WO2022190430A1

WO2022190430A1 - Control system, setting method, and network controller

Info

Publication number: WO2022190430A1
Application number: PCT/JP2021/034682
Authority: WO
Inventors: 成憲澤田
Original assignee: オムロン株式会社
Priority date: 2021-03-08
Filing date: 2021-09-22
Publication date: 2022-09-15
Also published as: JP2022136722A

Abstract

This control system for controlling a control target comprises: a plurality of devices that each repetitively execute a processing in a predetermined control period; a network to which the plurality of devices are connected and that complies with TSN; a determination means that determines a control reference time for the plurality of devices such that the processings executed by the plurality of devices are synchronized among the plurality of devices; a calculation means that calculates a schedule of traffic in the network according to the control reference time; and a setting means that sets both the control reference time and the schedule of traffic to the plurality of devices.

Description

Control system, setting method and network controller

This technology relates to a control system, a setting method, and a network controller including a network conforming to TSN (Time Sensitive Networking).

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

For example, Patent Document 1 (European Patent No. 03357218) discloses an industrial network using a network conforming to the TSN standard.

EP 03357218

　In order to achieve higher control accuracy, it is preferable to match the timing of receiving the signal from the controlled object and the timing of outputting the signal to the controlled object in the entire control system. However, the prior art does not consider such a point at all.

This technology provides a mechanism for improving control accuracy in control systems that include networks that comply with TSN.

According to an embodiment of the present technology, a control system for controlling a controlled object is provided. The control system includes a plurality of devices that repeatedly execute processing at a predetermined control cycle, a network conforming to TSN to which the plurality of devices are connected, and a plurality of devices so that the processing executed by the plurality of devices is synchronized among the plurality of devices. determining means for determining a control reference time for the plurality of devices; computing means for calculating a schedule of traffic in the network according to the control reference time; and setting means for setting the control reference time and the traffic schedule for the plurality of devices. including.

According to this configuration, since the control reference value can be shared among a plurality of devices, the timing of processing can be matched even when control over a plurality of devices is executed, so control accuracy is improved. be able to. At the same time, since a traffic schedule is calculated according to the determined control reference value, it is possible to improve the bandwidth utilization efficiency in a TSN-compliant network.

The setting means may set the traffic schedule in the switches that make up the network. According to this configuration, the switch can also transfer frames according to the traffic schedule according to the determined control reference value.

The control system may further include acquisition means for acquiring propagation delay times between adjacent devices among the plurality of devices. The calculating means may calculate the traffic schedule based on the propagation delay times. According to this configuration, the traffic schedule can be calculated more appropriately.

The control system may further include a user interface for accepting changes in settings when the traffic schedule calculated by the calculation means does not meet the requirements. According to this configuration, the user can change settings etc. via the user interface so that the traffic schedule can be properly calculated.

Changing the settings may include changing the transmission cycle of frames containing data necessary for managing the network. According to this configuration, it is possible to improve the possibility that the traffic schedule can be properly calculated by adjusting the frame for managing the network which is not directly related to data communication.

The setting change may include reducing the message communication band, out of the cyclic communication band and the message communication band allocated in the frame transferred through the network. According to this configuration, by adjusting the message communication bandwidth that is not directly related to cyclic communication, it is possible to increase the possibility of appropriately calculating the traffic schedule.

Changing settings may include changing the transmission cycle of data exchanged between multiple devices. According to this configuration, it is possible to increase the possibility of appropriately calculating the traffic schedule by appropriately changing the data transmission cycle according to the required control accuracy and the like.

The user interface may notify a proposal to replace the switches that make up the network. According to this configuration, it is possible to increase the possibility of appropriately calculating the traffic schedule by replacing the switch with a switch with higher performance.

According to another embodiment of the present technology, there is provided a setting method for a control system including a plurality of devices that repeatedly execute processing at a predetermined control cycle, and a TSN-compliant network to which the plurality of devices are connected. be. The configuration method includes determining a control reference time for a plurality of devices such that processing performed by the devices is synchronized among the plurality of devices, and calculating a schedule of traffic in the network according to the control reference time. and setting control reference times and traffic schedules to a plurality of devices.

According to yet another embodiment of the present technology, a network connected to a control system including a plurality of devices that repeatedly execute processing at a predetermined control cycle and a network that follows TSN to which the plurality of devices are connected A controller is provided. A network controller calculates a schedule of traffic in the network according to the determining means for determining control reference times for the plurality of devices and the control reference times such that processing performed by the plurality of devices is synchronized among the plurality of devices. Calculation means and setting means for setting control reference times and traffic schedules for a plurality of devices.

According to this technology, it is possible to provide a mechanism for improving control accuracy in a control system that includes a network that conforms to TSN.

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 a hardware configuration example of a PLC that configures the control system according to the present embodiment; FIG. 2 is a block diagram showing an example hardware configuration of a remote IO device that configures 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. 2 is a block diagram showing an example hardware configuration of a support device 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. 3 is a schematic diagram showing an example of data communication in the control system according to the embodiment; FIG. 5 is a diagram showing an example of a state in which control reference times do not match in the control system according to the present embodiment; FIG. 5 is a diagram showing an example of a state in which control reference times match in the control system according to the present embodiment; FIG. 12 is a diagram showing an example of a traffic scheduling result corresponding to the state shown in FIG. 11; FIG. 4 is a schematic diagram showing an example of a method of calculating a control reference time and a Qbv schedule in the control system according to the present embodiment; FIG. 5 is a schematic diagram showing an example of changes in frames related to adjustment of the control reference time and Qbv schedule in the control system according to the present embodiment; FIG. 7 is a flow chart showing a processing procedure for sharing a control reference time in the control system according to the present embodiment; FIG. FIG. 5 is a schematic diagram showing an example of a user interface screen for proposing a change in the transmission cycle of the network management band in the control system according to the present embodiment; FIG. 4 is a schematic diagram showing an example of a user interface screen for proposing a change of message communication band in the control system according to the present embodiment; FIG. 5 is a schematic diagram showing an example of a user interface screen for suggesting replacement of a switch in the control system according to the present embodiment; FIG. 5 is a schematic diagram showing an example of a user interface screen for proposing a change in the transmission cycle of cyclic communication in the control system according to the present embodiment; FIG. 5 is a schematic diagram showing another example of a method of calculating a control reference time and a Qbv schedule in the control system according to the present embodiment; FIG. 4 is a schematic diagram showing another example of the overall configuration of the control system according to the embodiment; FIG. 22 is a diagram showing an example of a state in which control reference times match in the control system shown in FIG. 21; FIG. 9 is a schematic diagram showing still another example of a method of calculating the control reference time and the Qbv schedule in the control system according to the present embodiment;

