writes the PublishedDataSet 62 to the message. The read group component 66 includes a component 67 that reads SubscribeDataSets 68 received from other devices.

Each message written by the write group component 64 of the Pub/Sub communication component 60 shown in FIG. 8 is assigned a stream ID of the TSN. Similarly, each message read by read group component 66 is assigned a stream ID of the TSN.

That is, a data path (that is, stream ID) is assigned corresponding to OPC UA data communication. For data communication (stream ID) associated with Pub/Sub communication, traffic types such as Isochronous communication and Cyclic-Synchronous communication (see FIG. 7), which use a relatively large amount of bandwidth, are often set.
(d3: state machine)
OPC UA defines a state machine for managing Pub/Sub communication as described above.

FIG. 9 is a diagram showing an example of a state machine related to Pub/Sub communication defined in OPU UA. 9, the states include an Operational state 70, a PreOperational state 72, a Paused state 74, a Disabled state 76 and an Error state 78. FIG.

Operational state means a state in which Pub/Sub communication is normally performed. The PreOperational state 72 means a state in the middle of transitioning to the Operational state 70 . A Paused state 74 means a state in which processing is paused. Disabled state 76 means a state in which processing is temporarily disabled. Error state 78 means a state in which some error has occurred in the Pub/Sub communication component.

In the control system 1 according to the present embodiment, in order to shift to the Operational state 70, the conditions for appropriately performing frame transfer on the TSN, that is, the time synchronization between devices is established, and each device traffic schedule must be configured for

<E. Overview>
Next, an outline of a communication method in the TSN of the control system 1 according to this embodiment will be described.

As described above, for Pub/Sub communication, rather than Isochronous communication (data transmission cycle is determined: synchronization guarantee) or Cyclic-Synchronous communication (delay time guarantee is required: delay guarantee). Communication using many bands is used.

When such communication is used, there is a possibility that a sufficient band cannot be allocated for communication used when transmitting configuration parameters (for example, configuration & diagnosis communication). Therefore, there is a possibility that new setting parameters cannot be transmitted.

Therefore, in the control system 1 according to the present embodiment, when it is necessary to transmit a new setting parameter, a process for securing a band necessary for the transmission can be executed.

<F. Communication Method Processing Procedure>
Next, an example of the processing procedure of the communication method in the control system 1 according to this embodiment will be described. In the control system 1, when it is necessary to transmit the setting parameters, the network controller 300 takes the initiative to stop part or all of the data communication in order to secure the bandwidth necessary for transmission.

(f1: Temporary stop/resume of all data communication)
An example process of temporarily suspending all data communication between networked devices in order to send configuration parameters will now be described.

FIG. 10 is a diagram showing a processing procedure in the control system 1 according to this embodiment. FIG. 10 shows configuration parameters for end devices 100-1 and 100-2 and network controller 300 from an information processing device (hereinafter also referred to as “support device 400”) for setting each device. shows an example of processing for sending

In the control system 1 shown in FIG. 10, it is assumed that OPC UA Pub/Sub communication is realized by scheduling traffic according to TSN.

First, the user operates the support device 400 to instruct the network controller 300 to stop data communication ((1) communication stop request). In this way, a request to stop data communication may be sent from the external support device 400 .

Then, network controller 300 instructs end devices 100-1 and 100-2 to stop cyclic communication between the end devices and to stop scheduling of traffic according to the TSN ((2) end device cyclic communication stop instruction + TSN scheduling stop instruction). In addition, the network controller 300 instructs the switch 200 to stop scheduling traffic according to TSN ((3) TSN scheduling stop instruction).

In this way, the process of instructing stoppage of data communication may include the process of instructing stoppage of scheduling of traffic according to TSN.

In accordance with instructions from network controller 300, each of end devices 100-1 and 100-2 stops cyclic communication between end devices 100 ((4) stop cyclic communication between end devices). In this way, it can include a process of instructing to stop data communication and a process of instructing to stop OPC UA Publish/Subscriber communication (Pub/Sub communication).

