Key data transmission method based on unidirectional transmission equipment

Abstract

The invention relates to the technical field of data transmission, in particular to a key data transmission method based on one-way transmission equipment, which comprises the following steps of: S1, initializing configuration; s2, starting the module; s3, receiving and coding data; s4, performing event sending; s5, events are received and queued; s6, decoding and recovering the data; and S7, data forwarding. According to the method, an innovative event driving and coding combination mechanism is adopted, higher data transmission reliability is provided, data transmission is converted into a state combination based on an underlying system event, the kernel-level event reliability guarantee mechanism of an operating system is fully utilized, and complete transmission of data is greatly ensured. According to the scheme, the system burden caused by a traditional data processing mode is avoided, and reliable data integrity guarantee can be provided for the industrial control system in a one-way non-feedback environment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of data transmission, in particular to a key data transmission method based on one-way transmission equipment. BACKGROUND

[0002] In industrial control systems, the transmission of key data (including control instructions, safety states, sensor readings, etc.) has extremely strict requirements for reliability. In special industrial environments such as power dispatching, nuclear power plant control, and railway signal systems, due to safety protection considerations, one-way transmission mechanisms must be used to prevent information backflow. At the same time, due to physical isolation or safety policy requirements, the transmission channel usually does not allow any form of feedback information, which makes the traditional reliability mechanism based on acknowledgement and retransmission inapplicable.

[0003] In this strict one-way and non-feedback transmission environment, ensuring the reliable transmission of key data faces major technical challenges. The existing technical solutions have obvious deficiencies in data reliability: 1. The simple retransmission mechanism based on UDP improves reliability by retransmitting data packets multiple times, but this method may still result in continuous packet loss and permanent data loss when the network condition deteriorates or the receiving end processing capacity is insufficient.

[0004] 2. The forward error correction (FEC) based solution improves reliability by adding redundant data at the sending end, but its error correction capability is limited and cannot guarantee data recovery in the case of continuous packet loss, and the encoding and decoding process will introduce additional computational burden.

[0005] 3. The multi-channel redundant transmission solution improves reliability by sending the same data through multiple independent channels, but the data synchronization and complex deduplication mechanism between channels will introduce new unreliable factors, and data loss may occur simultaneously when the system load is high. SUMMARY

[0006] To overcome the deficiencies of the prior art, the present application provides a key data transmission method based on one-way transmission equipment, which converts data transmission into a state combination based on underlying system events, fully utilizes the event reliability guarantee mechanism at the operating system kernel level, greatly ensures the complete transmission of data, avoids the system burden brought by traditional data processing methods, and can provide reliable data integrity protection for industrial control systems in a one-way and non-feedback environment.

[0007] The present application is realized by the following technical solutions: The application provides a key data transmission method based on a one-way transmission device, which comprises an upper layer device and a lower layer device, wherein the upper layer device comprises a configuration management module, a communication agent module, a data coding module and an event sending module; the lower layer device comprises a configuration management module, an event receiving module, a data decoding module and a data transmission module. The method comprises the following steps: S1, initialization configuration: the upper layer device and the lower layer device are respectively initialized according to the configuration management module; S2, module startup: the upper layer device starts the communication agent module, the data coding module and the event sending module; the lower layer device starts the event receiving module, the data decoding module and the data transmission module; S3, data receiving and coding: the control end connects the communication agent module of the upper layer device and sends signal data; the communication agent module receives the signal data and sends the signal data to the data coding module; the data coding module encodes the signal data into an encoded data block in a predetermined format; S4, event sending: the event sending module maps each bit of the encoded data block into an independent system event, and sends a data packet representing the system event to the lower layer device through a plurality of independent one-way transmission channels; the system event is distinguished by the load characteristics of the data packet; S5, event receiving and queuing: the event receiving module of the lower layer device listens to a plurality of one-way transmission channels, receives the data packet from the upper layer device, and according to the characteristics of each data packet, stores the corresponding binary event state value into the event queue corresponding to the channel; S6, data decoding and recovery: the data decoding module periodically reads the event state value from all the event queues, if a complete set of event state values is successfully read within a preset timeout time, the state values are combined and restored into an encoded data block according to the index number of each event queue; if the timeout time is exceeded, the data of this round is discarded; S7, data forwarding: the data decoding module decodes the restored encoded data block to obtain the original signal data, and sends the original signal data to the corresponding target point by the data transmission module.

