Linear topology communication management system

Abstract

The invention relates to the technical field of industrial control, in particular to a linear topology communication management system. The linear topology communication management system provided by the invention comprises a main node and a plurality of sub-nodes: the main node is connected with each sub-node through a single physical channel to realize half-duplex message frame communication, and the message frame comprises an addressing frame and a data frame; the main node is used for realizing incremental addressing of each sub-node based on linear topology and a self-defined addressing frame; and the main node is used for realizing step-by-step single-point access and broadcast of each sub-node based on a data frame with self-defined content, and realizing two-way transmission of data. According to the method, the determined child node access address is provided for the main node through the linear topology and the self-defined addressing frame, communication can be achieved only by relying on single full-duplex electrical connection between the two nodes, a hardware link and a topological structure are effectively simplified, and the method is particularly suitable for application scenes with low cost and strict limiting conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of industrial control, and more particularly to a linear topology communication management system. BACKGROUND

[0002] In the field of industrial control, for the low-cost simple application scenario of cascading a single master node and multiple slave nodes of equipment, a standard master-slave communication bus is usually adopted. Such bus architecture generally adopts a master-slave structure composed of one master device (master node) and multiple slave devices (slave nodes). The master node has the ability to actively initiate access and read-write to each slave node through the bus, which usually helps to improve the scalability of the bus.

[0003] In the architecture bus, the slave nodes are usually equipped with specific hardware identification codes or protocol physical layer chips to realize node addressing, so as to ensure that the master node can identify and access each slave node. Therefore, such a bus has high requirements for wiring, protocol and physical layer interface resources.

[0004] Implementing bus management requires complex interface resources and software protocol resources. Due to the limitation of bus topology in the prior art, each slave node usually needs to use a protocol chip to realize the bus function, which to some extent limits the flexibility of the application, increases the design complexity, and increases the product cost.

[0005] The management of node status requires a complex health management mechanism. With the development of the system towards simplicity and compactness, the implementation of the communication bus architecture tends to simplify the hardware link and topology structure to reduce the occupation of space resources and wiring resources. At the same time, considering the cost control and other factors, in order to realize the flexible expansion of the number of nodes and access management, it is urgent to develop a simple, efficient and low-resource occupation linear topology communication management bus. SUMMARY

[0006] The purpose of the present application is to provide a linear topology communication management bus to solve the problem that the prior art is difficult to realize effective communication management under the condition that the cost and wiring resources of the cascaded bus of a single master node and multiple slave nodes are strictly limited.

[0007] In order to achieve the above purpose, the present application provides a linear topology communication management system, which comprises a master node and a plurality of slave nodes.

[0008] The master node and each slave node are connected by a single physical channel to realize half-duplex message frame communication, and the message frame comprises an addressing frame and a data frame.

[0009] The master node realizes incremental addressing of each slave node based on linear topology and self-defined addressing frame.

[0010] The master node, based on data frames with custom content, enables hierarchical single-point access and broadcasting to each child node, and achieves bidirectional data transmission.

[0011] In some embodiments, the master node and each child node communicate via a UART interface to construct and transmit data message structures between the nodes.

[0012] In some embodiments, the message frame structure includes:

[0013] Read / write type, broadcast type, data source / destination address, uplink / downlink direction, access type, and custom data content.

[0014] In some embodiments, the child node is responsible for performing the forwarding action of message frames, wherein the message frames include downlink frames and uplink frames:

[0015] After a child node receives a downlink frame and completes parsing, it determines whether the destination address is its own node. If it is not its own node, it continues to forward the downlink frame to the next downstream node. After the transmission is completed, it is set to the listening state.

[0016] When a child node receives an uplink frame, it forwards it directly to the upstream preceding node, and then sets it to the listening state after the transmission is completed.

[0017] In some embodiments, the master node and each child node performing response actions on message frames further include:

[0018] When a child node receives a downlink frame and completes parsing, it determines whether the destination address is its own node. If it is, the downlink frame is not forwarded to subsequent nodes, and the child node performs corresponding actions based on the message frame content of the downlink frame.

[0019] In some embodiments, when the master node sends or the child node forwards a message frame and requests the destination child node to return response data, if no response message frame data is received from the destination child node within a specified window time, it is determined to be a timeout, and all nodes release bus occupancy.

[0020] In some embodiments, the incremental addressing operation performed between the master node and each child node further includes:

[0021] The master node sends addressing frames to downstream child nodes, and the child nodes incrementally forward these frames to subsequent downstream nodes in turn, thereby realizing the incremental addressing process of the child nodes.

