Data transmission system

Abstract

Embodiments of the present disclosure relate to a data transmission system, which includes: a first ring network including a plurality of first EPA switches; a second ring network including a plurality of second EPA switches; a plurality of first terminal devices communicatively connected to a first target switch among the plurality of first EPA switches and a second target switch among the plurality of second EPA switches; and a plurality of second terminal devices communicatively connected to a third target switch among the plurality of first EPA switches and a fourth target switch among the plurality of second EPA switches; the first target switch is different from the third target switch, and the second target switch is different from the fourth target switch. This data transmission system can ensure the stability of EPA network data transmission.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to the field of detection of control systems, and more particularly to a data transmission system for a control system. Background Art

[0002] EPA star networks rely on switches for data forwarding. A switch failure can paralyze the entire network, leading to drawbacks and instability. Furthermore, during implementation, all nodes in a star network must be connected to a switch, resulting in longer cabling lengths. Summary of the Invention

[0003] In response to the above problems, the present disclosure provides a data transmission system that can ensure the stability of EPA network data transmission.

[0004] According to one aspect of the present disclosure, a data transmission system is provided. The data transmission system includes: a first ring network including a plurality of first EPA switches; a second ring network including a plurality of second EPA switches; a first star network including a plurality of first terminal devices, the plurality of first terminal devices being communicatively connected to a first target switch among the plurality of first EPA switches and a second target switch among the plurality of second EPA switches; and a second star network including a plurality of second terminal devices, the plurality of second terminal devices being communicatively connected to a third target switch among the plurality of first EPA switches and a fourth target switch among the plurality of second EPA switches; the first target switch and the third target switch being different, and the second target switch and the fourth target switch being different.

[0005] In some embodiments, the first target switch includes: a ring network processing unit configured to copy the parsed first received message into two copies, so as to transmit the two copied messages to two first EPA switches adjacent to the first target switch in the first ring network, respectively, where the first received message comes from at least one terminal device among the plurality of first terminal devices.

[0006] In some embodiments, the first target switch further includes: a data feature information cache unit, which is communicatively connected to the ring network processing unit and configured to store data feature information of the first received message to form a forwarding list; the ring network processing unit is further configured to: query the forwarding list to determine whether the data feature information of the message from the two first EPA switches belongs to the forwarding list, and in response to determining that the data feature information belongs to the forwarding list, not send the message to the two first EPA switches.

[0007] In some embodiments, the ring network processing unit is further configured to: determine a first transmission message according to two messages respectively from two first EPA switches adjacent to the first target switch in the first ring network, so as to transmit the first transmission message to at least one of a plurality of first terminal devices.

[0008] In some embodiments, the ring network processing unit is further configured to: in response to determining that the time interval between the two messages is less than a predetermined interval threshold and the message sequence numbers corresponding to the two messages are the same, determine any one of the two messages as the first transmission message.

[0009] In some embodiments, the first target switch further includes: a star network processing unit, communicatively connected to the ring network processing unit, and configured to receive a first received message and parse the first received message to obtain the parsed first received message and transmit it to the ring network processing unit, and transmit the first transmission message from the ring network processing unit to at least one of a plurality of first terminal devices.

[0010] In some embodiments, the first target switch further includes: an EPA switching module, communicatively connected to the star network processing unit and a first terminal device of the EPA terminal type, and configured to transmit a first received message from the first terminal device of the EPA terminal type to the star network processing unit, and transmit the first transmission message from the star network processing unit to the first terminal device of the EPA terminal type.

[0011] In some embodiments, the first target switch further includes: an Ethernet data processing module, communicatively connected to an EPA protocol stack and a first terminal device of the general Ethernet terminal type, and configured to store general Ethernet data from the first terminal device of the general Ethernet terminal type and deliver the general Ethernet data to the EPA protocol stack when not periodic, and receive general Ethernet data from the EPA protocol stack and transmit it to the first terminal device of the general Ethernet terminal type; and an EPA protocol stack, communicatively connected to the EPA switching module, and configured to convert general Ethernet data into EPA aperiodic data to transmit the converted EPA aperiodic data to the EPA switching module, and convert EPA aperiodic data from the EPA switching module into general Ethernet data to transmit the converted general Ethernet data to the Ethernet data processing module.

