Data transmission method, heterogeneous network node and industrial control system

Abstract

The invention relates to the field of industrial automation control, and provides a data transmission method, a heterogeneous network node and an industrial control system. The method is applied to a logic layer of a heterogeneous network node, the heterogeneous network node further comprises a software layer and a hardware layer, the software layer is in communication connection with the logic layer, and the logic layer is in communication connection with the hardware layer. The method comprises the following steps: acquiring a first data frame sent by a software layer, and determining a data transmission priority and a data transmission strategy of the first data frame; determining a target network transmission mode; performing frame recombination on the first data frame based on the data transmission priority and the target network transmission mode to obtain a recombined data frame; and transmitting the recombined data frame based on the data transmission strategy and the target network transmission mode. According to the invention, the cost of hybrid networking of the heterogeneous network can be reduced, and the reliability and flexibility of networking can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of industrial automation control, and in particular to a data transmission method, a heterogeneous network node and an industrial control system. BACKGROUND

[0002] In the field of industrial control, parallel redundant network, seamless ring network and switching forwarding star network are commonly used control network architectures. However, the parallel redundant network adopts a double network architecture with high cost, the seamless ring network can achieve zero switching time in the event of a fault (i.e. the device does not need to perceive the interruption and automatically switches to the standby path) but has low bandwidth utilization (only about 50% is actually used), and the switching forwarding star network has low cost but poor real-time performance, which cannot meet the requirements of sub-millisecond fault recovery in industrial scenarios.

[0003] The compatibility of existing industrial control network devices is poor. When mixed networking is performed using the above network architectures (such as seamless ring network + star network, parallel redundant network + seamless ring network + star network, etc.), due to the limitations of a single protocol and other reasons, it is usually necessary to deploy additional protocol conversion gateway devices, which has high networking cost and poor networking reliability and flexibility (such as complex gateway configuration, which is difficult to quickly adjust the topology).

[0004] Based on the above, there is an urgent need to provide a data transmission method to solve the problem in the prior art that additional protocol conversion gateway devices need to be deployed when mixed networking is performed using heterogeneous networks, which has high networking cost and poor reliability and flexibility. SUMMARY

[0005] Therefore, the embodiments of the present application provide a data transmission method to solve the problem in the prior art that additional protocol conversion gateway devices need to be deployed when mixed networking is performed using heterogeneous networks, which has high networking cost and poor reliability and flexibility.

[0006] The embodiments of the present application provide a heterogeneous network node to solve the problem that the compatibility of existing industrial control network devices is poor, and when mixed networking is performed using heterogeneous networks, the heterogeneous networks in the mixed networking are difficult to interconnect due to the protocol limitations between the heterogeneous networks.

[0007] The embodiments of the present application provide an industrial control system to solve the problem in the prior art that additional protocol conversion gateway devices need to be deployed when mixed networking is performed using heterogeneous networks, which has high networking cost and poor reliability and flexibility.

[0008] In a first aspect, the embodiments of the present application provide a data transmission method applied to a logical layer of a heterogeneous network node, the heterogeneous network node further comprising a software layer and a hardware layer, the software layer being in communication connection with the logical layer, and the logical layer being in communication connection with the hardware layer; the method comprising the following steps:

[0009] obtain the first data frame sent by the software layer, and determine a data transmission priority and a data transmission strategy of the first data frame;

[0010] determine a target network transmission mode, the target network transmission mode being at least one of a parallel redundant network transmission mode, a seamless ring network transmission mode, or a switching forwarding star network transmission mode;

[0011] perform frame recombination on the first data frame based on the data transmission priority and the target network transmission mode, to obtain a recombined data frame;

[0012] perform transmission on the recombined data frame based on the data transmission strategy and the target network transmission mode.

[0013] In a second aspect, the embodiment of the present application provides a heterogeneous network node, comprising a software layer, a logic layer, and a hardware layer, wherein the software layer is in communication connection with the logic layer, and the logic layer is in communication connection with the hardware layer.

[0014] The logic layer is configured to implement the steps of the method of the first aspect.

[0015] In a third aspect, the embodiment of the present application provides an industrial control system, comprising a master heterogeneous network node, and at least one slave heterogeneous network node in communication connection with the master heterogeneous network node.

[0016] The network structure of the master heterogeneous network node and each slave heterogeneous network node is the same as that of the heterogeneous network node of the second aspect.

[0017] Compared with the prior art, the embodiment of the present application has at least the following beneficial effects: when mixed networking is performed by using heterogeneous networks, each heterogeneous network node can perform efficient data exchange processing (such as frame recombination) and reliable data transmission on the received / sent data frame through the internal logic layer, without needing to deploy an additional protocol conversion gateway device, so that the overall system design of the mixed networking can be simplified, the cost and complexity of the mixed networking can be reduced, and the system reliability and flexibility of the mixed networking can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0019] Figure 1 is a structural schematic diagram of the heterogeneous network node provided by an embodiment of the present application;

[0020] Figure 2 is a structural schematic diagram of a heterogeneous network node provided by another embodiment of the present application;

[0021] Figure 3 is a flow schematic diagram of a data transmission method provided by an embodiment of the present application;

[0022] Figure 4 is a schematic diagram of a parallel redundant network topology architecture provided by an embodiment of the present application;

[0023] Figure 5 is a schematic diagram of a seamless ring network topology architecture provided by an embodiment of the present application;

[0024] Figure 6 is a schematic diagram of a seamless ring network topology architecture provided by another embodiment of the present application;

[0025] Figure 7 is a schematic diagram of a switching forwarding star network topology architecture provided by an embodiment of the present application;

[0026] Figure 8 is a schematic diagram of a reorganized frame encapsulation structure provided by an embodiment of the present application;

[0027] Figure 9 is a system structure schematic diagram of an industrial control system provided by an embodiment of the present application;

[0028] Figure 10 is a system structure schematic diagram of an industrial control system provided by another embodiment of the present application;

[0029] Figure 11 is a system structure schematic diagram of an industrial control system provided by yet another embodiment of the present application;

[0030] Figure 12 is a structural schematic diagram of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0031] In the following description, for the purposes of explanation and not limitation, specific details are set forth, such as particular sequences of acts, in order to thoroughly understand embodiments of the present application. However, it will be apparent to those skilled in the art that the present application can be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known methods, devices, and circuits are omitted so as not to obscure the description of the present application with unnecessary detail.

