Remote IO module based on EBUS and multiple types of redundant buses

Abstract

The utility model relates to communication technical field and provide a kind of remote IO module based on EBUS and multi-type redundant bus, including bus coupler and at least one extension IO module, the bus coupler is used to connect industrial fieldbus, and communicate with the extension IO module by backplane bus;The backplane bus includes a EBUS bus and at least a redundant bus;The redundant bus is any one in CANFD bus, RS485 bus or Ethernet bus;The bus coupler has bus switching function, when EBUS bus communication is abnormal, it is automatically switched to the redundant bus and communicates.The utility model system normal working, preferentially through EBUS bus and carry out high-speed data exchange.Redundant bus is usually in standby state or simultaneously transmit identical data, depending on implementation strategy.The physical redundancy of hardware level is provided, single point failure does not cause system communication interruption, greatly improves the availability and reliability of system.

Description

Technical Field

[0001] This utility model relates to the field of communication technology, and more specifically, to a remote I / O module based on EBUS and multiple types of redundant buses. Background Technology

[0002] In industrial automation control systems, remote I / O modules are key components for enabling data interaction between programmable logic controllers (PLCs, PACs, etc.) and field sensors and actuators. They typically consist of a bus coupler and several expansion I / O modules. The bus coupler is responsible for communicating with upper-level industrial networks (such as Profinet, EtherCAT, Ethernet / IP, Modbus TCP, etc.) and sending control commands to the expansion I / O modules via the backplane bus. Simultaneously, it collects sensor data from the expansion modules and uploads it to the controller. Therefore, the performance of the backplane bus directly determines the data throughput, real-time performance, and stability of the entire I / O module.

[0003] Currently, there are two main types of backplane bus technologies used in this type of module: The first type of solution uses traditional serial communication technologies such as SPI, UART, or IIC. The advantages of this type of solution are its simplicity and low cost, and it is natively supported by most microcontrollers (MCUs). However, its disadvantages are particularly prominent: low transmission rate, limited bandwidth, short transmission distance, and poor immunity to electromagnetic interference (EMI). In complex industrial environments, devices such as motors and frequency converters generate strong electromagnetic noise, which can easily interfere with this type of single-ended signal transmission, leading to increased bit error rate and communication interruptions, failing to meet the demands of modern industrial control for high-speed, high-reliability communication.

[0004] The second type of solution employs high-speed serial bus technologies based on Low Voltage Differential Signaling (LVDS), such as RapidIO and PCIe, or dedicated high-speed buses like EBUS (the LVDS standard defined by Beckhoff for EtherCAT backplane communication). These solutions support high bandwidth (e.g., EBUS up to 100Mbps), low latency, and relatively long transmission distances, and the differential transmission method itself has a certain degree of common-mode interference immunity. However, their implementation is often very complex, typically requiring FPGAs (Field-Programmable Gate Arrays) and the integration of complex protocol IP cores. This not only significantly increases the cycle and difficulty of hardware design and debugging but also substantially raises costs. More importantly, FPGA chips are less resistant to interference in strong electromagnetic interference environments than industrially designed MCUs. Furthermore, these protocols typically lack defined hardware redundancy mechanisms; if the sole high-speed physical link fails due to strong interference, the entire backplane communication will be completely interrupted, lacking backup methods and failing to meet the requirements of high reliability and security applications.

[0005] In summary, existing backplane bus technologies face a dilemma: low-cost, easy-to-implement solutions (serial communication) suffer from performance and reliability bottlenecks; while high-performance solutions (high-speed differential buses) are complex to implement, costly, and lack redundant protection. In harsh industrial environments with strong electromagnetic interference, such as metallurgy, power, and rail transportation, designing a backplane bus that can guarantee high-speed data transmission, high reliability, strong anti-interference capabilities, and hardware-level redundancy backup has become a pressing technical problem to be solved in this field. Utility Model Content

[0006] The problem this invention addresses is: how to achieve a high-speed backplane bus that combines stability and anti-interference capabilities, supports long transmission distances, high bandwidth, low latency, low bit error rate, simple hardware interface, and easy-to-implement backup and redundancy design on the physical hardware link.

