A deterministic protocol conversion method for multi-protocol industrial devices

Abstract

This invention discloses a deterministic protocol conversion method for multi-protocol industrial equipment, relating to the field of Internet of Things (IoT) technology. The method includes the following steps: Step S1: Initialize hardware; Step S2: The multi-protocol industrial equipment is sequentially connected to a protocol access module via different physical connectors; Step S3: Send a conversion operation to the protocol conversion configuration module; Step S4: Based on the conversion parameters and rules in the conversion operation, and combined with the constraints in the deterministic protocol conversion algorithm, a deterministic scheduling scheme is obtained by solving the optimization objective using a Satisfiability Model Theory solver; Step S5: According to the deterministic scheduling scheme, the protocol conversion scheduler moves data from shared memory blocks according to the conversion operation and sends it to the corresponding protocol access module for protocol conversion. This invention improves the interoperability of the equipment, enhances the flexibility and scalability of the conversion system, reduces the cost and time of system implementation and maintenance, and effectively improves the stability and predictability of the system.

Description

Technical Field

[0001] This invention relates to the field of Internet of Things (IoT) technology, and in particular to a deterministic protocol conversion method for multi-protocol, multi-industry protocol devices. Background Technology

[0002] In the Industrial Internet of Things (IIoT), devices typically come from different vendors and use various communication protocols, such as industrial wired network protocols including CAN, EtherCAT, and PROFINET, and international industrial wireless network standards including LoRa, ZigBee, and WIA-PA. These protocols each have their own characteristics and cannot communicate directly with each other, limiting interoperability between devices. Traditional protocol conversion methods usually rely on middleware or gateway devices to achieve basic protocol access and conversion, but often face problems such as low transmission efficiency and difficulty in meeting real-time and deterministic requirements. Especially in industrial automation and control systems, these situations can lead to serious system failures or performance degradation.

[0003] With the widespread application of IIoT, a protocol conversion scheme capable of ensuring low latency and high reliability in complex networks is urgently needed to cope with industrial environments composed of multiple network protocols and to meet the stringent requirements of deterministic communication in the industrial sector. This scheme not only needs to efficiently handle data conversion between protocols but also must complete data transmission within a strict time window to avoid system failures caused by delays or errors. Therefore, designing an efficient and reliable deterministic protocol conversion method to achieve deterministic communication between devices using different protocols has become one of the key factors supporting the development of IIoT.

[0004] A search of existing literature revealed Chinese patent application number 202210050225.2, entitled "A Deterministic Conversion Method and Apparatus for Industrial Heterogeneous Network Protocols." This patent discloses a method where, after receiving information streams at the input port, they are timestamped and assigned corresponding control words. Subsequently, priorities are assigned within the device based on the quality of service (QoS) of the information streams. A gating list is designed according to constraints to control the output of information streams with different priorities, ultimately converting the output information streams into the corresponding protocols for transmission to the target network. While this patent addresses the determinism of protocol conversion, it requires designing protocol stacks for each protocol, resulting in high complexity and low transmission efficiency.

[0005] Other patents related to protocol conversion include: Chinese patent application number 201410019937, entitled "Multi-protocol conversion device and its implementation method based on wireless ZigBee, CAN bus and MODBUS / TCP", which discloses that: a microprocessor acts as the control center of the device, and completes data conversion between three protocols—wireless ZigBee network, CAN bus and MODBUS / TCP Ethernet—by opening an address translation mapping table, realizing a wireless / wired heterogeneous control network, and completing the parsing and distribution of information between different protocols; and Chinese patent application number 200810201577, entitled "A conversion method between multiple protocol buses", which discloses that: a microprocessor receives DeviceNet, Profibus and Modbus / TCP protocol data and saves it in the microprocessor, and performs protocol conversion periodically according to the data.

