JP7574698B2 - COMMUNICATION METHOD, COMMUNICATION SYSTEM, AND COMMUNICATION DEVICE - Google Patents

Description

This technology relates to a communication method, a communication system, and a communication device.

Efforts are underway to expand standard networks (e.g., Ethernet (registered trademark)) used in general information networks so that they can also be used in industrial networks. More specifically, the Institute of Electrical and Electronic Engineers (IEEE) 802.1 Time Sensitive Networking (TSN) (hereinafter also referred to as the "TSN standard") is known, which is based on Ethernet (registered trademark) and has been improved to make the network behave deterministically. According to the TSN standard, real-time communication can be more easily achieved using general-purpose hardware such as Ethernet (registered trademark).

For example, Patent Document 1 (EP 03357218) discloses an industrial network that uses a network conforming to the TSN standard.

European Patent No. 03357218

At production sites, the equipment and tools used are often changed in conjunction with changes to the type of product being produced or the production process. Such changes are also called changeovers. As a result of such changeovers, the devices connected to the industrial network will also be changed.

No consideration has been given to a mechanism for maintaining the required communication performance even if the connected device is changed.

This technology provides a mechanism for maintaining the required communication performance even when the devices connected to the network are changed.

According to an embodiment of the present technology, a communication method in a network conforming to TSN is provided. The communication method includes a step of acquiring communication setting information that defines frames exchanged on the network and capability information that defines performance information related to the TSN of devices connected to the network, a step of calculating a TSN setting including a communication schedule of frames in each device based on network configuration information that defines one or more connection forms of devices that may occur in the network, the communication setting information, and the capability information, and a step of providing the TSN setting to the devices connected to the network. The step of calculating the TSN setting includes a step of calculating the TSN setting so that the required frame forwarding can be realized in any of the connection forms included in the network configuration information.

According to this configuration, for example, if a change in the network configuration (device connection topology) is planned due to a change in setup, the TSN setting can be calculated using network configuration information that defines one or more possible device connection topology in the network, thereby maintaining the required communication performance in any network configuration.

When a predetermined condition is met, a step of calculating the TSN setting may be started. With this configuration, a network conforming to the TSN can be managed with a management entity such as a network controller at the center.

The step of calculating the TSN setting may be initiated in response to a request from a device connected to the network. With this configuration, the optimal TSN setting can be calculated when a new device is connected to the network.

The step of calculating the TSN setting may include a step of determining whether the setting information calculated for one connection topology included in the network configuration information can achieve the required frame forwarding in another connection topology included in the network configuration information. According to this configuration, it is possible to calculate a TSN setting that can maintain the required communication performance for any of the device connection topology defined in the network configuration information.

The communication method may further include a step of recalculating the TSN setting when a connection topology different from the device connection topology defined in the network configuration information is detected so that the required frame forwarding can be realized in the different connection topology. With this configuration, it is possible to calculate an appropriate TSN setting even for a connection topology that was not taken into account in the initial TSN setting calculation.

The communication method may further include a step of notifying the user of the need to reflect the recalculated TSN setting when it is determined that the recalculated TSN setting must be reflected. With this configuration, when there is a need to reflect a new TSN setting, the user has an opportunity to consider the impact on the network, etc.

The communication method may further include a step of providing the recalculated TSN setting to the device connected to the network in response to the explicit approval. According to this configuration, the TSN setting is reflected only when the user or the like explicitly approves it, thereby reducing the possibility of unintended malfunctions occurring in the network.

The communication method may further include a step of each device collecting adjacent node information, a step of generating a topology of the network based on the adjacent node information collected by each device, and a step of updating the network configuration information based on the generated topology.

According to another embodiment of the present technology, a communication system including a network conforming to TSN is provided. The communication system includes a network controller and one or more devices connected to the network. The network controller includes a means for acquiring communication setting information that defines frames exchanged on the network and capability information that defines performance information related to the TSN of one or more devices, network configuration information that defines one or more possible connection forms of devices in the network, a means for calculating a TSN setting including a communication schedule of frames in each device based on the communication setting information and the capability information, and a means for providing the TSN setting to one or more devices. The means for calculating the TSN setting calculates the TSN setting so that the required frame forwarding can be realized in any of the connection forms included in the network configuration information.

According to yet another embodiment of the present technology, a network controller that configures a network conforming to TSN is provided. The network controller includes a means for acquiring communication setting information that defines frames exchanged on the network and capability information that defines performance information related to the TSN of devices connected to the network, network configuration information that defines one or more possible device connection forms on the network, a means for calculating a TSN setting including a communication schedule of frames in each device based on the communication setting information and the capability information, and a means for providing the TSN setting to devices connected to the network. The means for calculating the TSN setting calculates the TSN setting so that necessary frame transfer can be realized in any of the connection forms included in the network configuration information.

This technology provides a mechanism for maintaining the required communication performance even when the devices connected to the network are changed.

