POF photoelectric hybrid cable online fault monitoring system and method

Abstract

The application relates to the technical field of optical fiber communication, and discloses a POF photoelectric hybrid cable online fault monitoring system and method, which aims to solve the problem that the existing method cannot realize online fault monitoring of the POF photoelectric hybrid cable, and the scheme mainly comprises the following steps: integrating an embedded micro TDR monitoring module in each active optical splitter, wherein the micro TDR monitoring module comprises a main control unit, a shared transmitting and receiving unit, an analog switch array, a safety coupling unit and a photoelectric mixed connector. The single set of measurement hardware is time division multiplexed through the analog switch array, and the safety coupling unit is combined to realize isolation coupling of the test pulse and the direct current remote power supply, so that online fault monitoring is realized on each downlink POF port without interrupting the service. In the initialization learning stage, a health baseline is established, in the periodic monitoring stage, impedance abnormality monitoring and accurate positioning are carried out according to the health baseline, and the cable aging trend is evaluated. The application realizes distributed online monitoring and accurate fault positioning of the POF photoelectric hybrid cable at low cost, and is suitable for FTTR networks.

Description

Technical Field

[0001] This invention relates to the field of optical fiber communication technology, specifically to an online fault monitoring system and method for POF hybrid optical-electric cables. Background Technology

[0002] Fiber to the Room (FTTR) technology is currently the mainstream solution for broadband access in homes and businesses. In an FTTR network, the main gateway simultaneously provides optical signals and DC remote power to multiple sub-gateways via an active optical splitter and a downstream POF (Plastic Optical Fiber) hybrid cable. The POF hybrid cable employs a flat ribbon structure of "copper wire-fiber-copper wire," containing two parallel copper conductors with a 50-ohm impedance to carry a typical 56V DC remote power supply voltage.

[0003] During long-term operation, POF hybrid optical cables are prone to abnormal impedance characteristics due to loose connectors, excessive bending, compression deformation, or moisture intrusion. This can lead to unstable remote power supply, degraded optical signals, and in severe cases, service interruptions, affecting the overall reliability of the FTTR network. However, the existing FTTR network architecture lacks online monitoring methods for the health status of power supply cables, making it difficult for maintenance personnel to detect and locate cable faults in a timely manner.

[0004] Currently, fault detection for such hybrid optical and electrical cables typically employs offline Time Domain Reflectometry (TDR). However, professional TDR equipment is bulky and expensive, making it impossible to integrate into miniaturized devices such as active optical splitters in FTTR networks. Furthermore, TDR testing requires disconnecting the cable from the equipment, interrupting ongoing power supply and services, which is a destructive testing method with low operational efficiency, failing to meet the high availability and intelligent operation and maintenance requirements of modern communication networks. Summary of the Invention

[0005] This invention aims to solve the problem that fault detection of POF hybrid optical and electrical cables in existing FTTR networks relies on offline, high-cost dedicated TDR equipment, and requires service interruption during detection, resulting in low operation and maintenance efficiency. It proposes an online fault monitoring system and method for POF hybrid optical and electrical cables.

[0006] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0007] In a first aspect, the present invention provides an online fault monitoring system for POF hybrid optical-electric cables, applied to FTTR networks. The system includes a TDR monitoring module integrated within each active optical splitter, the TDR monitoring module comprising:

[0008] The main control unit includes non-volatile memory for storing health baseline and signal propagation speed, and for generating control signals and scheduling monitoring processes;

[0009] The shared transmitting and receiving unit includes a differential pulse driving circuit and a dual-channel analog-to-digital converter. The input of the differential pulse driving circuit is connected to the output of the main control unit to generate test pulses. The output of the dual-channel analog-to-digital converter is connected to the input of the main control unit to synchronously acquire reflected signals.

[0010] An analog switch array includes two synchronously controlled analog switches, whose control terminals are connected to the main control unit, whose signal input terminals are connected to the output terminals of a differential pulse drive circuit, and whose signal output terminals are connected to the input terminals of a dual-channel analog-to-digital converter. It is used to time-division multiplex the shared transmit and receive unit to multiple downlink POF ports under the control of the main control unit.

[0011] Multiple safety coupling units are provided, each corresponding to a downstream POF port. The input of each safety coupling unit is connected to the output of a channel of the analog switch array, and the output of each safety coupling unit is connected to the POF hybrid cable via a hybrid optoelectronic connector. Each safety coupling unit includes a high-voltage DC blocking capacitor and a transient voltage suppressor. The high-voltage DC blocking capacitor is connected in series in the signal path to block DC high voltage and couple test pulses. The transient voltage suppressor is connected in reverse parallel between the two copper conductors of the POF hybrid cable to absorb line surges.

[0012] Multiple optoelectronic hybrid connectors, one end of each optoelectronic hybrid connector is connected to the output end of a corresponding safety coupling unit, and the other end is used to plug in a POF optoelectronic hybrid cable;

[0013] The monitoring process in the main control unit includes:

[0014] During the initialization learning phase, the control analog switch array sequentially selects each downlink POF port, transmits test pulses and receives reflected signals through the shared transmit and receive unit, and after digital differential and cumulative averaging processing, establishes a permanent reference baseline and a dynamic reference baseline and stores them in the non-volatile memory.

[0015] During the periodic monitoring phase, the analog switch array is controlled to select each downlink POF port in a time-division manner according to the set period, and the real-time differential reflection waveform is obtained through the shared transmit and receive unit. The real-time differential reflection waveform is compared with the dynamic reference baseline to determine whether there is a sudden impedance anomaly. If so, the fault distance is calculated based on the reflection time difference and the pre-stored propagation speed. The real-time differential reflection waveform is compared with the permanent reference baseline to assess the cable aging trend. A diagnostic report is generated and reported based on the impedance monitoring results and the cable aging assessment results.

[0016] Furthermore, the non-volatile memory also pre-stores a standard reference data package of the same model as the connected POF hybrid cable. The standard reference data package includes: calibrated propagation speed, standard connector interface reflection coefficient range, and typical noise level standard deviation under fault-free conditions. During the initialization learning phase, the main control unit measures the propagation speed and reflection amplitude of the test pulse, and compares the measured propagation speed and reflection amplitude with the calibrated propagation speed and standard connector interface reflection coefficient range, respectively. If the deviation exceeds the preset range, it is determined that there is an installation fault in the current downlink POF port, and the baseline storage for the downlink POF port is stopped, while an initialization abnormality alarm is reported. If the comparison is successful, the currently measured waveform is stored as a permanent reference baseline.