[0012] In some embodiments, the star network processing unit is further configured to perform a check on the first received message, and extract a media access control address and an Internet protocol address from the first received message.

[0013] In some embodiments, at least one of the first ring network and the second ring network is a dual-ring network.

[0014] In this data transmission system, two ring networks (the first ring network and the second ring network) are formed based on EPA switches, and a first star network is constructed for multiple first terminal devices based on a first target switch in the first ring network and a second target switch in the second ring network. A second star network is constructed for multiple second terminal devices based on a third target switch in the first ring network and a fourth target switch in the second ring network, thereby forming a network topology combining a ring network and a star network, effectively improving the stability of the network.

[0015] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present disclosure, nor is it used to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In combination with the accompanying drawings and with reference to the following detailed description, the above and other features, advantages, and aspects of the embodiments of the present disclosure will become more apparent. In the drawings, the same or similar reference numerals denote the same or similar elements.

[0017] Figure 1 FIG. 1 shows the topological structure of an EPA network in the prior art.

[0018] Figure 2 FIG. 2 shows a schematic diagram of the topological structure of the data transmission system according to the embodiment of the present disclosure.

[0019] Figure 3 FIG. 3 shows a schematic diagram of the topological structure of the data transmission system according to the embodiment of the present disclosure.

[0020] Figure 4 FIG. 4 shows a block diagram of the star-ring conversion module according to the embodiment of the present disclosure.

[0021] Figure 5 FIG. 5 shows a schematic diagram of the topological structure of the data transmission system according to the embodiment of the present disclosure. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The following describes exemplary embodiments of the present disclosure in conjunction with the accompanying drawings. Various details of the embodiments of the present disclosure are included to assist in understanding, and they should be considered merely exemplary. Therefore, those of ordinary skill in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present disclosure. Similarly, for the sake of clarity and conciseness, descriptions of well-known functions and structures are omitted in the following description.

[0023] As used herein, the term "comprising" and its variations mean open-ended inclusion, i.e., "including but not limited to". Unless otherwise specified, the term "or" means "and / or". The term "based on" means "at least partially based on". The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "first", "second", etc. may refer to different or the same objects. The terms "connected", "communicatively connected" may be direct connections or may be indirect connections via other devices, modules. There may also be other explicit and implicit definitions hereinafter.

[0024] As described above, the current EPA network has the problem of insufficient stability. For example, the current EPA network adopts a topological structure based on a ring network composed of multiple EPA terminals. Figure 1 FIG. shows the topological structure of an EPA network 100 in the prior art, in which multiple EPA terminals (such as including terminal 1, terminal 2, terminal 3, terminal 4, terminal 5, terminal 6, terminal 7, terminal 8) are connected in sequence to form a ring structure. In the EPA network 100, if two of the EPA terminals (such as terminal 1 and terminal 5) fail, it will cause the other EPA terminals (such as terminal 2 and terminal 6) in the EPA network to be unable to communicate, thus making the entire network unavailable. There are also other topological structures in the current EPA network, but there are also problems that when the terminals or switches in them fail, it is easy to cause the entire network to collapse and all terminals to be unable to communicate with each other, resulting in insufficient network stability.

[0025] To at least partially solve one or more of the above problems and other potential problems, the example embodiments of the present disclosure propose a data transmission system. In this data transmission system, two ring networks (a first ring network and a second ring network) are formed based on EPA switches, and multiple first terminal devices are used to construct a first star network based on a first target switch in the first ring network and a second target switch in the second ring network, and multiple second terminal devices are used to construct a second star network based on a third target switch in the first ring network and a fourth target switch in the second ring network, thereby forming a network topological structure combining a ring network and a star network, effectively improving the stability of the network.