1 is a schematic diagram showing an example of an overall configuration of a control system according to an embodiment of the present invention; FIG. 2 is a block diagram showing an example of a hardware configuration of an end device constituting the control system according to the present embodiment. 2 is a block diagram showing an example of a hardware configuration of a switch constituting the control system according to the present embodiment. FIG. 2 is a block diagram showing an example of a hardware configuration of a network controller constituting the control system according to the present embodiment. FIG. 4 is a schematic diagram showing a more detailed configuration of one port of the switch shown in FIG. 3. 1 is a diagram for explaining an example of processing related to frame forwarding in the control system according to the present embodiment. FIG. FIG. 2 is a diagram for explaining an overview of processing in the control system according to the present embodiment. FIG. 11 is a diagram showing a processing procedure of a topology generation process performed by a network controller of the control system according to the present embodiment. FIG. 11 is a diagram showing a processing procedure for detecting a change in topology by a network controller of the control system according to the present embodiment. FIG. 11 is a diagram showing a processing procedure in a Push mode in the control system according to the present embodiment. 4 is a diagram showing an example of communication setting information used in the control system according to the present embodiment. FIG. FIG. 11 is a diagram showing a processing procedure in a Request mode in the control system according to the present embodiment. FIG. 11 is a diagram showing another processing procedure in the Request mode in the control system according to the present embodiment. FIG. 11 is a diagram showing a processing procedure in a Push mode in a network controller of the control system according to the present embodiment. FIG. 11 is a diagram showing a processing procedure in a Request mode in a network controller of the control system according to the present embodiment.

The embodiment of the present technology will be described in detail with reference to the drawings. Note that the same or equivalent parts in the drawings will be given the same reference numerals and their description will not be repeated.

<A. Application Examples>
First, an example of the overall configuration of a control system 1 according to the present embodiment will be described. Fig. 1 is a schematic diagram showing an example of the overall configuration of a control system 1 according to the present embodiment.

The control system 1 shown in FIG. 1 is an example of a communication system that includes a network that complies with TSN. Therefore, the network-related processing in the control system 1 corresponds to communication processing in a network that complies with TSN.

In this specification, unless otherwise specified, the term "TSN" refers collectively to networks that conform to TSN. In addition, the term "TSN settings" encompasses the settings necessary to realize a network that conforms to TSN.

In this specification, a "device" includes any device connected to a network that conforms to the TSN. A "device" may typically include an end device and a switch.

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

The control system 1 shown in FIG. 1 includes end devices 100-1, 100-2, and 100-3 (sometimes collectively referred to as "end device 100"), switches 200-1 and 200-2, and a network controller 300. The network to which one or more of these devices are connected corresponds to the TSN.

End device 100-1 is connected to switch 200-1 via link 20. Switch 200-1 and switch 200-2 are connected via link 22. End device 100-2 can be connected to switch 200-2 via link 24, and end device 100-3 can be connected to switch 200-2 via link 26.

The network controller 300 is connected to the switch 200-1 via link 28.

The end devices 100-2 and 100-3 are selectively connected to the switch 200-2 by changing the setup. That is, the TSN shown in FIG. 1 can have a state in which the end devices 100-1 and 100-2 are connected, and a state in which the end devices 100-1 and 100-3 are connected.

Each of the end devices 100-1, 100-2, and 100-3 has a field bus 30 that is independent of the TSN. One or more field devices 40 are connected to the field bus 30. The one or more field devices 40 include an input device that acquires a field signal, and an output device or actuator that performs some action on the field according to instructions from the end device 100.

The network controller 300 is the entity that manages frame forwarding in the TSN, and determines the communication schedule for frame forwarding by calculating resource allocation and availability. Hereinafter, the calculation of resource allocation and availability by the network controller 300 is also referred to as "TSN calculation." Typically, the network controller 300 may operate in accordance with the provisions of IEEE 802.1Qcc, which is a lower standard of IEEE 802.1 TSN.

In the TSN, the identification label given to each frame includes a stream ID, a stream destination address, and a traffic class. The network controller 300 determines a unique stream ID for each frame transferred within the TSN, and determines a stream destination address and a traffic class according to the transfer path of each stream ID, and provides TSN settings to each of the end devices 100 and the switches 200. The TSN settings include a communication schedule determined taking into account the bandwidth for each stream.

In the control system 1 according to this embodiment, the network controller 300 performs appropriate resource allocation and availability calculations, so that optimal performance can be achieved for the entire TSN even if the devices connected to the TSN are changed due to a changeover or the like.

<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. 2 is a block diagram showing an example of a hardware configuration of an end device 100 constituting the control system 1 according to the present embodiment. Referring to Fig. 2, the end device 100 includes a processor 102, a main memory 104, a network interface 110, a storage 120, an internal bus interface 130, a field bus interface 132, and a memory card interface 134. Each component is electrically connected via a bus 138.

The processor 102 is composed of a CPU (Central Processing Unit), MPU (Micro-Processing Unit), GPU (Graphical Processing Unit), etc., and performs processing as a control device by reading various programs stored in the storage 120, expanding them in the main memory 104, and executing them.

The network interface 110 is responsible for data exchange (frame transmission) via the TSN. More specifically, the network interface 110 includes a transmission/reception control circuit 112, a transmission circuit 114, and a reception circuit 116. The transmission/reception control circuit 112 controls the transmission circuit 114 and the reception circuit 116 according to the TSN setting given in advance by the network controller 300. The transmission circuit 114 sends out frames on the TSN according to instructions from the transmission/reception control circuit 112. The reception circuit 116 receives frames that arrive via the TSN.

Storage 120 typically stores a system program 122 for implementing the functions of the control device, and a user program 124 that defines the control logic executed by the control device.