[0006] Chinese patent application number 200810201578.8, entitled "Multi-protocol Gateway and Protocol Conversion Method for Industrial Wireless Network Access to Industrial Ethernet and Fieldbus," discloses a method for microprocessor-controlled protocol conversion between MODBUS / TCP industrial Ethernet and PROFIBUS-DP fieldbus based on IEEE 802.15.4a for industrial wireless network access. Chinese patent application number 201610201994, entitled "Industrial Control Automation Network Communication Protocol Converter and Communication Protocol Conversion Method," describes a method using a microprocessor to convert between a free protocol and Modbus RTU and TCP / IP protocols. However, the aforementioned patents all perform protocol conversion on three fixed wired / wireless protocols, resulting in poor scalability and a lack of flexible online configuration options. Chinese patent application number 202110535853, entitled "High-speed Protocol Conversion Device and Parallel Processing Unit for Industrial Heterogeneous Networks," describes a method that utilizes a wireless module and network card to transmit and receive industrial wireless network data, industrial wired network data, and IPv6 backbone network data, respectively. After entering the protocol conversion unit, the data undergoes parallel processing and conversion, and the protocol conversion device can be controlled through an SDN management interface unit.

[0007] The aforementioned patents achieve access and high-speed conversion of various industrial wireless / wired protocols, but they do not guarantee the determinism of the protocol conversion process. Therefore, there is a need to design a deterministic protocol conversion method with strong versatility, scalability, and flexibility.

[0008] Therefore, those skilled in the art are dedicated to developing a deterministic protocol conversion method for multi-industry protocol devices. Summary of the Invention

[0009] In view of the above-mentioned deficiencies of the prior art, the technical problem to be solved by the present invention is that the industrial protocol conversion process is uncertain; the protocol conversion process is not modeled, and most of them are fixed conversions after one-to-one or many-to-one access, which lacks flexibility and scalability.

[0010] To achieve the above objectives, the present invention provides a deterministic protocol conversion method for multi-industry protocol devices, characterized in that the method includes the following steps:

[0011] Step S1: Initialize the hardware, including drivers, shared memory blocks, protocol access modules, protocol conversion configuration modules, and protocol conversion schedulers, and adjust the required modules to the ready state;

[0012] The protocol access module is used to connect devices with various industrial protocols, and stores the data received from multiple protocol devices into the shared memory block.

[0013] The protocol conversion configuration module is used to configure and maintain the conversion parameters and rules for various protocol devices;

[0014] The protocol conversion scheduler schedules the data in the shared memory block according to the conversion operation including conversion parameters and conversion rules, and communicates with multi-protocol devices through the protocol access module;

[0015] Step S2: Different protocol devices are connected to the protocol access module sequentially through different physical connectors;

[0016] Step S3: The conversion operation is sent to the protocol conversion configuration module;

[0017] Step S4: Based on the conversion parameters and conversion rules in the conversion operation, and combined with the constraints in the deterministic protocol conversion algorithm, the scheduling scheme is obtained by solving the optimization objective using the Satisfiability Model Theory solver.

[0018] Step S5: According to the scheduling scheme, the protocol conversion scheduler moves the data of the shared memory block according to the conversion operation and sends it to the corresponding protocol access module to perform protocol conversion;

[0019] Furthermore, in step S2, the various industrial protocol devices are connected to the protocol access module through their respective physical connectors and then transported to the shared memory block via a bus.

[0020] Furthermore, the protocol conversion configuration module in step S3 can be configured via SPI or TCP / IP communication protocol;

[0021] Furthermore, the set of transformation operations in step S3 is denoted by {ψ1,ψ2,…,ψ}. n} indicates that there are a total of n∈N * Transformation operations are described using a tuple, namely: The formulas represent, in order, the read sub-operation frame, the write sub-operation frame, the amount of data to be converted, the conversion operation cycle, the conversion operation deadline, and the allowed conversion jitter;

[0022] Furthermore, the constraints in step S4 include conflict-free constraints, sequence constraints, time delay constraints, and jitter constraints.

[0023] Definition of conflict-free constraints:

[0024]

[0025] in, This indicates the start time of data frame transmission. op and γ indicate that the sub-operation option can be r or w, i.e., read sub-operation or write sub-operation.

[0026] Sequence constraint definition:

[0027]

[0028] Delay constraints:

[0029] T n ≤D n (3)

[0030]

[0031] Where k represents a conversion cycle, meaning this value begins at the start of (k-1) and ends when the data frame transmission is complete. t n,k,w t represents the time taken for a write sub-operation. n,k,r and t n,k,w Related to transmission delay, as shown below:

[0032]

[0033] Where c is the link speed, l r , l w , l n This indicates the data size for reading commands, reading frame headers, writing frame headers, writing responses, and converting data.

