Bus communication system based on optical fiber

Abstract

The invention discloses an optical fiber-based bus communication system, which comprises a main line and a plurality of slave lines extending from the main line, and comprises a plurality of main control boards, each main control board comprises an FPGA (Field Programmable Gate Array); the main line comprises a main line master station and a plurality of main line slave stations, the slave lines take the main line slave stations as slave line master stations, and the main line further comprises a plurality of slave line slave stations; the master station issues an acquisition instruction to the corresponding slave station, the slave station packs data according to an agreed data packet format and sends the data, and the slave station in the intermediate link forwards the data in an unvarnished transmission mode; through the architecture of the FPGA and the optical fiber, the bus communication bandwidth of a control system in the industrial field can be improved, the time delay of overall control of the system is reduced, and the high-speed data processing capability of the FPGA is utilized to ensure that the optical fiber communication rate reaches an ideal state.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to an optical fiber-based bus communication system. Background Art

[0002] With the development of industry, many common bus control technologies have emerged in the industrial automation manufacturing industry, such as the common IIC bus, EtherCAT bus, CAN bus, Ethernet bus, etc. As long as the communication rate requirements can meet the use needs, these technologies have been continuously updated and iterated, and have become quite mature and widely used.

[0003] With the rapid development of AI in the industrial field in recent years, the market's requirements for the transmission rate of industrial buses have gradually increased. Existing technologies have been difficult to meet the communication rate requirements. Therefore, there is an urgent need to find a technical solution that can both increase the transmission rate and serve as a bus.

[0004] There are two main solutions for building control systems using bus solutions in the existing industrial field: (1) EtherCAT bus: Figure 5 This is a commonly used topology diagram of the EtherCAT bus. The EtherCAT bus communication rate is 100Mbit / s, the data refresh cycle is 100us, and the synchronization cycle between sites is 1us.

[0005] (2) Ethernet bus: such as Figure 6 The figure shows the Ethernet application topology diagram, with a maximum communication rate of 1000Mbps. There will be varying degrees of loss in actual application.

[0006] However, in actual application, the communication bandwidth can basically meet the needs of most industrial applications, but when the control system is large, the real-time performance will be affected by the limitation of its communication bandwidth. Moreover, in an environment with strong interference such as strong magnetic and electric fields, its anti-interference ability is poor, and the communication quality will be affected to a certain extent.

[0007] Therefore, improvements need to be made and an optical fiber-based bus communication system is urgently needed. Summary of the invention

[0008] The object of the present invention is to provide a bus communication system based on optical fiber to overcome the deficiencies in the prior art.

[0009] To achieve the above object, the present invention provides the following technical solutions: The present application discloses a bus communication system based on optical fiber, including a main line and a plurality of slave lines extending from the main line, including a plurality of main control boards, wherein the main control board includes an FPGA; The main line includes a main line master station and a plurality of main line slave stations, the slave line uses the main line slave station as a slave line master station, and also includes a plurality of slave line slave stations; The main control board includes two groups of optical fiber interfaces, which are respectively used for the communication of the main line and the slave line, namely the master station sending interface, the master station receiving interface and the slave station sending interface, the slave station receiving interface. The data is output through the master station sending interface and the slave station sending interface, and the data is received through the master station receiving interface and the slave station receiving interface; the master station sends the collection and acquisition instructions to the corresponding slave station, the slave station packages the data in the agreed data packet format and sends it, and the slave station in the middle link forwards the data by transparent transmission.

[0010] Preferably, the main control board includes the following situations: the main control board serves as a master station, the main control board serves as a slave station, and the main control board serves as both a master station and a slave station.

[0011] Preferably, when the main control board is used as a main line master station, it includes the following contents: the master station packages data through the slave station output interface of the main line slave station, and transmits the downlink data to the slave line slave station; the master station receives the uplink data through the slave station receiving interface of the main line slave station, and parses the uplink data content according to the data packet format.

[0012] Preferably, when the main control board is used as a slave line master station, it includes the following contents: the main control board parses the downlink data on the main line and performs corresponding data forwarding, and after packetization, sends it to the slave line slave station through the master station sending interface; when the main control board receives the uplink data sent by the slave line slave station, it receives the data through the master station receiving interface and parses and processes it, and after packetization, sends it to the main line master station through the slave station sending interface.

[0013] Preferably, when the main control board is used as a slave station, it includes the following contents: the slave station receiving interface of the main line slave station receives the downlink data and performs data analysis; the slave station output interface of the main line slave station is responsible for packaging and forwarding the information data uploaded to the corresponding master station, and transparently transmitting the downlink data of the master station that does not belong to this station.

[0014] Preferably, the main control board includes an identity information verification system, which includes an information carrier, information identification, and performs comparison based on the identity information to ensure the security and correspondence of the information.