An embodiment of this 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. Referring to FIG. 1, a control system 1 for controlling a controlled object includes PLCs (Programmable Logic Controllers) 100-1 to 100-4 (also collectively referred to as "PLC 100"), remote IO devices 150 1, 150-2 (sometimes collectively referred to as "remote IO device 150"), switches 200-1, 200-2 (sometimes collectively referred to as "switch 200"), and network controller 300. including. A support device 400 may be connected to the network controller 300 .

"IO" or "IO data" is a generic term for input data and output data used in control calculations for controlling a controlled object.

More specifically, the PLC 100-1 is connected via the link 20 to the switch 200-1. PLC 100-2 is connected via link 22 to switch 200-1. A remote IO device 150-1 is connected to the switch 200-1 via the link 24. FIG. A link 26 connects between the remote IO device 150-1 and the remote IO device 150-2.

Also, the PLC 100-3 is connected to the switch 200-2 via the link 32. PLC 100-4 is connected via link 34 to switch 200-2. A remote IO device 150-3 is connected to the switch 200-2 via the link 36. FIG. A link 38 connects between the remote IO device 150-3 and the remote IO device 150-4.

The switch 200-1 and the switch 200-2 are connected via the link 28. Furthermore, the network controller 300 is connected to the switch 200-1 via the link 40. FIG.

Each of the remote IO devices 150-1 to 150-4 has a field bus 42. One or more field devices 50 are connected to the fieldbus 42 . One or more field devices 50 include input devices that acquire field signals and output devices or actuators that perform some action on the field according to instructions from PLC 100 .

The control system 1 employs a network conforming to IEEE 802.1 TSN. In the following description, unless otherwise specified, the term "TSN" simply 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 will be described later, the IEEE 802.1 TSN standard includes several sub-standards.

In the control system 1 shown in FIG. 1, at least between the PLC 100, the remote IO device 150, and the switch 200, frame transfer conforming to IEEE 802.1 TSN as described later is realized. That is, the network to which PLC 100, remote IO device 150 and switch 200 are connected corresponds to TSN.

Links

20, 22, 24, 26 and

links

32, 34, 36, 38 form at least part of the TSN. Additionally, link 28 may also constitute a TSN.

The PLC 100, the remote IO device 150, the switch 200, and the network controller 300 that configure the control system 1 are time-synchronized with each other by a time synchronization entity (not shown). Time synchronization is realized according to IEEE 802.1 AS-2020, which is a lower standard of IEEE 802.1 TSN, and IEEE 1588, which is a precision time protocol (PTP).

As used herein, the term "device" includes any device connected to a network conforming to IEEE 802.1 TSN. In the control system 1 shown in FIG. 1 , “devices” can include the PLC 100 and the remote IO device 150 .

In this specification, "traffic schedule" means a definition for realizing scheduling according to IEEE 802.1 Qbv, and is also referred to as "Qbv schedule" below. The process of determining the "Qbv schedule" by calculation is also called "scheduling".

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, the network controller 300 schedules traffic according to IEEE 802.1 Qcc, which is a substandard of IEEE 802.1 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, in the control system 1, Ethernet (registered trademark) extended according to IEEE 802.1 TSN is implemented 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.

Note that the switch 200 does not need to implement OPC UA, and the OPC UA is mainly implemented in the PLC 100 and remote IO device 150. Therefore, at least some of the devices connected to the TSN are configured to perform data communication using a communication protocol conforming to OPC UA.

　Referring to FIG. 1 again, the control system 1 according to the present embodiment includes two control groups. Control group 2 includes PLCs 100-1, 100-2 and remote IO devices 150-1, 150-2. Control group 4 includes PLCs 100-3, 100-4 and remote IO devices 150-3, 150-4. In each of control group 2 and control group 4, the control reference time is set to match between devices.

Here, the "control reference time" means the update timing of the IO data referred to by the periodically executed control calculation. More specifically, the “control reference time” includes the timing of acquiring the field signal and the timing of outputting the field signal. By matching the control reference time between the PLC 100 and the remote IO device 150, the timing at which the field signal is acquired can be matched between a plurality of devices, and the timing at which the field signal is output to the control target can be set at a plurality of timings. devices. By making the control reference times the same, the control accuracy can be improved.

This embodiment provides a mechanism for matching the control reference time between devices in the control group.

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

(b1: PLC100)
FIG. 3 is a block diagram showing a hardware configuration example of the PLC 100 configuring the control system 1 according to this embodiment. Referring to FIG. 3, PLC 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), MPU (Micro-Processing Unit), GPU (Graphical Processing Unit), etc., reads various programs stored in the storage 120, expands them in the main memory 104, and executes them. By doing so, processing as a PLC is realized.

The network interface 110 is responsible for frame transfer via 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 the Qbv schedule given in advance from 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 the functions of the PLC and a user program 124 that defines control logic to be executed by the PLC.

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

The fieldbus interface 132 exchanges data with field devices via the fieldbus.

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) or FPGA (Field-Programmable Gate Array), etc.). Alternatively, the main part of the PLC 100 may be realized using hardware conforming to 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 PLC 100 may be implemented in processing circuitry including processors, ASICs, FPGAs, and the like.

(b2: remote IO device 150)
FIG. 4 is a block diagram showing a hardware configuration example of the remote IO device 150 that configures the control system 1 according to this embodiment. The remote IO device 150, like the switch 200, has a function of transferring frames according to a given Qbv schedule.