[0022] In some embodiments, the incremental addressing operation performed between the master node and each child node further includes:

[0023] After receiving the addressing enable signal from the host computer, the master node sends an addressing frame to the adjacent first child node.

[0024] After the first child node receives and parses the address frame, it latches the initial address in the address frame as its own address, then adds a preset value to the initial address as the incremental address, and reassembles a new address frame to forward to the adjacent second child node.

[0025] After receiving and parsing the address frame, the second child node latches the incremental address in the address frame as its own address, then adds a preset value to the incremental address as a new incremental address, and reassembles a new address frame to forward it to the adjacent third child node.

[0026] This process continues until the last child node receives the address frame, completing the addressing process.

[0027] In some embodiments, the incremental addressing operation between the master node and each child node further includes the following steps:

[0028] The master node repeatedly sends out addressing frames and confirms the status settings with the child nodes to ensure that all child nodes are successfully addressed.

[0029] In some embodiments, the master node and each child node determine the node status based on a custom polling management mechanism by identifying node information and the number of nodes.

[0030] In some embodiments, the master node and each child node determine the node status based on a custom polling management mechanism, further including:

[0031] Based on the preset maximum allowed number of nodes, the master node polls the information of each child node in ascending order of node address;

[0032] If the child nodes whose node addresses are in place, in ascending order, reply with a response frame, then the master node confirms that the child nodes are in place.

[0033] If none of the child nodes send an in-place response, the master node will report an error and re-execute the addressing and polling operations;

[0034] When a child node's response times out, the master node will assume that the corresponding child node may be missing and will continue to poll the child nodes with subsequent sequence numbers.

[0035] If none of the child nodes with a sequence number greater than or equal to the address respond, the master node considers the node preceding the node at the specified sequence number address to be the end node, thereby obtaining the number and location information of the nodes in place.

[0036] In some embodiments, the master node and each child node determine the node status based on a custom polling management mechanism, further including:

[0037] When the master node is initialized, it performs multiple polling operations to compare the results. If all polling results are consistent, the number of nodes is confirmed to be correct. If there are inconsistencies among the polling results, the master node will report an error and re-execute the addressing and polling operations.

[0038] In some embodiments, the master node manages node data by reading or writing data frame content of any access type from any child node through a hierarchical single-point access method.

[0039] In some embodiments, when the master node sends a broadcast message frame in the downward direction, each child node receives the data of the message frame and performs corresponding operations, and then passes it level by level until it reaches the end child node, so as to achieve a single access covering all child nodes.

[0040] This invention provides a linear topology communication management system that utilizes a linear topology and custom addressing frames to achieve incremental addressing of each child node. Based on the custom content of the data frame, the master node can perform single-point access and broadcasting to each child node. Communication can be achieved using only a single full-duplex electrical connection between two nodes. A custom polling mechanism is used to calculate the number of nodes and determine the node status, effectively simplifying the hardware link and topology structure. It is particularly suitable for low-cost applications with strict constraints, and can improve the system's flexibility and scalability while reducing product costs and interface resource consumption. Attached Figure Description

[0041] The above-described and other features, properties, and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, in which the same reference numerals consistently denote the same features.

[0042] in:

[0043] Figure 1 A principle block diagram of a linear topology communication management system according to an embodiment of the present invention is disclosed;

[0044] Figure 2 A diagram illustrating the UART protocol format according to an embodiment of the present invention is disclosed. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0046] For low-cost and simple application scenarios in industrial control where devices consist of a single master node and multiple cascaded slave nodes, this invention proposes a linear topology communication management system. This system eliminates the need for separate transceiver chips like RS485 and CAN, separate protocol parsing chips, and multiple hardwires. It relies solely on a single full-duplex electrical connection between two nodes. In particular, it can be widely applied in low-cost, strictly limited scenarios such as direct I / O connections between multiple microprocessors or programmable logic devices in industrial control, improving flexibility and scalability while reducing product costs and interface resource consumption.

[0047] Figure 1 A schematic diagram of a linear topology communication management system according to an embodiment of the present invention is disclosed, such as... Figure 1 As shown, the linear topology communication management system proposed in this invention includes a master node 100 and several child nodes 201, 202, ... 20n:

[0048] The master node 100 and each child node 201, 202, ... 20n communicate in half-duplex using a single physical channel connection. The message frame includes an address frame and a data frame.

