Optical-electrical load fiber channel communication mode adaptive switching method and system

Abstract

The present application relates to photoelectric load fiber channel communication mode adaptive switching method and system, belong to communication technical field, solve existing photoelectric load in the installed state cannot switch FC communication mode online, prone to mode misjudgment and so on. The method comprises: detecting whether the optical fiber physical link of the standard FC subcard meets the preset synchronization condition; after link synchronization, within the preset timeout time, receive and judge whether the data frame conforms to the characteristic heartbeat frame format broadcast by the ground detector, counted by the receiving counter; according to whether the receiving counter reaches the preset frame number threshold within the timeout time, determine whether the opposite end device is a ground detector or an avionics switch, if it is a ground detector, maintain point-to-point mode, if it is an avionics switch, switch to a switched networking mode by reconfiguring the working mode register of the standard FC subcard. The present application realizes the online disassembly-free, firmware-writing-free adaptive switching of the FC communication mode of the photoelectric load, and has high reliability.

Description

Technical Field

[0001] This invention relates to the field of optical fiber communication technology, and in particular to an adaptive switching method and system for optical fiber channel communication modes of optoelectronic payloads. Background Technology

[0002] Fibre Channel (FC) is a high-speed serial communication protocol widely used in avionics systems, especially the FC-AE (Fibre Channel Avionics Environment) protocol family, which is specifically optimized for airborne avionics environments and supports upper-layer protocols such as FC-AE-ASM, FC-AE-1553, and FC-AE-RDMA. Among these, the FC-AE-ASM (Anonymous Subscriber Messages) protocol, due to its support for real-time communication and high determinism and reliability, is widely used for data exchange between airborne avionics equipment such as optoelectronic detection pods, infrared imaging devices, and radar processors and core avionics switches. FC node devices support the following two main topology operating modes:

[0003] 1. Point-to-Point (P2P) Mode: Two FC node devices are directly connected via optical fiber, without the need for a switch. In this mode, the nodes establish a link through the raw signal exchange mechanism of FC-PH (Fibre Channel Physical Layer Standard), without performing the Switched Network Login (FLOGI) process. This mode has a simple structure and extremely low latency, making it suitable for stand-alone functional debugging of optoelectronic payloads before they leave the factory, rapid troubleshooting under field conditions, and status checks of payloads by ground-based testing instruments.

[0004] 2. Fabric Switched Networking Mode: Multiple FC nodes are interconnected through FC switches to form a switched network. Nodes obtain dynamically assigned node port IDs (N_Port IDs) by executing the FLOGI process and achieve data exchange between multiple nodes based on the switching routing mechanism based on FC-SW (Fibre Channel Switching Network Standard). This mode is the standard configuration for integrated communication between optoelectronic payloads and avionics switches (such as mission aircraft, display management systems, data storage units, etc.) in airborne environments.

[0005] In practical engineering applications, the firmware or driver of an FC controller is usually designed to support only one of the two modes mentioned above. This is because the P2P mode and Fabric mode differ significantly at multiple protocol layers, including link initialization protocol stack, login mechanism, address allocation method (fixed identifier vs. dynamic allocation by the switch), and frame routing logic. Traditionally, switching between the two modes on the same hardware device requires re-flashing the FC controller configuration program or firmware image. This not only necessitates disassembling the device casing to expose the flashing interface but also requires dedicated flashing tools and a software development environment.

[0006] Chinese patent CN102820986A, entitled "Adaptive Method, Apparatus, and Network Equipment for Fiber Channel Interface Operating Mode," provides an adaptive switching scheme for the operating mode of an FC interface. The core technology of this scheme includes: after detecting a link signal, the FC interface performs bit and word synchronization with the peer interface; if bit and word synchronization fails, the FC interface resets and switches to the network mode of the peer interface (i.e., configuring its own operating mode to match the peer's); if bit and word synchronization succeeds but the local interface cannot be in an active state (indicating the peer is operating in a non-FC network mode), a reset and switching operation is also performed. This patent mainly addresses the adaptation problem between FC interfaces and non-FC heterogeneous devices such as Ethernet protocols, but it does not address the identification and switching of different topology modes (P2P and Fabric) within the FC protocol. Furthermore, it relies solely on physical layer synchronization status judgment, lacking application layer identification capabilities and unable to distinguish whether the peer of the FC link is an avionics switch or a ground detection instrument.

[0007] Chinese patent CN102521053A, entitled "A Storage System and a Method for Online Switching of FC Port Operating Modes," proposes an online switching method for the operating modes of FC ports in a storage system. This method achieves port operating mode changes through the scheduling and switching between an active mode driving module and a passive mode driving module. However, this solution relies on manual triggering by the user through a graphical interface; it is not an automated, adaptive mode identification and switching process. Furthermore, its application scenario is a storage system, which differs significantly from the unattended maintenance and testing scenarios of avionics equipment.

[0008] Based on the above-mentioned existing technologies, the existing FC communication mode management schemes for airborne optoelectronic payloads mainly have the following disadvantages:

[0009] 1. FC communication mode switching relies on offline firmware flashing; the two FC communication modes cannot coexist or be dynamically switched online adaptively.