4, remote IO device 150 includes processor 152 , main memory 154 , network interface 160 , storage 170 , internal bus interface 180 and fieldbus interface 182 . Each component is electrically connected via bus 188 .

The processor 152 is composed of a CPU, MPU, GPU, etc., and reads various programs stored in the storage 170, develops them in the main memory 154, and executes them, thereby realizing processing as a remote IO device.

The network interface 160 is in charge of frame transfer via TSN. More specifically, network interface 160 has two ports and includes transmission/reception control circuit 162, transmission circuits 164-1 and 164-2, and reception circuits 166-1 and 166-2. Transmission/reception control circuit 162 controls transmission circuits 164-1, 164-2 and reception circuits 166-1, 164-2 according to a Qbv schedule given in advance by network controller 300. FIG. That is, the remote IO device 150 has functions corresponding to the switch 200 .

The storage 170 typically stores a system program 172 for realizing functions as a remote IO device and an application program 174 for realizing control processing executed by the remote IO device.

The internal bus interface 180 exchanges data with the I/O unit 190 mounted on the PLC 100.

The fieldbus interface 182 exchanges data with field devices via the fieldbus 42 .

FIG. 4 shows a configuration example in which necessary functions are provided by the processor 152 executing a program. , FPGA, etc.). Alternatively, the main part of the PLC 100 may be realized using hardware conforming to 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 the remote IO device 150 may be implemented in processing circuitry including processors, ASICs, FPGAs, and the like.

(b3: switch 200)
FIG. 5 is a block diagram showing a hardware configuration example of the switch 200 that configures the control system 1 according to this embodiment. 5, switch 200 includes transmission/reception control circuit 212 and transmission circuits 214-1, 214-2, 214-3, and 214-4 (hereinafter also 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. 5 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 the Qbv schedule given in advance from 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.

(b4: network controller 300)
FIG. 6 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. 6, 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, MPU, GPU, etc., and reads various programs stored in the storage 320, develops them in the main memory 304, and executes them, thereby realizing processing as a control device.

The network interface 310 is responsible for frame transfer via 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. 6 shows a configuration example in which necessary functions are provided by the processor 302 executing a program. In this way, the processing performed and the functions provided by the network controller 300 may be implemented by processing circuits including processors, ASICs, FPGAs, and the like.

(b5: support device 400)
FIG. 7 is a block diagram showing a hardware configuration example of the support device 400 that configures the control system 1 according to this embodiment. 7, support device 400 includes processor 402, main memory 404, optical drive 406, secondary storage device 408, USB controller 412, network interface 414, input unit 416, display unit 418 and storage 420 . These components are connected via bus 438 .

The processor 402 is composed of a CPU, MPU, GPU, etc., and reads various programs stored in the storage 420, develops them in the main memory 404, and executes them, thereby realizing processing as a support device.

The storage 420 typically stores an OS 422 for implementing basic processing and a network setting program 424 for implementing processing as described later.

The support device 400 has an optical drive 406, and from a recording medium 407 (for example, an optical recording medium such as a DVD (Digital Versatile Disc)) that stores a computer-readable program non-transitory, The stored program is read and installed in the storage 420 or the like.

Various programs executed by the support device 400 may be installed via the computer-readable recording medium 407, or may be installed by downloading from a server device on the network. Also, the functions provided by the support device 400 according to this embodiment may be realized by using some of the modules provided by the OS 422 .

The USB controller 412 controls data exchange with the network controller 300 via a USB connection. Network interface 414 controls the exchange of data with other devices over any network.

The input unit 416 is composed of a keyboard, mouse, etc., and receives user operations. A display unit 418 includes a display, various indicators, a printer, and the like, and outputs processing results from the processor 402 and the like.

FIG. 7 shows a configuration example in which necessary functions are provided by the processor 402 executing a program. In this way, the processing performed and the functions provided by the support device 400 may be implemented by processing circuits 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. In order to control traffic according to the Qbv schedule, a queue and gate configuration as shown below is employed.

FIG. 8 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. 8, 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, the transfer engine 218 includes a distribution circuit 224 and a 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, it 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, the timing control circuit 226 sequentially opens and closes the gate 222 according to the Qbv schedule 228 . This allows you to control traffic.

The port of PLC 100 (network interface 110), the port of remote IO device 150 (network interface 160), and the port of network controller 300 (network interface 310) also have the same configuration as in FIG.

In this way, each of the PLC 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. Processing Related to Commonization of Control Reference Time>
Next, a description will be given of processing related to common control reference times provided by the control system 1 according to the present embodiment.

(d1: control reference time and traffic scheduling)
FIG. 9 is a schematic diagram showing an example of data communication in the control system 1 according to this embodiment. Referring to FIG. 9, between PLC 100-1 and remote IO device 150-1, data necessary for control calculation of PLC 100-1 is periodically exchanged (data communication), and PLC 100-2 and remote IO device 150-1 It periodically exchanges data (data communication) with the device 150-2 necessary for the control calculation of the PLC 100-2.

At this time, in order to match the control reference times of the PLCs 100-1 and 100-2 and the remote IO devices 150-1 and 150-2, the control reference time is determined and traffic scheduling is performed.

FIG. 10 is a diagram showing an example of a state in which the control reference times in the control system 1 according to the present embodiment do not match. Referring to FIG. 10A, PLC 100-1 repeatedly executes processing including IO communication processing 62 and program execution 64 in each control cycle. Each of remote IO device 150-1 and remote IO device 150-2 repeatedly executes processing including IO communication processing 66 and control processing 68 in each control cycle. In this way, each of the PLC 100 and the remote IO device 150, which are devices connected to the TSN, repeatedly executes processing at a predetermined control cycle.

In IO communication processing 62 and IO communication processing 66, processing related to data communication including periodic exchange of IO data is executed. The control reference time of each device will exist during the IO communication process.

A frame 67 transmitted from the remote IO device 150-1 and a frame 69 transmitted from the remote IO device 150-2 corresponding to the execution timing of the IO communication process 66 shown in FIG. It is transmitted and transferred at the timing shown in (B).