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

The field bus interface 132 exchanges data with field devices via the field bus 30.

The memory card interface 134 is configured to allow the memory card 136 to be attached and detached, and allows data to be written to the memory card 136 and various data (such as user programs and trace data) to be read from the memory card 136.

Although FIG. 2 shows an example of a configuration in which the necessary functions are provided by the processor 102 executing a program, some or all of these provided functions may be implemented using a dedicated hardwired circuit (e.g., an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array)). Alternatively, the main part of the end device 100 may be realized using hardware that follows a general-purpose architecture (e.g., an industrial PC based on a general-purpose PC). In this way, the processes executed by the end device 100 and the functions provided may be realized by processing circuitry including a processor, an ASIC, an FPGA, etc.

(b2: switch 200)
3 is a block diagram showing an example of a hardware configuration of a switch 200 constituting the control system 1 according to the present embodiment. Referring to FIG. 3, the switch 200 includes a transmission/reception control circuit 212, transmission circuits 214-1, 214-2, 214-3, and 214-4 (hereinafter, sometimes collectively referred to as "transmission circuits 214"), and reception circuits 216-1, 216-2, 216-3, and 216-4 (hereinafter, sometimes collectively referred to as "reception circuits 216"). A pair of the transmission circuit 214 and the reception circuit 216 forms one port. Note that FIG. 3 illustrates a switch 200 having four ports, but there is no particular limit to the number of ports.

The transmission/reception control circuit 212 controls the transmission circuit 114 and the reception circuit 116 according to the TSN setting provided in advance by the network controller 300. More specifically, the transmission/reception control circuit 212 includes a transfer engine 218 and a queue 220.

The transmission/reception control circuit 212 may be realized by a processor executing firmware, or may be realized using a hardwired circuit such as an ASIC or FPGA. In addition, not only the transmission/reception control circuit 212 but also the entire circuit including the transmission circuit 114 and the reception circuit 116 may be realized on a single chip. In this way, the processes executed by the switch 200 and the functions provided may be realized by a processing circuit including a processor, an ASIC, an FPGA, etc.

(b3: network controller 300)
Fig. 4 is a block diagram showing an example of a hardware configuration of a network controller 300 constituting the control system 1 according to the present embodiment. Referring to Fig. 4, the network controller 300 includes a processor 302, a main memory 304, a network interface 310, and a storage 320. Each component is electrically connected via a bus 338.

The processor 302 is composed of a CPU, MPU, GPU, etc., and performs processing as a network controller by reading various programs stored in the storage 320, expanding them in the main memory 304, and executing them.

The network interface 310 is responsible for data exchange (frame transmission) via the TSN. More specifically, the network interface 310 includes a transmission/reception control circuit 312, a transmission circuit 314, and a reception circuit 316.

Storage 320 typically stores an OS 322 for implementing basic processing, and a network configuration program 324 for implementing processing as described below.

Figure 4 shows an example of a configuration in which the necessary functions are provided by the processor 302 executing a program, but some or all of these provided functions may be implemented using a dedicated hardwired circuit (e.g., an ASIC or FPGA. In this way, the processes executed by the network controller 300 and the functions provided may be realized by processing circuitry including a processor, ASIC, FPGA, etc.

<C. Main components for realizing TSN>
Next, a main configuration for implementing the TSN of the control system 1 according to the present embodiment will be described. That is, a configuration example of a port that transmits and receives frames in the TSN will be described.

Figure 5 is a schematic diagram showing a more detailed configuration of one port of the switch 200 shown in Figure 3. Referring to Figure 5, each port is composed of a pair of a transmitting circuit 214 and a receiving circuit 216. A forwarding engine 218 and a queue 220 are provided between the transmitting circuit 214 and the receiving circuit 216.

More specifically, the transfer engine 218 includes a distribution circuit 224 and a timing control circuit 226. In addition, the queue 220 includes multiple queues 220-1 to 220-M that correspond to each value of the traffic class.

The distribution circuit 224 stores the frame received via the receiving circuit 216 in one of the queues 220-1 to 220-M according to the header information of the frame, or transfers the frame to a distribution circuit 224 of another port. The distribution circuit 224 also performs the same judgment and processing on frames received from a distribution 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, it stores the frame in the queue 220 that corresponds to the traffic class of the frame. Through this processing by the distribution circuit 224, frames classified by traffic class are stored sequentially in the queues 220-1 to 220-M.

Gates 222-1 to 222-M are provided on the output side of queues 220-1 to 220-M, respectively. Each of gates 222-1 to 222-M (hereinafter sometimes collectively referred to as "gates 222") opens and closes according to a command from a timing control circuit 226. When a gate 222 opens, a frame stored in the associated queue 220 is sent from the transmission circuit 214. The timing control circuit 226 does not give an open command to multiple gates 222 at the same time. In other words, the timing control circuit 226 opens and closes the gates 222 in sequence according to a communication schedule 228 included in the TSN setting. As a result, frames are transferred according to a communication schedule whose TSN has been calculated in advance.

Note that 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 that shown in FIG. 5.

By controlling the storage of frames in queues 220 prepared for each traffic class as described above, and the sending of frames from queues 220 prepared for each traffic class, real-time frame transfer in TSN can be achieved.

D. Overview
Next, an overview of the processing in the TSN of the control system 1 according to the present embodiment will be described.