[0010] After the optoelectronic payload is installed, the equipment is usually securely mounted to the fuselage structure. The test port cover for the FC communication interface is often located in a hard-to-reach position inside the equipment, requiring specialized tools and a certain degree of disassembly work for removal and installation. More importantly, in field conditions, the hardware and software conditions for programming the FC configuration program are usually unavailable. There is a lack of dedicated programmers, target compilation environments, and technicians familiar with the program programming process. Therefore, when the optoelectronic payload experiences communication failure in the field, maintenance personnel often cannot troubleshoot by switching the optoelectronic payload to point-to-point mode to connect to the ground testing instrument. They can only remove the entire payload for troubleshooting or even return it to the factory for repair, which seriously affects the equipment's operational readiness and combat readiness.

[0011] 2. The dual-mode configuration corresponds to two independent software versions, posing a high risk to version management:

[0012] To adapt to the two FC working modes, the development and maintenance teams need to maintain two sets of firmware / driver versions in parallel, which can easily lead to problems such as version inconsistency, program embedding errors, and incorrect versions during on-site flashing, resulting in high costs for software iteration and version control.

[0013] 3. Single-physical-layer decision mechanisms have low recognition accuracy and are prone to pattern errors:

[0014] Existing FC adaptive handover schemes rely solely on physical layer bit and word synchronization states for judgment. Since both FC switches and ground detectors can establish normal physical links, FC physical layer primitives and synchronization states only reflect the protocol state machine and cannot carry any information about the "identity" of the peer device. Therefore, the physical layer cannot distinguish between the two types of devices, which can easily lead to mode decision errors, communication establishment failures, and insufficient identification reliability.

[0015] 4. Automatic handover schemes based on link layer state have inherent drawbacks:

[0016] Some existing studies have attempted to automatically identify the operating mode by monitoring specific primitive sequences or FLOGI execution results during the FC link initialization process. However, after establishing a physical link with the optoelectronic payload, avionics switches typically do not immediately complete FLOGI but wait for a period of time; and ground-based detectors do not initiate FLOGI at all in point-to-point mode. This scheme based on a single link layer state is prone to misjudgment when faced with complex and non-ideal initialization timing (such as link jitter and switch login delays), leading to mode locking errors that cannot be self-healed. Existing technologies lack a lightweight mechanism that can actively and accurately detect the "identity" of the peer device after confirming connectivity at the physical layer. Summary of the Invention

[0017] To address the aforementioned shortcomings of existing technologies, this invention provides an adaptive switching method and system for optical fiber channel communication modes of optoelectronic payloads. The aim is to solve problems such as the inability of optoelectronic payloads to switch FC communication modes online when already installed, the need to maintain two software versions for dual modes, and the low recognition accuracy and susceptibility to mode misjudgment in existing adaptive schemes.

[0018] To solve the above problems, the present invention adopts the following technical solution:

[0019] An adaptive switching method for optical-electric payload fiber optic channel communication modes includes the following steps:

[0020] Physical layer level 1 detection steps: After the standard FC daughter card of the optoelectronic payload is configured in point-to-point mode and powered on for initialization, the link status register of the standard FC daughter card is periodically read to obtain the link status of the optical fiber physical link. The link status includes optical signal lock status and word synchronization status. It is determined whether the link status meets the preset synchronization conditions. If yes, the application layer level 2 detection steps are entered; otherwise, polling and waiting are maintained.

[0021] Application layer level 2 detection steps: Within the preset timeout period, the data frames sent by the peer device are obtained from the standard FC daughter card and CRC checks are performed on each data frame. After the CRC check passes, the current data frame is judged according to the preset check conditions to determine whether it conforms to the format of the characteristic heartbeat frame continuously broadcast by the ground detector at a fixed period. If it conforms, the receive counter is incremented by 1; if it does not conform, the receive counter is decremented by 1 until it returns to 0.

[0022] Mode switching steps: If the receiver counter reaches the preset frame count threshold within the preset timeout period, the peer device is determined to be a ground detector, and the standard FC sub-card remains in point-to-point mode. If the receiver counter is still less than the preset frame count threshold when the preset timeout period expires, the peer device is determined to be an avionics switch. In this case, the standard FC sub-card's operating mode register is reconfigured using the network mode configuration parameters preset in the non-volatile memory, and the current communication mode of the standard FC sub-card is switched to the switching network mode.

[0023] Accordingly, the present invention also proposes an adaptive switching system for optical fiber channel communication modes of optoelectronic payloads, comprising:

[0024] The optoelectronic payload main control module includes a processor and a standard FC daughter card, wherein the processor is connected to the standard FC daughter card via a PCIe bus;

[0025] The standard FC daughter card supports point-to-point mode and switched networking mode, and provides a working mode register configuration interface for receiving configuration parameters to control the communication mode.