Gate open period 74 of switch 200-1, gate open period 76 of remote IO device 150-1, and gate open period of remote IO device 150-2 correspond to the timing of transmission and transfer of frame 67 and frame 69. 78 are set respectively.

As shown in FIG. 10A, the control reference time 71 of the PLC 100-1, the control reference time 72 of the remote IO device 150-1, and the control reference time 73 of the remote IO device 150-2 do not match. Assume the case.

The control system 1 sets the control reference time for multiple devices so that the processes executed by the multiple devices (PLC 100 and remote IO device 150) are synchronized between the multiple devices. For example, the remote IO device 150-1 and the remote IO device are controlled so that the control reference time 72 of the remote IO device 150-1 and the control reference time 73 of the remote IO device 150-2 match the control reference time 71 of the PLC 100-1. The period start time of the control period of 150-2 is shifted (offset).

It should be noted that since the devices that make up the control system 1 are time-synchronized with each other, the start timing of the control cycle can be arbitrarily set or changed.

FIG. 11 is a diagram showing an example of a state in which the control reference times match in the control system 1 according to the present embodiment. Referring to FIG. 11A, the cycle start times of the control cycles of remote IO device 150-1 and remote IO device 150-2 are adjusted so as to match control reference time 71 of PLC 100-1. More specifically, the control cycle of the remote IO device 150-1 is adjusted so that the cycle start time is earlier by the time difference between the control reference time 71 and the control reference time 72. FIG. On the other hand, the control cycle of the remote IO device 150-2 is adjusted so that the cycle start time is delayed by the time difference between the control reference time 71 and the control reference time 73. FIG.

Thus, between the PLC 100 and the remote IO device 150, the cycle start time of each control cycle can be adjusted so that the control reference times match. By adjusting the cycle start time of the control cycle, the frame transmission timing also changes.

With reference to FIG. 11(B), the timing at which the remote IO device 150-1 transmits the frame 67 advances according to the adjustment of the control cycle. On the other hand, the timing at which the remote IO device 150-2 transmits the frame 69 is delayed according to the adjustment of the control period.

As a result, the gate open period 78 of the remote IO device 150-2 is changed to the gate open period 79. Also, the gate open period 76 of the remote IO device 150-2 is changed to the gate open period 77. FIG. Furthermore, the gate open period 74 of the switch 200-1 is changed to the gate open period 75. FIG.

With such a change in the gate open period, in the remote IO device 150-1, only the frame 67 is transferred during the gate open period 77, and the frame 69 is not included in the gate open period 77. . Similarly, in switch 200 - 1 , only frame 67 is transferred during gate open period 75 , and frame 69 is not included in gate open period 75 .

If the cycle start time of each device's control cycle is adjusted so that the control reference time matches, the scheduled frame transfer cannot be realized. Therefore, the control system 1 according to the present embodiment adjusts so that the control reference times of the devices match, and also adjusts the traffic scheduling. The control accuracy of the control system 1 can be optimized by adjusting based on both control reference times and traffic scheduling.

FIG. 12 is a diagram showing an example of traffic scheduling results corresponding to the state shown in FIG. In the scheduling result shown in FIG. 12, switch 200-1 is changed to gate open period 75A in which frame 67 and frame 69 can be transferred. In the remote IO device 150-1, the gate open period 77A is changed so that the frame 67 and the frame 69 can be transferred. Note that the gate open period 79 set in the remote IO device 150-2 is maintained as it is.

The Qbv schedule (for example, the length and timing of the gate open period) is recalculated as the period start time of the control period of each device is adjusted so that the control reference times match. At this time, the propagation delay time 70 between devices and the transmission time of data are referred to.

(d2: overall processing procedure)
FIG. 13 is a schematic diagram showing an example of a method of calculating the control reference time and the Qbv schedule in the control system 1 according to the present embodiment. Referring to FIG. 13, first, network controller 300 corrects the time for synchronization with devices (PLC 100, remote IO device 150, switch 200, etc.) connected to TSN ((1) time correction ). Note that the time correction process may be performed by any time synchronization subject.

Subsequently, the network controller 300 acquires propagation delay times between each of the devices connected to the TSN and adjacent devices ((2) Acquisition of propagation delay times).

Then, the network controller 300 calculates the control reference time and the Qbv schedule ((3) Control reference time calculation/Qbv schedule calculation). At this time, various factors to be described later may be referred to.

After that, the network controller 300 transmits the control reference time setting and the Qbv schedule to the PLC 100 and the remote IO device 150 ((4-1) control reference time setting/Qbv schedule), and also transmits the Qbv schedule to the switch 200 (( 4-2) Qbv schedule).

The PLC 100 adjusts the timing at which the task scheduler periodically executes the control task according to the control reference time setting from the network controller 300 . At this time, the PLC 100 restarts the task scheduler ((5) task scheduler restart). PLC 100 also sets the Qbv schedule from network controller 300 to network interface 110 .

The remote IO device 150 adjusts the control cycle start timing according to the control reference time setting from the network controller 300 . Also, the remote IO device 150 sets the Qbv schedule from the network controller 300 to the network interface 160 .

The switch 200 sets the Qbv schedule from the network controller 300 in the timing control circuit 226.

The control reference time and Qbv schedule in the control system 1 are calculated and optimized by the above processing procedure.

(d3: factor considered in sharing control reference time)
As described above, the Qbv schedule is also recalculated as the control reference time is adjusted. However, there is a possibility that the use efficiency of the band will be lowered and the usable band will be insufficient due to the timing of the frame transfer being shifted.

Also, in a slave type device (a device having functions as an end device and a switch) such as the remote IO device 150, frames to be transferred from other devices and frames to be transmitted from the own device are different. may compete.

Therefore, when calculating the Qbv schedule in accordance with the adjustment of the control reference time, it is also possible for the user to change the design information of the control system 1 while referring to the following factors.

Factors typically referenced include control cycle length and bandwidth allocation.
14A and 14B are schematic diagrams showing an example of a frame change related to adjustment of the control reference time and the Qbv schedule in the control system 1 according to the present embodiment.