[0017] Furthermore, the comparison of the real-time differential reflection waveform with the dynamic reference baseline specifically includes:

[0018] The difference between the real-time differential reflection waveform and the dynamic reference baseline is calculated to obtain the fault characteristic waveform;

[0019] Based on the noise standard deviation of the permanent baseline, positive and negative thresholds are set;

[0020] When the fault characteristic waveform shows a peak value exceeding the positive threshold, it is determined that there is a high impedance anomaly at that location; when it shows a valley value below the negative threshold, it is determined that there is a low impedance anomaly at that location.

[0021] When a sudden impedance anomaly is detected, the reflection time difference is determined based on the time positions corresponding to the abnormal reflection peaks exceeding positive and falling below negative thresholds in the fault characteristic waveform. And combined with the pre-stored calibrated propagation speed Calculate the distance to the fault point The calculation formula is: .

[0022] Furthermore, the assessment of cable aging trends specifically includes:

[0023] According to the preset aging assessment cycle, the real-time differential reflection waveform measured at the moment is compared point by point with the permanent reference baseline stored in the non-volatile memory, and the deviation between the waveforms is calculated. The deviation is the cumulative deviation or root mean square error, which is calculated as follows: the amplitude of the real-time differential reflection waveform and the permanent reference baseline at the same time index is subtracted point by point, and the absolute value of the difference at each point is accumulated to obtain the cumulative deviation; or the absolute value of the difference is squared and accumulated to obtain the root mean square error.

[0024] The main control unit compares the deviation calculated in the current aging assessment cycle with the deviation in the previous cycle to obtain the rate of change of the deviation. When the cumulative deviation or root mean square error exceeds a preset aging threshold, or when the rate of change of the deviation exceeds a preset rate of change threshold, it determines that the POF optoelectronic hybrid cable has progressive aging or cumulative damage.

[0025] Furthermore, the differential pulse driving circuit adopts a high-speed LVDS driver chip, whose output differential step pulse amplitude is 3.3V and rise time is less than or equal to 5ns; the dual-channel analog-to-digital converter adopts a synchronous sampling ADC chip with a sampling rate of not less than 50MSPS and a resolution of 12 bits, and its input matching resistor is 50Ω; the high-voltage DC blocking capacitor is two NPO ceramic capacitors, each with a capacitance of 0.1μF and a withstand voltage of greater than or equal to 100V.

[0026] Furthermore, the main control unit is also configured to perform a dynamic reference baseline update step when periodic measurements are completed and no fault is detected:

[0027] If there are no faults in the periodic measurements for a preset number of consecutive times, and the deviation between the real-time differential reflection waveform obtained in each measurement and the permanent reference baseline is less than or equal to the noise standard deviation of the permanent reference baseline, then the real-time differential reflection waveform obtained in the most recent measurement is stored as a new dynamic reference baseline.

[0028] Furthermore, a thermistor is attached to each optoelectronic hybrid connector, the thermistor being used to sense the temperature of the corresponding optoelectronic hybrid connector and generate a corresponding temperature analog signal; the active beam splitter also includes:

[0029] The power conversion module has an input terminal for connecting to an external AC power source and an output terminal for outputting DC power to power the various modules inside the active optical splitter.

[0030] A multi-channel DC power management module has its input terminal electrically connected to the output terminal of the power conversion module. The multi-channel DC power management module integrates a power management chip, which distributes DC power to each downstream POF port, monitors the operating status of each downstream POF port in real time, and generates electrical operating parameters for each downstream POF port. These electrical operating parameters include real-time output voltage, real-time output current, chip junction temperature, and fault flag bits. The power management chip also includes a digital communication interface for outputting these electrical operating parameters.

[0031] The power supply terminal of the main control unit is electrically connected to the internal low-voltage output terminal of the power management chip, and is directly powered by the power management chip. The main control unit also includes a digital communication interface and an ADC sampling interface. Its digital communication interface is connected to the digital communication interface of the power management chip to periodically read the electrical operating parameters. Its ADC sampling interface is electrically connected to each thermistor to receive the temperature analog signal and convert it into real-time temperature data of each optoelectronic hybrid connector.

[0032] The main control unit is also configured to: during the periodic monitoring phase, when the real-time output current of a certain downlink POF port exceeds a preset current fluctuation threshold as read from the electrical operating parameters, or when the temperature of a certain optoelectronic hybrid connector exceeds a preset temperature threshold as determined by the real-time temperature data, trigger continuous impedance monitoring of the corresponding downlink POF port.

[0033] Furthermore, the diagnostic report includes the fault port number, fault type, fault distance, and timestamp;

[0034] The main control unit is also used to encapsulate the read electrical operating parameters and converted real-time temperature data with the diagnostic report according to the preset data frame format to generate a comprehensive status data frame, and prioritizes uploading the comprehensive status data frame to the next level active optical splitter through the cascaded optical fiber network, until the main gateway; when an uplink interruption of the optical fiber is detected, the main control unit transmits the comprehensive status data frame to the main gateway through its built-in Bluetooth communication module in the form of Bluetooth broadcast or Bluetooth Mesh message.

[0035] Furthermore, the main control unit is also configured to: receive a unified time reference synchronization signal periodically broadcast by the main gateway through a cascaded fiber optic network, and introduce random delay within a unified monitoring time window according to its own device ID or network level, wherein the random delay is a random value from 0 to the length of the monitoring time window.

[0036] In a second aspect, the present invention provides an online fault monitoring method for POF hybrid optical-electric cables, applied to the online fault monitoring system for POF hybrid optical-electric cables as described in the first aspect, the method comprising:

[0037] During the initialization and learning phase, the main control unit controls the analog switch array to sequentially select each downlink POF port, transmits test pulses and receives reflected signals through the shared transmit and receive unit, and after digital differential and cumulative averaging processing, establishes a permanent reference baseline and a dynamic reference baseline and stores them in the non-volatile memory.

[0038] During the periodic monitoring phase, the main control unit controls the analog switch array to select each downlink POF port in a time-division manner according to the set period, and obtains the real-time differential reflection waveform through the shared transmit and receive unit; compares the real-time differential reflection waveform with the dynamic reference baseline to determine whether there is a sudden impedance anomaly, and if so, calculates the fault distance based on the reflection time difference and the pre-stored propagation speed; compares the real-time differential reflection waveform with the permanent reference baseline to assess the cable aging trend; and generates and reports a diagnostic report based on the impedance monitoring results and cable aging assessment results.