[0026] The processor runs mode arbitration software, which is configured to execute the aforementioned adaptive switching method for optoelectronic payload fiber optic channel communication modes.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] (1) Unlike the existing schemes that rely on the link layer state for passive guessing, the present invention does not require disassembling the test port cover or re-burning the solidified program. It can automatically identify the type of the peer device (ground detector or avionics switch) under the same FC protocol framework and adaptively switch the FC communication working mode according to the type of the peer device.

[0029] (2) The present invention can switch communication modes by pre-setting configuration parameters corresponding to the two communication modes and by simply reconfiguring the working mode register of the standard FC daughter card during switching. There is no need to maintain separate firmware or drivers for the two modes, thereby eliminating reliability risks caused by inconsistent firmware versions, errors in the firmware program, etc., and reducing software version management costs.

[0030] (3) This invention uses a dual detection mechanism of physical layer and application layer. On the basis of successful synchronization of physical layer, it adds application layer identity recognition based on feature heartbeat frame, which solves the problem of easy misjudgment of single physical layer detection, effectively improves the reliability of device identification and mode switching, and realizes true "no need to remove cover, no need to burn, automatic adaptation" field intelligent maintenance. Attached Figure Description

[0031] Figure 1 This is a flowchart of an adaptive switching method for optical fiber channel communication mode of an optoelectronic payload according to one embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of the structure of a characteristic heartbeat frame;

[0033] Figure 3 This is a schematic diagram of the structure of an adaptive switching system for optoelectronic payload fiber optic channel communication modes according to one embodiment of the present invention. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, preferred embodiments of the invention will be described in detail below with reference to the accompanying drawings. The specific structures, parameters, steps, etc., described below are merely examples, and those skilled in the art can make various changes and adjustments without departing from the concept of this invention; such changes also fall within the protection scope of this invention.

[0035] like Figure 1As shown, one embodiment of the present invention proposes an adaptive switching method for optical fiber channel communication modes of optoelectronic payloads, the method comprising the following steps:

[0036] Step S1: Physical Layer Level 1 Inspection. Physical layer inspection is used to confirm the physical connectivity of the link and is the basis for data frame reception.

[0037] In the optoelectronic payload, the main control module includes a processor and a standard FC daughter card connected to the processor via a high-speed bus (i.e., PCIe bus) interconnecting peripheral components. After the system is powered on, the processor starts up, loads the operating system driver and initializes the PCIe bus. The standard FC daughter card completes basic hardware logic reset and is configured by default to point-to-point mode.

[0038] After the standard FC daughter card is powered on, initialized, and configured in point-to-point mode, the link status register of the standard FC daughter card is read periodically to obtain the link status of the optical fiber physical link, including the optical signal lock-in (LOS) status and word synchronization status.

[0039] Next, it is determined whether the obtained link status meets the preset synchronization conditions: when optical signal loss of lock (LOS=1) or word synchronization is not achieved, i.e. the preset synchronization conditions are not met, it is determined that the optical fiber physical link has not established a valid connection, polling is maintained and the link status is continuously monitored; when optical signal lock (LOS=0) and word synchronization is achieved, it is determined that the link status meets the preset synchronization conditions, and the application layer secondary detection step, i.e., step S2, is entered.

[0040] Successful link locking (i.e., LOS=0 and word synchronization) is a prerequisite for application layer detection. If the link is not synchronized, data frames sent by the peer device cannot be received regardless of the peer device type. Therefore, polling should be maintained until the link is synchronized or the system is powered off.

[0041] Step S2: Application layer secondary detection.

[0042] In this step, a preset timeout T1 (e.g., 2 seconds) is set, and a receive counter for receiving data frames and a data buffer for storing data frames are established. The receive counter is then initialized by setting its initial value to 0.

[0043] Step S2.1: The standard FC daughter card enters the real-time data receiving mode and receives data frames sent by the peer device. It obtains data frames from the standard FC daughter card's receive queue through the PCIe interface and performs cyclic redundancy check (CRC check) on each data frame to verify the integrity of the frame data during transmission.

[0044] Step S2.2: After the CRC check passes, determine whether the current data frame conforms to the format of the characteristic heartbeat frame continuously broadcast by the ground detector at a fixed period according to the preset check conditions. If it conforms, the receive counter is incremented by 1; if it does not conform, the receive counter is decremented by 1 until it returns to 0.

[0045] The ground-based detector continuously broadcasts characteristic data frames (i.e., characteristic heartbeat frames) at a fixed period T2 (e.g., 100ms). Figure 2 As shown, the characteristic heartbeat frame is not an ordinary data frame, but an identity credential specifically designed for the dual detection mechanism of the physical layer and application layer in this invention. The characteristic heartbeat frame adopts the FC-AE-ASM frame format and includes at least a fixed frame header, a payload data area, and a fixed frame tail. The fixed frame header includes a general FC frame header and a specific ASM frame header. The payload data area contains a fixed synchronization header, a device type identifier, a dynamic rolling timestamp, a cumulative sequence number, and a reserved space. The fixed synchronization header is located at the beginning of the payload data area and is used to quickly filter invalid data packets, reducing subsequent parsing overhead. The device type identifier is located after the fixed synchronization header and is used to declare the sender's identity as a ground detection instrument. The dynamic rolling timestamp is a 32-bit timestamp based on the ground detection instrument's internal clock. The cumulative sequence number is a 32-bit cumulative sequence number that increments by 1 for each frame sent, starting from 0. The fixed frame tail contains CRC checksum information (i.e., a CRC checksum). Optionally, the fixed synchronization header is the hexadecimal number 0x5A5A5A5A, and the device type identifier is the hexadecimal number 0xF001.