[0049] The master node 100, based on linear topology and custom addressing frames, implements incremental addressing of each child node 201, 202, ... 20n;

[0050] The master node 100, based on data frames with custom content, enables hierarchical single-point access and broadcasting to each child node 201, 202, ... 20n, and achieves bidirectional data transmission.

[0051] Furthermore, the master node 100 and each child node 201, 202, ... 20n, based on a custom polling management mechanism, determine the node status by identifying node information and quantity.

[0052] The linear topology communication management system proposed in this invention is based on a cascaded linear topology of a master node 100 and several child nodes 201, 202, ... 20n, and adopts a custom frame structure and cascaded access method.

[0053] Among them, the communication mechanism between the master node 100 and the child node 201, and between each child node 201, 202, ... 20n, adopts a single physical channel connection to achieve half-duplex communication. The hardware connection is extremely simple. All child nodes have only one input and one output physical connection, and it is allowed to continuously expand the child nodes within the system's receiving range.

[0054] This invention does not set specific restrictions on the electrical characteristics and parameters of the physical connection. It can be adjusted according to system cost requirements and interface constraints, and can flexibly adopt various signal transmission methods such as differential electrical signals and single-ended electrical signals to achieve various data transmission rates.

[0055] In this context, the direction of transmission from the child node to the master node is called the uplink direction, and the direction of transmission from the master node to the child node is called the downlink direction.

[0056] The following section uses a maximum number of child nodes of 32 as an example to illustrate the specific implementation of the present invention in detail.

[0057] To effectively reduce chip resource consumption and improve the applicability of the bus system, this invention is based on the UART (Universal Asynchronous Receiver / Transmitter) interface to realize the construction and transmission of data message structures between nodes, so that various microcontrollers and programmable logic devices can implement it.

[0058] Specifically, each data packet is sent or received in the form of multiple UART bytes.

[0059] Figure 2 A UART protocol format diagram according to an embodiment of the present invention is disclosed, such as... Figure 2 As shown, the UART communication protocol is a general asynchronous serial communication protocol that works by transmitting data bit by bit. Each binary bit is transmitted sequentially on a signal line. In the UART communication protocol, a high-level state on a signal line represents logic '1', and a low-level state represents logic '0'. When transmitting one byte of data via the UART communication protocol, an eight-level logic combination sequence of high and low levels is formed, corresponding to each bit of the byte.

[0060] This invention proposes a linear topology communication management system, whose message frame structure is designed as a master-slave responsive single-point frame access method.

[0061] Each message frame contains a fixed 2-byte frame header to distinguish different frame types.

[0062] Message frames are divided into two main categories: command frames and data frames.

[0063] The structure of the instruction frame only includes the frame header and does not contain any frame content, thereby enabling efficient transmission of control instructions.

[0064] In addition to the frame header, a data frame also contains up to N bytes of frame data content to meet the data transmission requirements.

[0065] Command frames further include various types such as read command frames and address command frames, all of which are uniformly 2 bytes long. In contrast, other types of complete frames include a frame header and frame data content, with a total length of (2+N) bytes.

[0066] Specifically, the function of the read instruction frame is for the master node to send read data instructions to the child node;

[0067] The addressing instruction frame is used by the master node to send incremental addressing instructions to the child nodes.

[0068] Furthermore, by designing different access types, read / write flags, and broadcast types in the frame header, various specific frame types can be accurately distinguished and identified, ensuring that specific frame types have specific frame headers.

[0069] The specific definition of the message frame structure is as follows:

[0070] Table 1 Message Frame Structure

[0071]

[0072] The access type and data content can be customized according to user resources, such as the master node issuing configuration information and the child node uploading status information.

[0073] Read / write types include: reading data / writing data;

[0074] Broadcast types include: broadcast access / unicast access;

[0075] The access type is specifically identified by a 7-bit number, where each number represents an access type and can be customized by the user. For example, "0x01" can be specified as access type 1, which means that the master node sends a request to the child node to obtain its software version number.

[0076] The linear topology communication management system proposed in this invention specifically retains several types of digital instruction frames in its bus management mechanism for implementing bus management actions. Specifically, these digitally encoded instruction frames are used to execute critical bus management actions, including but not limited to access methods such as the master node issuing incremental addressing instructions to child nodes and the master node polling child nodes to collect node information.

[0077] "Custom Data Content" allows users to completely define the content of frame data. By setting different access types, users can obtain or distribute the corresponding frame data content.