[0026] Figure 2The schematic diagram of the topological structure of the data transmission system 200 according to an embodiment of the present disclosure is shown. The data transmission system includes: a first ring network, a second ring network, a plurality of first terminal devices, and a plurality of second terminal devices. The first ring network includes a plurality of first EPA switches; the second ring network includes a plurality of second EPA switches. The plurality of first terminal devices are communicatively connected to a first target switch among the plurality of first EPA switches and a second target switch among the plurality of second EPA switches; the plurality of second terminal devices are communicatively connected to a third target switch among the plurality of first EPA switches and a fourth target switch among the plurality of second EPA switches; the first target switch is different from the third target switch, and the second target switch is different from the fourth target switch. In this embodiment, both the first ring network 201 and the second ring network 202 are single-ring networks.

[0027] For example, the data transmission system 200 includes a first ring network 201, a second ring network 202, a first group of terminal devices 203, and a second group of terminal devices 204. Among them, the first ring network 201 is formed by sequentially connecting a plurality of first EPA switches. It should be understood that the connection here can be a wired connection or a wireless connection. The plurality of first EPA switches include, for example, switches SWA1, SWA2... switches SWAn, where n is a positive integer greater than or equal to 2.

[0028] The second ring network 201 is formed by sequentially connecting a plurality of second EPA switches. The plurality of second EPA switches include, for example, switches SWB1, SWB2... switches SWBn. The number of second EPA switches included in the second ring network 202 may be the same as or different from the number of first EPA switches included in the first ring network 201.

[0029] The first group of terminal devices 203 includes multiple first terminal devices (such as terminal device D1, terminal device D2, terminal device D3, terminal device D4). Multiple first terminal devices in the first group of terminal devices 203 are all communicatively connected to the same first target switch among multiple first EPA switches in the first ring network 201, forming a star network with the first target switch as the central device. For example, multiple first terminal devices (such as terminal device D1, terminal device D2, terminal device D3, terminal device D4) in the first group of terminal devices 203 are all communicatively connected to the same first target switch (such as switch SWA1) among multiple first EPA switches in the first ring network 201. Moreover, multiple first terminal devices in the first group of terminal devices 203 are also all communicatively connected to the same second target switch among multiple second EPA switches in the second ring network 202, forming a star network with the second target switch as the central device. For example, multiple first terminal devices (such as terminal device D1, terminal device D2, terminal device D3, terminal device D4) in the first group of terminal devices 203 are all communicatively connected to the same second target switch (such as switch SWB1) among multiple second EPA switches in the second ring network 202. Therefore, multiple first terminal devices in the first group of terminal devices 203 form a double-star network based on the first target switch and the second target switch. Terminal device D1, terminal device D2, terminal device D3, and terminal device D4 all include a first port A and a second port B. Among them, the first port A is communicatively connected to switch SWA1 serving as the first target switch, and the second port B is communicatively connected to switch SWB1 serving as the second target switch.

[0030] The second group of terminal devices 204 includes multiple second terminal devices (such as terminal device D5, terminal device D6, terminal device D7... terminal device Dn). Multiple second terminal devices in the second group of terminal devices 204 are all communicatively connected to the same third target switch among multiple first EPA switches in the first ring network 201, forming a star network with this third target switch as the central device. For example, multiple second terminal devices (such as terminal device D5, terminal device D6, terminal device D7... terminal device Dn) in the second group of terminal devices 204 are all communicatively connected to the same third target switch (such as switch SWA2) among multiple first EPA switches in the first ring network 201 through the first port A. Moreover, multiple second terminal devices in the second group of terminal devices 203 are also all communicatively connected to the same fourth target switch among multiple second EPA switches in the second ring network 202, forming a star network with this fourth target switch as the central device. For example, multiple second terminal devices (such as terminal device D5, terminal device D6, terminal device D7... terminal device Dn) in the second group of terminal devices 204 are all communicatively connected to the same fourth target switch (such as switch SWB2) among multiple second EPA switches in the second ring network 202 through the second port B. Therefore, multiple second terminal devices in the second group of terminal devices 204 form a double-star network based on the third target switch and the fourth target switch.

[0031] It should be understood that the first target switch is different from the third target switch, and the second target switch is different from the fourth target switch.