[0008] Further, in step S3, the encoded data block in the predetermined format is a 32-bit data structure, which comprises, from low to high, a 6-bit cyclic sequence number field, a 2-bit data type identification field, an 8-bit target point index field and a 16-bit actual data load field.

[0009] Further, the data type identification field is used to identify the type of signal data, and the value thereof includes: 00 represents a switching value, 01 represents an integer value, 10 represents a custom data type, and 11 is a reserved value.

[0010] Furthermore, in step S4, the specific process of mapping each bit to a system event includes: Create a corresponding UDP sending client for each index number of the encoded data block; iterate through each bit of the encoded data block; If the value of this bit is 0, it indicates that the corresponding UDP sending client should send a Type 1 data packet; If the value of this bit is 1, it instructs the corresponding UDP sending client to send a Type 2 data packet; Among them, the first type of data packet and the second type of data packet have different load characteristics.

[0011] The payload of the first type of data packet is empty, while the payload of the second type of data packet contains at least one byte of data.

[0012] Furthermore, the specific process of step S5 includes: Create a UDP server and a corresponding event queue for each one-way transmission channel; Listen for read events from each UDP server; When a data packet is received, the event type is determined based on its payload characteristics: If it meets the first type of characteristics, then store the first state value in the corresponding event queue; If the second type of characteristic is met, the second state value is stored in the corresponding event queue.

[0013] Furthermore, the data encoding module includes a first buffer queue for storing signal data from the communication proxy module, and sequentially retrieves signal data from the first buffer queue for encoding; the event sending module includes a second buffer queue for caching encoded data blocks from the data encoding module, and sequentially retrieves encoded data blocks from the second buffer queue for event-based sending; the data decoding module includes a third buffer queue for caching restored encoded data blocks, and sequentially retrieves encoded data blocks from the third buffer queue for decoding.

[0014] Furthermore, the configuration information stored in the configuration management module includes at least connection information for defining communication ports, index information for matching target locations, and timeout parameters for controlling the decoding process.

[0015] Preferably, the connection information includes the agent end address port and the transmission channel address port set; the index information includes the target point address port set, the target point switch quantity index, the target point numerical data index and the target point custom data index; the timeout parameter is the decoding timeout time.

[0016] Preferably, by adding N sets of parallel data encoding modules, event sending modules, event receiving modules, and data decoding modules, and correspondingly adding N sets of unidirectional transmission channel sets, where each channel set contains multiple independent unidirectional transmission channels, the system can process N encoded data blocks in parallel, achieving a linear increase in data transmission throughput.

[0017] The beneficial effects of this invention are: First, by leveraging the non-lossable nature of I / O events handled by the operating system kernel, data is encoded into low-level event states for transmission. This ensures the reliable delivery of critical instructions and status information from both the physical and system-level perspectives. It overcomes the reliability bottleneck that traditional solutions (such as UDP retransmission, forward error correction (FEC), and multi-channel redundancy) cannot solve in a one-way, feedback-free environment. This elevates the reliability of data transmission from "probabilistic" to "deterministic," greatly reducing the risk of permanent data loss.

[0018] Second, the event data packets are extremely small (payload of only 0 or 1 byte), greatly saving network bandwidth, making it particularly suitable for narrowband industrial environments. The receiving end uses efficient I / O mechanisms such as epoll / io_uring to process events in batches. The decoding logic is simple (state combination), avoiding the computational burden caused by the complex encoding and decoding of FEC, and significantly improving data processing performance. The architecture supports linearly increasing system throughput by adding parallel encoding and decoding module groups, and there is no data synchronization dependency between groups, resulting in excellent scalability and avoiding the drawbacks of complex synchronization in traditional multi-channel solutions.