More specifically, each of the end devices 100-1 and 100-2 changes the state related to Pub/Sub communication from the Operational state 70 to the PreOperational state 72 (see FIG. 9). Such a state change can stop Pub/Sub communication and stop cyclic communication between end devices 100 . That is, the instruction to stop cyclic communication between end devices from the network controller 300 includes an instruction to change the state related to Pub/Sub communication.

Also, according to instructions from network controller 300, each of end devices 100-1, 100-2 and switch 200 stops scheduling traffic according to TSN. By stopping scheduling of traffic according to TSN, each of end devices 100-1, 100-2 and switch 200 performs frame forwarding according to standard Ethernet (registered trademark). That is, frames are not forwarded according to stream ID and traffic class, but are forwarded according to CSMA/CD (Carrier Sense Multiple Access with Collision Detection).

In this state, cyclic communication such as isochronous communication and communication requiring delay time guarantee (for example, cyclic-synchronous communication) related to OPC UA are stopped. Also, the scheduling of traffic according to TSN has been stopped. Therefore, it is possible to secure a band necessary for transmitting setting parameters.

Then, the support device 400 transmits (downloads) the setting parameters to the end devices 100-1 and 100-2 and the network controller 300 ((5) parameter transmission). After that, each of the end devices 100-1 and 100-2 and the network controller 300 reboots ((6) reboot). Note that the switch 200 may be restarted as necessary.

By the above procedure, the end devices 100-1 and 100-2 and the network controller 300 are ready to operate with the new setting parameters. Then, the network controller 300 instructs the switch 200 to restart scheduling of traffic according to TSN ((7) TSN scheduling restart instruction). In addition, network controller 300 instructs end devices 100-1 and 100-2 to resume cyclic communication between the end devices and to resume scheduling of traffic according to TSN ((8) end device cyclic communication restart instruction).

Following instructions from network controller 300, each of end devices 100-1, 100-2 and switch 200 resumes scheduling traffic according to TSN. Also, each of the end devices 100-1 and 100-2 resumes cyclic communication between the end devices 100 according to instructions from the network controller 300. FIG. More specifically, each of end devices 100-1 and 100-2 changes the state related to Pub/Sub communication from PreOperational state 72 to Operational state 70 (see FIG. 9). Such a state change allows Pub/Sub communication to resume and cyclic communication between end devices 100 to resume. That is, the instruction to resume cyclic communication between end devices from the network controller 300 includes an instruction to change the state related to Pub/Sub communication.

The setting parameters can be appropriately transmitted by the processing procedure as described above.
(f2: Temporary suspension/resume of some data communications)
In the above processing example, the case where all data communication between devices connected to the network is temporarily stopped has been described, but only part of the data communication may be temporarily stopped.

FIG. 11 is a diagram showing another processing procedure in the control system 1 according to this embodiment. In FIG. 11, cyclic communication is performed between end device 100-1 and end device 100-2, and in parallel, cyclic communication is performed between end device 100-1 and end device 100-3. Assume that communication is taking place. The end device 100-2 is connected to the port B of the switch 200, and the end device 100-3 is connected to the port C of the switch 200. FIG. An example of processing when exchanging the end device 100-2 in this state is shown.

First, the user uses any method to request the network controller 300 to replace the end device 100-1 and restore the setting parameters ((1) restore request).

Then, network controller 300 instructs end device 100-1 to stop cyclic communication with end device 100-2 and to stop scheduling of traffic according to TSN ((2-1) end cyclic communication stop instruction with the device 100-2). In addition, network controller 300 instructs end device 100-2 to stop cyclic communication between end devices and to stop scheduling of traffic according to TSN ((2-2) Cyclic communication stop instruction + TSN scheduling stop instruction).

In this way, the process of instructing stoppage of data communication may include the process of instructing stoppage of scheduling of traffic according to TSN.

Furthermore, the network controller 300 instructs the switch 200 to stop scheduling traffic according to the TSN of the port B ((3) stop TSN scheduling of the port B). That is, the network controller 300 instructs the switch 200 to stop forwarding frames on the port connected to the end device 100-2.