[0046] Specifically, the process of determining whether the current data frame conforms to the format of a characteristic heartbeat frame includes:

[0047] Check if the fixed synchronization header in the payload data area of ​​the current data frame is the first preset value, such as 0x5A5A5A5A;

[0048] If the fixed synchronization head is the first preset value, then continue to check whether the device type identifier in the net load data area is the second preset value, such as 0xF001;

[0049] If the device type identifier is the second preset value, then continue to verify whether the timestamp and cumulative sequence number in the payload data area both satisfy the monotonically increasing property, and whether the time interval between the current data frame and the adjacent previous data frame is within the preset allowable jitter range (e.g., T2±20%). The verification of the monotonically increasing property and time interval of the dynamic rolling timestamp and cumulative sequence number makes the identification of the feature heartbeat frame not only rely on static field matching, but also on the time characteristics and counting continuity of the frame sequence, thereby further enhancing the robustness and anti-interference ability of the pattern determination. It should be noted that if the current data frame is the first frame, the monotonically increasing property and time interval of the cumulative sequence number are not verified, and the verification is performed from the second frame onwards.

[0050] If all the above checks pass, the data frame is determined to conform to the format of the characteristic heartbeat frame.

[0051] The receiver counter uses a sliding count method:

[0052] If the current data frame conforms to the format of the characteristic heartbeat frame, the receive counter is incremented by 1;

[0053] If the current data frame does not conform to the characteristic heartbeat frame format, the receive counter remains at 0 when its current value is 0; when its current value is greater than 0, the receive counter is decremented by 1 until it returns to 0. In other words, if the current value of the receive counter is greater than 0 but multiple consecutive erroneous frames are received, the receive counter is decremented by 1 for each erroneous frame received until it returns to 0. Specifically, when the receive counter is greater than 0, it increments by 1 for each correctly received data frame conforming to the characteristic heartbeat frame format; and decrements by 1 for each data frame not conforming to the characteristic heartbeat frame format until it returns to 0. This design tolerates occasional single-frame errors, avoids frequent restarts of the detection process due to external interference, and prevents underflow of the receive counter due to an excessive number of erroneous frames accumulated after positive counting, thus improving the robustness of the method.

[0054] Physical layer detection, as a necessary but not sufficient condition, only confirms that the fiber optic link has been established; application layer detection further confirms the identity type of the peer device. If only physical layer detection is relied upon, it is impossible to distinguish whether the peer is a switch or a ground detection device after the connection is established; if only application layer detection is relied upon, no data frames can be received when the link is not synchronized. The two detection mechanisms complement each other and are indispensable.

[0055] This embodiment employs a dual-decision architecture combining physical layer level 1 (PLS) detection and application layer level 2 (PLS) detection. PLS detection confirms the physical connectivity of the fiber optic link, which is fundamental for data frame reception. However, PLS detection alone cannot distinguish the identity type of the peer device—whether it's an avionics switch or a ground-based detector, both will appear as "link synchronized" at the physical layer. Application layer level 2 (PLS) detection further confirms the identity type of the peer device, but it relies on the completion of physical layer synchronization before data frames can be received normally. If only PLS detection is used, no data frames can be received when the link is not synchronized. Therefore, PLS detection provides the prerequisite for data reception for PLS detection, while PLS detection supplements PLS detection with device identification capabilities; the two complement each other and are indispensable.

[0056] Step S3: Mode switching.

[0057] If the receiver counter reaches the preset frame count threshold N within the preset timeout period T1, the peer device is determined to be a ground detection device. At this time, the standard FC daughter card remains in point-to-point mode, and subsequent data interaction (such as parameter loading, command sending, status query, etc.) is completed with the ground detection device. Optionally, in this embodiment, the preset frame count threshold N is set to 3, that is, the determination condition is met when the receiver counter has correctly received 3 characteristic heartbeat frames.

[0058] Conversely, if the receive counter does not reach the preset frame count threshold N within the preset timeout period T1 (i.e., the receive counter is still less than the preset frame count threshold N when the preset timeout period T1 expires), the peer device is determined to be an avionics switch. In this case, the standard FC daughter card's operating mode register is reconfigured using the network mode configuration parameters preset in the non-volatile memory, switching the standard FC daughter card's current communication mode to switched network mode. Switching to network mode only occurs when the receive counter count fails to reach N and eventually times out.

[0059] When the peer device is determined to be an avionics switch, the current communication mode of the standard FC sub-card is switched to a switched networking mode, specifically including:

[0060] Write a soft reset command to the standard FC daughter card to return it to its initial state and wait for the standard FC daughter card to complete its internal reset process;

[0061] Shutting down all receive and transmit channels of the standard FC daughter card and stopping upper-layer application software from accessing the FC interface prevents invalid or erroneous data interaction during configuration switching.