Referring to FIG. 14(A), the frame in the initial state includes a cyclic communication band 80, a message communication band 82, a network management band 84, and a setting band 86.

The cyclic communication band 80 is a band used for cyclic data exchange between the PLCs 100 or between the PLC 100 and the remote IO device 150 .

The message communication band 82 is a band used for exchanging data at arbitrary timing, and is also called an event communication band. Message communication band 82 is used, for example, by any user program, event notification, TCP application, and the like.

The network management band 84 is a band used for exchanging data necessary for network management such as synchronization. The network management band 84 is used, for example, for time correction, adjacent node detection, loop avoidance, and the like.

The setting band 86 is a band used for exchanging data necessary for arbitrary settings for devices connected to the network. The setting band 86 is, for example, a band used for setting from the support device 400, initial setting, and the like.

For example, as shown in FIG. 14(B), the band included in one frame can be expanded by lengthening the control period. As a result, for example, more cyclic communication bands 80 can be assigned to one frame. As a result, an empty band 88 can also be prepared. Vacant band 88 may be used for exchanging arbitrary data such as images and videos.

Alternatively, as shown in FIG. 14(C), by reducing the network management band 84 and/or the setting band 86, a larger cyclic communication band 80 can be allocated.

By adjusting the length of the control cycle and the allocation of the band in this way, the control system 1 as a whole can exhibit higher control accuracy.

(d4: Processing procedure related to sharing of control reference time)
Next, an example of a processing procedure for sharing the control reference time in the control system 1 according to the present embodiment will be described.

FIG. 15 is a flowchart showing a processing procedure for sharing the control reference time in the control system 1 according to the present embodiment. Each step shown in FIG. 15 is typically realized by executing the network setting program 324 by the processor 302 of the network controller 300, or by executing the network setting program 424 by the processor 402 of the support device 400. is realized by A case where the network controller 300 executes processing will be described below as a typical example.

The network controller 300 determines control reference times for a plurality of target devices among the devices that configure the control system 1 (step S2). That is, the network controller 300 determines the control reference times for the plurality of devices such that the processes executed by the plurality of devices are synchronized among the plurality of devices.

Also, the network controller 300 acquires the propagation delay time between the devices of the control system 1 (step S4). Network controller 300 acquires the propagation delay time between adjacent devices among the plurality of devices (PLC 100 and remote IO device 150) that configure control system 1 . Each device measures the propagation delay time.

Then, the network controller 300 follows the control reference time set for the plurality of target devices and calculates the traffic schedule (Qbv schedule) in the TSN of the control system 1 based on the propagation delay time and the like (step S6 ).

The network controller 300 determines whether the Qbv schedule has been properly calculated (step S8). If the Qbv schedule can be calculated appropriately (YES in step S8), network controller 300 sets the control reference time setting and the Qbv schedule to each of PLC 100 and remote IO device 150 (step S40). That is, the network controller 300 sets a control reference time and a traffic schedule (Qbv schedule) to a plurality of devices (PLC 100 and remote IO device 150). Also, the network controller 300 sets the Qbv schedule to the switch 200 (step S42). That is, the network controller 300 sets a traffic schedule (Qbv schedule) to the switches 200 that configure the TSN.

If the Qbv schedule cannot be calculated properly (NO in step S8), the network controller 300 determines whether there is a free band based on the current settings (step S10). If there is a free band (YES in step S10), network controller 300 expands cyclic communication band 80 assigned to the frame (step S12). Then, the network controller 300 recalculates the Qbv schedule in the TSN of the control system 1 with the expanded cyclic communication band 80 assigned to the frame (step S36).

If there is no free band (NO in step S10), network controller 300 determines whether the bands currently assigned to network management band 84 and setting band 86 exceed the minimum necessary size. (step S14). If the bands assigned to the current network management band 84 and the setting band 86 exceed the minimum necessary size (YES in step S14), the network controller 300 sets the network management band assigned to the frame. 84 and/or setting band 86 are reduced to the minimum necessary, and cyclic communication band 80 is expanded (step S16). Then, the network controller 300 recalculates the Qbv schedule in the TSN of the control system 1 with a setting that expands the cyclic communication band 80 (step S36).

If the bands assigned to the current network management band 84 and setting band 86 do not exceed the minimum required size (NO in step S14), network controller 300 transmits a frame including network management band 84. It is determined whether or not the cycle can be lengthened (step S18). If the transmission cycle of frames including network management band 84 can be lengthened (YES in step S18), network controller 300 lengthens the transmission cycle of frames including network management band 84 and increases cyclic communication band 80. Enlarge (step S20). Then, the network controller 300 recalculates the Qbv schedule in the TSN of the control system 1 with a setting that expands the cyclic communication band 80 (step S36).

If the transmission cycle of frames including network management band 84 cannot be lengthened (NO in step S18), network controller 300 reduces message communication band 82 based on the maximum usage rate of message communication band 82. It is determined whether or not there is (step S22). If message communication band 82 can be reduced (YES in step S22), network controller 300 reduces message communication band 82 and expands cyclic communication band 80 (step S24). Then, the network controller 300 recalculates the Qbv schedule in the TSN of the control system 1 with a setting that expands the cyclic communication band 80 (step S36).

If the message communication band 82 cannot be reduced (NO in step S22), the network controller 300 determines whether the network switch can be replaced (step S26). If the switch in the network can be replaced (YES in step S26), network controller 300 executes bandwidth allocation according to the switch after replacement (step S28). The network controller 300 recalculates the Qbv schedule in the TSN of the control system 1 with the bandwidth allocation setting according to the switch after replacement (step S36).

If the network device cannot be replaced (NO in step S26), the network controller 300 proposes to the user to change the transmission cycle of cyclic communication (step S30). Note that the control cycle may also be changed by changing the transmission cycle of cyclic communication.

If the user permits the change of the transmission cycle of cyclic communication (YES in step S32), network controller 300 recalculates the Qbv schedule in the TSN of control system 1 with the setting after changing the transmission cycle of cyclic communication. (step S36). Then, the processing from step S40 is executed.