[0032] In the field of industrial control, process automation and discrete automation control systems have high requirements for network reliability and flexibility of network topology. The compatibility of existing industrial control network devices is poor. When mixed networking is adopted using heterogeneous networks, due to the protocol restrictions between heterogeneous networks, it is difficult to realize interconnection and intercommunication between the mixed networking heterogeneous networks. In order to realize the interconnection and intercommunication between the heterogeneous networks, an additional protocol conversion gateway device needs to be deployed, which has high networking cost and poor networking reliability and flexibility (such as complex gateway configuration, difficult to quickly adjust topology).

[0033] In view of this, the embodiments of the present application provide a data transmission method, a heterogeneous network node and an industrial control system. When mixed networking is adopted using heterogeneous networks, each heterogeneous network node can realize efficient data exchange processing (such as frame reorganization of received / transmitted data frames) and reliable data transmission of the received / transmitted data frames through the internal logic layer of the heterogeneous network node, without deploying an additional protocol conversion gateway device, which can simplify the overall system design of the mixed networking, reduce the cost and complexity of the mixed networking, and improve the system reliability and flexibility of the mixed networking.

[0034] A data transmission method, a heterogeneous network node and an industrial control system according to an embodiment of the present application will be described in detail below with reference to the accompanying drawings.

[0035] Figure 1 is a structural schematic diagram of a heterogeneous network node provided by an embodiment of the present application. Please refer to Figure 1 The heterogeneous network node of the embodiment of the present application includes a software layer 101, a logic layer 102 and a hardware layer 103; the software layer 101 is in communication connection with the logic layer 102, and the logic layer 102 is in communication connection with the hardware layer 103; wherein the software layer 101 includes a user layer software 1011, a protocol stack software 1012 and a driver layer software 1013.

[0036] The user layer software 1011 is the software directly facing the specific needs of the user, and is the main interface for the user to interact with the computer system or the intelligent device.

[0037] The protocol stack software 1012 is the highest layer of the protocol stack, which is responsible for processing the application data request and response of the user layer software 1011, and realizing the interaction and management of data. The protocol stack provides a protocol stack function programming interface to the user layer, which supports periodic and aperiodic data interaction, protocol stack management and diagnosis, etc., and provides strong communication support for the application of the user layer.

[0038] The driving layer software 1013 is responsible for controlling and managing the hardware interface of the hardware layer 103 of the heterogeneous network node, mainly involving the basic operating system functions such as task creation and message queue of the operating system (OS), and the integration of the TCP / IP protocol stack, providing the necessary software environment and support for the operation of the protocol stack to ensure that they can work efficiently and stably.

[0039] The logic layer 102 is responsible for managing the transmission of data flow, and has key functions such as multiplexing of multiple data flows, priority scheduling of data flow, link redundancy and switching, to ensure the real-time and reliability of data. In addition, it is also responsible for realizing the dynamic switching of the target network transmission mode.

[0040] The hardware layer 103 is mainly responsible for connecting external devices to ensure smooth transmission of network data.

[0041] Figure 2 is a structural schematic diagram of the heterogeneous network node provided by another embodiment of the application. Please refer to Figure 2 The heterogeneous network node includes a software layer 101, a logic layer 102 and a hardware layer 103. The software layer 101 includes a processor (which can also be referred to as a processor system (PS)). The hardware layer 103 includes at least two physical layer interfaces (for example, including a physical layer interface one (PHY1), a physical layer interface two (PHY2)). The logic layer 102 includes: a software setting control register (CTL_REG), a data exchange processing component (which can also be referred to as an HAC component), at least two parallel redundant network port controllers (for example, including a parallel redundant network port controller one (MAC3), a parallel redundant network port controller two (MAC4)), at least two switching network port controllers (for example, including a switching network port controller one (MAC1), a switching network port controller two (MAC2)) and at least two network selection switches (for example, including a network selection switch one (MUX1), a network selection switch two (MUX2)). The software setting control register is in communication connection with the processor; the data exchange processing component is in communication connection with the processor; each parallel redundant network port controller is in communication connection with the processor; each switching network port controller is in communication connection with the switching processing component, and one network selection switch is in communication connection with one switching network port controller, one parallel redundant network port controller and one physical layer interface.

[0042] According to different application scenario requirements, the software setting control register (CTL_REG) of the logic layer 102 and the data exchange processing component (HAC component) can establish a communication connection with the processor (PS) of the software layer 101 through an AXI (Advanced eXtensible Interface) interface, a PCIe (Peripheral Component Interconnect Express) interface, or a USB interface.

[0043] As an example, the data exchange processing component (HAC component) is integrated with a register (REG), a data frame reorganization unit, and a clock calibration module (PTP).

[0044] The clock calibration module (PTP) supports the two-step time calibration mode of IEEE1588:

[0045] 1) The logic layer of the heterogeneous network node automatically records the accurate sending time when the PTP message leaves the HAC component, and stores it in the TX_Timestamp register of the PTP, with a precision of nanoseconds. The protocol stack software of the master clock module (the master clock calibration module of the master network node of the control network) sends this time stamp through the Follow_Up message.

[0046] 2) The logic layer of the heterogeneous network node automatically records the arrival time when the PTP message enters the HAC component, and stores it in the RX_Timestamp register of the PTP after filtering by a jitter suppression algorithm and a sliding window mean filter, for reading by the driver. The protocol stack software of the master clock module sends this time stamp through the Delay_Resp message.

[0047] 3) The logic layer of the heterogeneous network node maintains a local message, and according to its own time calibration master-slave state, if it is a slave, it analyzes the time stamp in the PTP message to calibrate the local clock.

[0048] 4) The protocol stack software of the heterogeneous network node can read the local clock and its state of the logic layer through related registers.