[0062] Load the configuration parameters corresponding to the switching networking mode from the non-volatile memory, i.e., the networking mode configuration parameters.

[0063] Reconfigure the working mode register of the standard FC daughter card using the networking mode configuration parameters, and configure the working mode register to switchable networking mode.

[0064] After the standard FC daughter card switches its working mode to the switched networking mode, it initiates the FLOGI login process, connects to the avionics switch, and enters normal networking communication.

[0065] This embodiment achieves rapid mode switching by reconfiguring the operating mode register of the standard FC daughter card, eliminating the need for any firmware reprogramming process. This avoids the risks of version inconsistencies and programming errors caused by equipment disassembly, reliance on specialized tools, and parallel maintenance of two software versions. This significantly reduces field maintenance costs and improves equipment availability and combat readiness. Furthermore, a single software version is compatible with both FC modes, eliminating the need for a dual-version parallel maintenance mechanism, thus removing risks such as firmware version inconsistencies and firmware errors, and reducing software version management costs.

[0066] Furthermore, at the time of shipment, two sets of FC configuration parameters (point-to-point mode configuration parameters and network mode configuration parameters) are stored in the non-volatile memory of the optoelectronic payload main control module. The point-to-point mode configuration parameters are used to configure the standard FC daughter card in point-to-point mode, and the network mode configuration parameters are used to configure the standard FC daughter card in switched network mode. Both the point-to-point mode configuration parameters and the network mode configuration parameters include the working mode configuration word, login method, node port identifier, link timing / timeout parameters, and other physical layer signal control words.

[0067] To address link status changes or maintenance needs, this invention also provides a mode re-detection mechanism.

[0068] Specifically, during the operation of the photoelectric load or after a mode switch, the triggering conditions are continuously monitored to ensure they are met. These triggering conditions include the following three scenarios:

[0069] (1) User manual trigger: When maintenance personnel input a retest command through the external interface of the equipment;

[0070] (2) Link recovery after interruption: When the physical fiber optic link is disconnected for some reason and then reconnected;

[0071] (3) Continuous loss of characteristic heartbeat frames: In point-to-point mode, if the number of consecutive loss of characteristic heartbeat frames sent by the ground detector exceeds the preset loss threshold, it is determined that the original peer device (ground detector) has lost connection.

[0072] When any of the above triggering conditions are detected, the physical layer level 1 detection steps are re-executed to re-determine the type of the peer device and complete the corresponding mode switch, thereby realizing automatic reconnection after link recovery or adaptive switching after device replacement.

[0073] Furthermore, as a further optimization of the present invention, a rotary code switch can be installed outside the photoelectric payload device as a means of manual auxiliary redundancy. This rotary code switch includes at least three positions: automatic, forced point-to-point, and forced networking.

[0074] When the rotary code switch is in the automatic position, the above-mentioned physical layer level 1 detection steps, application layer level 2 detection steps, and mode switching steps are executed, that is, the adaptive switching method of the present invention works normally.

[0075] When the rotary switch is in the forced point-to-point position, the automatic detection result is ignored, the current communication mode of the standard FC daughter card is forcibly configured to point-to-point mode, and the mode switching step is prohibited.

[0076] When the rotary code switch is in the forced networking position, the automatic detection result is ignored, the current communication mode of the standard FC daughter card is forcibly configured to the switching networking mode, and the mode switching step is prohibited.

[0077] By setting the aforementioned rotary switch, maintenance personnel can manually force the FC daughter card to operate in scenarios where the automatic detection function fails or special maintenance needs arise, further improving the availability and flexibility of the photoelectric load in different maintenance scenarios.

[0078] This invention employs a dual-decision architecture of physical layer level-one detection and application layer level-two detection to achieve fully automatic adaptive switching of FC communication modes. This solves problems such as the inability of optoelectronic payloads to switch FC communication modes online when already installed, the need to maintain two software versions for dual modes, and the low identification accuracy and susceptibility to mode misjudgment in existing adaptive schemes. Unlike existing schemes that rely on passive guessing based on link layer status, this invention's method does not require disassembling the test port cover or rewriting the firmware. It can automatically identify the type of the peer device (ground detector or avionics switch) within the same FC protocol framework and adaptively switch the FC communication working mode according to the peer device type. Furthermore, this method pre-sets configuration parameters corresponding to the two communication modes (point-to-point mode configuration parameters and network mode configuration parameters) in non-volatile memory, and only needs to reconfigure the working mode register of the standard FC daughter card during switching to complete the communication mode switch. This eliminates the need to maintain separate firmware or drivers for the two modes, thereby eliminating reliability risks caused by inconsistent firmware versions or firmware errors and reducing software version management costs. This method employs a dual detection mechanism at both the physical and application layers. Building upon successful synchronization at the physical layer, it adds application-layer identity recognition based on feature-based heartbeat frames. This solves the problem of misjudgment that is common with single-physical-layer detection, effectively improving the reliability of device identification and mode switching, and achieving truly intelligent field maintenance that is "cover-free, programmable, and automatically adaptable."