On the other hand, if the user does not permit the change of the cyclic communication transmission cycle (NO in step S32), the network controller 300 notifies the user of the failure of the Qbv schedule (step S34).

Through the above processing, it is possible to implement settings for matching the control reference times between devices.

(d5: User interface example)
Next, an example of a user interface related to sharing the control reference time in the control system 1 according to the present embodiment will be described.

As described above, the bandwidth allocated to cyclic communication can be increased by lengthening the control cycle and/or reducing the bandwidth other than the cyclic communication bandwidth 80. The network controller 300 and/or the support device 400 can implement optimal bandwidth allocation and scheduling according to control requests and the like through interaction with the user via the following user interfaces. That is, network controller 300 and/or support device 400 has a user interface for accepting changes in settings when the calculated Qbv schedule does not meet requirements.

FIG. 16 is a schematic diagram showing an example of a user interface screen that proposes changing the transmission cycle of the network management band 84 in the control system 1 according to this embodiment. User interface screen 450 shown in FIG. 16 is typically provided to the user in response to the processing in step S18 of FIG. That is, the user interface screen 450 notifies the user of conditions such as synchronization control and detection accuracy, and waits for permission from the user to lengthen the transmission cycle of frames including the network management band 84 .

Referring to FIG. 16, a user interface screen 450 displays information on time synchronization accuracy 451 with a time stamp function, control synchronization accuracy 452, and topology change detection accuracy 453. FIG.

The current accuracy 454 and the expected accuracy 455 when the transmission cycle of the network management band 84 is changed are displayed as the time synchronization accuracy 451 with the timestamp function.

As the control synchronization accuracy 452, the current accuracy 456 and the expected accuracy 457 when the transmission cycle of the network management band 84 is changed are displayed.

The current accuracy 458 and the expected accuracy 459 when the transmission cycle of the network management band 84 is changed are displayed as the topology change detection accuracy 453 .

When the user presses the "Accept" button, the transmission cycle of the network management band 84 is changed and the Qbv schedule is recalculated.

In this way, the user is presented with the details of the possible effects of changing the band allocated to the network management band 84, and upon the user's approval, the Qbv schedule corresponding to the changed band allocation is recalculated. be. That is, changing the settings for recalculating the Qbv schedule may include changing the transmission period of frames containing data necessary for managing TSNs.

FIG. 17 is a schematic diagram showing an example of a user interface screen for proposing a change of the message communication band 82 in the control system 1 according to the present embodiment. User interface screen 460 shown in FIG. 17 is typically provided to the user in response to the processing in step S22 of FIG. That is, the user interface screen 460 notifies the user of the usage status of the message communication band 82 and waits for permission from the user to reduce the message communication band 82 .

Referring to FIG. 17, user interface screen 460 includes usage rate table 461 indicating current bandwidth usage rate, allocation setting table 462 indicating current bandwidth allocation settings, and allocation setting table 462 indicating changed bandwidth allocation settings. 463.

A change in bandwidth allocation is proposed (allocation setting table 463) based on the current bandwidth usage rate (utilization rate table 461) and the current bandwidth allocation setting (allocation setting table 462).

When the user presses the "Accept" button, the message communication band 82 is reduced and the Qbv schedule is recalculated.

In this way, the current usage rate of the message communication band 82 and the range that can be reduced are presented to the user, and with the user's approval, the Qbv schedule corresponding to the reduced message communication band 82 is recalculated. In other words, even if the setting change for recalculating the Qbv schedule includes reducing the message communication band 82 out of the cyclic communication band 80 and the message communication band 82 allocated in the frame in which the TSN is transferred, good.

FIG. 18 is a schematic diagram showing an example of a user interface screen for suggesting switch replacement in the control system 1 according to the present embodiment. User interface screen 470 shown in FIG. 18 is typically provided to the user in response to the processing in step S26 of FIG. That is, the user interface screen 470 displays the section of the network in which the frame transfer is critical, and also suggests to the user to replace the switch to eliminate the critical section.

Referring to FIG. 18, user interface screen 470 includes network status display 471 indicating the current network status and network status display 472 indicating the expected network status after switch replacement. A network status display 472 displays a message 473 indicating which switch is to be replaced.

Such switch replacement proposals are searched by a search engine on the web based on the descriptors of the switch being used, and if there is a switch with higher function than the switch being used, the switch with the higher function is searched. is determined as a candidate for replacement.

The user refers to the user interface screen 470 and appropriately replaces the switches that make up the network. In this way, the user interface provided by the network controller 300 and/or the support device 400 notifies a proposal for replacement of the switches 200 that make up the TSN.

FIG. 19 is a schematic diagram showing an example of a user interface screen that proposes changing the transmission cycle of cyclic communication in the control system 1 according to the present embodiment. User interface screen 480 shown in FIG. 19 is typically provided to the user in response to the processing in step S30 of FIG. That is, user interface screen 480 proposes to the user to change the transmission cycle of cyclic communication.

Referring to FIG. 19, a user interface screen 480 includes a frame setting display 481 showing the state of the currently set frame and a frame setting display 482 showing the state of the proposed new frame.

A frame setting display 481 shown in FIG. 19 indicates that three

frames

483, 484, and 485 are cyclically communicated. In contrast, frame setting display 482 shows that two

frames

486 and 487 are cyclically communicated. In particular, the data DS3 and data DS4 contained in the frame 484 and the data DS5 contained in the frame 485 are set to be sequentially arranged in the frame 487 . As a result, the communication cycle of data DS3, DS4 and DS5 is three times longer than the current frame setting.

In this way, the proposed modification of the data allocation for each frame of cyclic communication is presented to the user, and upon acceptance by the user, the Qbv schedule is recalculated according to the new data allocation.

It should be noted that the notification or proposal to the user as described above may be sent as an event message by any device using Pub/Sub communication of OPC UA.

As described above, the control system 1 according to the present embodiment presents changes to the control cycle, band allocation, communication cycle, etc. to the user via the user interface screen when adjustment is difficult due to insufficient bandwidth or the like. , the Qbv schedule and the like are recalculated based on the changed settings when the user approves. That is, changing the settings for recalculating the Qbv schedule may include changing the transmission cycle of data exchanged between multiple devices.