FIG. 6 is a diagram for explaining an example of processing related to frame forwarding in the control system 1 according to this embodiment. As shown in FIG. 6(A), assume that a frame is transmitted from end device 100-1 to end device 100-2 and end device 100-3.

Switches 200-1 and 200-2 exist along the route. As described with reference to FIG. 5, end device 100 and switch 200 realize real-time frame transfer by controlling the opening and closing timing of gate 222.

The opening and closing time and opening and closing timing of gate 222 are typically calculated based on the transmission time required for the frame transmission process and the frame propagation delay time. The transmission time is calculated according to the size of the frame being sent (frame size). The propagation delay time varies according to the length of the transfer path. Generally, the propagation delay time is calculated based on the value measured when an arbitrary frame is transmitted.

Figure 6 (B) shows an example of the timing of gate 222 in the network configuration shown in Figure 6 (A). In the time chart shown in Figure 6 (B), the upper section indicates the open state of gate 222.

After gate 222 of end device 100-1 opens, the frame is transmitted to switch 200-1. Gate 222 of switch 200-1 opens with a delay reflecting the time it takes for the frame from end device 100-1 to arrive and be stored in queue 220. After gate 222 of switch 200-1 opens, the frame is transmitted to switch 200-2.

End device 100-2 is connected to port 1 of switch 200-2, and end device 100-3 is connected to port 2 of switch 200-2. For example, assume that there is a difference between the propagation delay time to end device 100-2 connected to port 1 of switch 200-2 and the propagation delay time to end device 100-3 connected to port 2 of switch 200-2. In such a case, a certain time difference occurs between the timing at which gate 222 corresponding to port 1 of switch 200-2 opens and the timing at which gate 222 corresponding to port 2 of switch 200-2 opens.

Figure 7 is a diagram for explaining an overview of the processing in the control system 1 according to this embodiment. Figure 7 (A) shows a state in which an end device 100-2 is connected to port 1 of the switch 200-2, and Figure 7 (B) shows a state in which an end device 100-3 is connected to port 2 of the switch 200-2.

Referring to FIG. 7(C), the length or timing of the port open time when only end device 100-2 is connected as shown in FIG. 7(A) may differ from the length or timing of the port open time when only end device 100-3 is connected as shown in FIG. 7(B).

When both end device 100-2 and end device 100-3 are connected to switch 200-2, the port open time is set to include the state in which only one of them is connected.

For example, when not all devices are connected to the TSN and the network controller 300 performs a TSN calculation, a new device may be connected, or the network configuration may change due to a change in setup, etc. In such a case, if the initial TSN calculation did not take into account the changed network configuration, it will be necessary to perform the TSN calculation again.

The control system 1 according to this embodiment therefore performs TSN calculations so that appropriate frame forwarding can be performed for any network configuration. By performing such TSN calculations, the network configuration can be changed as desired while the TSN is operating. In other words, the TSN calculations are performed to ensure the gate opening/closing times and bandwidth by taking into account the worst values between the possible network configurations.

E. Processing Procedure
Next, an example of a processing procedure in the control system 1 according to the present embodiment will be described.

Figure 8 is a diagram showing the processing procedure of the topology generation process by the network controller 300 of the control system 1 according to this embodiment. From the topology generated by the processing procedure shown in Figure 8, candidate connection forms for devices included in the network configuration information are determined.

Referring to FIG. 8, each of the end devices 100 and switches 200 connected to the TSN advertises information about its own node to adjacent nodes. For advertising information about its own node, a protocol such as LLDP (Link Layer Discovery Protocol) defined as IEEE 802.1AB can be used.

First, each of the end devices 100 and switches 200 connected to the TSN acquires adjacent node information ((1) Acquire adjacent node information). The adjacent node information is acquired by collecting information advertised by the connected end devices 100 and/or switches 200.

Next, the network controller 300 collects adjacent node information from each of the end devices 100 and the switches 200 ((2) Collecting adjacent node information). Note that protocols such as SNMP (Simple Network Management Protocol) and NETCONF may be used to collect the adjacent node information.

Then, the network controller 300 generates a TSN topology based on the collected adjacent node information ((3) Topology generation). In this way, the network controller 300 generates a TSN topology based on the adjacent node information collected by each device.

Furthermore, if a previously generated topology exists, the network controller 300 compares the previously generated topology with the currently generated topology ((4) Topology Matching). Note that if a change in the TSN topology is detected by the topology matching, it may be added to the network configuration information as a new connection form of the device. In other words, the network controller 300 may update the network configuration information based on the generated topology.

The topology is generated by the network controller 300 according to the above procedure.

Figure 9 is a diagram showing a processing procedure for detecting a change in topology by the network controller 300 of the control system 1 according to the present embodiment. Referring to Figure 9, similar to Figure 8, each of the end devices 100 and switches 200 connected to the TSN advertises information about its own node to adjacent nodes.

First, referring to FIG. 9(A), when the switch 200-2 connected to the TSN detects the information advertised by the end device 100-2, it updates the adjacent node information using the detected information ((1) Updating adjacent node information). Then, the switch 200-2 notifies the network controller 300 of the updated adjacent node information ((2) Notifying adjacent node information).

Referring to FIG. 9(B), when the switch 200-2 connected to the TSN detects further information advertised by the end device 100-3, it updates the adjacent node information using the detected information ((1) Updating adjacent node information). Then, the switch 200-2 notifies the network controller 300 of the updated adjacent node information ((2) Notifying adjacent node information).