[0049] In some embodiments, the data exchange processing component (HAC component) and the processor (PS) interact through a data buff, a descriptor buff, and a control register. The data buff is a destination or source DDR (Double Data Rate) space for the data exchange processing component (HAC component) to receive or send data, which is configured by the processor (PS) and followed by the logic layer. The descriptor buff is a buff for storing each descriptor in the DDR. The descriptor is a set of data structures pre-allocated and initialized by the processor (PS) and followed by the logic layer. The data structure of each descriptor includes a state flag of transmission, a byte number, a data buff address, a next descriptor address, and a PTP timestamp, etc., forming a descriptor linked list to constitute a ring queue. The descriptor ring queue supports 2048 dynamically configurable descriptors. The control register is used for the HAC component to interact with the control and state thereof through the control register.

[0050] Data receiving mechanism of the HAC component: After receiving a data frame, the HAC component directly writes the data into the data buff according to the buffer address in the current RX descriptor, updates the descriptor state after the writing is completed, and triggers an interrupt to notify the processor (PS).

[0051] Data sending mechanism of the HAC component: The processor (PS) writes the data to be sent into the data buff and initializes the TX descriptor. After the HAC component reads the descriptor, the data is moved from the DDR to the HAC component for sending. After the sending is completed, the descriptor state is updated and an interrupt is triggered to notify the processor (PS).

[0052] Queue management strategy of the HAC component for interacting data: ①Depth configurable (256-2048 descriptors); ②Lock-free design (atomic pointer update); ③Data path acceleration, 64-byte aligned burst transmission. For example, the AXI4 bus protocol supports a maximum of 256 bits (32 bytes) of bit width, and through double data rate, 64 bytes / clock cycle of burst transmission can be realized. The logic layer uses the DMA mode to write data into the data buff (located in the DDR chip), and the burst length of the DMA controller is configured to match the 64-byte alignment, so that 64 bytes / clock cycle of burst transmission can be realized.

[0053] Figure 3 is a flowchart of a data transmission method provided by an embodiment of the present application. The data transmission method can be applied to the logic layer 102 (as shown in Figure 2 ) of a heterogeneous network node.

[0054] Please refer to Figure 3 , the data transmission method comprises the following steps:

[0055] In step S301, a first data frame is acquired, and a data transmission priority and a data transmission strategy of the first data frame are determined.

[0056] The first data frame can be an Ethernet data frame sent by the software layer 101 or the hardware layer 103. The Ethernet data frame can be control data, configuration data, or general network data. The control data includes control instructions, device state feedback, instantaneous values (such as temperature and pressure) collected by sensors, actuator action signals, and the like. The configuration data includes device parameter settings (such as IP addresses and communication protocol parameters), system initialization parameters, security policy rules, network topology configurations, and the like. The general network data includes operation and maintenance logs, diagnosis reports, and the like.

[0057] As an example, please refer to Figure 2 The processor (PS) of the software layer 101 of a certain heterogeneous network node establishes a communication connection with a double data rate memory (DDR), reads a first data frame from the double data rate memory (DDR), and transmits the first data frame to the logic layer 102 (programmable logic, PL), so that the logic layer 102 acquires the first data frame.

[0058] In step S302, a target network transmission mode is determined. The target network transmission mode is at least one of a parallel redundant network transmission mode, a seamless ring network transmission mode, or a switching forwarding star network transmission mode.

[0059] The parallel redundant network transmission mode refers to a data transmission mode using a parallel redundant network topology architecture.

[0060] Figure 4 FIG. 1 is a schematic diagram of a parallel redundant network topology architecture according to an embodiment of the present application. Please refer to Figure 4 The parallel redundant network topology architecture includes a heterogeneous network node one (which can be a controller in particular), a heterogeneous network node two (which can be a switch one in particular), a heterogeneous network node three (which can be a switch two in particular), a heterogeneous network node four (which can be an I / O module one in particular), and a heterogeneous network node five (which can be an I / O module two in particular). The heterogeneous network node one, the heterogeneous network node four, and the heterogeneous network node five each include a physical layer interface one (i.e., interface one 1) and a physical layer interface two (i.e., interface two 2).

[0061] The seamless ring network transmission mode refers to a data transmission mode using a seamless ring network topology architecture.

[0062] Figure 5 FIG. 2 is a schematic diagram of a seamless ring network topology architecture according to an embodiment of the present application. Please refer to Figure 5The seamless ring network topology architecture includes heterogeneous network node one (which can be a controller in particular), heterogeneous network node four (which can be I / O module one in particular), and heterogeneous network node five (which can be I / O module two in particular); wherein the heterogeneous network node one, the heterogeneous network node four, and the heterogeneous network node five all include a physical layer interface one (i.e., interface one 1) and a physical layer interface two (i.e., interface two 2).

[0063] The switch forwarding star network transmission mode refers to a manner of data transmission by using a switch forwarding star network topology architecture.

[0064] Figure 6 FIG. 1 is a schematic diagram of a switch forwarding star network topology architecture according to an embodiment of the present application. Referring to FIG. 1, Figure 6 The switch forwarding star network topology architecture includes heterogeneous network node one (which can be a controller in particular), heterogeneous network node four (which can be I / O module one in particular), and heterogeneous network node five (which can be I / O module two in particular); wherein the heterogeneous network node one, the heterogeneous network node four, and the heterogeneous network node five all include a physical layer interface one (i.e., interface one 1) and a physical layer interface two (i.e., interface two 2).

[0065] The switch forwarding star network architecture is a special case of the seamless ring network topology architecture, and the main difference between the two is that no diagnosis information related to the seamless ring network is reported.

[0066] In step S303, the first data frame is frame-recombined based on the data transmission priority and the target network transmission mode, to obtain a recombined data frame.

[0067] In step S304, the recombined data frame is transmitted based on the data transmission strategy and the target network transmission mode.

[0068] The technical scheme provided by the embodiments of the present application can, when hybrid networking is performed by using heterogeneous networks, enable each heterogeneous network node to perform efficient data exchange processing (such as frame-recombining the received / transmitted data frame) and reliable data transmission on the received / transmitted data frame by using the internal logic layer of the heterogeneous network node, without the need for an additional protocol conversion gateway device, thereby simplifying the overall system design of the hybrid networking, reducing the cost and complexity of the hybrid networking, and improving the system reliability and flexibility of the hybrid networking.