[0039] The beneficial effects of this invention are as follows: The POF hybrid optical cable online fault monitoring system and method provided by this invention, through the high integration of an embedded micro-TDR monitoring module with the main control unit as the core inside the active optical splitter, constructs a low-cost, online, and distributed POF hybrid optical cable monitoring system. This system utilizes an analog switch array to achieve time-division multiplexing of hardware resources for individual transmitting and receiving units, and, in conjunction with a safety coupling unit, couples test pulses to the energized cable, realizing online impedance monitoring of the cables connected to each downlink POF port without interrupting remote power supply and optical signal transmission. By establishing a permanent baseline and a dynamic reference baseline, it can detect sudden impedance anomalies caused by connector loosening, moisture, etc., in real time and achieve high-precision fault location; it can also assess the progressive aging trend of the cable through long-term waveform comparison, realizing an upgrade from fault repair to health prevention in the operation and maintenance mode. Simultaneously, each level of active optical splitter independently monitors and intelligently reports, enabling the aggregation of fault information without adding additional network equipment, achieving penetrating fault location from the network to the cable, significantly improving the operation and maintenance efficiency and reliability of FTTR all-optical networking. Attached Figure Description

[0040] Figure 1 A schematic diagram of the FTTR network provided for the embodiment;

[0041] Figure 2 A schematic diagram of the POF hybrid optical cable online fault monitoring system provided in the embodiment;

[0042] Figure 3 A schematic diagram of the TDR monitoring module provided in the embodiment;

[0043] Figure 4 A schematic diagram of the monitoring process provided for the embodiment;

[0044] Figure 5 A schematic diagram of the active beam splitter provided in the embodiment;

[0045] Figure 6 This is a flowchart illustrating the online fault monitoring method for POF hybrid optical cable provided in this embodiment. Detailed Implementation

[0046] The fault detection of POF hybrid optical cables in existing FTTR networks relies on offline, high-cost dedicated TDR equipment, which requires service interruption, leading to low operational efficiency. Therefore, there is an urgent need for an online, non-intrusive, and low-cost POF hybrid optical cable fault monitoring solution that can be integrated into active optical splitters to achieve real-time early warning and precise location of power supply cable faults, thereby improving the operational efficiency and reliability of FTTR networks.

[0047] Based on this, the technical solution of this invention is proposed. In this invention, an embedded micro-TDR monitoring module with a main control unit as the core is integrated inside the active optical splitter. A shared differential pulse drive circuit and a dual-channel analog-to-digital converter are time-division multiplexed to multiple downlink POF ports through an analog switch array. The high-voltage DC blocking capacitor in the safety coupling unit couples the test pulse to the POF hybrid optical cable carrying DC remote power supply, while isolating high-voltage DC and absorbing line surges, realizing online signal injection and reflected wave acquisition without interrupting services. The main control unit performs digital differential and cumulative averaging processing on the acquired signal to suppress common-mode noise, obtains the real-time differential reflection waveform, and compares it with a pre-established and stored permanent reference baseline to assess the cable aging trend. At the same time, it compares it with the dynamic reference baseline in real time to detect sudden impedance anomalies. When an anomaly is detected, the fault distance is calculated based on the reflection time difference and the pre-stored propagation speed. Finally, a diagnostic report is generated and reported, thereby realizing distributed online monitoring and accurate fault location of the entire network of POF hybrid optical cables.

[0048] The technical solutions in this embodiment will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0049] The POF hybrid fiber optic cable online fault monitoring system provided in this embodiment is applied to an FTTR network. Please refer to [link / reference]. Figure 1 In an FTTR network, there is a main gateway, multiple active optical splitters, and multiple sub-gateways. Each sub-gateway is connected to an active optical splitter via a POF hybrid optical-electrical cable, and each active optical splitter is connected to the main gateway in a multi-level cascade manner.

[0050] Please see Figure 2 The POF hybrid cable online fault monitoring system provided in this embodiment includes a TDR monitoring module integrated inside each active optical splitter, which is used to perform online fault monitoring and fault location of each POF hybrid cable connected to it.

[0051] Please see Figure 3The TDR monitoring module includes: a main control unit, a shared transmit and receive unit, an analog switch array, multiple safety coupling units, and multiple optoelectronic hybrid connectors.

[0052] (1) The main control unit includes a non-volatile memory for storing the health baseline and signal propagation speed, and for generating control signals and scheduling monitoring processes.

[0053] Specifically, the main control unit is the control core of the TDR monitoring module, and it integrates non-volatile memory. This non-volatile memory is used to store the pre-calibrated signal propagation speed and the health baseline (including permanent baseline and dynamic reference baseline) established during the initialization learning phase. The main control unit is responsible for generating the control signals required for the entire monitoring process and scheduling the execution timing of each stage, such as initialization learning, periodic monitoring, fault diagnosis, and data reporting.

[0054] (2) A shared transmitting and receiving unit, including a differential pulse driving circuit and a dual-channel analog-to-digital converter. The input terminal of the differential pulse driving circuit is connected to the output terminal of the main control unit to generate test pulses. The output terminal of the dual-channel analog-to-digital converter is connected to the input terminal of the main control unit to synchronously acquire reflected signals.

[0055] Specifically, the shared transmitter and receiver unit is the core measurement component of the TDR monitoring module, consisting of a differential pulse drive circuit and a dual-channel analog-to-digital converter. The input of the differential pulse drive circuit is connected to the output of the main control unit. When the main control unit issues a trigger command, the differential pulse drive circuit generates a low-voltage (3.3V) differential step pulse with a fast rise edge (typically 5ns). This pulse serves as a probe signal injected into the POF hybrid cable. The output of the dual-channel analog-to-digital converter is connected to the input of the main control unit. Its two acquisition channels correspond one-to-one with the two copper conductors of the POF hybrid cable, used to synchronously acquire the voltage signals of the reflected waves on the two copper conductors. Through dual-channel synchronous acquisition, the main control unit can subsequently perform digital differential processing on the two signals, effectively suppressing common-mode noise introduced by 56V DC remote power supply and environmental radiation. This shared transmitter and receiver unit serves only one downlink POF port at a time. Through time-division multiplexing of the analog switch array, a single set of measurement hardware achieves polling monitoring of multiple ports, significantly reducing system costs while ensuring measurement performance.

[0056] In this embodiment, the differential pulse driving circuit uses a high-speed LVDS driver chip, whose output differential step pulse amplitude is 3.3V and rise time is less than or equal to 5ns (typical value 5ns); the dual-channel analog-to-digital converter uses a synchronous sampling ADC chip with a sampling rate of not less than 50MSPS and a resolution of 12 bits, and its input matching resistor is 50Ω.

[0057] (3) An analog switch array, comprising two synchronously controlled analog switches, whose control terminals are connected to the main control unit, whose signal input terminals are connected to the output terminals of the differential pulse drive circuit, and whose signal output terminals are connected to the input terminals of the dual-channel analog-to-digital converter, for time-division multiplexing of the shared transmit and receive units to multiple downlink POF ports under the control of the main control unit.