When SNMP is used, for example, the network controller 300 can be notified of the updated adjacent node information using an SNMP trap. When NETCONF is used, NETCONF Event Notifications can be used.

According to the above procedure, changes in TSN (topology) and the like are detected.
Next, some of the process procedures for providing TSN settings from the network controller 300 to each of the end device 100 and the switch 200 will be described. For example, assume that OPC Unified Architecture (OPC UA), which is internationally standardized as IEC 62541, is used as a communication stack for performing data communication between devices using TSN. The combination of TSN and OPC UA is also called "OPC UA over TSN".

Typical data communication methods between the network controller 300 and the end device 100 include "Push" mode and "Request" mode.

Below, examples of processing procedures in each mode are shown according to the type of data communication method. Note that, for simplicity of explanation, it is assumed that only one switch 200 exists in the TSN.

Figure 10 is a diagram showing the processing procedure in the Push mode in the control system 1 according to this embodiment. Referring to Figure 10, the network controller 300 loads the network configuration information and the communication setting information ((1) Loading the network configuration information and the communication setting information).

The network configuration information includes all network configurations that result from the changeover (each state of the changeover). That is, the network configuration information includes one or more definitions of the device connection forms that can occur in the TSN. For example, the network configuration information may include both the network configuration shown in FIG. 7(A) and the network configuration shown in FIG. 7(B).

The communication setting information includes information that defines the frames exchanged on the TSN. Typically, the communication setting information includes a definition of the frames exchanged between end devices 100.

Fig. 11 is a diagram showing an example of communication setting information used in the control system 1 according to this embodiment. Fig. 11 shows an example of communication setting information for an arbitrary end device 100. Referring to Fig. 11, the communication setting information includes, for example, information indicating whether transmission or reception is performed, information indicating the destination or source of transmission, data size, and period. The communication setting information shown in Fig. 11 is defined for each end device 100.

By referencing the communication setting information of each end device 100, it is possible to determine the bandwidth that must be secured in the TSN.

Referring again to FIG. 10, each end device 100 loads communication setting information for its own device ((2) Loading communication settings). The communication setting information is the same as that shown in FIG. 11.

Next, the network controller 300 collects TSN capability information from each of the end devices 100 and the switches 200 ((3) Collecting TSN capability information). The TSN capability information is information that defines performance information related to the TSN of the devices connected to the TSN. For example, the TSN capability information includes information such as the transfer rate, the number of traffic classes that can be supported, and the number of ports.

Then, the network controller 300 performs a TSN calculation based on the network configuration information, communication setting information, and the collected TSN capability information ((4) TSN calculation). In the TSN calculation, a stream is determined for each frame exchanged, and a communication schedule is determined taking into account the bandwidth for each stream (frame). At this time, the communication schedule is determined taking into account all network configurations that may result from the changeover, so that frame transfer can continue regardless of the network configuration.

Finally, the network controller 300 provides the TSN setting determined by the TSN calculation to the end device 100 and the switch 200, respectively ((5) TSN setting).

Each of the end device 100 and the switch 200 determines and activates a communication schedule 228 in accordance with the TSN setting from the network controller 300 ((6) Communication Schedule).

By following the above procedure, the communication schedule is reflected in the end devices 100 and switches 200 included in the TSN.

Figure 12 is a diagram showing the processing procedure in the Request mode in the control system 1 according to this embodiment. The processing procedure shown in Figure 12 is executed in a state where all end devices 100 to be attached or detached during a changeover are connected to the TSN. In other words, the state of being connected to the TSN indicates the changes to the network configuration.

Referring to FIG. 12, each end device 100 loads communication setting information for its own device ((1) Loading communication settings). The communication setting information is the same as that shown in FIG. 11. Then, each end device 100 requests the network controller 300 to perform a TSN calculation to provide the TSN setting ((2) TSN calculation request). At this time, the TSN calculation request sent from each end device 100 includes the communication setting information and the TSN capability information.

In response to the TSN calculation request, the network controller 300 loads the network configuration information ((3) Loading network configuration information). The loaded network configuration information includes each state of the changeover. In other words, the network configuration information includes all network configurations resulting from the changeover. Next, the network controller 300 collects TSN capability information from each of the switches 200 ((4) Collecting TSN capability information).

The network controller 300 performs a TSN calculation based on the TSN calculation request (including communication setting information and TSN capability information) from the end device 100, the TSN capability information from the switch 200, and the network configuration information ((5) TSN calculation). At this time, a communication schedule is determined so that frame forwarding can be continued regardless of the network configuration, taking into account all network configurations that may result from the changeover.

Finally, the network controller 300 provides the TSN setting determined by the TSN calculation to the end device 100 and the switch 200, respectively ((6) TSN setting).

Each of the end device 100 and the switch 200 determines and activates a communication schedule 228 in accordance with the TSN setting from the network controller 300 ((7) Communication Schedule).

By following the above procedure, the communication schedule is reflected in the end devices 100 and switches 200 included in the TSN.

<F. Unregistered Devices>
As described above, the TSN setting is calculated taking into account all network configurations that occur due to setup changes, but there is also a possibility that a new end device will be connected to the TSN. In this case, the TSN setting is recalculated. However, since the TSN setting before the recalculation may be changed, a notification of this may be sent to the user.