[0069] In some embodiments, determining the data transmission priority and the data transmission strategy of the first data frame includes:

[0070] Determining the data transmission priority of the first data frame based on the data category and the data transmission requirement of the first data frame;

[0071] Determining the data transmission strategy based on the data transmission priority.

[0072] Data categories, including but not limited to control data, configuration data, and general network data.

[0073] Data transmission requirements, including performance requirements (such as bandwidth, delay, etc.), reliability requirements (such as data integrity, availability, etc.), compatibility and adaptability requirements (such as protocol compatibility, heterogeneous network adaptation, device and interface adaptation, etc.), and service-specific requirements (such as real-time service requirements for remote control, automatic driving, etc. ultra-low delay, low jitter, preferentially guaranteeing transmission speed; and such as high reliability (packet loss rate <0.1%) and anti-interference ability (such as resistance to electromagnetic interference) required by industrial control scenarios.

[0074] Generally, different data categories or service scenarios correspond to different data transmission requirements, and different data transmission requirements correspond to different data transmission priorities. For example, the real-time requirements of control data, configuration data, and general network data for data transmission decrease in turn, and their data transmission priorities are arranged in turn from high to low as follows: control data > configuration data > general network data, that is, the data transmission priority of control data is the highest, the data transmission priority of configuration data is the second, and the data transmission priority of general network data is the lowest.

[0075] Different data transmission priorities correspond to different data transmission strategies. As an example, assume that the data transmission priorities include levels 0-7, where level 0 is the highest priority, levels 1-3 are high priorities, levels 4-6 are medium priorities, and level 7 is the lowest priority. The data transmission strategy corresponding to level 0 is straight-through path transmission. Straight-through path transmission refers to the heterogeneous network node, upon receiving the target MAC address field of the first data frame, immediately querying its own MAC address table to determine the forwarding port, and starting to forward the received partial data to the target port while the remaining data frame is still in the receiving process, to achieve "receiving while forwarding". The data transmission strategy corresponding to levels 1-3 is queue non-empty time exclusive bandwidth transmission. Queue non-empty time exclusive bandwidth transmission refers to when there is data to be transmitted in a certain data queue (non-empty state), the queue will preferentially occupy all available bandwidth, and other queues cannot temporarily obtain bandwidth resources until the data of the queue is processed (becomes an empty queue). The data transmission strategy corresponding to levels 4-6 is quality-of-service-unprotected transmission, i.e., BEST EFFORT transmission. BEST EFFORT transmission refers to the heterogeneous network node not providing any explicit quality-of-service guarantee (such as bandwidth, delay, jitter, packet loss rate, etc.) for data transmission, and only "trying its best" to transmit data from the source end to the destination end. The data transmission strategy corresponding to level 7 is available remaining bandwidth allocation transmission, i.e., after deducting the part of the total bandwidth that has been reserved, occupied, or allocated to other services, the remaining available bandwidth is allocated to data with a data transmission priority of level 7 according to a proportion of 5%. Generally, the proportion of bandwidth allocated to data with levels 1-3 to the total bandwidth is ≥75%.

[0076] In some embodiments, each heterogeneous network node can pre-set the bandwidth allocation weight corresponding to each type of service according to historical traffic access frequency and other information of each type of service. In the subsequent data transmission process, each heterogeneous network node can monitor the communication response time of each type of service in real time, and if the communication response time of a certain type of service does not meet the service requirement (such as the communication response time exceeding the pre-set threshold range), the bandwidth allocation weight of the type of service can be updated by setting the control register (CTL_REG) of the software of the logical layer.

[0077] For example, a certain heterogeneous network node detects that the actual response time of control data is 500 ms (assuming that the pre-set threshold range is <100 ms, 500 ms > 100 ms, exceeding the pre-set threshold range), and can determine that the transmission of control data does not meet the service requirement. At this time, the bandwidth allocation weight of control data can be updated by setting the control register (CTL_REG) of the software of the logical layer, such as from the original 20% to 40%.

[0078] By detecting the communication response time of various services in real time, and dynamically adjusting the bandwidth allocation weight of each service according to the monitoring result, the efficiency and reliability of data transmission can be ensured.

[0079] In some embodiments, determining the target network transmission mode comprises:

[0080] determining the network topology architecture of the control system in which the heterogeneous network node is currently located;

[0081] if the network topology architecture is a parallel redundant network topology architecture, determining the target network transmission mode as a parallel redundant network transmission mode;

[0082] if the network topology architecture is a seamless ring network topology architecture, determining the target network transmission mode as a seamless ring network transmission mode;

[0083] if the network topology architecture is a switching forwarding star network topology architecture, determining the target network transmission mode as a switching forwarding star network transmission mode.

[0084] In an example, if the network topology architecture of the control system in which the heterogeneous network node one is currently located is a parallel redundant network topology architecture as shown in Figure 4 , then the target network transmission mode corresponding to the heterogeneous network node one is a parallel redundant network transmission mode.

[0085] In another example, if the network topology architecture of the control system in which the heterogeneous network node one is currently located is a seamless ring network topology architecture as shown in Figure 5 , then the target network transmission mode corresponding to the heterogeneous network node one is a seamless ring network transmission mode.

[0086] In yet another example, if the network topology architecture of the control system in which the heterogeneous network node one is currently located is a switching forwarding star network topology as shown in Figure 7 , then the target network transmission mode corresponding to the heterogeneous network node one is a switching forwarding star network transmission mode.

[0087] In some embodiments, based on the data transmission priority and the target network transmission mode, the first data frame is frame-recombined to obtain a recombined data frame, comprising:

[0088] determining the VLAN tag corresponding to the data transmission priority, and the transmission mode tag corresponding to the target network transmission mode;

[0089] based on the VLAN tag and the transmission mode tag, frame-recombining the first data frame to obtain a recombined data frame.