[0034] Jitter constraint definition:

[0035]

[0036] in, To convert jitter.

[0037] Furthermore, the formula for solving the scheduling scheme in step S4 is:

[0038] Furthermore, the Satisfiability Model Theory solver in step S4 is a Z3 solver; furthermore, the scheduling scheme includes a table containing the start time of each data frame, i.e.

[0039] Furthermore, the conversion operation is performed sequentially in time for each data frame;

[0040] Furthermore, each data frame is transmitted in its own time slot.

[0041] The universal protocol conversion model proposed in this invention is applicable to data flows from various connected industrial protocol devices. This universality improves device interoperability, enhances the flexibility and scalability of the conversion system, reduces the complexity of integrating new devices, and lowers the cost and time of system implementation and maintenance. Furthermore, a deterministic protocol conversion mechanism is proposed. By solving a scheduling scheme, it ensures that each conversion operation is completed within a predetermined time. This feature is particularly critical for real-time requirements in industrial environments, especially in scenarios requiring high reliability, low latency, and high efficiency. It effectively improves system stability and predictability, meets the performance requirements of large-scale industrial applications, and provides technical support for future industrial intelligent development, possessing broad market demand and application prospects. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the process framework for the deterministic protocol conversion method for multi-industry protocol devices according to the present invention;

[0043] Figure 2 This is a deterministic protocol conversion framework diagram according to an embodiment of the present invention;

[0044] Figure 3 This is a flowchart illustrating the deterministic protocol conversion process according to an embodiment of the present invention.

[0045] Figure 4 This is a schematic diagram of the switching and scheduling scheme according to an embodiment of the present invention. Detailed Implementation

[0046] The following description, with reference to the accompanying drawings, illustrates several preferred embodiments of the present invention to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms, and the scope of protection of the present invention is not limited to the embodiments mentioned herein.

[0047] In the accompanying drawings, components with the same structure are indicated by the same numerical designation, and components with similar structures or functions are indicated by similar numerical designations. The dimensions and thicknesses of each component shown in the drawings are arbitrary, and the present invention does not limit the dimensions and thicknesses of each component. To make the illustrations clearer, the thickness of some components has been appropriately exaggerated in the drawings.

[0048] The present invention addresses the shortcomings of existing industrial protocol conversion methods in terms of flexibility and determinism by providing a deterministic protocol conversion method for devices with multiple industrial protocols.

[0049] like Figure 1-4 As shown, the method is located in the protocol conversion scheduler, where the protocol access module is used to connect devices with multiple industrial protocols, such as EtherCAT, Profinet, ZigBee, LoRa, etc., and corresponds one-to-one with each protocol device;

[0050] Shared memory blocks are used to store data from various protocol devices, which are stored in the form of input / output data blocks;

[0051] The protocol access module receives data from various protocol devices and stores it in a shared memory block;

[0052] The protocol conversion configuration module is used to configure and maintain the conversion parameters and rules for various protocol devices;

[0053] The protocol conversion scheduler schedules input / output data in the shared memory block according to conversion parameters and conversion rules, and communicates with multi-protocol devices through the protocol access module to ensure the real-time and deterministic nature of the conversion operation.

[0054] The following example illustrates the deterministic protocol conversion method using the conversion between multiple protocols. The conversion parameters and rules included in the conversion operation are shown in Table 1:

[0055] Table 1 Conversion Operation Table

[0056]

[0057] like Figure 3 As shown, the method includes the following steps:

[0058] Step S1: First, perform initialization, including drivers, memory and other related hardware, protocol access modules, protocol conversion configuration modules, and protocol conversion schedulers. Prepare all necessary modules to be ready.

[0059] Preferably, the RS485 bus can be used to connect the protocol access module and set the correct baud rate, for example, 0.5 Mbps.

[0060] Furthermore, the protocol conversion configuration module can be configured using communication protocols such as SPI and TCP / IP.