[0015] Preferably, when the master station sends data, the data is sent to the corresponding slave station. The slave station parses the data sent by the master station and extracts the identity information of the master station. If the identity information is consistent with the identity information pre-stored in this station, the data is processed; if the identity information is inconsistent, the data is transmitted to the next slave station for processing.

[0016] Preferably, the data packet format is a basic data frame format, including a frame header, a frame trailer, identity information, data length, a valid data packet, and a cyclic redundancy check value.

[0017] Beneficial effects of the present invention: (1) The present invention can improve the bus communication bandwidth of industrial control systems and reduce the delay of overall system control through the architecture of FPGA and optical fiber. The high-speed data processing capability of FPGA can ensure that the optical fiber communication rate reaches an ideal state; (2) Fiber optic communication is not subject to electromagnetic interference because the frequency of light waves is much higher than that of ordinary electromagnetic waves. Fiber optic communication confines light to be transmitted inside the pipeline, and electromagnetic waves (a type of light wave) with a similar frequency to it are difficult to penetrate the outer protective layer of the fiber optic and interfere with the internal optical signal. Therefore, it can solve the problem of unstable system communication caused by interference in harsh environments.

[0018] The features and advantages of the present invention will be described in detail through embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the internal design framework of a main control board of an optical fiber-based bus communication system of the present invention; Figure 2 It is a practical application framework diagram of the present invention; Figure 3 is the optical fiber data frame format of the present invention; Figure 4 It is the slave station application topology architecture of the present invention; Figure 5 It is the EtherCAT bus application topology diagram of the prior art; Figure 6 It is a diagram of Ethernet topology in the prior art. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below through the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the scope of the present invention. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0021] See also Figure 1The embodiment of the present invention provides a bus communication system based on optical fiber, which mainly solves the problems of low communication bandwidth, high latency and insufficient anti-interference ability. The present invention uses optical fiber for data communication, and its maximum communication bandwidth can reach 10.3Gbps, and the commonly used SFP+ optical module can reach 4.25Gbps. In addition, the optical fiber has strong anti-interference ability, which can effectively avoid the risk of communication interference in a strong interference environment.

[0022] The present invention is a bus communication system based on optical fiber, referring to Figure 1 , which is the internal structure diagram of the main control board designed this time. The design uses FPGA as the main control unit, and uses its high-speed, low-power, and programmable characteristics to plug in 2 sets of optical fiber interfaces. The FPGA's unique high-speed interface can ensure the optical fiber communication bandwidth, and at the same time, it can process the optical fiber data at high speed to ensure the real-time performance of the system; FPGA has 2 sets of optical fiber interfaces, one set for the main line communication, and one set for the slave line communication. The main control board can be a master station or a slave station, or both. In actual applications, the master and slave station functions can be determined according to specific program design; the main control board uses SD as the information carrier of the slave station ID, and the direction of the data is determined by different SD card ID information.

[0023] During the main line communication process: When the main control board is used as the master station: 1. The master station packages data through the "slave station SFP_TX_UNIT" module of the main line, and uses the SFP_TX interface to transmit data to the slave station; 2. The master station receives the uplink data through the main line SFP_RX interface, and the "slave station SFP_RX_UNIT" module parses the uplink data content according to the data packet format; When the main control board is used as a slave: 1. The main line SFP_RX interface receives the downlink data to the "slave station SFP_RX_UNIT" module for data analysis. The ID_MES_MEM module will automatically read the ID information of the current slave station when it is powered on. ID_CHECK checks the ID information in the ID_MES_MEM module and the ID in the downlink data packet. If they are consistent, the entire packet of data will be sent to the DATA_CTRL module for specific operation arrangements; If they are inconsistent, the slave station automatically ignores the packet data and forwards it to the next slave station; 2. The "Slave Station SFP_TX_UNIT" module is mainly responsible for packaging and forwarding the information data that the current slave station needs to upload to the master station. At the same time, it transparently transmits the downlink data of the master station that does not belong to this station.

[0024] During slave line communication: When the main control board is used as the master station: 1. The main control board will first parse the downlink data on the main line, and then forward the corresponding data, assemble the data through the "master station SFP_TX_UNIT" module, and send it to the slave station of the slave line through the slave line SFP_TX interface; 2. When the main control board receives the uplink data sent by the slave station of the slave line, it receives the data through the slave line SFP_RX interface, the "master station SFP_RX_UNIT" module receives the data and parses it, forwards it to the "DATA_CTRL" module for packet assembly, and then the "slave station SFP_TX_UNIT" module sends it to the master station of the main line through the main line SFP_TX interface; When the main control board is used as a slave: It works in the same way as a slave in the main line.