[0032] In some embodiments, in the data transmission system 200, there are also other groups of terminal devices (such as the third group of terminal devices, etc.). The third group of terminal devices can form a double-star network based on EPA switch SWAn and EPA switch SWBn, for example.

[0033] In the data transmission system 200, two independent ring networks are formed by two groups of switches. Each group of terminal devices in two groups or multiple groups of terminal devices forms a star network with the same switch in one of the two independent ring networks as the central device. Moreover, each group of terminal devices in two groups or multiple groups of terminal devices also forms a star network with the same switch in the other ring network of the two independent ring networks as the central device, thus forming a double-star network.

[0034] Therefore, in the data transmission system 200, the normal operation of other terminal nodes will not be affected by the failure of any single terminal; the normal operation of the network can still be guaranteed even if a single switch in the data transmission system 200 fails; the normal operation of the network is not affected even if a single switch ring network in the data transmission system 200 fails. Additionally, even if both switches connecting the same terminal device in the data transmission system 200 fail, it will only affect the data communication between the terminal devices connected to these switches, and will not cause a total failure of the entire network (i.e., the data transmission system 200).

[0035] In addition, it should be noted that in the data transmission system 200, the terminal device is connected to two groups of EPA switches through a double-star network topology, and two independent ring networks are formed between the two groups of switches. Therefore, all terminal nodes only need to be connected to the two adjacent switches, and then the switches are cascaded to form a ring network, which reduces the wiring length.

[0036] Figure 3 The schematic diagram of the topology structure of the data transmission system according to the embodiments of the present disclosure is shown. In some embodiments, the first EPA switch (such as switch SWA1, switch SWA2) and the second EPA switch (such as switch SWB1, switch SWB2) serving as the target switches include a star-ring conversion module 211 and an EPA switching module 212. In some embodiments, the first EPA switch and the second EPA switch further include an EPA protocol stack 213 and an Ethernet data processing module 214. The star-ring conversion module 211 is communicatively connected to the EPA switching module 212. The EPA switching module 212 is communicatively connected to the EPA protocol stack 213, and the EPA switching module 212 is also communicatively connected to a plurality of EPA nodes 215. The EPA node 215 is, for example, a first terminal device of the EPA terminal type and can send and receive EPA messages. The EPA protocol stack 213 is communicatively connected to the Ethernet data processing module 214. The Ethernet data processing module 214 is communicatively connected to an Ethernet node 216. The Ethernet node 216 is, for example, a first terminal device of the Ethernet terminal type and can transmit messages conforming to the Ethernet protocol. It should be understood that the message formats of the messages conforming to the Ethernet protocol and the EPA messages are different. To achieve data transmission between Ethernet devices (including terminals and switches) and EPA devices (including terminals and switches), it is necessary to convert between the message formats of the messages conforming to the Ethernet protocol and the EPA messages.

[0037] It should be understood that the main functions of the Ethernet data processing module 214 involve processing the data flow from the switch to the protocol stack, storing the ordinary Ethernet data from the switch, and delivering the data to the EPA protocol stack at non-periodic times. The EPA protocol stack packs and encapsulates it into EPA non-periodic data and sends it to the EPA system network. It also processes the data flow from the protocol stack to the switch, receives the non-periodic data from the EPA protocol stack, and sends it to the switch.

[0038] Regarding the EPA switching module 212, it is communicatively connected to the star network processing unit 211 and the EPA node 215 (such as the first terminal device of the EPA terminal type). The EPA switching module 212 is configured to transmit the received message regarding the terminal device from the first terminal device of the EPA terminal type to the star network processing unit, and transmit the transmitted message regarding the terminal device from the star network processing unit to the first terminal device of the EPA terminal type.

[0039] It should be understood that the EPA switching module 212 is used to externally connect multiple EPA node devices, perform one-to-many data forwarding, and realize data interaction between the EPA node and the EPA protocol stack unit.