[0061] Step S2: Wait for the multi-protocol devices to connect to the protocol access module sequentially. If the connection is complete, proceed to step S3; otherwise, wait for all protocol devices to connect successfully. During the connection waiting process, if a timeout occurs, the program will exit the check, report the error message, and terminate the program.

[0062] Furthermore, different protocol devices are connected to the shared memory block via different physical connectors and protocol access modules and then transported to the shared memory block via a bus.

[0063] Step S3: Wait for the conversion operation to be sent to the protocol conversion configuration module. If the conversion operation data is successfully received, it will be sent to the protocol conversion scheduler for scheduling, proceeding to S4; otherwise, it will continue to wait for the correct data to arrive.

[0064] For the protocol conversion process, {ψ1,ψ2,…,ψ n} represents the set of transformation operations, with a total of n ∈ N. * Transformation operations. Each transformation operation can be viewed as a loop process, consisting of two sub-operations: a read sub-operation and a write sub-operation, representing reading source protocol data and writing target protocol data, respectively.

[0065] Describing it using a tuple, that is: The following parameters are represented in sequence: read sub-operation frame, write sub-operation frame, amount of data to be converted, conversion operation cycle, conversion operation deadline, and allowed conversion jitter.

[0066] Suppose that in the industrial field there exists ν∈N * Multiple protocol industrial devices can be connected; in the above tuples... Let r represent the flow of conversion operation n during the k-th read from the source protocol device src∈ν, where r represents the read sub-operation. Similarly, Let w represent the process of transformation operation n writing to the target protocol device (dst∈ν) in the k-th iteration, where w represents the write sub-operation. Here, a protocol device can be either the source or the target protocol device. k∈N * This indicates the order of conversion operations. The conversion operation cycle is denoted by Tn, which is set by the user or actual scenario requirements, and the conversion operation duration is denoted by Dn. Generally, the values ​​of Tn and Dn are equal.

[0067] Taking Table 1 as an example, the conversion operation uses srcPro to represent the source protocol name and dstPro to represent the target protocol name. If there are multiple devices with the same protocol, the protocol names need to be distinguished. srcAdd represents the source protocol address and dstAdd represents the target protocol address, which represent the starting address of the data to be converted. byteSize represents the length of the data to be converted. convPeriod represents the conversion period in milliseconds. convDdl represents the conversion deadline in milliseconds. convJitter represents the tolerable conversion jitter in microseconds.

[0068] Step S4: The protocol conversion scheduler schedules the conversion operations. Based on the conversion parameters and rules in the conversion operation, and combined with the constraints in the deterministic protocol conversion algorithm, the Satisfiability Model Theory (SMT) solver is used to solve the optimization objective to obtain a scheduling scheme. If a scheduling scheme is obtained, proceed to S5; otherwise, return to S3.

[0069] Furthermore, the connected industrial protocol data is scheduled on the TDMA-based transmission line, constraints are established according to the set parameters, and the optimization problem is solved in the protocol conversion scheduler to obtain the scheduling scheme.

[0070] The constraints in the deterministic protocol conversion method include conflict-free constraints, order constraints, delay constraints, and jitter constraints.

[0071] 1) No-conflict constraint: Ensures that only one data frame is transmitted through the TDMA-based physical cable at a time.

[0072]

[0073] in, This indicates the start time of data frame transmission. op and γ indicate that the sub-operation option can be r or w, i.e., read sub-operation or write sub-operation.

[0074] 2) Sequence constraint: Define that the conversion operation must obtain the source protocol data before converting to the target protocol data.

[0075] Therefore, the following transformation sequence constraint is constructed so that during the transformation, the read operation is completed before the write operation.

[0076]

[0077] 3) Delay constraint: It stipulates that the conversion time between protocols, that is, the time from the start of conversion to the output of the target protocol data, must be less than the conversion deadline in the conversion rules.

[0078] T n ≤D n(3)

[0079]

[0080] Where k represents a conversion cycle, meaning this value begins at the start of (k-1) and ends when the data frame transmission is complete. t n,k,w t represents the time taken for a write sub-operation. n,k,r and t n,k,w Related to transmission delay, as shown below:

[0081] The computational and propagation delays here are very small and can be ignored.