Figure 13 is a diagram showing another processing procedure in the Request mode in the control system 1 according to this embodiment. Figure 13 shows a case where an end device 100-4 is newly connected to a TSN. In the Request mode, the end device 100 requests a TSN calculation from the network controller 300, so that the network controller 300 can detect the connection of a new unregistered end device 100 to a TSN.

Referring to FIG. 13, the end device 100-4 that has newly connected to the TSN loads communication setting information for its own device ((1) Load communication setting). Then, the end device 100-4 requests the network controller 300 to calculate the TSN to provide the TSN setting ((2) TSN calculation request).

In response to the TSN calculation request, the network controller 300 loads the network configuration information ((3) Loading Network Configuration Information). The network controller 300 then performs a TSN calculation based on the TSN calculation request (including communication setting information and TSN capability information) from the end device 100-4 and the information used in the previous TSN calculation ((4) Calculating TSN). In this way, when the network controller 300 detects a connection topology different from the device connection topology defined in the network configuration information, it executes a process of recalculating the TSN setting so that the necessary frame forwarding can be realized in the different connection topology.

Then, the network controller 300 judges whether the TSN setting before the recalculation (the existing TSN setting) can be used in the TSN calculation. If the TSN setting needs to be reconfigured, the network controller 300 notifies the user or the like that the reconfiguration is necessary ((5) Notification of the need for reconfiguration). In this way, when the network controller 300 judges that the recalculated TSN setting needs to be reflected, it executes a process of notifying the user of the need for the reconfiguration.

When approval is received from a user or the like ((6) Approval), the network controller 300 provides the TSN setting determined by the TSN calculation to the end device 100-4 ((7-1) TSN setting), and also provides the TSN setting determined by the TSN calculation to each of the existing end devices 100 and switches, and instructs them to restart ((7-2) TSN setting + restart). In this way, in response to explicit approval, the network controller 300 executes a process of providing the recalculated TSN setting to the devices connected to the TSN.

Each of the end device 100 and the switch 200 determines and activates a communication schedule 228 in accordance with the TSN setting from the network controller 300 ((8) Communication Schedule).

If a new end device 100 is connected to the TSN by following the above procedure, the new communication schedule will be reflected.

As shown in FIG. 13, in Request mode, when an end device 100 connects to a TSN, a TSN calculation request is sent to the network controller 300, so that it can be determined whether the connected end device 100 is unregistered.

The network controller 300 determines whether the connection of an unregistered end device 100 to the TSN requires a change to the bandwidth or communication schedule used by the other end devices 100, i.e., whether the impact on the bandwidth or communication schedule allocated to the other end devices 100 is within an acceptable range. If the impact on the bandwidth or communication schedule is not within an acceptable range, the network controller 300 requests the user or the like to approve the reconfiguration of the TSN setting. When approval is obtained from the user or the like, the end devices 100 and switches 200 connected to the TSN restart according to the new TSN setting, and the initial sequence is executed again.

If the impact on the bandwidth or communication schedule is within an acceptable range, the TSN setting is provided only to the end device 100-4 that has newly connected to the TSN.

In addition, a method of notifying users etc. may be used, such as using OPC UA subscriptions.

<G. Processing Procedure in Network Controller>
Next, a process procedure in the network controller 300 of the control system 1 according to the present embodiment will be described.

Figure 14 is a diagram showing the processing procedure in Push mode in the network controller 300 of the control system 1 according to this embodiment. Each step shown in Figure 14 is typically realized by the processor 302 of the network controller 300 executing the network setting program 324. In the Push mode shown in Figure 14, when a predetermined condition is met, the process of calculating the TSN setting is started.

Referring to FIG. 14, when the start condition for TSN calculation is met (YES in step S100), the network controller 300 acquires network configuration information related to the target TSN (step S102), and also acquires communication setting information and TSN capability information of each end device 100 (step S104). That is, the network controller 300 executes a process of acquiring communication setting information that defines frames exchanged on the TSN, and TSN capability information that defines performance information related to the TSN of devices connected to the TSN.

The network controller 300 selects one TSN configuration included in the network configuration information (step S106), and performs a TSN calculation including stream settings, bandwidth allocation for each stream, and communication schedule determination (step S108). That is, the network controller 300 executes a process to calculate a TSN setting including a communication schedule for frames in each device based on the network configuration information, communication setting information, and TSN capability information. The network controller 300 then sets the TSN setting determined by the TSN calculation as the current TSN setting.

Next, the network controller 300 calculates or updates the TSN settings so that the necessary frame forwarding can be achieved in any of the connection topologies included in the network configuration information, using the following procedure:

The network controller 300 selects another TSN configuration included in the network configuration information (step S110) and performs TSN calculations including stream configuration, bandwidth allocation for each stream, and communication schedule determination (step S112).

Then, based on the TSN setting determined by this TSN calculation, the network controller 300 determines whether there are any items for which the required frame forwarding cannot be performed with the current TSN setting (step S114).

If there is an item that does not allow the necessary frame forwarding in the current TSN setting (YES in step S114), the network controller 300 changes the value of the item in the current TSN setting that does not allow the necessary frame forwarding to the value of the corresponding item in the TSN setting determined by the current TSN calculation (step S116). The network controller 300 sets the changed TSN setting as the new current TSN setting.