[0078] For example, access type "0x01" is specified as representing access type 1, specifically meaning that the master node requests the software version number of the child node. In this scenario, the frame data content is the software version number returned by the child node in response to this request, specifically presented as a series of values, such as "0x010203...", etc.

[0079] The linear topology communication management system proposed in this invention, as a bus structure, can realize functions such as forwarding message frames, responding to message frames, incremental addressing, node information and quantity identification, single-point access and node data management, and node broadcasting. It should be noted that the execution of these functions is not necessarily sequential. This description only breaks down the various independent key actions or rules of the bus in link management, and these actions or rules combine to form the behavior of the entire communication management system.

[0080] First, the specific scheme for the message frame forwarding function in the linear topology communication management system proposed in this invention is described.

[0081] In the linear topology communication management system proposed in this invention, the message frame includes a downlink frame and an uplink frame:

[0082] When a child node receives a downlink frame and completes parsing, it will determine whether the destination address is its own node. If it is not its own node, the frame will continue to be forwarded to the next downstream node. After the frame is sent, it will be set to the listening state.

[0083] When a child node receives an uplink frame, it will forward it directly to the upstream preceding node, and then set it to the listening state after sending is complete.

[0084] The specific scheme for the response message frame function in the linear topology communication management system proposed in this invention will be described below.

[0085] When a child node receives a downlink frame and completes parsing, it determines whether the destination address is its own. If it is, the frame is not forwarded further, and the corresponding action is performed according to the content of the message frame.

[0086] For example, if the message frame is a data write frame, the child node performs local data writing according to the frame content; or if the message frame is a read instruction frame, the child node initiates the sending of an access response data frame to the upstream preceding node.

[0087] Furthermore, the response message frame function introduces a response timeout mechanism. When the master node sends a message frame or a child node forwards a message frame and requests the destination child node to return response data, if the response message frame data sent by the destination child node is not received within a specified window time, it is judged as a timeout. After the response timeout mechanism is triggered, all nodes release bus occupation. All nodes, including the master node, are only allowed to occupy the bus when they are idle.

[0088] The following section will describe the specific scheme for implementing incremental addressing in the linear topology communication management system proposed in this invention.

[0089] The incremental addressing operation performed between the master node and each child node further includes:

[0090] The master node sends addressing frames to downstream child nodes, and the child nodes incrementally forward these frames to subsequent downstream nodes in turn, thereby realizing the incremental addressing process of the child nodes.

[0091] by Figure 1 For example, the master node 100 and each child node 201, 202, ... 20n perform incremental addressing operations. The specific implementation steps are as follows:

[0092] After receiving the addressing enable signal from the host computer, the master node 100 sends an addressing frame to the adjacent first child node 201.

[0093] After receiving and parsing the address frame, the first child node 201 latches the initial address in the address frame as its own address, then adds a preset value to the initial address as the incremental address, and reassembles a new address frame to forward to the adjacent second child node 202.

[0094] After receiving and parsing the address frame, the second child node 202 latches the incremental address in the address frame as its own address, then adds a preset value to the incremental address as a new incremental address, and reassembles a new address frame to forward to the adjacent third child node.

[0095] This process continues until the last child node 20n receives the addressing frame, thus completing the addressing process.

[0096] In this embodiment, the preset value is 1.

[0097] The incremental addressing of the master node 100 and each child node 201, 202, ... 20n further includes the following steps:

[0098] The master node 100 repeatedly sends out addressing frames and confirms the status settings with the child nodes 201, 202, ... 20n to ensure that all child nodes are successfully addressed.

[0099] Furthermore, the master node and each child node, based on a custom polling management mechanism, determine the node status by identifying node information and the number of nodes.

[0100] The following section will elaborate on the specific scheme of the custom polling management mechanism in the linear topology communication management system proposed in this invention.

[0101] The master node and each child node determine the node status based on a custom polling management mechanism, further including:

[0102] Based on the preset maximum allowed number of nodes, the master node polls the information of each child node in ascending order of node address;

[0103] If the child nodes whose node addresses are in place, in ascending order, reply with a response frame, then the master node confirms that the child nodes are in place.

[0104] If none of the child nodes send an in-place response, the master node will report an error and re-execute the addressing and polling operations;

[0105] When a child node's response times out, the master node will assume that the corresponding child node may be missing and will continue to poll the child nodes with subsequent sequence numbers.