[0007] To address the aforementioned issues, this invention provides a remote I / O module based on EBUS and multiple types of redundant buses, comprising a bus coupler and at least one extended I / O module. The bus coupler is used to connect to an industrial fieldbus and communicate with the extended I / O module via a backplane bus. The backplane bus includes an EBUS bus and at least one redundant bus; The redundant bus is any one of CANFD bus, RS485 bus or Ethernet bus; The bus coupler has a bus switching function, which automatically switches to the redundant bus for communication when the EBUS bus communication is abnormal.

[0008] Optionally, the EBUS bus uses LVDS differential signal transmission with a communication rate of 100Mbps; the redundant bus uses differential signal transmission, wherein the CANFD bus communication rate is not less than 8Mbps, the RS485 bus communication rate is not less than 10Mbps, and the Ethernet bus communication rate is 100Mbps.

[0009] Optionally, the bus coupler includes a main control MCU, which is connected to the EBUS bus and the redundant bus respectively through a bus driver chip; The extended I / O module includes a slave MCU, which is connected to the backplane bus through a corresponding bus driver chip.

[0010] Optionally, when the redundant bus is a CANFD bus, the bus driver chip includes a SIT1043 chip; When the redundant bus is an RS485 bus, the bus driver chip includes a MAX485 chip; When the redundant bus is an Ethernet bus, the bus driver chip includes a KSZ8041 chip or a CH390H chip.

[0011] Optionally, the master MCU runs the EtherCAT master protocol and supports real-time diagnostics of the EBUS bus; the slave MCU runs the EtherCAT slave protocol and supports communication protocols corresponding to the redundant bus.

[0012] Optionally, the communication protocol corresponding to the redundant bus includes one of CANopen, ModbusRTU, or UDP protocols; When the main control MCU detects an EBUS communication anomaly, it automatically switches to the redundant bus and uses the corresponding protocol to communicate.

[0013] Optionally, the backplane bus supports bus or star topology, with a maximum transmission distance of not less than 10 meters and a maximum number of nodes of not less than 32.

[0014] Compared with existing technologies, the remote I / O module based on EBUS and multiple types of redundant buses of this invention has the following advantages: During normal operation, this system prioritizes high-speed data exchange via the EBUS bus. The redundant bus is typically in standby mode or simultaneously transmitting the same data, depending on the implementation strategy. The main control MCU continuously diagnoses the communication status of the EBUS bus. Upon detecting an EBUS bus communication anomaly, the main control MCU immediately issues a control command. This command controls the relevant bus driver circuitry, physically switching the data transmission path from the EBUS bus to the redundant bus. This provides hardware-level physical redundancy, ensuring that a single point of failure will not cause system communication interruption, significantly improving system availability and reliability. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of a traditional serial communication backplane bus; Figure 2 This is a schematic diagram of a high-speed differential backplane bus based on FPGA. Figure 3 This is a diagram showing the overall architecture of the remote I / O module based on EBUS and multiple types of redundant buses in this embodiment of the present invention. Figure 4 This is a block diagram of the Ethernet to EBUS bus conversion circuit at the coupler end in an embodiment of this utility model; Figure 5 This is a block diagram of the SPI to Ethernet bus conversion circuit at the coupler end in an embodiment of this utility model; Figure 6 This is a block diagram of the Ethernet switch circuit at the expansion module end in an embodiment of this utility model; Figure 7 This is a flowchart illustrating the backplane bus redundancy control in an embodiment of this utility model. Detailed Implementation

[0016] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0017] In the attached diagram, the Z-axis represents the vertical direction, i.e., up and down, with the positive direction of the Z-axis representing up and the negative direction representing down. The X-axis represents the horizontal direction, specifically the left and right positions, with the positive direction of the X-axis representing the right side and the negative direction representing the left side. The Y-axis represents the front and back positions, with the positive direction of the Y-axis representing the rear and the negative direction representing the front. It should be noted that the aforementioned representations of the Z, Y, and X axes are merely for ease of description and simplification of the present invention, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0018] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this utility model described herein can be implemented in sequences other than those illustrated or described herein.

[0019] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" 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; 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 utility model based on the specific circumstances.

[0020] In the description of this specification, references to terms such as "embodiment," "one embodiment," and "one implementation" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or implementation is included in at least one embodiment or illustrative embodiment of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or implementation. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or implementations.