[0040] Specifically, the first terminal device of the EPA terminal type, which is the EPA node 215, sends an EPA message to the EPA switching module 212, and this EPA message is regarded as the received message regarding the terminal device. The EPA switching module 212 transmits the received message regarding the terminal device to the star network processing unit 2111 of the star-ring conversion module 211. The EPA switching module 212 also receives the transmitted message regarding the terminal device from the star network processing unit 2113 of the star-ring conversion module 211 and sends this transmitted message to the corresponding target EPA node (such as the first terminal device of the EPA terminal type).

[0041] Regarding the star-ring conversion module 211, it is used to implement the conversion between the star network side and the ring network side in order to achieve data transmission. Figure 4 The block diagram of the star-ring conversion module according to the embodiment of the present disclosure is shown. The star-ring conversion module 211 includes, for example, a star network processing unit 2111, a data feature information caching unit 2112, and a ring network processing unit 2113.

[0042] Among them, the star network processing unit 2111 is communicatively connected to the EPA switching module 212 and the ring network processing unit 2113. The star network processing unit 2111 is configured to receive and parse the received message regarding the terminal device, so as to obtain the parsed received message regarding the terminal device. The star network processing unit 2111 also sends the transmitted message regarding the terminal device from the ring network processing unit 2113, for example, sends it to the EPA switching module 212.

[0043] For example, the first target switch includes a ring network processing unit 2113, and the ring network processing unit 2113 is configured to copy the parsed first received message into two copies, so as to respectively transmit the two copied messages to two first EPA switches adjacent to the first target switch in the first ring network. The first received message comes from at least one terminal device among a plurality of first terminal devices. It should be understood that the first received message is a message from a terminal device communicatively connected to the first target switch.

[0044] For example, the ring network processing unit 2113 is further configured to: use at least one of the two messages respectively from the two first EPA switches as the first transmitted message, so as to send it to at least one terminal device among a plurality of first terminal devices. It should be understood that the first transmitted message is a message sent by the first EPA switch to a terminal device communicatively connected to the first EPA switch.

[0045] For example, the ring network processing unit 2113 is further configured to: in response to determining that the time interval between the two messages is less than a predetermined interval threshold and the message sequence numbers corresponding to the two messages are the same, use one of the two messages as the first transmitted message. It should be understood that the predetermined interval threshold can be reasonably set according to the specific application scenario. The ring network processing unit 2113 receives two messages from two first EPA switches adjacent to the first target switch in the first ring network 201, determines the time interval between the two messages. If the time interval is less than the predetermined interval threshold and the message sequence numbers corresponding to the two messages are the same, then the ring network processing unit 2113 can determine that the two messages are actually the same. The ring network processing unit 2113 performs redundancy processing, selects any one of the messages as the first transmitted message, so as to send it to at least one terminal device among a plurality of first terminal devices via the star network processing unit 2111.

[0046] Specifically, the star network processing unit 2111 is provided with a sending channel and a receiving channel. The star network processing unit 2111 receives a received message (i.e., a received message about the terminal device) from the EPA switching module 212 based on the receiving channel. Then, the star network processing unit 2111 verifies the received message about the terminal device. If the verification fails, the star network processing unit 2111 discards the received message. If the verification is successful, the star network processing unit 2111 parses the received message about the terminal device to extract information such as the media access control address (MAC address) and the Internet protocol address (IP address) from the received message about the terminal device. The star network processing unit 2111 transmits the parsed received message about the terminal device to the ring network processing unit 2113. Based on the sending channel, the star network processing unit 2111 sends the sending message about the terminal device from the ring network processing unit 2113 to the EPA switching module 212.

[0047] Regarding the ring network processing unit 2113, it is configured to copy the parsed received message about the terminal device into two copies, so as to respectively transmit the two parsed received messages about the terminal device to two first EPA switches adjacent to the first target switch in the first ring network.

[0048] For example, the first target switch further includes a data feature information caching unit 2112. The data feature information caching unit 2112 is communicatively connected to the ring network processing unit 2113 and is configured to store the data feature information of the first received message already sent by the ring network processing unit 2113 to form a forwarding list. The ring network processing unit is further configured to: query the forwarding list to determine whether the data feature information of the messages from the two first EPA switches belongs to the forwarding list, and in response to determining that the data feature information belongs to the forwarding list, not send the messages to the two first EPA switches.