In accordance with an instruction from network controller 300, end device 100-1 stops cyclic communication with end device 100-2 ((4-1) stop cyclic communication with end device 100-2). Also, according to an instruction from the network controller 300, the end device 100-2 stops cyclic communication between the end devices 100 ((4-2) stop cyclic communication between end devices). In this way, it can include a process of instructing to stop data communication and a process of instructing to stop OPC UA Publish/Subscriber communication (Pub/Sub communication).

As described above, cyclic communication may be stopped by, for example, changing the state associated with Pub/Sub communication from Operational state 70 to PreOperational state 72 (see FIG. 9). In this case, by changing the state of only the specific end device 100, cyclic communication with the specific end device 100 can be stopped. Thus, the process of instructing to stop Pub/Sub communication can include the process of instructing to change the state of OPC UA.

Further, according to an instruction from the network controller 300, the end device 100-2 stops scheduling traffic according to TSN, and the switch 200 stops scheduling traffic according to TSN for port B only. Thus, the process of instructing the stop of data communication may include the process of instructing switch 200 to stop scheduling of traffic according to TSN only for a specific port.

In this state, Pub/Sub communication and TSN-based traffic scheduling are suspended only between end device 100-1 and end device 100-2. Therefore, it is possible to secure a band necessary for transmitting setting parameters.

On the other hand, cyclic communication continues between the end device 100-1 and the end device 100-2. That is, between the end device 100-1 and the end device 100-2, Pub/Sub communication and traffic scheduling according to the TSN are continued.

In this state, the user replaces the end device 100-2 ((5) replace end device). Subsequently, the network controller 300 transmits necessary setting parameters to the end device 100-2 ((6) restore). After that, the end device 100-1 reboots ((7) reboot). Note that the switch 200 may be restarted as necessary.

By the above procedure, the replacement of the end device 100-2 is completed, and it becomes ready to operate with the new setting parameters. Then, the network controller 300 instructs the switch 200 to resume scheduling of traffic according to the TSN of the port B ((8) TSN scheduling resume instruction of the port B). Further, the network controller 300 instructs the end device 100-1 to resume cyclic communication with the end device 100-2 ((9-1) Instruction to resume cyclic communication with the end device 100-2). . In addition, network controller 300 instructs end device 100-2 to restart cyclic communication between end devices and to restart scheduling of traffic according to TSN ((9-2) cyclic communication restart instruction).

According to instructions from the network controller 300, the end device 100-1 resumes cyclic communication with the end device 100-2. Also, according to an instruction from the network controller 300, the end device 100-2 resumes cyclic communication between the end devices 100. FIG. As described above, resumption of cyclic communication may be realized, for example, by changing the state associated with Pub/Sub communication from PreOperational state 72 to Operational state 70 (see FIG. 9). Such a state change allows Pub/Sub communication to be resumed and cyclic communication in the control system 1 to be resumed.

Following instructions from network controller 300, end device 100-2 and switch 200 each resume scheduling traffic according to TSN.

The setting parameters can be appropriately transmitted by the processing procedure as described above.
FIG. 12 is a schematic diagram showing an example of a frame structure in the process shown in FIG. 11. FIG. FIG. 12 shows an example structure of a frame transmitted to the end device 100-2 via port B of the switch 200. In FIG.

Referring to FIG. 12, in the state before data communication is stopped, data related to cyclic communication occupies most of the frame, and management data and setting data are allocated to the remaining portion. On the other hand, since there is no data related to cyclic communication in the state after data communication is stopped, more bandwidth can be allocated to setting data.

(f3: secure bandwidth by controlling frame transfer)
In the above processing example, the case where data communication is stopped by changing the state related to Pub/Sub communication has been described. Not limited to this, data communication may be substantially stopped by controlling frame transfer.

For example, when the OPC UA Pub/Sub communication from the end device 100-1 is realized by multicast, data communication with a specific end device 100 is stopped by changing to unicast. good too.

For example, a frame transmitted by multicast from the end device 100-1 to the end devices 100-2 and 100-3 may be changed to be transmitted by unicast to the end device 100-2.

Alternatively, the snooping function of IGMP (Internet Group Management Protocol) may be used to prevent frames from being forwarded to a specific end device 100 using a Multicast Leave Group message or the like.