[0058] Specifically, the analog switch array is a key component for enabling a single measurement hardware setup to support multi-port monitoring. This array consists of two synchronously controlled high-bandwidth analog switches, each with a 1:4 channel configuration. The control terminals of both analog switches are connected to the main control unit, receiving the same channel selection command to ensure they always switch synchronously to the same target port. The signal input of the first analog switch is connected to the output of the differential pulse drive circuit, switching the test pulse to the designated downlink POF port. The signal output of the second analog switch is connected to the input of the dual-channel analog-to-digital converter, switching the reflected signal from the same target port to the acquisition circuit. Through this synchronous one-to-one switching architecture, the main control unit can time-division multiplex the shared transmit and receive units to any downlink POF port at different times, thus achieving polling monitoring of multiple ports with a single differential pulse drive circuit and a single dual-channel analog-to-digital converter. In this embodiment, the analog switch uses a high-bandwidth device (such as the CH444P chip), with a -3dB bandwidth of not less than 300MHz and a channel isolation better than -70dB under 100MHz high-frequency conditions, ensuring that the nanosecond-level test pulse maintains waveform integrity when passing through the switch array, and that signals between different ports do not interfere with each other.

[0059] (4) Multiple safety coupling units, each safety coupling unit corresponds to a downlink POF port, the input of each safety coupling unit is connected to the output of a channel of the analog switch array, and the output of each safety coupling unit is connected to the POF optoelectronic hybrid cable through an optoelectronic hybrid connector; the safety coupling unit includes a high voltage DC blocking capacitor and a transient voltage suppressor. The high voltage DC blocking capacitor is connected in series in the signal path to block DC high voltage and couple test pulses. The transient voltage suppressor is connected in reverse parallel between the two copper conductors of the POF optoelectronic hybrid cable to absorb line surges.

[0060] Specifically, the core function of the safety coupling unit is to safely inject test pulses into the energized cable without interrupting DC remote power supply and optical signal transmission, while protecting the downstream precision measurement circuitry from high voltage and surge impacts. Each downlink POF port corresponds to an independent safety coupling unit. The input of this unit is connected to the output of one channel of the analog switch array to receive test pulses from the shared transmit and receive unit; its output is electrically connected to the two copper conductors of the POF hybrid cable via an optoelectronic hybrid connector.

[0061] The safety coupling unit consists of two parts: a high-voltage DC blocking capacitor and a transient voltage suppressor. The high-voltage DC blocking capacitor uses two 0.1μF NPO ceramic capacitors with a withstand voltage of not less than 100V, connected in series in the signal path of the two copper conductors. The function of the high-voltage DC blocking capacitor is to block the 56V DC remote power supply voltage carried on the POF hybrid cable, preventing high voltage reverse breakdown of downstream low-voltage devices such as analog switches and analog-to-digital converters. Simultaneously, because the capacitor exhibits extremely low capacitive reactance to nanosecond-level test pulses (less than 0.1Ω at a 70MHz main frequency), the test pulse can be efficiently coupled to the cable for propagation. The choice of NPO material ensures high stability of the capacitance value under temperature, voltage, and time variations, thus maintaining measurement consistency. The transient voltage suppressor uses two unidirectional TVS diodes (such as SMBJ58A), connected in reverse parallel between the two copper conductors of the POF hybrid cable, with a clamping voltage of approximately 70V. When a transient surge occurs on the line due to lightning strikes, electrostatic discharge, or equipment switching, the TVS diode quickly conducts, absorbing the surge energy and clamping it to a safe voltage range, preventing high-voltage spikes from damaging downstream circuits. Through the coordinated operation of the high-voltage DC blocking capacitor and the transient voltage suppressor, the safety coupling unit achieves efficient coupling of test pulses, reliable isolation of DC high voltage, and effective suppression of transient surges, providing hardware assurance for online non-intrusive impedance monitoring.

[0062] (5) Multiple optoelectronic hybrid connectors, one end of each optoelectronic hybrid connector is connected to the output end of a corresponding safety coupling unit, and the other end is used to plug in a POF optoelectronic hybrid cable.

[0063] Specifically, the optoelectronic hybrid connector is a physical interface component that enables simultaneous input of test signals and optical signals into the POF (Polyelectric Optical Fiber) hybrid cable. Each downstream POF port corresponds to an independent optoelectronic hybrid connector. One end of the connector is electrically connected to the output of the corresponding safety coupling unit, receiving the test pulse after coupling through a high-voltage DC blocking capacitor; the other end is used to insert into the POF hybrid cable, achieving integrated electrical and optical connection. Specifically, the optoelectronic hybrid connector adopts an onboard optoelectronic hybrid flange structure, internally integrating metal pins or springs for transmitting electrical signals and fiber optic ferrules for transmitting optical signals. The metal pins are soldered or crimped to the output of the safety coupling unit, ensuring that the test pulse can be transmitted to the two copper conductors of the POF hybrid cable with low loss; the fiber optic ferrule is aligned with the optical transceiver module inside the active beam splitter, ensuring transparent transmission of the optical signal. Through this integrated design, the optoelectronic hybrid connector simultaneously performs three major functions within a single physical interface: test pulse injection, DC remote power supply transmission, and optical signal coupling. This avoids signal reflection and reliability issues caused by additional wiring, providing a reliable connection solution for online fault monitoring.

[0064] Please see Figure 4 Based on the above system, the monitoring process in the main control unit includes the following steps:

[0065] Step 1: During the initialization learning phase, the analog switch array is controlled to sequentially select each downlink POF port, transmit test pulses and receive reflected signals through the shared transmit and receive unit, and after digital differential and cumulative averaging processing, establish a permanent reference baseline and a dynamic reference baseline and store them in the non-volatile memory.

[0066] In this embodiment, the non-volatile memory also pre-stores a standard reference data package of the same model as the connected POF hybrid cable. The standard reference data package includes: calibrated propagation speed, standard connector interface reflection coefficient range, and typical noise level standard deviation under fault-free conditions. During the initialization learning phase, the main control unit measures the propagation speed and reflection amplitude of the test pulse, and compares the measured propagation speed and reflection amplitude with the calibrated propagation speed and standard connector interface reflection coefficient range, respectively. If the deviation exceeds the preset range, it is determined that there is an installation fault in the current downlink POF port, and the baseline storage for the downlink POF port is stopped, while an initialization anomaly alarm is reported. If the comparison is successful, the currently measured waveform is stored as a permanent reference baseline.

[0067] Specifically, during the initialization learning phase, upon the system's first power-on or after installation and debugging, the main control unit controls the analog switch array to sequentially select each downstream POF port. For the currently selected port, the main control unit triggers the differential pulse drive circuit of the shared transmit and receive unit to transmit a test pulse. This pulse is injected into the POF optoelectronic hybrid cable via the analog switch array and the safety coupling unit. The incident wave propagates in the cable and generates a reflected wave when it encounters an impedance discontinuity. The reflected wave returns along the original path and is synchronously acquired by a dual-channel analog-to-digital converter after passing through the safety coupling unit and the analog switch array. The main control unit performs digital differential analysis on the dual signals obtained from multiple "transmit-acquisition" cycles to suppress common-mode noise and performs cumulative averaging to improve the signal-to-noise ratio, obtaining the reference reflected waveform for that port.