[0049] For example, the ring network processing unit 2113 receives a first received message from the star network processing unit 2111 for forwarding to the first EPA switch in the first ring network 201. Among them, the first received message is a message received by the star network processing unit 2111 from at least one of a plurality of first terminal devices. The data feature information caching unit 2112 is used to store the data feature information of the first received message received by the ring network processing unit 2113 from the star network processing unit 2111. That is, the data feature information caching unit 2112 is used to store the data feature information of the first received message forwarded by the ring network processing unit 2113 to the first ring network 201. The data feature information includes, for example, information such as the MAC address and IP address of the first terminal device. The data feature information is obtained by parsing the first received message.

[0050] It should be understood that the EPA switch in the ring network forwards message data to the EPA switch adjacent to it. When the first target switch receives the message data forwarded by the EPA switch adjacent to it, the ring network processing unit 2113 queries the forwarding list to determine whether the data feature information of the message from the two first EPA switches adjacent to the first target switch belongs to the forwarding list. If the data feature information of the message belongs to the forwarding list, the ring network processing unit 2113 determines that the message is a message forwarded to the first ring network 201 via the first target switch. After being forwarded by the first switch in the first ring network 201, it returns to the first target switch again. Therefore, the ring network processing unit 2113 performs forwarding suppression and no longer forwards the message.

[0051] In some embodiments, the first target switch further includes a star network processing unit 2111. The star network processing unit 2111 is communicatively connected to the ring network processing unit 2113 and is configured to receive the first received message and parse the first received message to obtain the parsed first received message, and transmit the first transmitted message from the ring network processing unit 2113.

[0052] In some embodiments, the first target switch further includes an EPA switching module. The EPA switching module is communicatively connected to the star network processing unit and the first terminal device of the EPA terminal type and is configured to transmit the first received message from the first terminal device of the EPA terminal type to the star network processing unit, and transmit the first transmitted message from the star network processing unit to the first terminal device of the EPA terminal type.

[0053] In some embodiments, the first target switch further includes an Ethernet data processing module and an EPA protocol stack. The Ethernet data processing module is communicatively connected to the EPA protocol stack and a first terminal device of the general Ethernet terminal type, and is configured to store general Ethernet data from the first terminal device of the general Ethernet terminal type, deliver the general Ethernet data to the EPA protocol stack in non-periodic times, and receive general Ethernet data from the EPA protocol stack and send it to the first terminal device of the general Ethernet terminal type. The EPA protocol stack is communicatively connected to the EPA switching module, and is configured to convert the general Ethernet data into EPA non-periodic data for transmitting the converted EPA non-periodic data to the EPA switching module, and convert the EPA non-periodic data from the EPA switching module into general Ethernet data for transmitting the converted general Ethernet data to the Ethernet data processing module.

[0054] In some embodiments, the star network processing unit is further configured to verify a first received message, and extract a media access control address and an Internet protocol address from the first received message.

[0055] Figure 5 The schematic diagram of the topological structure of the data transmission system according to the embodiments of the present disclosure is shown. In some embodiments, at least one of the first ring network 201 and the second ring network 202 is a dual-ring network. For example, in some embodiments, one of the first ring network 201 and the second ring network 202 is a dual-ring network, and the other is a single-ring network. In some embodiments, both the first ring network 201 and the second ring network 202 are dual-ring networks.

[0056] Specifically, regarding the ring network, the ring network processing unit 2113 has two interfaces for communicatively connecting with the ring network processing units 2113 of other EPA switches (i.e., two first EPA switches adjacent to the current first target switch in the first ring network) that form the ring network. For example, the ring network processing unit 2113 in the EPA switch SWA1 is communicatively connected to one of the interfaces of the ring network processing unit 2113 in the EPA switch SWA2 through one of the two interfaces, and the ring network processing unit 2113 in the EPA switch SWA1 is communicatively connected to one of the interfaces of the ring network processing unit 2113 in the EPA switch SWAn (assuming the EPA switch SWAn is adjacent to the EPA switch SWA1) through the other of the two interfaces.