[0082]

[0083] Where c is the link speed, l r , l w , l n This indicates the data size for reading commands, reading frame headers, writing frame headers, writing responses, and converting data.

[0084] 4) Jitter Constraints: Transition jitter (8) is defined, and the transition jitter constraints in (9) are constructed to ensure that Must be J n Within the range.

[0085]

[0086] in, To convert jitter.

[0087] Finally, an optimization objective (10) is established, which aims to provide guaranteed jitter for all conversion operations and solve for the scheduling scheme of conversion operations.

[0088]

[0089] Preferably, the SMT solver can be the Z3 solver, or other solvers.

[0090] Step S5: Begin protocol conversion. According to the scheduling scheme and the conversion rules in the conversion operation, the data in the shared memory block is moved and sent to the corresponding protocol access module via a bus (e.g., RS485), thus forming conflict-free data transmission and ensuring the determinism of the protocol conversion. During the protocol conversion, if a new conversion operation arrives, the protocol conversion process is reconfigured, returning to S3; otherwise, the current protocol conversion continues.

[0091] Furthermore, the scheduling scheme is a table containing the start time of each data frame, i.e. Each data frame will undergo conversion operations sequentially according to time.

[0092] like Figure 4 As shown in the diagram, the protocol conversion scheduling scheme of a specific embodiment of the present invention is illustrated. The horizontal axis represents time. In this diagram, time slots are used as the unit. The upper right diagonal represents read sub-operations, and the lower right diagonal represents write sub-operations. It can be observed that each data frame is transmitted in its own time slot, avoiding conflicts and ensuring the determinism of the conversion operation.

[0093] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A deterministic protocol conversion method for multi-protocol industrial equipment, characterized in that, The above method includes the following steps: Step S1: Initialize the hardware; Step S2: The multi-protocol industrial equipment is sequentially connected to the protocol access module via different physical connectors; Step S3: Send the conversion operation to the protocol conversion configuration module; Step S4: Based on the conversion parameters and conversion rules in the conversion operation, and combined with the constraints in the deterministic protocol conversion algorithm, the Satisfiability Model Theory solver is used to solve the optimization objective to obtain a deterministic scheduling scheme; Step S5: According to the deterministic scheduling scheme, the protocol conversion scheduler moves the data of the shared memory block according to the conversion operation and sends it to the corresponding protocol access module to perform protocol conversion; The hardware includes a driver, a shared memory block, a protocol access module, a protocol conversion configuration module, and a protocol conversion scheduler; The protocol access module is used to connect devices with various industrial protocols, and after receiving data from multi-protocol industrial devices, it stores it in the shared memory block; The protocol conversion configuration module is used to receive the conversion operation, configure and maintain the conversion parameters and conversion rules in the conversion operation; The protocol conversion scheduler schedules the data in the shared memory block according to the conversion operation, and communicates with the multi-protocol industrial equipment through the protocol access module; The set of transformation operations in step S3 is as follows: It indicates that there are a total of Transformation operations are described using a tuple. These represent, in order, the read sub-operation frame, the write sub-operation frame, the amount of data to be converted, the conversion operation cycle, the conversion operation deadline, and the allowed conversion jitter; The constraints in step S4 include conflict-free constraints, sequence constraints, time delay constraints, and jitter constraints. Definition of conflict-free constraints: .(1) in, and Indicates the start time of data frame transmission. and The options for representing a suboperation can be r or w, a read suboperation or a write suboperation; Sequence constraint definition: .(2) Delay constraints: ,(3) ,(4) ,(5) Where k represents a conversion cycle, which begins at the start of (k−1) and ends when the data frame transmission is complete; This indicates the time consumed by the write sub-operation. and Related to transmission delay, as shown below: ,(6) ,(7) Where c is the link speed. , , , , This indicates the data size for reading commands, reading frame headers, writing frame headers, writing responses, and converting data. Jitter constraint definition: ,(8) .(9) in, To convert jitter; The optimization objective of step S4 is: ; The scheduling scheme is a table containing the start time of each data frame. The conversion operation is performed sequentially for each data frame according to time, and each data frame is transmitted in its own time slot.

Images