In this way, the network controller 300 performs a process to determine whether the configuration information calculated for one connection topology included in the network configuration information can achieve the necessary frame forwarding in another connection topology included in the network configuration information.

If the required frame transfer can be performed with the current TSN setting (NO in step S114), step S116 is skipped.

Next, the network controller 300 determines whether selection of all TSN configurations included in the network configuration information has been completed (step S118).

If selection of all TSN configurations included in the network configuration information has not been completed (NO in step S118), the process from step S110 onwards is repeated.

If the selection of all TSN configurations included in the network configuration information has been completed (YES in step S118), the network controller 300 transmits the current TSN settings to each of the end devices 100 and the switches 200 (step S120). That is, the network controller 300 executes a process of providing the TSN settings to the devices connected to the TSN.

This completes the TSN calculation by the network controller 300.
Fig. 15 is a diagram showing a processing procedure in the Request mode in the network controller 300 of the control system 1 according to this embodiment. Each step shown in Fig. 15 is typically realized by the processor 302 of the network controller 300 executing the network setting program 324. In the Request mode shown in Fig. 15, a process of calculating a TSN setting is started in response to a request from a device connected to the TSN.

Referring to FIG. 15, when the network controller 300 receives a TSN calculation request (YES in step S200), it acquires the communication setting information and TSN capability information included in the TSN calculation request (step S202), and also acquires network configuration information related to the target TSN (step S204). That is, the network controller 300 executes a process of acquiring communication setting information that defines frames exchanged on the TSN, and TSN capability information that defines performance information related to the TSN of the device connected to the TSN.

The network controller 300 selects one TSN configuration included in the network configuration information (step S206), and performs a TSN calculation including stream settings, bandwidth allocation for each stream, and communication schedule determination (step S208). That is, the network controller 300 executes a process of calculating a TSN setting including a communication schedule for frames in each device based on the network configuration information, communication setting information, and TSN capability information. The network controller 300 then sets the TSN setting determined by the TSN calculation as the current TSN setting.

Next, the network controller 300 calculates or updates the TSN settings so that the necessary frame forwarding can be achieved in any of the connection topologies included in the network configuration information, using the following procedure:

The network controller 300 selects another TSN configuration included in the network configuration information (step S210) and performs TSN calculations including stream configuration, bandwidth allocation for each stream, and communication schedule determination (step S212).

Then, based on the TSN settings determined by this TSN calculation, the network controller 300 determines whether there are any items for which the required frame forwarding cannot be performed with the current TSN settings (step S214).

If there is an item that does not allow the necessary frame forwarding in the current TSN setting (YES in step S214), the network controller 300 changes the value of the item in the current TSN setting that does not allow the necessary frame forwarding to the value of the corresponding item in the TSN setting determined by the current TSN calculation (step S216). The network controller 300 sets the changed TSN setting as the new current TSN setting.

In this way, the network controller 300 performs a process to determine whether the configuration information calculated for one connection topology included in the network configuration information can achieve the necessary frame forwarding in another connection topology included in the network configuration information.

If the required frame transfer can be performed with the current TSN setting (NO in step S214), processing in step S216 is skipped.

Next, the network controller 300 determines whether selection of all TSN configurations included in the network configuration information has been completed (step S218).

If selection of all TSN configurations included in the network configuration information has not been completed (NO in step S218), the process from step S210 onwards is repeated.

If the selection of all TSN configurations included in the network configuration information has been completed (YES in step S218), the network controller 300 transmits the current TSN settings to each of the end devices 100 and the switches 200 (step S220). That is, the network controller 300 executes a process of providing the TSN settings to the devices connected to the TSN.

This completes the TSN calculation by the network controller 300.
<H. Notes>
The present embodiment as described above includes the following technical idea.

[Configuration 1]
A communication method in a network conforming to Time Sensitive Networking (TSN), comprising:
A step of acquiring communication setting information that defines frames exchanged on the network and capability information that defines performance information related to TSNs of devices connected to the network (S104; S204);
A step of calculating a TSN setting including a communication schedule of frames in each device based on network configuration information that defines one or more connection forms of devices that may occur in the network, the communication setting information, and the capability information (S106 to S118; S206 to S218);
providing the TSN setting to a device connected to the network (S120; S220);
A communication method including steps (S110 to S118; S210 to S218) of calculating the TSN setting so that the necessary frame forwarding can be realized in any of the connection topologies included in the network configuration information.

[Configuration 2]
2. The method of claim 1, wherein the step of calculating the TSN setting is initiated when a predetermined condition is met.

[Configuration 3]
2. The method of claim 1, wherein the step of calculating the TSN setting is initiated in response to a request from a device connected to the network.

[Configuration 4]
A communication method according to any one of configurations 1 to 3, wherein the step of calculating the TSN setting includes a step (S114; S214) of determining whether the setting information calculated for one connection topology included in the network configuration information can realize the necessary frame forwarding in another connection topology included in the network configuration information.

[Configuration 5]
The communication method according to any one of configurations 1 to 4, further comprising a step of recalculating the TSN setting when a connection topology different from the device connection topology defined in the network configuration information is detected so that the necessary frame forwarding can be realized in the different connection topology.

[Configuration 6]
The communication method according to configuration 5, further comprising the step of notifying the need for reflection when it is determined that the recalculated TSN setting needs to be reflected.