[0019] Third, the strict one-way transmission mechanism meets the security isolation requirements of industrial control systems, preventing information backflow. The "all or nothing" decoding mechanism (discarding incomplete data upon timeout) ensures the determinism of the receiving end's behavior, thereby significantly improving the system's functional safety level. It avoids complex acknowledgment, retransmission, synchronization, and deduplication mechanisms, reducing system complexity and thus reducing potential failure points, improving the overall system's stability and robustness. It ensures the transmission of critical data in safety-critical scenarios such as power dispatching and nuclear power plant control, significantly improving the security and operational stability of industrial control systems. At the same time, it avoids the high cost and complexity of traditional redundancy solutions, providing a reliable and practical communication solution for critical industrial infrastructure.

[0020] In summary, this invention, through a clever event-driven mechanism, transforms the reliability problem of network data transmission into the reliability problem of operating system kernel events. Thus, under the extreme constraint of one-way feedback, it achieves a leap in reliability, performance, and security, providing crucial communication assurance for critical industrial infrastructure. Attached Figure Description

[0021] Figure 1This is a system architecture block diagram of a unidirectional transmission device in an embodiment of the present invention.

[0022] Figure 2 This is an overall flowchart of key data transmission in an embodiment of the present invention.

[0023] Figure 3 This is a flowchart of the data encoding module in an embodiment of the present invention.

[0024] Figure 4 This is a flowchart of the event sending module in an embodiment of the present invention.

[0025] Figure 5 This is a flowchart of the event receiving module in an embodiment of the present invention.

[0026] Figure 6 This is a flowchart of the data decoding module in an embodiment of the present invention.

[0027] Figure 7 This is a flowchart of the lower-level device data transmission module in an embodiment of the present invention. Detailed Implementation

[0028] To clearly illustrate the technical features of this solution, the following detailed implementation method will be used to describe the solution.

[0029] A key data transmission method based on a unidirectional transmission device, the unidirectional transmission device including an upper-layer device and a lower-layer device, the method comprising the following steps: S1. Initialization Configuration: Both the upper-layer and lower-layer devices are initialized according to the configuration management module. The configuration information stored in the configuration management module includes at least connection information for defining communication ports, index information for matching target locations, and timeout parameters for controlling the decoding process. Connection information includes the agent end address port and the transmission channel address port set; index information includes the target location address port set, target location switch quantity index, target location numerical data index, and target location custom data index; the timeout parameter is the decoding timeout period.

[0030] The proxy address and port are used by the upper-layer device to start the communication proxy; The transmission channel address port set is used by the event transceiver module to create sending clients and listening servers; The target location address and port set is used for matching conditions in data selection; Target point switch quantity index, used by the device to match specific switch quantity information according to the target point; Numerical data index for target locations, used by the device to match numerical data information based on target locations; A custom data index for target locations is used by the device to match specific information based on the target location. The switch quantity index, numerical data index, and custom data index are subsets of the target address port.

[0031] S2. Module Startup: The upper-layer device starts the communication proxy module, data encoding module, and event sending module; the lower-layer device starts the event receiving module, data decoding module, and data transmission module.

[0032] S3. Data Reception and Encoding: The control terminal connects to the communication proxy module of the upper-layer device and sends signal data; the communication proxy module receives the signal data and sends it to the data encoding module; the data encoding module encodes the signal data into encoded data blocks of a predetermined format.

[0033] The predefined format of the encoded data block is a 32-bit data structure, which includes, from least significant bit to most significant bit, a 6-bit cyclic sequence number field, a 2-bit data type identifier field, an 8-bit target point index field, and a 16-bit actual data payload field.

[0034] The data type identifier field is used to identify the type of signal data. Its values ​​include: 00 for switch quantity, 01 for integer value, 10 for custom data type, and 11 for reserved value.

[0035] The serial number field is a cyclic serial number from 0 to 63, and the target point index field is used to match the point address in the configuration file. In the actual data load field, when the data type is a switch quantity, it can represent a maximum of 16 switch quantities, and when the data type is an integer, it is represented as -32768 to 32767.

[0036] S4. Event-based transmission: The event transmission module maps each bit of the encoded data block to an independent system event, and sends the data packets representing the system events to the lower-level devices through multiple independent unidirectional transmission channels.