[0057] The ring network processing unit 2113 is responsible for forwarding packets of the ring network and the sending and receiving functions of local packets. The ring network processing unit 2113 receives the parsed received packets regarding the terminal devices from the star network processing unit 2111, and copies the parsed received packets regarding the terminal devices into two copies, which are distributed to the two interfaces required by the ring network.

[0058] It should be understood that in the data transmission system 200, the EPA terminals are connected to two groups of EPA switches through a double-star network topology, and at the same time, two independent ring network connections are formed between the two groups of switches. All terminal nodes only need to be connected to the two adjacent switches and then cascade the switches, which reduces the wiring length.

[0059] In the data transmission system 200, the terminal device can be an EPA type terminal (which can send and receive EPA packets), or a common Ethernet terminal (which sends and receives packets of the common Ethernet protocol). It can not only realize the mutual communication between EPA and EPA devices, and between EPA and common Ethernet devices, but also realize the mutual communication between common Ethernet devices across switches.

[0060] In some embodiments, important devices can also be backed up to achieve device redundancy. When one device fails, it can be switched to another device with the same function for backup.

[0061] In some embodiments, the EPA protocol stack includes a clock competition module, a clock synchronization module, a real-time data processing module, a non-real-time data processing module, a data redundancy module, etc.

[0062] It should be understood that the star network processing unit 2111 is mainly responsible for processing star network data, which can be divided into a sending channel and a receiving channel. When the receiving channel processes the received packet, it first performs a check. If the check is correct, it extracts information such as the packet MAC and IP. The sending channel sends the data output by the ring network processing unit 2113 to the EPA switching module 212.

[0063] The data feature information cache unit 2112 is mainly responsible for collecting and storing the data feature information output by the star network, and for the ring network engine to query whether the feature information of the forwarded packet is in the storage table during ring network forwarding. If it exists, it means that the packet is sent by the device connected locally and forwarding suppression should be performed. If it does not exist, the packet is received and forwarded.

[0064] The ring network processing unit 2113 is responsible for the forwarding of ring network packets and the sending and receiving functions of local packets. It copies the star network data into two copies and distributes them to the two interfaces required by the ring network. At the same time, it receives the two-way data of the ring network, performs redundancy simultaneously, and selects one way to output to the star network processing unit 2111.

[0065] It should be understood that the second target switch, the third target switch, and the fourth target switch are similar to the first target switch, and thus will not be elaborated herein.

[0066] It is worth noting that for the nodes forming a star network based on the first target switch, the mutual forwarding communication of data is realized through the star network processing unit 2111 inside the first target switch. At the same time, the data sent by the star network nodes will be sent to the ring network ports of other first EPA switches through the ring network ports of the first target switch. After the received data is redundantly processed by the first EPA switch, it is sent to other star network EPA nodes connected to the first EPA switch, thereby realizing the mutual communication between the EPA nodes.

[0067] For ordinary Ethernet nodes, the first target switch places the packets of the Ethernet devices connected to the switch in the non-real-time data segment of the EPA packet for sending. The data passes through the two ring network ports of the first target switch and the same data is sent out from the two ports. After the other first EPA switches receive the packets and perform redundant processing, the data is sent to the Ethernet devices, thereby realizing the mutual communication between the Ethernet devices.

[0068] The ring networks are connected in a single-ring or double-ring manner, and the data transmitted in the ring networks is mutually redundant, so that a line fault will not affect the normal operation of the entire network.

[0069] At the same time, the two groups of switches are independent of each other. Both the EPA nodes and the ordinary Ethernet nodes are connected to the two groups of EPA switches through two channels. Through the internal redundant processing mechanism, link redundancy is realized to ensure that link faults do not affect the normal operation of the devices.

[0070] It is worth noting that in the data transmission system 200 of the present disclosure, redundancy is increased, and the possible failure risks of a single ring network and a single star network are reduced. Moreover, at the same time, the communication between EPA devices and ordinary Ethernet devices is realized through the EPA switch. Further, the wiring difficulty in the engineering implementation process is reduced.