[Configuration 7]
7. The method of claim 6, further comprising providing the recalculated TSN setting to a device connected to the network in response to explicit authorization.

[Configuration 8]
each device collecting neighbor node information;
generating a topology of the network based on neighbor node information collected by each device;
and updating the network configuration information based on the generated topology.

[Configuration 9]
A communication system (1) including a network conforming to Time Sensitive Networking (TSN),
A network controller (300);
One or more devices (100, 200) connected to the network,
The network controller includes:
A means for acquiring communication setting information that defines frames exchanged on the network and capability information that defines performance information related to TSNs of the one or more devices (S104; S204);
A means for calculating a TSN setting including a communication schedule of frames in each device based on network configuration information defining one or more possible connection forms of devices in the network, the communication setting information, and the capability information (S106 to S118; S206 to S218);
means for providing the TSN setting to the one or more devices (S120; S220);
A communication system, wherein the means for calculating the TSN setting calculates the TSN setting so as to realize necessary frame forwarding in any of the connection topologies included in the network configuration information.

[Configuration 10]
A network controller (300) for configuring a network conforming to TSN (Time Sensitive Networking),
A means for acquiring communication setting information that defines frames exchanged on the network and capability information that defines performance information related to TSNs of devices connected to the network (S104; S204);
A means for calculating a TSN setting including a communication schedule of frames in each device based on network configuration information defining one or more possible connection forms of devices in the network, the communication setting information, and the capability information (S106 to S118; S206 to S218);
means for providing the TSN setting to a device connected to the network (S120; S220);
A communication device, wherein the means for calculating the TSN setting calculates the TSN setting so as to realize necessary frame forwarding in any of the connection topologies included in the network configuration information.

I. Advantages
According to the communication control system of the present embodiment, when a change in the network configuration (device connection topology) is planned due to a change in setup or the like, the TSN setting is calculated using network configuration information that defines one or more possible device connection topology in the network, so that the required communication performance can be maintained in any network configuration. Therefore, even if a change in setup occurs, the required communication performance and control performance can be maintained.

The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

1 Control system, 20, 22, 24, 26, 28 Link, 30 Field bus, 40 Field device, 100 End device, 102, 302 Processor, 104, 304 Main memory, 110, 310 Network interface, 112, 212, 312 Transmission/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 Communication schedule, 300 Network controller, 322 OS, 324 Network configuration program.

Claims (10)

A communication method in a network conforming to Time Sensitive Networking (TSN), comprising:
acquiring communication setting information that defines frames exchanged on the network, and capability information that defines performance information related to TSNs of devices connected to the network;
A step of calculating a TSN setting including a communication schedule of frames in each device based on network configuration information that defines one or more connection forms of devices that may occur in the network, the communication setting information, and the capability information;
providing the TSN settings to devices connected to the network;
A communication method, wherein the step of calculating the TSN setting includes a step of calculating the TSN setting so that required frame forwarding can be realized in any of the connection topologies included in the network configuration information. The communication method according to claim 1, wherein the step of calculating the TSN setting is initiated when a predetermined condition is met. The communication method according to claim 1, wherein the step of calculating the TSN setting is initiated in response to a request from a device connected to the network. The communication method according to any one of claims 1 to 3, wherein the step of calculating the TSN setting includes a step of determining whether the setting information calculated for one connection topology included in the network configuration information can realize the necessary frame forwarding in another connection topology included in the network configuration information. The communication method according to any one of claims 1 to 4, further comprising a step of recalculating the TSN setting when a connection topology different from the device connection topology defined in the network configuration information is detected so that the required frame forwarding can be realized in the different connection topology. The communication method according to claim 5, further comprising a step of notifying the need for reflecting the recalculated TSN setting when it is determined that the recalculated TSN setting needs to be reflected. The method of claim 6, further comprising providing the recalculated TSN setting to a device connected to the network in response to explicit authorization. each device collecting neighbor node information;
generating a topology of the network based on neighbor node information collected by each device;
The communication method according to any one of claims 1 to 7, further comprising: updating the network configuration information based on the generated topology. A communication system including a network conforming to Time Sensitive Networking (TSN),
A network controller;
one or more devices connected to the network;
The network controller includes:
A means for acquiring communication setting information that defines frames exchanged on the network and capability information that defines performance information related to TSNs of the one or more devices;
A means for calculating a TSN setting including a communication schedule of frames in each device based on network configuration information that defines one or more connection forms of devices that may occur in the network, the communication setting information, and the capability information;
means for providing the TSN setting to the one or more devices;
A communication system, wherein the means for calculating the TSN setting calculates the TSN setting so as to realize necessary frame forwarding in any of the connection topologies included in the network configuration information. A network controller that configures a network conforming to TSN (Time Sensitive Networking),
A means for acquiring communication setting information that defines frames exchanged on the network and capability information that defines performance information related to TSNs of devices connected to the network;
A means for calculating a TSN setting including a communication schedule of frames in each device based on network configuration information that defines one or more connection forms of devices that may occur in the network, the communication setting information, and the capability information;
means for providing the TSN setting to a device connected to the network;
A communication device, wherein the means for calculating the TSN setting calculates the TSN setting so as to realize necessary frame forwarding in any of the connection topologies included in the network configuration information.

Images