[0079] In another embodiment, such as Figure 3 As shown, this embodiment provides an adaptive switching system for optical-electric payload fiber optic channel communication mode. The system mainly includes an optical-electric payload master control module, which is connected to the peer device via an optical fiber cable. One end of the optical fiber cable is connected to the optical-electric payload master control module, and the other end is connected to the peer device (ground detector or avionics switch), which is used to realize data interaction between the optical-electric payload master control module and the peer device.

[0080] The optoelectronic payload main control module includes a processor and a standard FC daughter card, and the processor is connected to the standard FC daughter card via a PCIe bus.

[0081] The standard FC daughter card supports the FC-AE-ASM protocol, supports both point-to-point mode and switched networking mode, and provides a working mode register configuration interface for receiving configuration parameters to control the communication mode.

[0082] The processor runs mode arbitration software, which is used to execute the adaptive switching method for optical-to-electrical payload fiber optic channel communication mode described in the foregoing embodiments, including a physical layer level-one detection step, an application layer level-two detection step, and a mode switching step.

[0083] Specifically, the mode arbitration software reads and writes the register mapping address of the standard FC daughter card to read the link status register, configure the working mode register (mode switching control), and control the soft reset of the standard FC daughter card.

[0084] In this embodiment, the processor can be a Phytium series processor, such as the Phytium 2000 processor, running a domestically developed operating system that provides a standard driver framework. The mode arbitration software runs as a high-priority task at the application layer of the domestic operating system, responsible for performing link status polling, feature heartbeat frame parsing, and driving the mode switching of the standard FC daughter card by writing I / O control instructions to registers. Alternatively, the mode arbitration software can also be implemented as a kernel driver module of the domestic operating system. Optionally, the domestic operating system can be a Tianmai operating system, etc.

[0085] The ground testing instrument is a ground testing device for the optoelectronic payload. It has an FC communication interface and operates in a fixed point-to-point mode. It can broadcast a characteristic heartbeat frame conforming to the FC-AE-ASM frame format to the optoelectronic payload at a fixed period of T2. This frame contains a custom frame header and specific payload content for identification.

[0086] In this embodiment, after the system powers on, the processor starts, loads the operating system driver, and initializes the PCIe bus. The standard FC daughter card completes a basic hardware logic reset. The mode arbitration software starts with the system and configures the standard FC daughter card to point-to-point mode by default.

[0087] After the mode arbitration software starts, it first performs the physical layer level one detection step, which involves periodically reading the link status register of the standard FC daughter card to obtain the link status of the optical fiber physical link and determining whether the link status meets the preset synchronization conditions. If it does, it proceeds to the application layer level two detection step; otherwise, it maintains polling and waiting.

[0088] When entering the application layer level 2 detection step, the mode arbitration software sets the preset timeout T1 and initializes the receive counter (initial value is 0), and allocates a data buffer area for receiving data frames; the standard FC daughter card enters the real-time data receiving mode and begins to receive data frames from the peer device.

[0089] Within the preset timeout period T1, the mode arbitration software continuously monitors the value of the receive counter and performs CRC verification on each received data frame. After the verification is successful, it performs characteristic heartbeat frame format verification and updates the receive counter using a sliding count method based on the verification result.

[0090] When the receiver counter reaches the preset frame count threshold N within the preset timeout period T1, the mode arbitration software determines that the peer device is a ground detector. At this time, the standard FC daughter card maintains the point-to-point mode.

[0091] When the preset timeout period T1 is reached and the receiver counter has not yet reached the preset frame count threshold N, the mode arbitration software determines that the peer device is an avionics switch. At this time, the mode arbitration software loads the networking mode configuration parameters from the non-volatile memory, reconfigures the working mode register of the standard FC sub-card using the networking mode configuration parameters, and switches the current communication mode of the standard FC sub-card to the switching networking mode.

[0092] In this embodiment, the optoelectronic payload main control module also includes non-volatile memory. When the optoelectronic payload leaves the factory, two sets of FC configuration parameters are stored in the non-volatile memory: point-to-point mode configuration parameters and network mode configuration parameters. The point-to-point mode configuration parameters are used to configure the standard FC daughter card in point-to-point mode, while the network mode configuration parameters are used to configure the standard FC daughter card in switched network mode. The specific contents of the two sets of configuration parameters are shown in Table 1.

[0093] Table 1 FC Configuration Parameter Table

[0094]

[0095] Among the above configuration parameters, the point-to-point mode uses a short timeout threshold to quickly detect link anomalies and retry, while the switched networking mode uses a long timeout threshold to accommodate possible delays during switch login. Both are matched to the communication characteristics of their respective topologies.

[0096] In this embodiment, the pattern arbitration software is also configured to perform a pattern re-detection process.

[0097] Specifically, during the operation of the optoelectronic payload or after a mode switch, the mode arbitration software continuously monitors whether the triggering conditions are met. These triggering conditions include user manual triggering, link recovery, and continuous loss of characteristic heartbeat frames.