[0090] The VLAN tag can be a tag based on the IEEE 802.1Q-Virtual Local Area Network (VLAN) marking protocol.

[0091] The transmission mode label includes a transmission path identifier and a sequence number.

[0092] If the target network transmission mode is the seamless ring network transmission mode, the transmission mode label is a seamless ring network label representing the seamless ring network transmission mode. If the target network transmission mode is the switch-forwarding star network transmission mode, the transmission mode label is a switch-forwarding star network label representing the switch-forwarding star network transmission mode. If the target network transmission mode is the parallel redundancy network transmission mode, the transmission mode label is a parallel redundancy network label representing the parallel redundancy network mode. The seamless ring network label, the switch-forwarding star network label, and the parallel redundancy network label are different.

[0093] In some embodiments, based on the VLAN label and the transmission mode label, frame reorganization is performed on the first data frame to obtain a reorganized data frame, including:

[0094] A reorganized frame encapsulation structure corresponding to the transmission mode label is obtained, the reorganized frame encapsulation structure including a frame header area, a first label area, a second label area, a data area, and a check area;

[0095] The frame header field, the VLAN label, the transmission mode label, the application data of the first data frame, and the check field of the first data frame are sequentially filled into the frame header area, the first label area, the second label area, the data area, and the check area to obtain the reorganized data frame.

[0096] Figure 8 is a schematic diagram of the reorganized frame encapsulation structure provided by an embodiment of the present application. Please refer to Figure 8 The reorganized frame encapsulation structure includes a frame header area (14 bytes), a first label area (4 bytes), a second label area (6 bytes), a data area (maximum 1496 bytes), and a check area (4 bytes). The frame header area is the outer layer of the reorganized frame encapsulation structure, used to fill a standard Ethernet frame header, including a preamble, a destination MAC address, and a source MAC address. The first label area is the middle layer of the reorganized frame encapsulation structure, used to fill a VLAN label, which is used to distinguish QoS (Quality of Service) levels. The second label area is the inner layer of the reorganized frame encapsulation structure, used to fill a transmission mode label, which includes a transmission path identifier and a sequence number. The data area is the payload area (message payload) of the reorganized frame encapsulation structure, used to fill application data. The check area is used to fill a message checksum.

[0097] In some embodiments, based on the data transmission strategy and the target network transmission mode, the reorganized data frame is transmitted, including:

[0098] If the target network transmission mode is the seamless ring network transmission mode, the reorganized data frame is transmitted according to the data transmission strategy, and the first source MAC address and the first sequence number of the reorganized data frame are recorded;

[0099] The second data frame is acquired, and the second source MAC address and the second sequence number of the second data frame are extracted;

[0100] If the first source MAC address is consistent with the second source MAC address, and the first sequence number is consistent with the second sequence number, the transmission of the second data frame is terminated;

[0101] If the first source MAC address is inconsistent with the second source MAC address, and / or the first sequence number is inconsistent with the second sequence number, the transmission of the second data frame is continued.

[0102] As an example, please refer to Figure 1 、 2 , 5 and 6, assuming that the network topology architecture of the control system in which the heterogeneous network node one currently locates is the seamless ring network topology architecture, the target network transmission mode is the seamless ring network transmission mode, and the heterogeneous network node one can change the target network transmission mode to the seamless ring network transmission mode by configuring the software of the logical layer to set the control register (CTL_REG) of the software of the protocol stack of the software layer. The processor (PS) of the software layer of the heterogeneous network node one needs to transmit the first data frame to the data exchange processing component (HAC component) of the logical layer, the data exchange processing component calls the data frame reorganization unit after receiving the first data frame, the data frame reorganization unit determines the VLAN label corresponding to the data transmission priority of the first data frame, and determines the transmission mode label corresponding to the target network transmission mode, and acquires the reorganized data frame structure corresponding to the transmission mode label, fills the frame header field, the VLAN label, the transmission mode label, the application data of the first data frame and the check field into the frame header area, the first label area, the second label area, the data area and the check area in sequence, and obtains the reorganized data frames A1 and A2. The data exchange processing component transmits the reorganized data frame A1 to the switch network port controller one (MAC1) and transmits the reorganized data frame A2 to the switch network port controller two (MAC2) at the same time. The switch network port controller one (MAC1) transmits the reorganized data frame A1 to the network selection switch one (MUX1), and then transmits it to the physical layer interface one (PHY1) via the network selection switch one (MUX1) (i.e. Figure 5to the interface 1 1 of the heterogeneous network node four, the interface 1 1 of the heterogeneous network node five, and then to the interface 2 of the heterogeneous network node one. The MAC controller 2 transmits the recombined data frame A2 to the network selection switch 2 (MUX2), and then transmits the recombined data frame A2 to the physical layer interface 2 (PHY2) via the network selection switch 2 (MUX2) (i.e. Figure 5 to the interface 2 of the heterogeneous network node one. The MAC controller 2 transmits the recombined data frame A2 to the network selection switch 2 (MUX2), and then transmits the recombined data frame A2 to the physical layer interface 2 (PHY2) via the network selection switch 2 (MUX2) (i.e.

[0103] When the heterogeneous network node one transmits the recombined data frame Al to the interface 1 1 of the heterogeneous network node four via the physical layer interface 1 (PHY1), the heterogeneous network node one records the first source MAC address and the first sequence number of the recombined data frame Al. When the heterogeneous network node one receives the second data frame sent by the heterogeneous network node five, the heterogeneous network node one extracts the second source MAC address and the second sequence number of the second data frame, and then determines whether the first source MAC address is consistent with the second source MAC address and whether the first sequence number is consistent with the second sequence number. If the first source MAC address is consistent with the second source MAC address and the first sequence number is consistent with the second sequence number, it indicates that the second data frame and the first data frame are the same data frame, which is a loopback message. In this case, the transmission of the second data frame is terminated to avoid repeated transmission of the message in the loop network, causing resource occupation, and even causing a loop network storm.

[0104] If the second source MAC address of the second data frame is not consistent with the first source MAC address of the first data frame, and / or the second sequence number of the second data frame is not consistent with the first sequence number of the first data frame, it indicates that the second data frame and the first data frame are not the same data frame. In this case, the transmission of the second data frame is continued.