[0068] To ensure the accuracy of the established permanent baseline, a standard reference data package of the same type as the connected POF hybrid cable is pre-stored in the non-volatile memory. This data package includes the signal propagation speed calibrated experimentally, the standard connector interface reflection coefficient range, and the standard deviation of typical noise levels under fault-free conditions. The main control unit extracts the actual signal propagation speed and reflection amplitude at the connector from the reference waveform and compares these two measured values ​​with the pre-stored calibrated propagation speed and standard connector interface reflection coefficient range. If the measured value exceeds the preset range (e.g., excessive propagation speed deviation or abnormal reflection amplitude), it is determined that there is an installation fault such as improper installation, loose connector, or cable damage at the current port. The main control unit immediately stops storing the baseline for that port and reports an initialization fault alarm via indicator light or Bluetooth. If the comparison passes, the current link is confirmed to be in a healthy state, and the main control unit stores the reference waveform as a permanent baseline in the non-volatile memory.

[0069] In this embodiment, the main control unit is further configured to perform a dynamic reference baseline update step when the periodic measurement is completed and no fault is detected: if there is no fault in the periodic measurement for a preset number of consecutive times, and the deviation between the real-time differential reflection waveform obtained in each measurement and the permanent reference baseline is less than or equal to the noise standard deviation of the permanent reference baseline, then the real-time differential reflection waveform obtained in the most recent measurement is stored as a new dynamic reference baseline.

[0070] Specifically, after the periodic measurement is completed and no fault is detected in this round of monitoring, the main control unit further determines whether the update conditions are met: if no fault is found in the periodic measurement for a preset number of consecutive times (e.g., 3 consecutive times), and the deviation between the real-time differential reflection waveform obtained in each measurement and the permanent reference baseline is less than or equal to the noise standard deviation of the permanent reference baseline, it indicates that the current cable condition is healthy and the environmental conditions are stable. At this time, the main control unit stores the real-time differential reflection waveform obtained in the most recent measurement as a new dynamic reference baseline for real-time comparison in subsequent periodic monitoring.

[0071] Step 2: During the periodic monitoring phase, the analog switch array is controlled to select each downlink POF port in a time-division manner according to the set period. Real-time differential reflection waveforms are obtained through the shared transmit and receive units. The real-time differential reflection waveforms are compared with the dynamic reference baseline to determine whether there is a sudden impedance anomaly. If so, the fault distance is calculated based on the reflection time difference and the pre-stored propagation speed. The real-time differential reflection waveforms are compared with the permanent reference baseline to assess the cable aging trend. A diagnostic report is generated and submitted based on the impedance monitoring results and the cable aging assessment results.

[0072] In this embodiment, comparing the real-time differential reflection waveform with the dynamic reference baseline specifically includes:

[0073] The difference between the real-time differential reflection waveform and the dynamic reference baseline is calculated to obtain the fault characteristic waveform;

[0074] Based on the noise standard deviation of the permanent baseline, positive and negative thresholds are set;

[0075] When the fault characteristic waveform shows a peak value exceeding the positive threshold, it is determined that there is a high impedance anomaly at that location; when it shows a valley value below the negative threshold, it is determined that there is a low impedance anomaly at that location.

[0076] When a sudden impedance anomaly is detected, the reflection time difference is determined based on the time positions corresponding to the abnormal reflection peaks exceeding positive and falling below negative thresholds in the fault characteristic waveform. And combined with the pre-stored calibrated propagation speed Calculate the distance to the fault point The calculation formula is: .

[0077] In this embodiment, assessing the aging trend of the cable specifically includes:

[0078] According to the preset aging assessment cycle, the real-time differential reflection waveform measured at the moment is compared point by point with the permanent reference baseline stored in the non-volatile memory, and the deviation between the waveforms is calculated. The deviation is the cumulative deviation or root mean square error, which is calculated as follows: the amplitude of the real-time differential reflection waveform and the permanent reference baseline at the same time index is subtracted point by point, and the absolute value of the difference at each point is accumulated to obtain the cumulative deviation; or the absolute value of the difference is squared and accumulated to obtain the root mean square error.

[0079] The main control unit compares the deviation calculated in the current aging assessment cycle with the deviation in the previous cycle to obtain the rate of change of the deviation. When the cumulative deviation or root mean square error exceeds a preset aging threshold, or when the rate of change of the deviation exceeds a preset rate of change threshold, it determines that the POF optoelectronic hybrid cable has progressive aging or cumulative damage.

[0080] Specifically, after the system is running normally, the main control unit controls the analog switch array to select each downlink POF port in a time-division manner according to a preset cycle (such as once per hour), and obtains the real-time differential reflection waveform of each port through the shared transmit and receive unit. Subsequently, the main control unit executes a dual comparison mechanism:

[0081] First, the real-time differential reflection waveform is compared with the dynamic reference baseline. Specifically, the difference between the two is calculated to obtain the fault characteristic waveform. .like The amplitude at a certain time point exceeds a preset dynamic threshold (this threshold is the noise standard deviation of a permanent reference baseline). As a benchmark setting, it is usually taken as to If a peak value exceeding a positive threshold is observed, it is considered a high impedance anomaly (e.g., loose connector, oxidation); if a trough value below a negative threshold is observed, it is considered a low impedance anomaly (e.g., cable dampness, compression). The time difference between the occurrence of the abnormal reflection peaks is used to determine the location. And the calibrated propagation speed of the signal pre-stored in the non-volatile memory in this type of POF hybrid optical cable. Using the formula The distance between the fault point and the active optical splitter is calculated to achieve precise positioning.

[0082] Second, the real-time differential reflection waveform is compared with the permanent baseline waveform over a longer period (e.g., monthly or quarterly). By calculating the deviation between waveforms (e.g., the cumulative value of the absolute value of the point-by-point difference or the root mean square error), the presence of progressive overall aging or cumulative damage in the cable is assessed. When the deviation exceeds a preset aging threshold or the rate of change of the deviation exceeds a preset rate of change threshold, it is determined that the cable has an aging trend, and an aging warning message is generated.

[0083] Finally, based on the impedance monitoring results and cable aging assessment results, the main control unit generates a diagnostic report containing the fault port number, fault type, fault distance, and timestamp, and reports it to the main gateway and network management platform to achieve unified and visualized management of the health status of the entire network of POF optical-electric hybrid cables.