[0106] If none of the child nodes with a sequence number greater than or equal to the address respond, the master node considers the node preceding the node at the specified sequence number address to be the end node, thereby obtaining the number and location information of the nodes in place.

[0107] Furthermore, when the master node is initialized, multiple polling operations are performed to compare the results. If all polling results are consistent, the number of nodes is confirmed to be correct. If there are inconsistencies among all polling results, the master node will report an error and re-execute the addressing and polling operations.

[0108] The specific scheme for single-point access and node data management functions in the linear topology communication management system proposed in this invention will be described below.

[0109] After the master node completes the above addressing, node information and quantity confirmation operations, it can send single-point access message frames in the downstream direction.

[0110] When a message frame is written, the message frame will be passed from each child node to the target node, and the target node will receive the data and execute it.

[0111] When a message frame is read, the message frame will be passed from each child node to the target node. The target node will send a message frame responding to the read data back to the uplink, which will then be passed from each child node to the master node.

[0112] The master node manages node data by reading or writing data of any access type to any child node through a hierarchical single-point access method.

[0113] The specific scheme of the node broadcast function in the linear topology communication management system proposed in this invention will be described below.

[0114] After the master node completes the addressing, node information and quantity confirmation operations, it can send broadcast message frames in the downstream direction. The broadcast message frame is a write message frame by default. The broadcast message frame will be received by each child node and the corresponding operations will be performed. At the same time, it will be passed level by level until the end child node, which can achieve a single access to cover all nodes.

[0115] The linear topology communication management system proposed in this invention can construct a linear topology system architecture under strict constraints on cost and cabling resources. Although devices based on CAN or RS485 buses are functionally alternatives, these devices are limited by their specific electrical and physical layer connections and topologies, and cannot meet the application scenarios targeted by this invention under the dual constraints of cost and cabling resources.

[0116] Specifically, the linear topology communication management system of this invention eliminates the reliance on separate transceiver chips and protocol parsing chips required for standards such as RS485 and CAN bus. It also eliminates the need for multiple hardwired connections, requiring only a single full-duplex electrical connection between two nodes for communication. This greatly simplifies the system structure and reduces costs. This system is particularly suitable for low-cost, strictly limited scenarios such as direct I / O connections between microprocessors or programmable logic devices in industrial control.

[0117] The linear topology communication management system proposed in this invention has the following beneficial effects:

[0118] 1) By using linear topology and custom addressing frames, the master node is provided with a definite access address for child nodes. Based on this address, the location and information of all node devices can be identified. No additional hardware identification code or protocol physical layer chip is required to realize the self-addressing of all nodes, simplifying wiring and hardware connection, and reducing resource consumption and cost.

[0119] 2) Based on the custom content of the data frame, the master node can access each child node through single-point access and broadcast, etc. At the same time, the reserved frame definition has great scalability and flexibility, which can realize the master node to manage the data of the child nodes. On the basis of low-cost topology using a single physical connection line, the master node can access the data of all nodes and realize bidirectional data transmission.

[0120] 3) Based on a custom polling management mechanism, simple node status management is achieved through node count calculation and node status judgment, simplifying hardware links and topology, and realizing low-cost system health status detection.

[0121] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not specifically singular and may include plural forms. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0122] Those skilled in the art will understand that information, signals, and data can be represented using any of a variety of different techniques and arts. For example, the data, instructions, commands, information, signals, bits, symbols, and chips described throughout the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or optical particles, or any combination thereof.

[0123] Those skilled in the art will further appreciate that the various illustrative logic blocks, modules, circuits, and algorithm steps described in conjunction with the embodiments disclosed herein can be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and steps are described above in a generalized manner in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Those skilled in the art may implement the described functionality in different ways for each specific application, but such implementation decisions should not be construed as departing from the scope of the invention.

[0124] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0125] The above embodiments are provided for those skilled in the art to implement or use the present invention. Those skilled in the art can make various modifications or changes to the above embodiments without departing from the inventive concept of the present invention. Therefore, the protection scope of the present invention is not limited to the above embodiments, but should be the maximum scope that conforms to the innovative features mentioned in the claims.

Claims

1. A linear topology communication management system, characterized by, It comprises one master node and several slave nodes: The master node and each slave node adopt single physical channel connection to realize half-duplex message frame communication, and the message frame comprises an addressing frame and a data frame; The master node realizes incremental addressing of each slave node based on linear topology and self-defined addressing frame; The master node realizes step-by-step single-point access and broadcast of each slave node based on self-defined content data frame, and realizes bidirectional data transmission.