(d6: Modified example of overall processing procedure)
FIG. 20 is a schematic diagram showing another example of the method of calculating the control reference time and the Qbv schedule in the control system 1 according to the present embodiment. In FIG. 20, processing such as proposing to the user is added to the calculation method shown in FIG.

Referring to FIG. 20, network controller 300 first corrects the time for synchronization with devices (PLC 100, remote IO device 150, switch 200, etc.) connected to the TSN ((1) time correction ). Note that the time correction process may be performed by any time synchronization subject.

Then, the network controller 300 calculates the control reference time and the Qbv schedule ((3) Control reference time calculation/Qbv schedule calculation). In the result of this calculation, if a situation such as insufficient bandwidth occurs, the network controller 300 searches for improvement proposal contents such as those shown in FIGS. ). The network controller 300 notifies the user of the content of the improvement proposal as necessary ((5) Notify user).

When permission (approval) is obtained from the user ((6) permission), the network controller 300 recalculates the Qbv schedule ((7) Qbv schedule recalculation).

After that, the network controller 300 transmits the control reference time setting and the Qbv schedule to the PLC 100 and the remote IO device 150 ((8-1) control reference time setting/Qbv schedule), and also transmits the Qbv schedule to the switch 200 (( 8-2) Qbv schedule).

The PLC 100 adjusts the timing at which the task scheduler periodically executes the control task according to the control reference time setting from the network controller 300 . At this time, the PLC 100 restarts the task scheduler ((9) task scheduler restart). PLC 100 also sets the Qbv schedule from network controller 300 to network interface 110 .

<E. Application example>
As a modified example, application to a configuration example in which one or a plurality of field devices 50 are connected to the PLC 100 via the fieldbus 42 will be described.

FIG. 21 is a schematic diagram showing another example of the overall configuration of the control system 1 according to this embodiment. Referring to FIG. 21, each of PLCs 100-1 and 100-2 has a field bus 42. FIG. One or more field devices 50 are connected to the fieldbus 42 . As the fieldbus 42, for example, a synchronized network such as EtherCAT (registered trademark) is adopted.

In order to match the control reference time in the control system 1 shown in FIG. 21, both communication processing of the field bus 42 and communication processing of TSN must be referred to.

FIG. 22 is a diagram showing an example of a state in which the control reference times in the control system 1 shown in FIG. 21 match. 22, each of PLC 100-1 and PLC 100-2 performs processing including IO communication processing 61 related to fieldbus 42, IO communication processing 63 related to TSN, and program execution 64 for each control cycle. Execute repeatedly.

For example, if the logic for maintaining time synchronization in the IO communication processing 61 related to the field bus 42 is common between devices, the task schedulers of the PLC 100-1 and PLC 100-2 can adjust the timing of periodically executing the control task. , the control reference time can be matched. However, there is a possibility that the Qbv schedule will be shifted by adjusting the timing of the periodic execution of the control task by the task scheduler. Even in such a case, recalculation of the Qbv schedule and the like are executed by the same procedure as described above.

FIG. 23 is a schematic diagram showing still another example of the method of calculating the control reference time and the Qbv schedule in the control system 1 according to the present embodiment. In FIG. 23, processing for reflecting communication processing in the fieldbus 42 is added to the calculation method shown in FIG. However, processing related to the remote IO devices 150-1 and 150-2 is excluded.

Referring to FIG. 23, first, network controller 300 corrects the time for synchronization with devices (PLC 100, switch 200, etc.) connected to TSN ((1) time correction). Note that the time correction process may be performed by any time synchronization subject.

Also, each of the PLCs 100 acquires the propagation delay time of the fieldbus 42 ((3) acquisition of the propagation delay time of the fieldbus 42). Then, the network controller 300 acquires the information of the fieldbus 42 from each of the PLCs 100 ((4) fieldbus information acquisition). The acquired information of the fieldbus 42 includes, for example, the propagation delay time of the fieldbus 42, the topology of the fieldbus 42, frame information flowing through the fieldbus 42, and the like.

Then, the network controller 300 calculates the control reference time and the Qbv schedule ((5) Control reference time calculation/Qbv schedule calculation). After that, the network controller 300 transmits the control reference time setting and the Qbv schedule to the PLC 100 ((6-1) control reference time setting/Qbv schedule), and also transmits the Qbv schedule to the switch 200 ((6-2) Qbv schedule). schedule).

The PLC 100 adjusts the timing at which the task scheduler periodically executes the control task according to the control reference time setting from the network controller 300 . At this time, the PLC 100 restarts the task scheduler ((7) task scheduler restart). PLC 100 also sets the Qbv schedule from network controller 300 to network interface 110 .

Furthermore, the PLC 100 resets the synchronization timing of the fieldbus 42 according to the control reference time setting from the network controller 300 ((8) fieldbus synchronization timing resetting). The process of resetting the synchronization timing of the fieldbus 42 includes, for example, the process of setting the EtherCAT interrupt timing and EtherCAT time synchronization.

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

[Configuration 1]
A control system (1) for controlling a controlled object,
a plurality of devices (100, 150) that repeatedly execute processing at a predetermined control cycle;
a network (20, 22, 24, 26, 28, 32, 34, 36, 38) according to TSN (Time Sensitive Networking) to which the plurality of devices are connected;
determining means (S2) for determining a control reference time for the plurality of devices such that processes executed by the plurality of devices are synchronized among the plurality of devices;
calculating means (S6) for calculating a schedule of traffic in said network according to said control reference time;
A control system comprising setting means (S42, S44) for setting the control reference time and the traffic schedule to the plurality of devices.

[Configuration 2]
The control system according to configuration 1, wherein the setting means sets the schedule of the traffic in the switches (200) constituting the network (S44).

[Configuration 3]
(S4) further comprising acquisition means for acquiring a propagation delay time between adjacent devices among the plurality of devices,
3. The control system according to

configuration

1 or 2, wherein said calculating means calculates a schedule of said traffic based on said propagation delay time.