[0084] In this embodiment, a thermistor is attached to each opto-hybrid connector. The thermistor senses the temperature of the corresponding opto-hybrid connector and generates a corresponding temperature analog signal. Please refer to [link to relevant documentation]. Figure 5 The active beam splitter further includes:

[0085] The power conversion module has an input terminal for connecting to an external AC power source and an output terminal for outputting DC power to power the various modules inside the active optical splitter.

[0086] A multi-channel DC power management module has its input terminal electrically connected to the output terminal of the power conversion module. The multi-channel DC power management module integrates a power management chip, which distributes DC power to each downstream POF port, monitors the operating status of each downstream POF port in real time, and generates electrical operating parameters for each downstream POF port. These electrical operating parameters include real-time output voltage, real-time output current, chip junction temperature, and fault flag bits. The power management chip also includes a digital communication interface for outputting these electrical operating parameters.

[0087] The power supply terminal of the main control unit is electrically connected to the internal low-voltage output terminal of the power management chip, and is directly powered by the power management chip. The main control unit also includes a digital communication interface and an ADC sampling interface. Its digital communication interface is connected to the digital communication interface of the power management chip to periodically read the electrical operating parameters. Its ADC sampling interface is electrically connected to each thermistor to receive the temperature analog signal and convert it into real-time temperature data of each optoelectronic hybrid connector.

[0088] The main control unit is also configured to: during the periodic monitoring phase, when the real-time output current of a certain downlink POF port exceeds a preset current fluctuation threshold as read from the electrical operating parameters, or when the temperature of a certain optoelectronic hybrid connector exceeds a preset temperature threshold as determined by the real-time temperature data, trigger continuous impedance monitoring of the corresponding downlink POF port.

[0089] Specifically, in this embodiment, to further enhance the system's real-time response capability and achieve early warning of potential faults, the active beam splitter integrates power management and temperature monitoring functions, and links them with the TDR monitoring module. Specifically, a thermistor is attached to each optoelectronic hybrid connector to sense the temperature at the connector end in real time and generate a temperature simulation signal. Simultaneously, the active beam splitter has an internal power conversion module, whose input is connected to an external AC power source, and whose output provides DC power to power the internal modules. A multi-channel DC power management module integrates a power management chip, which not only distributes DC remote power to each downstream POF port but also monitors the operating status of each port in real time, generating electrical operating parameters including real-time output voltage, real-time output current, chip junction temperature, and fault flags, and outputting them externally through a digital communication interface. The main control unit is directly powered by the internal low-voltage output of the power management chip, without the need for additional power conversion. The main control unit connects to the digital communication interface of the power management chip through its digital communication interface, periodically reading the electrical operating parameters of each downstream POF port, and simultaneously connects to each thermistor through its ADC sampling interface to convert the temperature simulation signal into real-time temperature data. During the periodic monitoring phase, the main control unit not only performs routine fault monitoring according to a preset cycle, but also continuously monitors the aforementioned electrical parameters and temperature data. When the real-time output current of a certain downstream POF port exceeds the preset current fluctuation threshold, or when the temperature of a certain optoelectronic hybrid connector exceeds the preset temperature threshold based on real-time temperature data, the main control unit immediately triggers continuous impedance monitoring of that downstream POF port. This linkage triggering mechanism enables the system to quickly initiate high-frequency impedance measurements in the early stages of physical faults such as power supply anomalies (e.g., short circuits, overloads) or connector overheating, thereby promptly identifying and locating potential fault points. This upgrades traditional passive periodic monitoring to event-driven proactive protection, further improving the system's fault response speed and operational reliability.

[0090] In this embodiment, the main control unit is also used to encapsulate the read electrical operating parameters and converted real-time temperature data with the diagnostic report according to a preset data frame format to generate a comprehensive status data frame, and prioritize uploading the comprehensive status data frame to the next-level active optical splitter through the cascaded optical fiber network, up to the main gateway; when an uplink interruption of the optical fiber is detected, the main control unit transmits the comprehensive status data frame to the main gateway through its built-in Bluetooth communication module in the form of Bluetooth broadcast or Bluetooth Mesh message.

[0091] Specifically, in this embodiment, the main control unit also constructs a comprehensive status data frame and a dual-channel reporting mechanism to achieve comprehensive aggregation and reliable transmission of system health status. In practical applications, the main control unit encapsulates periodically read electrical operating parameters (including real-time output voltage, real-time output current, chip junction temperature, and fault flag bits) and converted real-time temperature data of each optoelectronic hybrid connector according to a preset data frame format and diagnostic report, generating a comprehensive status data frame containing power status, temperature status, and diagnostic information. Regarding data transmission strategy, the main control unit prioritizes uploading the comprehensive status data frame level by level to the next-level active optical splitter via a cascaded fiber optic network, ultimately converging to the main gateway and reporting to the network management platform, utilizing the high bandwidth and high reliability of the fiber optic network to achieve routine data reporting. When the main control unit detects an uplink interruption, as a backup redundancy mechanism, the main control unit immediately switches to its built-in Bluetooth communication module, transmitting the comprehensive status data frame to the main gateway or surrounding Bluetooth gateway devices in the form of Bluetooth broadcast or Bluetooth Mesh messages, ensuring that alarm information is not lost in the event of a fiber optic link failure. Through a dual-channel reporting mechanism, unified and visualized management of the impedance, power, and temperature status of the entire POF hybrid optical and electrical cables is achieved, providing maintenance personnel with penetrating fault location capabilities and significantly improving the maintenance reliability of the FTTR multi-level cascaded network.

[0092] In this embodiment, the main control unit is further configured to: receive a unified time reference synchronization signal periodically broadcast by the main gateway through a cascaded fiber optic network, and introduce random delay within a unified monitoring time window according to its own device ID or network level, wherein the random delay is a random value from 0 to the length of the monitoring time window.

[0093] Specifically, to avoid mutual interference caused by multiple active optical splitters simultaneously transmitting test pulses in a multi-level cascaded FTTR network architecture, the main control unit is also configured with a network-level collaborative working mechanism. In practical applications, the main gateway periodically broadcasts a unified time reference synchronization signal to the entire network through the management channel of the cascaded fiber optic network. The main control units of each active optical splitter receive this synchronization signal through the cascaded fiber optic network and establish a unified monitoring time window accordingly. Based on this, each main control unit introduces a random delay within the unified monitoring time window according to its own device ID or network level. The value of this random delay ranges from 0 to a random value between the length of the monitoring time window. Through this time-division distributed mechanism, even if the monitoring cycles of multiple active optical splitters are completely consistent, the actual time of their test pulse transmission will be staggered due to the random delay. This effectively avoids collisions or mutual interference of test pulses on the cascaded fiber optic or shared line when multiple devices are measuring simultaneously, ensuring the stability of the distributed monitoring system and the accuracy of the measurement results.