[0021] like Figures 1 to 7As shown, this utility model embodiment provides a remote IO module based on EBUS and multiple types of redundant buses, including a bus coupler and at least one extended IO module. The bus coupler is used to connect to an industrial fieldbus and communicate with the extended IO module through a backplane bus. The backplane bus includes one EBUS bus and at least one redundant bus; The redundant bus can be any one of CANFD bus, RS485 bus or Ethernet bus; The bus coupler has a bus switching function. When the EBUS bus communication is abnormal, it automatically switches to the redundant bus for communication.

[0022] The bus coupler includes a main control MCU, which is connected to the EBUS bus and the redundant bus respectively through a bus driver chip; The extended I / O module includes a slave MCU, which is connected to the backplane bus through a corresponding bus driver chip.

[0023] During normal system operation, high-speed data exchange is prioritized via the EBUS bus. The redundant bus is typically in standby mode or simultaneously transmitting the same data, depending on the implementation strategy. The master MCU continuously diagnoses the communication status of the EBUS bus (e.g., by detecting link signal quality, protocol layer CRC error rate, heartbeat timeout, etc.). Fault decision and switchover: Once an EBUS bus communication anomaly is diagnosed, the master MCU immediately issues a control command. Switchover execution: The command controls the relevant bus driver circuitry to physically switch the data transmission path from the EBUS bus to the redundant bus.

[0024] It provides physical redundancy at the hardware level, ensuring that a single point of failure will not cause system communication interruption, greatly improving system availability and reliability. In harsh electromagnetic environments, if the high-speed EBUS bus is interfered with, it can automatically degrade to a medium-speed bus with stronger anti-interference capabilities (such as CANFD, RS485) or another high-speed bus (Ethernet) to continue operation. Through seamless or short-term interruption switching, the continuity and determinism of control command and sensor data transmission are guaranteed, meeting the stringent requirements of industrial control for real-time performance and stability.

[0025] The master and slave MCUs handle application layer protocols (such as EtherCAT). The bus driver chip acts as a level converter and signal amplifier, converting the standard CMOS / TTL levels of the MCU pins into differential signals suitable for long-distance transmission (such as LVDS, CAN differential, RS485 differential) and providing sufficient drive capability. Through a specialized driver chip, the signal transmission quality on the backplane is guaranteed, reducing attenuation, reflection, and crosstalk. This architecture clearly separates "protocol processing" (MCU) and "physical interface" (driver chip), making the design more modular and easily adaptable to different bus types.

[0026] The EBUS bus uses LVDS differential signal transmission with a communication rate of 100Mbps. The redundant bus uses differential signal transmission, with the CANFD bus communication rate being no less than 8Mbps, the RS485 bus communication rate being no less than 10Mbps, and the Ethernet bus communication rate being 100Mbps.

[0027] Both LVDS and the redundant bus employ differential signal transmission, using the voltage difference between the two cables to represent the signal, effectively canceling common-mode interference during transmission. The high-speed characteristics of the primary link and the available bandwidth of the backup link are clearly defined, ensuring that the backup link can still meet basic communication performance requirements after being activated, rather than being merely a symbolic backup.

[0028] When the redundant bus is a CANFD bus, the bus driver chip includes the SIT1043 chip; When the redundant bus is an RS485 bus, the bus driver chip includes the MAX485 chip; When the redundant bus is an Ethernet bus, the bus driver chip includes the KSZ8041 chip or the CH390H chip.

[0029] The MCU controls a dedicated chip through a standard digital interface. The dedicated chip automatically completes all complex physical layer signal processing (such as encoding, decoding, and timing control), avoiding complex analog circuit design, greatly shortening the development time and reducing the risk.

[0030] The main control MCU runs the EtherCAT master protocol and supports real-time diagnostics of the EBUS bus. The slave MCU runs the EtherCAT slave protocol and supports communication protocols corresponding to redundant buses.

[0031] The EtherCAT protocol handles the packing, unpacking, synchronization, and real-time scheduling of data frames. The EtherCAT master protocol itself, or monitoring programs added on top of it, can analyze parameters such as telegram loss rate, slave response timeout, and CRC error counters to determine the health status of the EBUS link in real time. Throughout the communication process, diagnostic functions run continuously as background tasks, providing accurate and reliable data for fault decision-making.