[0037] The specific process of mapping each bit to a system event includes: Create a corresponding UDP sending client for each index number of the encoded data block; iterate through each bit of the encoded data block; If the value of this bit is 0, it indicates that the corresponding UDP sending client should send a Type 1 data packet; If the value of this bit is 1, it instructs the corresponding UDP sending client to send a Type 2 data packet; Among them, the first type of data packet and the second type of data packet have different load characteristics.

[0038] The payload of the first type of data packet is empty, while the payload of the second type of data packet contains at least one byte of data.

[0039] S5. Event Reception and Queuing: The event reception module of the lower-layer device listens to multiple unidirectional transmission channels, receives data packets from the upper-layer device, and stores the corresponding binary event status value into the event queue corresponding to the channel according to the characteristics of each data packet.

[0040] Create a UDP server and a corresponding event queue for each one-way transmission channel; Listen for read events from each UDP server; When a data packet is received, the event type is determined based on its payload characteristics: If it meets the first type of characteristics, then store the first state value in the corresponding event queue; If the second type of characteristic is met, the second state value is stored in the corresponding event queue.

[0041] S6. Data Decoding and Recovery: The data decoding module periodically reads event status values ​​from all event queues. If a complete set of event status values ​​is successfully read within the preset timeout period, the read status values ​​are combined and restored into an encoded data block according to the index number of each event queue. If the timeout occurs, the data for this round is discarded.

[0042] S7. Data forwarding: The data decoding module decodes the restored encoded data block to obtain the original signal data, which is then sent to the corresponding target location by the data transmission module.

[0043] The data encoding module includes a first buffer queue for storing signal data from the communication proxy module, and sequentially retrieves signal data from the first buffer queue for encoding; the event sending module includes a second buffer queue for caching encoded data blocks from the data encoding module, and sequentially retrieves encoded data blocks from the second buffer queue for event-based sending; the data decoding module includes a third buffer queue for caching restored encoded data blocks, and sequentially retrieves encoded data blocks from the third buffer queue for decoding.

[0044] By adding N sets of parallel data encoding modules, event sending modules, event receiving modules, and data decoding modules, and correspondingly adding N sets of unidirectional transmission channels, where each set of channels contains multiple independent unidirectional transmission channels, the system can process N encoded data blocks in parallel, achieving a linear increase in data transmission throughput.

[0045] This embodiment provides a complete system implementation for reliably transmitting switching signals of an industrial control system over a one-way UDP channel.

[0046] See Figure 1 Unidirectional transmission equipment is divided into upper-layer equipment and lower-layer equipment.

[0047] The upper-layer device includes: a configuration management module, a communication proxy module, a data encoding module, and an event sending module.

[0048] The lower-level device includes: a configuration management module, an event receiving module, a data decoding module, and a data transmission module.

[0049] The configuration management module stores the following key information: Agent address and port: for example, 192.168.1.10:5000, for the control terminal to connect.

[0050] Transmission channel address port set: contains 32 UDP address port pairs, used to establish 32 independent unidirectional channels.

[0051] Target point address port set: for example, [("PLC1", "192.168.3.10:2000"), ("PLC2", "192.168.3.11:2000")].

[0052] Target point switch quantity index: For example, {"PLC1": [0, 1, 2, ..., 15], "PLC2": [16, 17, ..., 31]}, which maps the points to the data bits.

[0053] Decoding timeout (Time): For example, 50ms.

[0054] When the system starts, both the upper and lower layer devices read the configuration files and complete the initialization of each module. The upper layer device starts the communication proxy module to listen on the specified port and initializes 32 UDP clients (Clis). The lower layer device initializes 32 UDP servers (Servs), each server corresponding to an event queue (Qs), and creates a Socket connection to the target point (such as PLC1, PLC2).

[0055] For data transmission process, please refer to [link / reference]. Figure 2 : The control terminal sends a command data message containing 16 switch statuses to the communication agent module. The communication agent module receives the data and places it into the buffer queue of the data encoding module.

[0056] See Figure 3 The data encoding module performs the following steps: S301: Initialize a 32-bit data structure A, with all bits set to 0.