[0094] In summary, the POF hybrid optical cable online fault monitoring system provided in this embodiment achieves online fault monitoring without interrupting remote power supply and optical signal transmission by highly integrating an embedded micro TDR monitoring module with a main control unit as the core within the active optical splitter. It utilizes an analog switch array to achieve time-division multiplexing of multiple ports using a single set of transmitting and receiving hardware. Combined with a safety coupling unit, test pulses are coupled to the energized cable. This solves the problem of existing technologies relying on offline, high-cost dedicated TDR equipment and requiring service interruption during testing. During the initialization learning phase, pre-stored standard reference data packets are used for status verification, ensuring that a permanent baseline is established only in a healthy state, while a dynamic baseline is also established simultaneously. During the periodic monitoring phase, a dual comparison mechanism is employed: comparing the real-time waveform with the dynamic baseline, and combining reflection time difference and calibrated propagation speed to accurately locate sudden impedance anomalies (within 1 meter of 100 meters); and comparing the real-time waveform with the permanent baseline over a long period, using waveform deviation calculation to assess the cable's progressive aging trend. This achieves an upgrade in maintenance mode from fault repair to health prevention. Furthermore, the system integrates power management and temperature monitoring functions. High-frequency continuous monitoring is triggered when the power supply current fluctuates or the connector temperature is abnormal, forming event-driven proactive protection. A dual-channel reporting mechanism with fiber priority and Bluetooth backup ensures reliable aggregation of fault information to the network management platform. Random delays are introduced at each level of active optical splitter based on a unified time reference broadcast by the main gateway, effectively avoiding mutual interference when multiple devices are measuring simultaneously. This embodiment achieves distributed online health management of POF hybrid optical cables in a multi-level cascaded FTTR network with extremely low hardware costs, significantly improving the operation and maintenance efficiency and reliability of all-optical networking.

[0095] Based on the above technical solution, this embodiment also provides an online fault monitoring method for POF hybrid optical-electric cables, applied to the online fault monitoring system for POF hybrid optical-electric cables as described in the embodiment. Please refer to... Figure 6 The method includes:

[0096] During the initialization and learning phase, the main control unit controls the analog switch array to sequentially select each downlink POF port, transmits test pulses and receives reflected signals through the shared transmit and receive unit, and after digital differential and cumulative averaging processing, establishes a permanent reference baseline and a dynamic reference baseline and stores them in the non-volatile memory.

[0097] During the periodic monitoring phase, the main control unit controls the analog switch array to select each downlink POF port in a time-division manner according to the set period, and obtains the real-time differential reflection waveform through the shared transmit and receive unit; compares the real-time differential reflection waveform with the dynamic reference baseline to determine whether there is a sudden impedance anomaly, and if so, calculates the fault distance based on the reflection time difference and the pre-stored propagation speed; compares the real-time differential reflection waveform with the permanent reference baseline to assess the cable aging trend; and generates and reports a diagnostic report based on the impedance monitoring results and cable aging assessment results.

[0098] It is understood that since the POF optical-electric hybrid cable online fault monitoring method described in this embodiment is based on the POF optical-electric hybrid cable online fault monitoring system described in the embodiment, the method disclosed in the embodiment is relatively simple to describe because it corresponds to the system disclosed in the embodiment. For relevant parts, please refer to the system description.

Claims

1. A POF (Polyelectric Fiber Optic) hybrid cable online fault monitoring system, applied to FTTR (Fiber to the Rectifier) ​​network, characterized in that, The system includes a TDR monitoring module integrated inside each active optical splitter, the TDR monitoring module comprising: The main control unit includes non-volatile memory for storing health baseline and signal propagation speed, and for generating control signals and scheduling monitoring processes; The shared transmitting and receiving unit includes a differential pulse driving circuit and a dual-channel analog-to-digital converter. The input of the differential pulse driving circuit is connected to the output of the main control unit to generate test pulses. The output of the dual-channel analog-to-digital converter is connected to the input of the main control unit to synchronously acquire reflected signals. An analog switch array includes two synchronously controlled analog switches, whose control terminals are connected to the main control unit, whose signal input terminals are connected to the output terminals of a differential pulse drive circuit, and whose signal output terminals are connected to the input terminals of a dual-channel analog-to-digital converter. It is used to time-division multiplex the shared transmit and receive unit to multiple downlink POF ports under the control of the main control unit. Multiple safety coupling units are provided, each corresponding to a downstream POF port. The input of each safety coupling unit is connected to the output of a channel of the analog switch array, and the output of each safety coupling unit is connected to the POF hybrid cable via a hybrid optoelectronic connector. Each safety coupling unit includes a high-voltage DC blocking capacitor and a transient voltage suppressor. The high-voltage DC blocking capacitor is connected in series in the signal path to block DC high voltage and couple test pulses. The transient voltage suppressor is connected in reverse parallel between the two copper conductors of the POF hybrid cable to absorb line surges. Multiple optoelectronic hybrid connectors, one end of each optoelectronic hybrid connector is connected to the output end of a corresponding safety coupling unit, and the other end is used to plug in a POF optoelectronic hybrid cable; The monitoring process in the main control unit includes: During the initialization learning phase, the control analog switch array sequentially selects each downlink POF port, transmits test pulses and receives reflected signals through the shared transmit and receive unit, and after digital differential and cumulative averaging processing, establishes a permanent reference baseline and a dynamic reference baseline and stores them in the non-volatile memory. During the periodic monitoring phase, the analog switch array is controlled to select each downlink POF port in a time-division manner according to the set period, and the real-time differential reflection waveform is obtained through the shared transmit and receive unit. The real-time differential reflection waveform is compared with the dynamic reference baseline to determine whether there is a sudden impedance anomaly. If so, the fault distance is calculated based on the reflection time difference and the pre-stored propagation speed. The real-time differential reflection waveform is compared with the permanent reference baseline to assess the cable aging trend. A diagnostic report is generated and reported based on the impedance monitoring results and the cable aging assessment results.

2. The POF hybrid cable online fault monitoring system according to claim 1, characterized in that, The non-volatile memory also pre-stores a standard reference data package of the same model as the connected POF hybrid cable. The standard reference data package includes: calibrated propagation speed, standard connector interface reflection coefficient range, and typical noise level standard deviation under fault-free conditions. During the initialization learning phase, the main control unit measures the propagation speed and reflection amplitude of the test pulse, and compares the measured propagation speed and reflection amplitude with the calibrated propagation speed and standard connector interface reflection coefficient range, respectively. If the deviation exceeds the preset range, it is determined that there is an installation fault in the current downlink POF port, and the baseline storage for the downlink POF port is stopped, while an initialization abnormality alarm is reported. If the comparison is successful, the currently measured waveform is stored as a permanent reference baseline.