[0025] See also Figure 2 , which is a schematic diagram of the application framework using optical fiber as the bus, is the practical application idea of ​​the present invention. When the master station sends data, the master station sends data to slave station 1 through optical fiber. Slave station 1 parses the data frame content sent by the master station and extracts the target ID information of the master station. If the ID information is consistent with the ID information pre-stored in the SD card of this station, the data of this frame is placed in the buffer area for processing and use; if the ID information is inconsistent, the data continues to be transmitted to the next slave station through the optical fiber transmission port of this slave station, and the next-level slave station repeats the same work.

[0026] When the slave station uploads data, the master station sends the acquisition instruction to the corresponding slave station. The slave station packages the data according to the agreed data packet format and sends it. The slave station in the middle link can forward the data by transparent transmission.

[0027] like Figure 3 As shown in the figure, it is the basic data frame format sent by the optical fiber interface, which includes a frame header, a frame trailer, ID information, data length, a valid data packet, a CRC check value, etc. The ID information is used to compare with the ID of the bus data frame to determine whether to receive the bus data.

[0028] This design invention can be further expanded on the basis of the basic framework. By utilizing the programmable characteristics of FPGA, the same FPGA can simultaneously complete the functional design of the master and slave stations without affecting each other.

[0029] like Figure 4 As shown, in order to expand the application architecture, the master station module acts as the master station on the main line, responsible for the overall operation scheduling of the system, and slave stations 1, 2, etc. are used as slave stations in the main line, receiving data from the master station and providing real-time feedback of their own status information.

[0030] The slave station can also be used as the master station in the slave line. The slave station connected to the slave line receives the data from the master station, analyzes it, and forwards it to the slave station in the slave line. The data of the slave station in the slave line is organized and packaged by the master line slave station and uploaded to the master station. This application solution allows the slave station to be built flexibly.

[0031] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An optical fiber-based bus communication system, characterized in that: It includes a main line and several slave lines extending from the main line, and several main control boards. Each main control board integrates an FPGA chip to realize overall scheduling, data transmission, and data monitoring; The main line includes a main line master station and a plurality of main line slave stations, the slave line uses the main line slave station as a slave line master station, and also includes a plurality of slave line slave stations; The main control board includes two groups of optical fiber interfaces, which are respectively used for the communication of the main line and the slave line, namely the master station sending interface and the master station receiving interface and the slave station sending interface and the slave station receiving interface. Data is output through the master station sending interface and the slave station sending interface, and data is received through the master station receiving interface and the slave station receiving interface, so as to realize the transmission of data in the main line and the slave line; The master station sends acquisition instructions to the corresponding slave station, and the slave station packages the data in the agreed data packet format and sends it. The slave station in the middle link forwards the data by transparent transmission; Optical fiber is used as the bus for data transmission, and the optical fiber communication bandwidth is guaranteed through the FPGA high-speed interface. At the same time, the optical fiber data is processed at high speed to ensure the real-time performance of the system.

2. The optical fiber-based bus communication system according to claim 1, characterized in that: The main control board includes the following situations: the main control board serves as a master station, the main control board serves as a slave station, and the main control board serves as both a master station and a slave station.

3. The optical fiber-based bus communication system according to claim 1, characterized in that: When the main control board is used as a main line master station, it includes the following contents: the master station packages data through the slave station output interface of the main line slave station, and transmits the downlink data to the slave line slave station; the master station receives the uplink data through the slave station receiving interface of the main line slave station, and parses the uplink data content according to the data packet format.

4. The optical fiber-based bus communication system according to claim 1, characterized in that: When the main control board is used as a slave line master station, it includes the following contents: the main control board parses the downlink data on the main line and forwards the corresponding data, and sends it to the slave line slave station through the master station sending interface after packetization; When the main control board receives the uplink data sent by the slave station of the slave line, it receives the data through the master station receiving interface and parses and processes the data, and then sends it to the main line master station through the slave station sending interface after packetization.

5. The optical fiber-based bus communication system according to claim 1, characterized in that: When the main control board is used as a slave station, it includes the following contents: the slave station receiving interface of the main line slave station receives the downlink data and performs data analysis; the slave station output interface of the main line slave station is responsible for packaging and forwarding the information data uploaded to the corresponding master station, and transparently transmitting the downlink data of the master station that does not belong to this station.

6. The optical fiber-based bus communication system according to claim 1, characterized in that: The main control board includes an identity information verification system, which includes an information carrier and information identification, and performs comparison based on the identity information to ensure the security and correspondence of the information.

7. The optical fiber-based bus communication system according to claim 1, characterized in that: When the master station sends data, it sends the data to the corresponding slave station. The slave station parses the data sent by the master station and extracts the identity information of the master station. If the identity information is consistent with the identity information pre-stored in the station, the data is processed; If the identity information is inconsistent, the data will be transmitted to the next slave station for processing.

8. The optical fiber-based bus communication system according to claim 1, characterized in that: The data packet format is a basic data frame format, including a frame header, a frame trailer, identity information, data length, a valid data packet, and a cyclic redundancy check value.

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