For example, a frame transmitted by multicast from end device 100-1 to end devices 100-2, 100-3 and 100-4 is changed to be transmitted by multicast to end devices 100-3 and 100-4. In addition, the end device 100-2 may be excluded from multicast targets using a Multicast Leave Group message or the like.

<G. Processing procedure>
Next, a processing procedure in the network controller 300 of the control system 1 according to this embodiment will be described.

FIG. 13 is a diagram showing a processing procedure in network controller 300 of control system 1 according to the present embodiment. Each step shown in FIG. 13 is typically implemented by processor 302 of network controller 300 executing network setting program 324 .

Referring to FIG. 13, when network controller 300 receives a request to secure a band (YES in step S100), it specifies data communication to be stopped to secure the band (step S102). The network controller 300 then identifies a device associated with the identified data communication (step S104), and identifies data communication to be stopped in the identified device (step S106).

Network controller 300 transmits an instruction to stop the target data communication to each of the identified devices (step S108). The instruction to stop target data communication includes an instruction to stop cyclic communication between end devices, an instruction to stop TSN scheduling, and the like.

Thus, in response to the request, the network controller 300 instructs some or all of the devices connected to the network to stop data communication.

If network controller 300 needs to transmit a traffic schedule (YES in step S110), network controller 300 calculates a traffic schedule to be transmitted (step S112). If transmission of the traffic schedule is unnecessary (NO in step S110), the process of step S112 is skipped.

The network controller 300 then sends configuration parameters (which may include a traffic schedule) to the target device (step S114). Thus, the network controller 300 transmits configuration parameters to some or all devices connected to the network. Also, the process of transmitting the configuration parameters may include the process of transmitting a traffic schedule according to the TSN from the network controller 300 to the target end device 100 .

When the period for securing the bandwidth has expired (YES in step S116), network controller 300 transmits an instruction to the target device to resume the target data communication (step S118). That is, after transmitting the setting parameters, the network controller 300 instructs some or all of the devices connected to the network to resume data communication. Then the process ends.

<H. Note>
The present embodiment as described above includes the following technical ideas.

[Configuration 1]
A communication method in a network that complies with TSN (Time Sensitive Networking), wherein at least part of devices (100) connected to the network are configured to perform data communication with a communication protocol that complies with OPC UA (OPC Unified Architecture). and
instructing some or all devices connected to the network to stop data communication in response to the request (S100, S102, S104, S106, S108);
transmitting configuration parameters to some or all devices connected to the network (S110, S112, S114);
and a step (S116, S118) of instructing some or all of the devices connected to the network to resume data communication after the transmission of the setting parameters.

[Configuration 2]
The communication method according to configuration 1, wherein the step of instructing suspension of data communication includes a step of instructing suspension of scheduling of traffic according to TSN (S108).

[Configuration 3]
3. The communication method according to configuration 2, wherein the step of instructing to stop data communication includes a step of instructing a switch to stop scheduling traffic according to TSN only for a specific port (S108).

[Configuration 4]
4. The communication method according to any one of configurations 1 to 3, wherein the step of instructing suspension of data communication includes a step of instructing suspension of OPC UA Publish/Subscriber communication (S108).

[Configuration 5]
5. The communication method according to configuration 4, wherein the step of instructing to stop OPC UA Publish/Subscriber communication includes a step of instructing to change the state of OPC UA (S108).

[Configuration 6]
5. The communication method according to any one of the configurations 1-4, wherein the request is sent from an external support device (400).

[Configuration 7]
6. The communication according to any one of the configurations 1-5, wherein the step of sending the configuration parameters includes the step of sending (S112, S114) a schedule of traffic according to the TSN from the network controller to the target end device. Method.

[Configuration 8]
A communication system (1) including a network according to TSN (Time Sensitive Networking),
a network controller (300);
and one or more devices (100) connected to the network, at least part of the one or more devices being configured to perform data communication using a communication protocol conforming to OPC UA (OPC Unified Architecture). cage,
The communication system is
means (S100, S102, S104, S106, S108) for instructing some or all devices connected to the network to stop data communication in response to a request;
means for transmitting setting parameters to some or all devices connected to the network (S110, S112, S114);
a means (S116, S118) for instructing some or all devices connected to the network to resume data communication after the transmission of the setting parameters.