[0098] When the mode arbitration software detects that any trigger condition is met, it re-executes the physical layer level 1 detection steps, re-determines the type of the peer device, and completes the corresponding mode switch, thereby achieving automatic reconnection after link recovery or adaptive switching after device replacement.

[0099] Furthermore, as a further preferred embodiment, the system also includes a rotary switch disposed outside the photoelectric load device. This rotary switch has at least three positions: automatic, forced point-to-point, and forced networking.

[0100] When the rotary code switch is in the automatic position, the mode arbitration software performs the physical layer level 1 detection step, the application layer level 2 detection step, and the mode switching step.

[0101] When the rotary switch is in the forced point-to-point position, the mode arbitration software ignores the automatic detection result, forces the current communication mode of the standard FC daughter card to be configured as point-to-point mode, and prohibits the execution of the mode switching step.

[0102] When the rotary code switch is in the forced networking position, the mode arbitration software ignores the automatic detection result, forces the current communication mode of the standard FC daughter card to be configured as the switching networking mode, and prohibits the execution of the mode switching step.

[0103] By setting the aforementioned rotary switch, maintenance personnel can manually force the standard FC daughter card to operate in scenarios where the automatic detection function fails or special maintenance needs arise, further improving the availability and flexibility of the photoelectric load in different maintenance scenarios.

[0104] The adaptive switching system for optoelectronic payload fiber optic channel communication modes provided in this embodiment has the following advantages:

[0105] This system can complete mode switching by dynamically reconfiguring the working mode register of the standard FC daughter card through mode arbitration software. It does not require disassembling the equipment, nor does it require special programming tools and compilation environment. It solves the problem of traditional solutions relying on offline programming and greatly improves the efficiency of airborne equipment field maintenance and equipment deployment rate.

[0106] The system adopts a single software that is compatible with both point-to-point and switched networking modes, eliminating the dual-version parallel maintenance mechanism, effectively avoiding problems such as version inconsistency and firmware fixation errors, and reducing software iteration and maintenance costs.

[0107] This system employs a two-tier decision mechanism at the physical and application layers, utilizing a custom-defined feature heartbeat frame to accurately distinguish the identity of the peer device. This solves the problem of misjudgment caused by single-physical-layer detection, significantly improving the reliability of identification and handover. Simultaneously, its frame interval jitter tolerance and cumulative sequence number verification mechanism adapt to high-vibration and strong electromagnetic interference environments in aviation. In particular, the feature heartbeat frame uses the FC-AE-ASM frame format, requiring no modification to the standard protocol stack, avoiding protocol compatibility issues, and eliminating the need for additional system modification costs.

[0108] This system can reduce manual operations such as disassembly and plugging and unplugging of equipment, and reduce damage to hardware caused by static electricity, dust and mechanical vibration. At the same time, the system adopts pure software logic switching without hardware modification, so the system is more stable and more suitable for the harsh environment of airborne aviation.

[0109] The platform boasts strong versatility and scalability. Developed based on the standard FC-AE-ASM protocol and a domestically developed operating system, the system can be directly migrated to other FC architecture avionics equipment such as radar processors and onboard storage units, making it widely applicable.

[0110] The adaptive switching system for optical fiber channel communication mode of the optoelectronic payload provided in this embodiment has been verified in principle in a certain type of optoelectronic payload prototype. The specific verification results are as follows:

[0111] Ground-based detector access scenario: After the system starts up, the mode arbitration software completes the identification of the peer device in about 0.3 to 0.5 seconds. The standard FC daughter card is locked in point-to-point mode and establishes normal communication with the ground-based detector.

[0112] Avionics switch access scenario: After the system starts up, the mode arbitration software determines that no characteristic heartbeat frame has been received after a 2-second timeout period, automatically switches the standard FC sub-card to the switched networking mode, and successfully completes the FLOGI login process to access the avionics switch.

[0113] Recognition accuracy: In a laboratory environment, the ground detection instrument was tested 100 times in the access scenario. The mode arbitration software correctly identified and locked the point-to-point mode in all cases, with a recognition success rate of 100%. The avionics switch was tested 50 times in the access scenario. All of them successfully switched to the switched networking mode and completed FLOGI login, with a switching success rate of 100%.

[0114] The entire switching process does not require disassembling the device casing or re-flashing the FC daughter card firmware; it is completed automatically by the mode arbitration software.