[Configuration 4]
4. The configuration according to any one of configurations 1 to 3, further comprising a user interface (450, 460, 470, 480) for accepting a setting change when the traffic schedule calculated by the calculating means does not meet the requirements. Control system as described.

[Configuration 5]
5. The control system according to configuration 4, wherein changing the settings includes changing a transmission cycle of frames containing data necessary for managing the network.

[Configuration 6]
6. The control system according to

configuration

4 or 5, wherein the change of setting includes reducing the message communication band among the cyclic communication band and the message communication band allocated in the frame transferred through the network.

[Configuration 7]
7. The control system according to any one of configurations 4 to 6, wherein changing the setting includes changing a transmission cycle of data exchanged between the plurality of devices.

[Configuration 8]
8. The control system according to any one of the configurations 4-7, wherein the user interface notifies a proposal for replacement of a switch (200) constituting the network.

[Configuration 9]
A plurality of devices (100, 150) that repeatedly execute processing at a predetermined control cycle, and a network (20, 22, 24, 26, 28, 32) according to TSN (Time Sensitive Networking) to which the plurality of devices are connected , 34, 36, 38), comprising:
determining a control reference time for the plurality of devices so that the processes executed by the plurality of devices are synchronized among the plurality of devices (S2);
calculating (S6) a schedule of traffic in the network according to the control reference time;
and setting the control reference time and the traffic schedule to the plurality of devices (S42, S44).

[Configuration 10]
A plurality of devices (100, 150) that repeatedly execute processing at a predetermined control cycle, and a network (20, 22, 24, 26, 28, 32) according to TSN (Time Sensitive Networking) to which the plurality of devices are connected , 34, 36, 38), comprising:
determining means (S2) for determining a control reference time for the plurality of devices such that processes executed by the plurality of devices are synchronized among the plurality of devices;
calculating means (S6) for calculating a schedule of traffic in said network according to said control reference time;
and setting means (S42, S44) for setting the control reference time and the traffic schedule to the plurality of devices.

The embodiments disclosed this time should be considered 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, 26, 28, 32, 34, 36, 38, 40 link, 42 field bus, 50 field device, 61, 62, 63, 66 IO communication processing, 64 program execution, 67, 69, 483, 484, 485, 486, 487 frame, 68 control processing, 70 propagation delay time, 71, 72, 73 control reference time, 74, 75, 75A, 76, 77, 77A, 78, 79 gate open period, 80 cyclic communication band, 82 message communication band, 84 network management band, 86 setting band, 88 empty band, 100 PLC, 102, 152, 302, 402 processor, 104, 154, 304, 404 main memory, 110, 160 , 310, 414 network interface, 112, 162, 212, 312 transmission/reception control circuit, 114, 164, 214, 314 transmission circuit, 116, 166, 216, 316 reception circuit, 120, 170, 320, 420 storage, 122, 172 System program, 124 User program, 130, 180 Internal bus interface, 132, 182 Field bus interface, 134 Memory card interface, 136 Memory card, 138, 188, 338, 438 Bus, 140, 190 I/O unit, 150 Remote IO Device, 174 Application program, 200 Switch, 218 Transfer engine, 220 Queue, 222 Gate, 224 Distribution circuit, 226 Timing control circuit, 228 Schedule, 300 Network controller, 322, 422 OS, 324, 424 Network setting program, 400 Support Device, 406 optical drive, 407 recording medium, 408 secondary storage device, 412 USB controller, 416 input section, 418 display section, 450, 460, 470, 480 user interface screen, 451, 452 synchronization accuracy, 453 detection accuracy, 454 , 455, 456, 457, 458, 459 accuracy, 461 usage rate table, 462, 463 allocation setting table, 471, 472 network status display, 473 message, 481, 482 frame setting display.

Claims

A control system for controlling a controlled object,
a plurality of devices that repeatedly execute processing at a predetermined control cycle;
a network according to TSN (Time Sensitive Networking) to which the plurality of devices are connected;
determining means for determining a control reference time for the plurality of devices such that processes performed by the plurality of devices are synchronized among the plurality of devices;
computing means for computing a schedule of traffic in the network according to the control reference time;
and setting means for setting the control reference time and the traffic schedule to the plurality of devices.
The control system according to claim 1, wherein said setting means sets the schedule of said traffic in switches constituting said network.
Further comprising acquisition means for acquiring a propagation delay time between adjacent devices among the plurality of devices,
3. A control system according to claim 1 or 2, wherein said calculating means calculates a schedule of said traffic based on said propagation delay times.
The control system according to any one of claims 1 to 3, further comprising a user interface for accepting a setting change when the traffic schedule calculated by said calculating means does not meet the requirements.
The control system according to claim 4, wherein changing the setting includes changing a transmission cycle of frames containing data necessary for managing the network.
6. The control system according to claim 4 or 5, wherein said change of setting includes reducing said message communication band among a cyclic communication band and a message communication band allocated in a frame transferred through said network.
The control system according to any one of claims 4 to 6, wherein changing the setting includes changing a transmission cycle of data exchanged between the plurality of devices.
The control system according to any one of claims 4 to 7, wherein said user interface notifies a proposal for replacement of switches constituting said network.
A setting method for a control system including a plurality of devices that repeatedly execute processing at a predetermined control cycle and a network that follows TSN (Time Sensitive Networking) to which the plurality of devices are connected,
determining a control reference time for the plurality of devices such that processes performed by the plurality of devices are synchronized among the plurality of devices;
calculating a schedule of traffic in the network according to the control reference time;
and setting the control reference time and the traffic schedule to the plurality of devices.
A network controller connected to a control system including a plurality of devices that repeatedly execute processing at a predetermined control cycle and a network that follows TSN (Time Sensitive Networking) to which the plurality of devices are connected,
determining means for determining a control reference time for the plurality of devices such that processes performed by the plurality of devices are synchronized among the plurality of devices;
computing means for computing a schedule of traffic in the network according to the control reference time;
setting means for setting the control reference time and the traffic schedule to the plurality of devices.