[0105] In some embodiments, the above method further comprises:

[0106] obtaining a third data frame sent by the hardware layer, and parsing the third data frame to obtain a parsing result;

[0107] If it is determined based on the parsing result that the third data frame is a non-loop network data frame, the third data frame is converted into a loop network data frame.

[0108] The loop network data frame is transmitted based on a data transmission strategy and a target network transmission mode.

[0109] The non-loop network data frame refers to a data frame from an external device, which does not belong to the network nodes in the currently constructed seamless loop network architecture.

[0110] As an example, please refer to Figure 1 , 2 , 6 and 8, assuming that the network topology architecture of the control system in which the heterogeneous network node one currently locates is a seamless ring network topology architecture, the target network transmission mode is a seamless ring network transmission mode, and the heterogeneous network node one can change the target network transmission mode to the seamless ring network transmission mode by configuring the software of the logical layer of the protocol stack of the software layer of the heterogeneous network node one to set the control register (CTL_REG). Figure 8 When the heterogeneous network node one receives a third data frame sent from an external device, the third data frame is parsed to obtain the transmission mode label of the second label area, i.e., the parsing result. If the transmission mode label is a non-seamless ring network label, it is determined that the third data frame is a non-ring network data frame, and the third data frame is converted into a ring network data frame. Specifically, the third data frame can be frame-recombined according to the recombined data frame structure shown in

[0111] In the seamless ring network architecture, all the heterogeneous network nodes are cascaded in a hand-in-hand manner. As the number of cascades increases, the transmission delay of the message in each node will increase. In order to minimize the network cascade delay, the rules of the seamless ring network transmission protocol of the embodiments of the present application are as follows: 1) the default forwarding mechanism is a straight-through forwarding. 2) the data of the ring network forwarding is de-duplicated, i.e., the loopback data is filtered / removed. 3) a special mark sequence number is used, which is accumulated once for each sent message in the logic.

[0112] In the seamless ring network transmission mode, the logic layer of the sending network node in the seamless ring network architecture first performs frame recombination on the to-be-transmitted data frame to insert a seamless ring network label (i.e., a transmission mode label) in the to-be-transmitted data frame, to obtain a recombined data frame, and then sends the recombined data frame from two directions at the same time. If the recombined data frame is a unicast message, a non-destination network node receives the recombined data frame from one port and forwards it to another port, and continues to transmit it to the next network node, until the recombined data frame is transmitted to the only destination network node. If the recombined data frame is a multicast message or needs to be transmitted to at least two destination network nodes, when the sending network node receives the recombined data frame again within a preset time (not more than the sequence number register value) (after checking the entire packet content, it is completely confirmed that it is the recombined data frame that has been sent before), the sending network node removes the recombined data frame and terminates the transmission of the recombined data frame, so as to avoid the recombined data frame repeatedly circulating in the seamless ring network architecture, causing resource occupation and consumption.

[0113] In some embodiments, in order to avoid network storm in the seamless ring network, the logical layer of each heterogeneous network node in the seamless ring network architecture records the data frame that has been forwarded when forwarding data, and stores the source MAC address, sequence number, index and complete message CRC32 check value of the data frame that has been forwarded into a message fingerprint database. When receiving a data frame, the source MAC address, sequence number, index and complete message CRC32 check value of the data frame are extracted, and it is queried whether there is a record with the same source MAC address, sequence number, index and complete message CRC32 check value in the message fingerprint database. If there is, the data frame is removed; if not, the data frame is continuously transmitted. The message storage structure of the message fingerprint database adopts a three-level storage structure: first level: source MAC address; second level: sequence number + index; third level: complete message CRC32 check value. The message storage depth of the message fingerprint database can be configured in the range of 1-10 records.

[0114] In some embodiments, if the target network transmission mode is the parallel redundant network transmission mode, the recombined data frame is transmitted according to the data transmission strategy.

[0115] As an example, please refer to Figure 1 , 2Assuming the network topology of the control system currently in which heterogeneous network node one resides is a parallel redundant network topology, then the target network transmission mode is the parallel redundant network transmission mode. The protocol stack software of heterogeneous network node one changes the target network transmission mode to the parallel redundant network transmission mode by configuring the software setting control register (CTL_REG) of the logic layer. The software layer of heterogeneous network node one copies the first data frame to be transmitted into two copies and simultaneously sends them to the parallel redundant network port controller one (MAC3) and the parallel redundant network port controller two (MAC4) of the logic layer. Parallel redundant network port controller one (MAC3) receives and determines the VLAN tag corresponding to the data transmission priority of the first data frame, as well as the transmission mode tag corresponding to the target network transmission mode. It then obtains the reassembled frame encapsulation structure corresponding to the transmission mode tag and sequentially fills the frame header field, VLAN tag, transmission mode tag, application data of the first data frame, and check field into the frame header area, first tag area, second tag area, data area, and check area to obtain reassembled data frame one. Similarly, Parallel Redundant Network Controller 2 (MAC4) reassembles the first data frame in the manner described above to obtain reassembled data frame 2. Parallel Redundant Network Controller 1 (MAC3) transmits reassembled data frame 1 to Network Selection Switch 1 (MUX1), then via Network Selection Switch 1 (MUX1) to Physical Layer Interface 1 (PHY1), then via Physical Layer Interface 1 (PHY1) to Heterogeneous Network Node 2, and then via Heterogeneous Network Node 2 to Heterogeneous Network Node 4 and Heterogeneous Network Node 5. Parallel Redundant Network Controller 2 (MAC4) transmits reassembled data frame 2 to Network Selection Switch 2 (MUX2), then via Network Selection Switch 2 (MUX2) to Physical Layer Interface 2 (PHY2), then via Physical Layer Interface 2 (PHY2) to Heterogeneous Network Node 3, and then via Heterogeneous Network Node 3 to Heterogeneous Network Node 4 and Heterogeneous Network Node 5.