[Configuration 9]
A network controller (300) configuring a network conforming to TSN (Time Sensitive Networking), wherein at least a part of one or more devices (100) connected to the network is a communication protocol conforming to OPC UA (OPC Unified Architecture) It is configured to perform data communication with
The network controller
means (S100, S102, S104, S106, S108) for instructing some or all devices connected to the network to stop data communication in response to a request;
means for transmitting setting parameters to some or all devices connected to the network (S110, S112, S114);
a means (S116, S118) for instructing some or all devices connected to the network to resume data communication after the transmission of the setting parameters.

<I. Advantage>
According to the control system according to the present embodiment, in a network that combines TSN and OPC UA, it is possible to secure a necessary band when transmission of setting parameters and the like is required.

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, 20, 22, 24 link, 30 fieldbus, 40 field device, 60 communication component, 61 route component, 62 PublishedDataSet, 63 connection component, 64 write group component, 65, 67 component, 66 read group component, 68 SubscribeDataSet, 70 Operational state, 72 PreOperational state, 74 Paused state, 76 Disabled state, 78 Error state, 100 End device, 102, 302 Processor, 104, 304 Main memory, 110, 310 Network interface, 112, 212, 312 Transmission and reception Control circuit, 114, 214, 314 transmission circuit, 116, 216, 316 reception circuit, 120, 320 storage, 122 system program, 124 user program, 130 internal bus interface, 132 field bus interface, 134 memory card interface, 136 memory card , 138, 338 bus, 140 I/O unit, 200 switch, 218 transfer engine, 220 queue, 222 gate, 224 distribution circuit, 226 timing control circuit, 228 schedule, 300 network controller, 322 OS, 324 network setting program, 400 support equipment.

Claims (9)

A communication method in a network that complies with TSN (Time Sensitive Networking), wherein at least part of devices connected to the network are configured to perform data communication with a communication protocol that complies with OPC UA (OPC Unified Architecture),
instructing some or all devices connected to the network to stop data communication in response to a request;
sending configuration parameters to some or all devices connected to the network;
and a step of instructing some or all devices connected to the network to resume data communication after the transmission of the setting parameters. 2. The communication method according to claim 1, wherein the step of instructing stop of data communication includes the step of instructing stop of scheduling of traffic according to TSN. 3. The communication method according to claim 2, wherein the step of instructing to stop data communication includes the step of instructing a switch to stop scheduling traffic according to TSN only for a specific port. 4. The communication method according to any one of claims 1 to 3, wherein the step of instructing to stop data communication includes a step of instructing to stop OPC UA Publish/Subscriber communication. 5. The communication method according to claim 4, wherein the step of instructing to stop OPC UA Publish/Subscriber communication includes a step of instructing to change the state of OPC UA. The communication method according to any one of claims 1 to 4, wherein said request is sent from an external support device. The communication method according to any one of claims 1 to 5, wherein the step of sending configuration parameters comprises sending a schedule of traffic according to TSN from a network controller to a target end device. A communication system including a network according to TSN (Time Sensitive Networking),
a network controller;
and one or more devices connected to the network, wherein at least part of the one or more devices are configured to perform data communication using a communication protocol according to OPC UA (OPC Unified Architecture),
The communication system is
means for instructing some or all devices connected to the network to stop data communication in response to a request;
means for transmitting configuration parameters to some or all devices connected to the network;
means for instructing some or all devices connected to the network to resume data communication after transmission of the configuration parameters. A network controller configuring a network that complies with TSN (Time Sensitive Networking), wherein at least a portion of one or more devices connected to the network performs data communication using a communication protocol that complies with OPC UA (OPC Unified Architecture). is configured to
The network controller
means for instructing some or all devices connected to the network to stop data communication in response to a request;
means for transmitting configuration parameters to some or all devices connected to the network;
and means for instructing some or all devices connected to the network to resume data communication after the transmission of the configuration parameters.

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