[0071] The above has described the embodiments of the present disclosure. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, the practical application, or the improvement of the technology in the market, or to enable other ordinary technicians in the technical field to understand the embodiments disclosed herein.

[0072] The above are only optional embodiments of the present disclosure and are not intended to limit the present disclosure. For those skilled in the art, various changes and modifications can be made to the present disclosure. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included within the protection scope of the present disclosure.

Claims

1. A data transmission system, characterized in that, including: a first ring network including a plurality of first EPA switches; a second ring network including a plurality of second EPA switches; a first star network including a plurality of first terminal devices, the plurality of first terminal devices being communicatively connected to a first target switch among the plurality of first EPA switches and a second target switch among the plurality of second EPA switches; and a second star network including a plurality of second terminal devices, the plurality of second terminal devices being communicatively connected to a third target switch among the plurality of first EPA switches and a fourth target switch among the plurality of second EPA switches; the first target switch is different from the third target switch, and the second target switch is different from the fourth target switch; the first target switch includes: a ring network processing unit configured to copy a parsed first received message into two copies so as to transmit the two copied messages to two first EPA switches adjacent to the first target switch in the first ring network respectively, the first received message being from at least one of the plurality of first terminal devices; the first target switch further includes: a data feature information caching unit communicatively connected to the ring network processing unit and configured to store data feature information of the first received message so as to form a forwarding list; the ring network processing unit is further configured to: query the forwarding list to determine whether data feature information of messages from the two first EPA switches belongs to the forwarding list, and in response to determining that the data feature information belongs to the forwarding list, not send the messages to the two first EPA switches; the ring network processing unit is configured to: in response to determining that a time interval between two messages respectively from two first EPA switches adjacent to the first target switch in the first ring network is less than a predetermined interval threshold and sequence numbers of the two messages are the same, determine any one of the two messages as a first transmitted message; the first target switch further includes: an Ethernet data processing module communicatively connected to an EPA protocol stack and a first terminal device of a general Ethernet terminal type, and configured to store general Ethernet data from the first terminal device of the general Ethernet terminal type and deliver the general Ethernet data to the EPA protocol stack in a non-periodic manner, and receive general Ethernet data from the EPA protocol stack and send it to the first terminal device of the general Ethernet terminal type; and an EPA protocol stack configured to convert general Ethernet data into EPA non-periodic data so as to transmit the converted EPA non-periodic data, and convert EPA non-periodic data into general Ethernet data so as to transmit the converted general Ethernet data to the Ethernet data processing module.

2. The data transmission system according to claim 1, wherein The ring network processing unit is further configured to: determine a first transmission message according to two messages respectively from two first EPA switches adjacent to the first target switch in the first ring network, so as to transmit the first transmission message to at least one of a plurality of first terminal devices.

3. The data transmission system according to claim 1, characterized in that, The first target switch further includes: A star network processing unit, communicatively connected to the ring network processing unit, and configured to receive a first received message and parse the first received message, so as to obtain the parsed first received message and transmit it to the ring network processing unit, and transmit the first transmission message from the ring network processing unit to at least one of a plurality of first terminal devices.

4. The data transmission system according to claim 3, characterized in that, The first target switch further includes: An EPA switching module, communicatively connected to the star network processing unit and a first terminal device of EPA terminal type, and configured to transmit a first received message from the first terminal device of EPA terminal type to the star network processing unit, and transmit the first transmission message from the star network processing unit to the first terminal device of EPA terminal type.

5. The data transmission system according to claim 4, wherein An EPA protocol stack, communicatively connected to the EPA switching module, and configured to convert ordinary Ethernet data into EPA aperiodic data, so as to transmit the converted EPA aperiodic data to the EPA switching module, and convert the EPA aperiodic data from the EPA switching module into ordinary Ethernet data, so as to transmit the converted ordinary Ethernet data to the Ethernet data processing module.

6. The data transmission system according to claim 3, characterized in that The star network processing unit is further configured to perform verification on the first received message, and extract a media access control address and an Internet protocol address from the first received message.

7. The data transmission system according to claim 1, wherein At least one of the first ring network and the second ring network is a dual-ring network.

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