[0057] S302: Retrieve instruction data from the buffer queue. Assume the instruction is to send the switch status to point PLC1: [1, 0, 1, 0, ..., 1] (16 bits in total).

[0058] S303: Serial number S increments by 1 (cycles from 0 to 63). Data type T is set to 00 (switching quantity). Target point P is converted to 8 bits of binary according to the index configured in PLC1, for example, 00000001.

[0059] S304: Fill the 16 switch states sequentially into the 16-bit actual data field D, and finally generate a 32-bit data structure A.

[0060] S305: Send A into the buffer queue of the event sending module.

[0061] See Figure 4 The event sending module performs the following steps: S401: The module has initialized 32 UDP clients Clis[0] to Clis

[31] .

[0062] S402: Retrieve data structure A from the buffer queue and parse it bit by bit; assume that bit 0 of A is 1, bit 1 is 0, ..., bit 31 is 1.

[0063] S403: Notify each client to send an event in parallel: notify Clis[0] to send event E1 (because A[0]=1), notify Clis[1] to send event E0 (because A[1]=0), ..., notify Clis

[31] to send event E1 (because A

[31] =1).

[0064] S404: Upon receiving the notification, each client executes the following: For E0 events, a UDP packet with an empty payload is sent; for E1 events, a UDP packet with a payload of 1 byte (content is 0) is sent; these 32 tiny UDP packets are sent to the lower-layer device through 32 independent channels.

[0065] See Figure 5 The event receiving module of the lower-level device performs the following steps: S501: The module has initialized 32 UDP server Servs[0] to Servs

[31] and their corresponding queues Qs[0] to Qs

[31] .

[0066] S502: The kernel notifies that a data packet has arrived. Suppose Servs[0] receives a packet.

[0067] S503: Read the packet and find that its payload length is greater than 0. It is determined to be an E1 event and the binary value 1 is stored at the tail of the queue Qs[0]. Similarly, when Servs[1] receives an empty packet, it stores 0 in Qs[1].

[0068] See Figure 6 The data decoding module performs the following steps: S601: Initialize data structure A, all bits are 0.

[0069] S602: Synchronously attempt to read one value from the head of each of the 32 event queues Qs[0] to Qs

[31] .

[0070] S603: Determine whether 32 values ​​were successfully read within a 50ms timeout period.

[0071] If yes (success): Enter S604. Set the read values ​​to the corresponding bits of A according to the queue index: A[0] = value read by Qs[0] (1), A[1] = value read by Qs[1] (0), ..., A

[31] = value read by Qs

[31] (1); at this point, the data block is completely restored to A.

[0072] If no (timeout): Proceed to S605; discard incomplete data from this round and wait for the next round. This is crucial for ensuring data integrity.

[0073] S606: Send the successfully restored complete data structure A into the buffer queue of the data transmission module.

[0074] See Figure 7 The data transmission module performs the following steps: S701: Retrieve data structure A from the queue.

[0075] S702: Parse the target point field P (00000001) of A, which corresponds to PLC1. Parse the actual data field D to obtain 16 switch states [1, 0, 1, 0, ..., 1].

[0076] S703: According to the protocol of PLC1 in the configuration, encapsulate the switch status into a data packet PKT that can be recognized by the PLC.

[0077] S704: Send the PKT to PLC1 via the established Socket connection to 192.168.3.10:2000.

[0078] This completes a full one-way reliable transmission process. The system continues to run, processing subsequent data.

[0079] Of course, the above description is not limited to the examples above. Technical features not described in this invention can be implemented by or using existing technology, and will not be repeated here. The above embodiments and drawings are only used to illustrate the technical solutions of this invention and are not intended to limit this invention. This invention has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this invention do not depart from the spirit of this invention and should also fall within the scope of protection of the claims of this invention.