[0032] The EtherCAT protocol offers extremely high real-time performance and flexible topology, meeting the needs of complex applications such as high-performance motion control. Utilizing the protocol's own mechanisms for diagnostics allows for more accurate and rapid detection (capable of detecting physical layer faults at the application layer), avoiding potential misjudgments that can occur when relying solely on hardware signal detection.

[0033] The communication protocol corresponding to the redundant bus includes one of the following protocols: CANopen, ModbusRTU, or UDP. When the main control MCU detects an EBUS communication anomaly, it automatically switches to the redundant bus and uses the corresponding protocol to communicate.

[0034] This is a "protocol redundancy" design. The system needs to maintain two protocol stacks. Under normal circumstances, EtherCAT over EBUS works. During switching, not only the physical layer switches, but the application layer communication also switches to the corresponding redundant protocol (such as EtherCAT over UDP or converting to ModbusRTU over RS485).

[0035] Specifically, after the switching command is issued, the master MCU pauses the EtherCAT over EBUS protocol stack, starts another protocol stack (such as the UDP protocol stack) prepared for the redundant bus, and communicates with the slave station through the new physical link according to the new protocol rules.

[0036] Even after the physical layer and protocol layer have switched, the master station and slave station can still perform data parsing and exchange according to the predetermined rules to ensure that the control function is not interrupted.

[0037] The backplane bus supports bus or star topology, with a maximum transmission distance of no less than 10 meters and a maximum number of nodes of no less than 32.

[0038] Bus topology saves on cabling, while star topology offers good fault isolation.

[0039] Although the present invention has been disclosed above, its protection scope is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the protection scope of the present invention.

Claims

1. A remote I / O module based on EBUS and multiple types of redundant buses, comprising a bus coupler and at least one extended I / O module, wherein the bus coupler is used to connect to an industrial fieldbus and communicate with the extended I / O module via a backplane bus, characterized in that: The backplane bus includes an EBUS bus and at least one redundant bus; The redundant bus is any one of CANFD bus, RS485 bus or Ethernet bus; The bus coupler includes a main control MCU, which is connected to the EBUS bus and the redundant bus respectively through a bus driver chip; The extended I / O module includes a slave MCU, which is connected to the backplane bus through a corresponding bus driver chip. The bus coupler has a bus switching function, which automatically switches to the redundant bus for communication when the EBUS bus communication is abnormal.

2. The remote I / O module based on EBUS and multiple types of redundant buses according to claim 1, characterized in that, The EBUS bus uses LVDS differential signal transmission with a communication rate of 100Mbps; the redundant bus uses differential signal transmission, wherein the CANFD bus communication rate is not less than 8Mbps, the RS485 bus communication rate is not less than 10Mbps, and the Ethernet bus communication rate is 100Mbps.

3. The remote I / O module based on EBUS and multiple types of redundant buses according to claim 1, characterized in that, When the redundant bus is a CANFD bus, the bus driver chip includes a SIT1043 chip; when the redundant bus is an RS485 bus, the bus driver chip includes a MAX485 chip; when the redundant bus is an Ethernet bus, the bus driver chip includes a KSZ8041 chip or a CH390H chip.

4. The remote I / O module based on EBUS and multiple types of redundant buses according to claim 1, characterized in that, The master MCU runs the EtherCAT master protocol and supports real-time diagnostics of the EBUS bus; the slave MCU runs the EtherCAT slave protocol and supports communication protocols corresponding to the redundant bus.

5. The remote I / O module based on EBUS and multiple types of redundant buses according to claim 4, characterized in that, The communication protocol corresponding to the redundant bus includes one of CANopen, ModbusRTU or UDP protocol; when the main control MCU detects an EBUS communication abnormality, it automatically switches to the redundant bus and uses the corresponding protocol to communicate.

6. The remote I / O module based on EBUS and multiple types of redundant buses according to claim 1, characterized in that, The backplane bus supports bus or star topology, with a maximum transmission distance of not less than 10 meters and a maximum number of nodes of not less than 32.

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