[0116] When the software layer of heterogeneous network node one receives the data to be processed sent by the parallel redundant network port controller one (MAC3) and the parallel redundant network port controller two (MAC4) of the logic layer, the processor of the software layer can choose to perform calculations on the data to be processed sent by the parallel redundant network port controller one (MAC3) or the parallel redundant network port controller two (MAC4).

[0117] In some embodiments, after power-on, the logical layer of heterogeneous network nodes defaults to a silent, inactive network interface state. The protocol stack software can change the target network transmission mode by configuring the control register (CTL_REG), and the change takes effect immediately.

[0118] For example, the steps for switching the target network transmission mode are as follows:

[0119] 1) Initialization state: initialization: all ports remain silent after power on; configuration state: control mode selection: 000: silent mode (default); 001: seamless ring network transmission mode; 002: parallel redundant network transmission mode; 003: switch forwarding star network transmission mode.

[0120] 2) Mode switching process: ① Pre-check stage: check PHY link state; ② Silent transition stage: close all port MAC layer sending, empty Ethernet data FIFO buffer; ③ Target mode loading stage: seamless ring network transmission mode: load seamless ring network label processing engine; parallel redundant network transmission mode: initialize parallel receiving queue; switch forwarding star network transmission mode: initialize receiving queue.

[0121] 3) Exception handling mechanism: ① Rollback strategy: automatically restore the previous stable state after switching fails; ② Watchdog protection: trigger hardware reset within 500ms if switching is not completed.

[0122] All the optional technical solutions described above can be combined to form optional embodiments of the present application, which will not be described one by one here.

[0123] In summary, the technical solutions provided by the embodiments of the present application have at least the following beneficial effects:

[0124] 1) Support dynamic switching of redundant network transmission mode, seamless ring network transmission mode and switch forwarding star network transmission mode, use "parallel redundant over VLAN" and "seamless ring over VLAN" encapsulation technology to solve the problem of interconnection between heterogeneous networks in traditional technical solutions.

[0125] 2) Use FPGA technology to optimize logic resource reuse rate and implement mixed network traffic scheduling, use dynamic load balancing algorithm to automatically allocate traffic proportion of control data, configuration data and general network data according to network state, ensure deterministic and low latency transmission of control data, and meet high reliability requirements of industrial control scenarios.

[0126] 3) The logical layer of the heterogeneous network node is provided with a data exchange processing component, which can realize efficient data packet processing and accurate time synchronization.

[0127] 4) The logical layer of the heterogeneous network node is provided with a software setting control register (CTL_REG), which can be flexibly configured through the software setting control register (CTL_REG) Data flow and exchange logic can adapt to the data transmission requirements of diversified application scenarios.

[0128] 5) By integrating data exchange processing, data packet processing, and time synchronization functions in the logical layer of the heterogeneous network node, the need for external components can be reduced, system design can be simplified, cost and complexity can be reduced, and system flexibility can be improved.

[0129] 6) By cooperation between the logical layer and the hardware layer of the heterogeneous network node, high-performance and low-latency data transmission can be achieved.

[0130] 7) The AXI interface is supported, different hardware platforms can be seamlessly integrated, and thus the flexibility and scalability of the hybrid networking can be improved.

[0131] Figure 9 is a system structure schematic diagram of an industrial control system provided by an embodiment of the present application. Please refer to Figure 9 , the industrial control system comprises one master heterogeneous network node, and slave heterogeneous network nodes 1 to N (which can be switches 1 to N) in communication connection with the master heterogeneous network node, and first to M-th slave heterogeneous network nodes (such as I / O modules 1 to M) in communication connection with the slave heterogeneous network nodes 1 to N, which constitute a parallel redundancy network architecture as a whole. The network structure of the master heterogeneous network node, the slave heterogeneous network nodes 1 to N, and the first to M-th slave heterogeneous network nodes is shown in Figure 2 .

[0132] Figure 10 is a system structure schematic diagram of an industrial control system provided by another embodiment of the present application. Please refer to Figure 10 , the industrial control system comprises one master heterogeneous network node, and first to M-th slave heterogeneous network nodes; wherein the master heterogeneous network node is in communication connection with the first to M-th slave heterogeneous network nodes respectively, and adjacent slave heterogeneous network nodes are in communication connection, which constitute a seamless ring network architecture as a whole. The network structure of the master heterogeneous network node, the first to M-th slave heterogeneous network nodes is shown in Figure 2 .

[0133] Figure 11 is a system structure schematic diagram of an industrial control system provided by still another embodiment of the present application. Please refer to Figure 11 , the industrial control system comprises one master heterogeneous network node, and first to M-th slave heterogeneous network nodes; wherein the master heterogeneous network node is in communication connection with the first slave heterogeneous network node, and adjacent slave heterogeneous network nodes are in communication connection, which constitute a switching forwarding star network architecture as a whole. The network structure of the master heterogeneous network node, the first to M-th slave heterogeneous network nodes is shown in Figure 2 .

[0134] The following are embodiments of the apparatus described in this application, which can be used to execute the embodiments of the method described in this application. For details not disclosed in the apparatus embodiments of this application, please refer to the embodiments of the method described in this application.

[0135] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0136] Figure 12 This is a schematic diagram of the electronic device 1200 provided in an embodiment of this application. For example... Figure 12 As shown, the electronic device 1200 of this embodiment includes: a processor 1201, a memory 1202, and a computer program 1203 stored in the memory 1202 and executable on the processor 1201. When the processor 1201 executes the computer program 1203, it implements the steps in the various method embodiments described above. Alternatively, when the processor 1201 executes the computer program 1203, it implements the functions of each module / unit in the various device embodiments described above.

[0137] Electronic device 1200 may be a desktop computer, laptop, handheld computer, cloud server, or other electronic device. Electronic device 1200 may include, but is not limited to, a processor 1201 and a memory 1202. Those skilled in the art will understand that... Figure 12 This is merely an example of electronic device 1200 and does not constitute a limitation on electronic device 1200. It may include more or fewer components than shown, or different components.