Claims

1. A key data transmission method based on a unidirectional transmission device, characterized in that: Unidirectional transmission devices include upper-layer and lower-layer devices, and the method is as follows: S1. Upper-layer and lower-layer devices are initialized according to the configuration management module; S2. The upper-layer device starts the communication proxy module, data encoding module, and event sending module; the lower-layer device starts the event receiving module, data decoding module, and data transmission module. S3. The control terminal connects to the communication proxy module and sends signal data; the communication proxy module receives the signal data and sends it to the data encoding module; the data encoding module encodes the signal data into encoded data blocks of a predetermined format. S4. The event sending module maps each bit of the encoded data block to an independent system event, and sends the data packet representing the system event to the lower-level device through a one-way transmission channel. The system events are distinguished by the characteristics of the data packet payload. S5. The event receiving module listens to the one-way transmission channel, receives data packets from the upper-layer device, and stores the corresponding binary event status value into the event queue corresponding to the channel according to the characteristics of each data packet. S6. The data decoding module reads event status values ​​from all event queues. If a complete set of event status values ​​is read within the preset timeout period, the read status values ​​are combined and restored into encoded data blocks according to the index number of each event queue. If the timeout occurs, discard the data from this round. S7. The data decoding module decodes the restored encoded data block to obtain the original signal data, which is then sent to the corresponding target location by the data transmission module.

2. The key data transmission method based on a unidirectional transmission device according to claim 1, characterized in that: In step S3, the pre-formatted encoded data block is a 32-bit data structure, which includes, from low to high bits, a 6-bit cyclic sequence number field, a 2-bit data type identifier field, an 8-bit target point index field, and a 16-bit actual data payload field.

3. The key data transmission method based on a unidirectional transmission device according to claim 2, characterized in that: The data type identifier field is used to identify the type of signal data, and its values ​​include: 00 represents a switch value, 01 represents an integer value, 10 represents a user-defined data type, and 11 is a reserved value.

4. The key data transmission method based on a unidirectional transmission device according to claim 1, characterized in that: In step S4, the specific process of mapping each bit to a system event includes: Create a corresponding UDP sending client for each index number of the encoded data block; iterate through each bit of the encoded data block; If the value of this bit is 0, it indicates that the corresponding UDP sending client should send a Type 1 data packet; If the value of this bit is 1, it indicates that the corresponding UDP sending client should send a Type 2 data packet; Among them, the first type of data packet and the second type of data packet have different load characteristics.

5. The key data transmission method based on a unidirectional transmission device according to claim 4, characterized in that: The payload of the first type of data packet is empty, while the payload of the second type of data packet contains at least one byte of data.

6. The key data transmission method based on a unidirectional transmission device according to claim 1, characterized in that: The specific process of step S5 includes: Create a UDP server and a corresponding event queue for each one-way transmission channel; Listen for read events from each UDP server; When a data packet is received, the event type is determined based on its payload characteristics: If it meets the first type of characteristics, then store the first state value in the corresponding event queue; If the second type of characteristic is met, the second state value is stored in the corresponding event queue.

7. The key data transmission method based on a unidirectional transmission device according to claim 1, characterized in that: The data encoding module includes a first buffer queue for storing signal data from the communication proxy module, and sequentially retrieves signal data from the first buffer queue for encoding; the event sending module includes a second buffer queue for caching encoded data blocks from the data encoding module, and sequentially retrieves encoded data blocks from the second buffer queue for event-based sending; the data decoding module includes a third buffer queue for caching restored encoded data blocks, and sequentially retrieves encoded data blocks from the third buffer queue for decoding.

8. The key data transmission method based on a unidirectional transmission device according to claim 1, characterized in that: The configuration management module stores configuration information including at least connection information for defining communication ports, index information for matching target locations, and timeout parameters for controlling the decoding process.

9. The key data transmission method based on a unidirectional transmission device according to claim 7, characterized in that: The connection information includes the agent's address and port and the transmission channel's address and port set; the index information includes the target point's address and port set, the target point's switch quantity index, the target point's numerical data index, and the target point's custom data index; the timeout parameter is the decoding timeout period.

10. The key data transmission method based on a unidirectional transmission device according to claim 1, characterized in that: By adding N sets of parallel data encoding modules, event sending modules, event receiving modules, and data decoding modules, and correspondingly adding N sets of unidirectional transmission channels, where each set of channels contains multiple independent unidirectional transmission channels, the system can process N encoded data blocks in parallel, achieving a linear increase in data transmission throughput.

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