[0115] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0116] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An adaptive switching method for optical fiber channel communication modes of optoelectronic payloads, characterized in that, Includes the following steps: Physical layer level 1 detection steps: After the standard FC daughter card of the optoelectronic payload is configured in point-to-point mode and powered on for initialization, the link status register of the standard FC daughter card is periodically read to obtain the link status of the optical fiber physical link. The link status includes optical signal lock status and word synchronization status. It is determined whether the link status meets the preset synchronization conditions. If yes, the application layer level 2 detection steps are entered; otherwise, polling and waiting are maintained. Application layer level 2 detection steps: Within the preset timeout period, the data frames sent by the peer device are obtained from the standard FC daughter card and CRC checks are performed on each data frame. After the CRC check passes, the current data frame is judged according to the preset check conditions to determine whether it conforms to the format of the characteristic heartbeat frame continuously broadcast by the ground detector at a fixed period. If it conforms, the receive counter is incremented by 1. If it does not meet the requirements, the receive counter is decremented by 1 until it returns to 0; Mode switching steps: If the receiver counter reaches the preset frame count threshold within the preset timeout period, the peer device is determined to be a ground detector. At this time, the standard FC daughter card remains in point-to-point mode. If the receive counter is still less than the preset frame count threshold when the preset timeout period arrives, the peer device is determined to be an avionics switch. At this time, the working mode register of the standard FC sub-card is reconfigured using the network mode configuration parameters preset in the non-volatile memory, and the current communication mode of the standard FC sub-card is switched to the switching network mode.

2. The adaptive switching method for optical fiber channel communication mode of photoelectric payload according to claim 1, characterized in that, The characteristic heartbeat frame adopts the FC-AE-ASM frame format, which includes a fixed frame header, a payload data area, and a fixed frame tail. The fixed frame header includes a general FC frame header and a dedicated ASM frame header. The payload data area contains a fixed synchronization header, a device type identifier, a dynamic rolling timestamp, and a cumulative sequence number. The fixed frame tail contains CRC check standard information.

3. The adaptive switching method for optical fiber channel communication mode of photoelectric payload according to claim 2, characterized in that, The specific process for determining whether the current data frame conforms to the format of the characteristic heartbeat frame includes: Check whether the fixed synchronization header in the payload data area of ​​the current data frame is the first preset value; If the fixed synchronization head is the first preset value, then continue to check whether the device type identifier in the net load data area is the second preset value; If the device type identifier is the second preset value, then continue to verify whether the dynamic rolling timestamp and cumulative sequence number in the net load data area both satisfy monotonically increasing, and whether the time interval between the current data frame and the adjacent previous data frame is within the preset allowable jitter range. If all the above checks pass, the data frame is determined to conform to the format of the characteristic heartbeat frame.

4. The adaptive switching method for optical fiber channel communication mode of optoelectronic payload according to claim 1 or 2, characterized in that, When the peer device is determined to be an avionics switch, before reconfiguring the operating mode register of the standard FC daughter card, it is also necessary to... Includes the following steps: Write a soft reset command to the standard FC daughter card to return it to its initial state and wait for the standard FC daughter card to complete its internal reset process. Shut down all receive and transmit channels of the standard FC daughter card and stop upper-layer application software from accessing the FC interface.

5. The adaptive switching method for optical fiber channel communication mode of optoelectronic payload according to claim 1 or 2, characterized in that, The non-volatile memory also stores point-to-point mode configuration parameters, which are used to configure the standard FC daughter card in point-to-point mode. Both the point-to-point mode configuration parameters and the networking mode configuration parameters include working mode configuration words, login method, node port identifier, and link timing / timeout parameters.

6. The adaptive switching method for optical fiber channel communication mode of optoelectronic payload according to claim 1 or 2, characterized in that, When the triggering condition is detected, the physical layer level 1 detection step is re-executed; the triggering conditions include: manual triggering by the user, recovery after link interruption, or the number of times the characteristic heartbeat frames sent by the ground detector are continuously lost in point-to-point mode exceeds a preset loss threshold.

7. The adaptive switching method for optical fiber channel communication mode of optoelectronic payload according to claim 6, characterized in that, The user-manual triggering is achieved through a rotary switch located outside the device; The rotary switch includes at least an automatic position, a forced point-to-point position, and a forced network position; When the rotary switch is in the automatic position, the physical layer level 1 detection step, the application layer level 2 detection step, and the mode switching step are executed. When the rotary switch is in the forced point-to-point position, the current communication mode of the standard FC daughter card is forcibly configured to point-to-point mode, and the mode switching step is prohibited. When the rotary code switch is in the forced networking position, the current communication mode of the standard FC sub-card is forcibly configured to the switching networking mode, and the mode switching step is prohibited.

8. The adaptive switching method for optoelectronic payload fiber optic channel communication modes according to claim 1 or 2, characterized in that, The fixed period is 100ms, the preset timeout is 2s, and the preset frame rate threshold is 3.

9. An adaptive switching system for optoelectronic payload fiber optic channel communication modes, characterized in that, include: The optoelectronic payload main control module includes a processor and a standard FC daughter card, wherein the processor is connected to the standard FC daughter card via a PCIe bus; The standard FC daughter card supports point-to-point mode and switched networking mode, and provides a working mode register configuration interface for receiving configuration parameters to control the communication mode. The processor runs mode arbitration software, which is configured to perform the method as described in any one of claims 1 to 8.

10. The optoelectronic payload fiber optic channel communication mode adaptive switching system according to claim 9, characterized in that, The processor is a Phytium series processor, and the mode arbitration software runs on the application layer high-priority task of the domestic operating system, or is implemented as the kernel driver module of the domestic operating system.

Images