[0138] The processor 1201 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0139] The memory 1202 can be an internal storage unit of the electronic device 1200, for example, a hard disk or a memory of the electronic device 1200. The memory 1202 can also be an external storage device of the electronic device 1200, for example, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, or the like equipped on the electronic device 1200. The memory 1202 can also include both the internal storage unit and the external storage device of the electronic device 1200. The memory 1202 is used to store computer programs and other programs and data required by the electronic device.

[0140] It should be clearly understood by those skilled in the art that, for the convenience and brevity of description, only the above division of functional units and modules is exemplified, and in actual application, the above functions can be completed by different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0141] If the integrated module / unit is realized in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, all or part of the processes in the above-mentioned embodiment methods can also be instructed by a computer program to related hardware to complete, and the computer program can be stored in a readable storage medium. When the processor executes the computer program, the steps of each method embodiment described above can be implemented. The computer program can include computer program code, which can be in the form of source code, object code, executable files, or some intermediate forms, etc. The computer readable medium can include any entity or device capable of carrying computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc. It should be noted that the content included in the computer readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction, for example, in some jurisdictions, according to legislation and patent practice, the computer readable medium does not include electrical carrier signals and electrical signals.

[0142] The above examples are only used to illustrate the technical solutions of the present application, but not limit the same; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalent ones; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A data transmission method, characterized in that, A logical layer applied to heterogeneous network nodes, wherein the heterogeneous network nodes further include a software layer and a hardware layer, wherein the software layer is communicatively connected to the logical layer, and the logical layer is communicatively connected to the hardware layer; the method includes the following steps: Acquire the first data frame and determine the data transmission priority and data transmission strategy of the first data frame; Determine the target network transmission mode; Based on the data transmission priority and the target network transmission mode, the first data frame is reassembled to obtain a reassembled data frame. The reconstructed data frame is transmitted based on the data transmission strategy and the target network transmission mode.

2. The data transmission method according to claim 1, characterized in that, Determining the data transmission priority and data transmission strategy of the first data frame includes: Based on the data category and data transmission requirements of the first data frame, the data transmission priority of the first data frame is determined; If the data transmission priority is the highest priority, then the data transmission strategy is direct path transmission; If the data transmission priority is high priority, then the data transmission strategy is to exclusively use bandwidth for transmission when the queue is not empty; If the data transmission priority is medium priority, then the data transmission strategy is transmission without quality of service guarantee; If the data transmission priority is the lowest priority, then the data transmission strategy is to allocate the remaining bandwidth for transmission.

3. The data transmission method according to claim 1, characterized in that, Determine the target network transmission mode, including: Determine the network topology of the control system in which the heterogeneous network nodes are currently located; If the network topology is a parallel redundant network topology, then the target network transmission mode is determined to be a parallel redundant network transmission mode. If the network topology is a seamless ring network topology, then the target network transmission mode is determined to be a seamless ring network transmission mode. If the network topology is a switching-forwarding star network topology, then the target network transmission mode is determined to be a switching-forwarding star network transmission mode.

4. The data transmission method according to claim 1, characterized in that, Based on the data transmission priority and the target network transmission mode, the first data frame is reassembled to obtain a reassembled data frame, including: Determine the VLAN tag corresponding to the data transmission priority, and the transmission mode tag corresponding to the target network transmission mode; Based on the VLAN tag and transmission mode tag, the first data frame is reassembled to obtain a reassembled data frame.

5. The data transmission method according to claim 4, characterized in that, Based on the VLAN tag and transmission mode tag, the first data frame is reassembled to obtain a reassembled data frame, including: Obtain the reassembled frame encapsulation structure corresponding to the transmission mode label. The reassembled frame encapsulation structure includes a frame header area, a first label area, a second label area, a data area, and a check area. The frame header field, VLAN tag, transmission mode tag, application data of the first data frame, and check field are sequentially filled into the frame header area, first tag area, second tag area, data area, and check area to obtain the reassembled data frame.

6. The data transmission method according to claim 1, characterized in that, Based on the data transmission strategy and the target network transmission mode, the reconstructed data frame is transmitted, including: If the target network transmission mode is a seamless ring network transmission mode, the reconstructed data frame is transmitted according to the data transmission strategy, and the first source MAC address and the first sequence number of the reconstructed data frame are recorded. Acquire the second data frame, and extract the second source MAC address and the second sequence number of the second data frame; If the first source MAC address is the same as the second source MAC address, and the first sequence number is the same as the second sequence number, then the transmission of the second data frame is terminated. If the first source MAC address is inconsistent with the second source MAC address, and / or the first sequence number is inconsistent with the second sequence number, then the transmission of the second data frame continues.

7. The data transmission method according to claim 1, characterized in that, The method further includes: Obtain the third data frame sent by the hardware layer, parse the third data frame, and obtain the parsing result; If the third data frame is determined to be a non-ring network data frame based on the parsing result, then the third data frame is converted into a ring network data frame; Based on the data transmission strategy and the target network transmission mode, the ring network data frames are transmitted.

8. A heterogeneous network node, characterized in that, include: The system comprises a software layer, a logic layer, and a hardware layer, wherein the software layer is communicatively connected to the logic layer, and the logic layer is communicatively connected to the hardware layer. The logic layer is configured to implement the steps of the method as described in any one of claims 1 to 7.

9. The heterogeneous network node according to claim 8, characterized in that, The software layer includes a processor; the hardware layer includes at least two physical layer interfaces; the logic layer includes: a software setting control register, a data exchange processing component, at least two parallel redundant network port controllers, at least two switching network port controllers, and at least two network selection switches. The software setting control register is communicatively connected to the processor; the data exchange processing component is communicatively connected to the processor; each of the parallel redundant network port controllers is communicatively connected to the processor; each of the switching network port controllers is communicatively connected to the switching processing component; and a network selection switch is communicatively connected to one switching network port controller, one parallel redundant network port controller, and one physical layer interface.

10. An industrial control system, characterized in that, include: A primary heterogeneous network node, and at least one secondary heterogeneous network node communicatively connected to the primary heterogeneous network node; The network structures of the master heterogeneous network node and each of the slave heterogeneous network nodes are the same as the network structure of the heterogeneous network node in claim 8.

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