3. The POF hybrid cable online fault monitoring system according to claim 2, characterized in that, The comparison of the real-time differential reflection waveform with the dynamic reference baseline specifically includes: The difference between the real-time differential reflection waveform and the dynamic reference baseline is calculated to obtain the fault characteristic waveform; Based on the noise standard deviation of the permanent baseline, positive and negative thresholds are set; When the fault characteristic waveform shows a peak value exceeding the positive threshold, it is determined that there is a high impedance anomaly at that location; when it shows a valley value below the negative threshold, it is determined that there is a low impedance anomaly at that location. When a sudden impedance anomaly is detected, the reflection time difference is determined based on the time positions corresponding to the abnormal reflection peaks exceeding positive and falling below negative thresholds in the fault characteristic waveform. And combined with the pre-stored calibrated propagation speed Calculate the distance to the fault point The calculation formula is: .

4. The POF hybrid optical cable online fault monitoring system according to claim 1, characterized in that, The assessment of cable aging trends specifically includes: According to the preset aging assessment cycle, the real-time differential reflection waveform measured at the moment is compared point by point with the permanent reference baseline stored in the non-volatile memory, and the deviation between the waveforms is calculated. The deviation is the cumulative deviation or root mean square error, which is calculated as follows: the amplitude of the real-time differential reflection waveform and the permanent reference baseline at the same time index is subtracted point by point, and the absolute value of the difference at each point is accumulated to obtain the cumulative deviation; or the absolute value of the difference is squared and accumulated to obtain the root mean square error. The main control unit compares the deviation calculated in the current aging assessment cycle with the deviation in the previous cycle to obtain the rate of change of the deviation. When the cumulative deviation or root mean square error exceeds a preset aging threshold, or when the rate of change of the deviation exceeds a preset rate of change threshold, it determines that the POF optoelectronic hybrid cable has progressive aging or cumulative damage.

5. The POF hybrid optical cable online fault monitoring system according to claim 1, characterized in that, The differential pulse drive circuit uses a high-speed LVDS driver chip, whose output differential step pulse amplitude is 3.3V and rise time is less than or equal to 5ns; the dual-channel analog-to-digital converter uses a synchronous sampling ADC chip with a sampling rate of not less than 50MSPS and a resolution of 12 bits, and its input matching resistor is 50Ω; the high-voltage DC blocking capacitor consists of two NPO ceramic capacitors, each with a capacitance of 0.1μF and a withstand voltage greater than or equal to 100V.

6. The POF hybrid optical cable online fault monitoring system according to claim 1, characterized in that, The main control unit is also configured to perform a dynamic reference baseline update step when periodic measurements are completed and no fault is detected: If there are no faults in the periodic measurements for a preset number of consecutive times, and the deviation between the real-time differential reflection waveform obtained in each measurement and the permanent reference baseline is less than or equal to the noise standard deviation of the permanent reference baseline, then the real-time differential reflection waveform obtained in the most recent measurement is stored as a new dynamic reference baseline.

7. The POF hybrid optical cable online fault monitoring system according to claim 1, characterized in that, Each optoelectronic hybrid connector is equipped with a thermistor, which is used to sense the temperature of the corresponding optoelectronic hybrid connector and generate a corresponding temperature analog signal; the active beam splitter also includes: The power conversion module has an input terminal for connecting to an external AC power source and an output terminal for outputting DC power to power the various modules inside the active optical splitter. A multi-channel DC power management module has its input terminal electrically connected to the output terminal of the power conversion module. The multi-channel DC power management module integrates a power management chip, which distributes DC power to each downstream POF port, monitors the operating status of each downstream POF port in real time, and generates electrical operating parameters for each downstream POF port. These electrical operating parameters include real-time output voltage, real-time output current, chip junction temperature, and fault flag bits. The power management chip also includes a digital communication interface for outputting these electrical operating parameters. The power supply terminal of the main control unit is electrically connected to the internal low-voltage output terminal of the power management chip, and is directly powered by the power management chip. The main control unit also includes a digital communication interface and an ADC sampling interface. Its digital communication interface is connected to the digital communication interface of the power management chip to periodically read the electrical operating parameters. Its ADC sampling interface is electrically connected to each thermistor to receive the temperature analog signal and convert it into real-time temperature data of each optoelectronic hybrid connector. The main control unit is also configured to: during the periodic monitoring phase, when the real-time output current of a certain downlink POF port exceeds a preset current fluctuation threshold as read from the electrical operating parameters, or when the temperature of a certain optoelectronic hybrid connector exceeds a preset temperature threshold as determined by the real-time temperature data, trigger continuous impedance monitoring of the corresponding downlink POF port.

8. The POF hybrid optical cable online fault monitoring system according to claim 7, characterized in that, The diagnostic report includes the fault port number, fault type, fault distance, and timestamp; The main control unit is also used to encapsulate the read electrical operating parameters and converted real-time temperature data with the diagnostic report according to the preset data frame format to generate a comprehensive status data frame, and prioritizes uploading the comprehensive status data frame to the next level active optical splitter through the cascaded optical fiber network, until the main gateway; when an uplink interruption of the optical fiber is detected, the main control unit transmits the comprehensive status data frame to the main gateway through its built-in Bluetooth communication module in the form of Bluetooth broadcast or Bluetooth Mesh message.

9. The POF hybrid optical cable online fault monitoring system according to claim 1, characterized in that, The main control unit is also configured to receive a unified time reference synchronization signal periodically broadcast by the main gateway through a cascaded fiber optic network, and introduce random delay within a unified monitoring time window according to its own device ID or network level, wherein the random delay is a random value from 0 to the length of the monitoring time window.

10. A method for online fault monitoring of a POF (Polyelectric-Fluorescent) hybrid cable, characterized in that, The method, applied to the POF hybrid cable online fault monitoring system as described in any one of claims 1 to 9, comprises: During the initialization and learning phase, the main control unit controls the analog switch array to sequentially select each downlink POF port, transmits test pulses and receives reflected signals through the shared transmit and receive unit, and after digital differential and cumulative averaging processing, establishes a permanent reference baseline and a dynamic reference baseline and stores them in the non-volatile memory. During the periodic monitoring phase, the main control unit controls the analog switch array to select each downlink POF port in a time-division manner according to the set period, and obtains the real-time differential reflection waveform through the shared transmit and receive unit; compares the real-time differential reflection waveform with the dynamic reference baseline to determine whether there is a sudden impedance anomaly, and if so, calculates the fault distance based on the reflection time difference and the pre-stored propagation speed; compares the real-time differential reflection waveform with the permanent reference baseline to assess the cable aging trend; and generates and reports a diagnostic report based on the impedance monitoring results and cable aging assessment results.

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