2. The linear topology communications management system of claim 1, wherein, The master node and each slave node realize construction and transmission of data message structure between nodes by adopting UART interface.

3. The linear topology communications management system of claim 1, wherein, The message frame structure comprises: Read / write type, broadcast type, data source / destination address, uplink / downlink direction, access type and self-defined data content.

4. The linear topology communications management system of claim 1, wherein, The slave node is responsible for executing message frame forwarding action, and the message frame comprises downlink frame and uplink frame: When the slave node receives the downlink frame and completes analysis, it is judged whether the destination address is the node, if not, the downlink frame is forwarded to the next node in the downlink, and after sending, it is reset to the listening state; When the slave node receives the uplink frame, it is directly forwarded to the previous node in the uplink, and after sending, it is reset to the listening state.

5. The linear topology communications management system of claim 1, wherein, The master node and each slave node execute response action of the message frame, further comprising: When the slave node receives the downlink frame and completes analysis, it is judged whether the destination address is the node, if it is the node, the downlink frame is not forwarded to the next node in the downlink, and corresponding action is executed according to the content of the downlink frame.

6. The linear topology communications management system of claim 5, wherein, When the master node sends or the slave node forwards the message frame, and the destination slave node is required to return response data, if the response message frame data of the destination slave node is not received within a specified specific window time, it is judged as timeout, and all nodes release bus occupation.

7. The linear topology communications management system of claim 1, wherein, The master node and each slave node execute incremental addressing operation, further comprising: The master node sends the addressing frame to the downlink slave node, and the slave node sequentially forwards the incremental address to the next node in the downlink, thereby realizing the incremental addressing process of the slave node.

8. The linear topology communications management system of claim 7, wherein, The master node and each slave node execute incremental addressing operation, further comprising: After the master node receives the addressing enable signal sent by the upper computer, it sends the addressing frame to the adjacent first slave node; After the first slave node receives and analyzes the addressing frame, it latches the initial address in the addressing frame as the address of the node, then adds a preset value to the initial address as the incremental address, re-composes the new addressing frame and forwards it to the adjacent second slave node; After the second slave node receives and analyzes the addressing frame, it latches the incremental address in the addressing frame as the address of the node, then adds a preset value to the incremental address as the new incremental address, re-composes the new addressing frame and forwards it to the adjacent third slave node; In this way, until the last slave node receives the addressing frame, the addressing is completed.

9. The linear topology communications management system of claim 8, wherein, The master node and each slave node execute incremental addressing operation, further comprising the following steps: The master node repeatedly sends the addressing frame multiple times, and confirms the state setting with the slave node to ensure that all slave nodes are successfully addressed.

10. The linear topology communications management system of claim 1, wherein, The master node and each slave node judge the node state based on self-defined polling management mechanism through identification of node information and node number.

11. The linear topology communications management system of claim 10, wherein, The master node and each sub-node judge the node state based on a self-defined polling management mechanism, and further comprises: According to the preset maximum allowed node number, the master node polls each sub-node information in order from small to large node address; If the node address is in the order of small to large, the sub-node replies the response frame, and the master node confirms that the sub-node is in the on-site state; If all sub-nodes do not send the on-site response, the master node will report an error and re-execute the addressing and polling operation; When the response of a certain sub-node appears timeout, the master node will consider that the corresponding sub-node has the possibility of not being on-site, and continue to poll the sub-nodes with subsequent sequence number addresses; If the sequence number is greater than or equal to the address of the sub-node, the master node considers that the previous node of the sequence number address node is the end node, thereby obtaining the on-site node number and position information.

12. The linear topology communications management system of claim 11, wherein, The master node and each sub-node judge the node state based on a self-defined polling management mechanism, and further comprises: When the master node is initialized, multiple polling operations are performed to compare the results, if all the polling results remain consistent, it is confirmed that the node number is correct, if there is an inconsistent condition in all the polling results, the master node will report an error and re-execute the addressing and polling operation.

13. The linear topology communications management system of claim 1, wherein, The master node reads or writes the data frame content of any access type of any sub-node through the way of step-by-step single-point access, and manages the node data.

14. The linear topology communications management system of claim 1, wherein, When the master node sends a broadcast message frame in the downward direction, each sub-node receives the data of the message frame and performs corresponding operations, and at the same time, the message frame will be transmitted step by step until it reaches the end sub-node, realizing single access covering all sub-nodes.

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