Optical fiber access equipment

Abstract

The invention provides an optical fiber access device, and relates to the technical field of communication, the optical fiber access device comprises a programmable logic device, an RS485 interface chip and an SFP optical module, the RS485 interface chip is connected with the SFP optical module through the programmable logic device, the RS485 interface chip is used for sending first sampling data to the programmable logic device, and the programmable logic device is connected with the RS485 interface chip; the programmable logic device is used for converting the private frame structure into a PECL level and sending the PECL level to the SFP optical module, and the SFP optical module is used for converting the PECL level into an optical signal to be transmitted on an optical fiber; the first sampling data is TTL (Transistor-Transistor Logic) level converted by the RS485 interface chip based on an RS485 interface level, and the private frame structure is a private communication frame structure constructed by the programmable logic device based on the first sampling data, the second sampling data and the third sampling data. By using the optical fiber communication technology, the limitation of the connection distance of the traditional RS485 cable is successfully broken through, and the transparent transmission distance of the RS485 communication interface can be increased.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and in particular, to an optical fiber access device. Background Art

[0002] As the mainstream serial standard in the field of industrial communication, the RS485 data interface realizes advantages such as strong anti-interference ability and multi-node networking by virtue of the differential signal transmission mechanism, and is widely used in scenarios such as smart grids and remote device management. However, in the prior art, access devices based on the RS485 data interface generally achieve communication through cable connections. This method limits the transmission distance due to its physical layer characteristics (the cable connection distance generally does not exceed 1000 meters), resulting in the inability of communication devices based on the RS485 data interface to meet the long-distance communication requirements.

[0003] With the development of the industrial Internet of Things, the demands for multi-kilometer-level monitoring and cross-regional device interconnection have increased sharply. There is an urgent need for an access device that can improve the communication transmission distance while maintaining the compatibility of the RS485 protocol. Summary of the Invention

[0004] An embodiment of this application provides an optical fiber access device that can improve the communication transmission distance while maintaining the compatibility of the RS485 protocol.

[0005] An embodiment of this application provides an optical fiber access device, including a programmable logic device, an RS485 interface chip, and a small form-factor pluggable (SFP) optical module. The RS485 interface chip is connected to the SFP optical module through the programmable logic device. The RS485 interface chip is used to send first sampled data to the programmable logic device. The programmable logic device is used to convert a private frame structure into a positive emitter-coupled logic (PECL) level and send it to the SFP optical module. The SFP optical module is used to convert the PECL level into an optical signal for transmission on an optical fiber.

[0006] Wherein, the first sampled data is a transistor-transistor logic (TTL) level converted by the RS485 interface chip based on the RS485 interface level. The private frame structure is a private communication frame structure constructed by the programmable logic device based on the first sampled data, second sampled data, and third sampled data. The first sampled data includes first-channel RS485 interface data and second-channel RS485 interface data. The second sampled data includes data line data and clock line data of a synchronous and half-duplex communication I2C bus obtained by the programmable logic device. The third sampled data includes configuration information of the optical fiber access device.

[0007] Optionally, each private frame in the private frame structure includes a first time slot, a second time slot, a third time slot, a fourth time slot, and a fifth time slot. The first time slot is used to transmit framing bytes and overhead information. The framing bytes are used for frame synchronization, and the overhead information is used for device management. The second time slot is used to transmit the data of the first RS485 interface. The third time slot is used to transmit the data of the second RS485 interface. The fourth time slot is used to transmit the clock line data of the I2C bus. The fifth time slot is used to transmit the data line data of the I2C bus.

[0008] Optionally, the data structure formed by the framing bytes and the overhead information is a matrix data of 8 rows * 16 columns.

[0009] Optionally, the matrix data includes:

[0010] A first field, which is used to indicate the framing bytes and is not scrambled.

[0011] A second field, which is a multi-frame indicator.

[0012] A third field, which is used to indicate the alarm information of the remote device connected to the RS485 interface chip.

[0013] A fourth field, which is used to indicate the alarm information of the optical path connected to the SFP optical module.

[0014] A fifth field, which is used to indicate transmission error information.

[0015] A sixth field, which is used to indicate the configuration information.

[0016] A seventh field, which is used to indicate reserved information.

[0017] An eighth field, which is used to indicate the check code of the first field.

[0018] Optionally, the frame period of the first time slot is 819.2 us.

[0019] Optionally, the transmission rate of each of the first time slot, the second time slot, the third time slot, the fourth time slot, and the fifth time slot is 2.5 Mbps.

[0020] Optionally, the frame rate of the private frame structure is 12.5 Mbps.

[0021] Optionally, the private frame structure is a private communication frame structure using bit-interleaved multiplexing.

[0022] Optionally, it further includes a power supply drop detection module, in which an energy storage capacitor is arranged, and the energy storage capacitor is electrically connected to the programmable logic device.

[0023] Optionally, it further includes a crystal oscillator, which is used to send the working clock information of 25Mhz to the programmable logic device.

[0024] In the embodiment of the present application, the RS485 interface chip can implement the conversion function of the two-way RS485 interface level, that is, it can convert the interface levels corresponding to the collected first-way RS485 interface data and the second-way RS485 interface data into TTL levels to obtain the first sampling data, and send the first sampling data to the programmable logic device for further processing by the programmable logic device. The docking of the RS485 interface chip and the programmable logic device is realized. In addition, the programmable logic device can also sample the data of the data line and the clock line of the I2C bus to obtain the second sampling data; sample the configuration information to obtain the third sampling data. The programmable logic device constructs a private frame structure based on the first sampling data, the second sampling data and the third sampling data, and converts the private frame structure into PECL level and sends it to the SFP optical module, so that the SFP optical module can convert the PECL level into an optical signal and transmit it on the optical fiber. In this way, using optical fiber communication technology, the limitation of the connection distance of the traditional RS485 cable is successfully broken through, and the distance of transparent transmission of the RS485 communication interface can be increased. Description of the Drawings

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0026] Figure 1 It is a schematic structural diagram of an optical fiber access device provided by an embodiment of the present application;

[0027] Figure 2 It is a schematic diagram of a private frame structure provided by an embodiment of the present application;

[0028] Figure 3 It is a schematic diagram of matrix data in the first time slot provided by an embodiment of the present application. Detailed Embodiments

[0029] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0030] The terms "first", "second", etc. in the embodiments of the present application are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0031] As Figure 1 shown, the embodiments of the present application provide an optical fiber access device, including a programmable logic device, an RS485 interface chip, and a Small Form Pluggable (SFP) optical module. The RS485 interface chip is connected to the SFP optical module through the programmable logic device. The RS485 interface chip is used to send first sampling data to the programmable logic device. The programmable logic device is used to convert a private frame structure into a Pseudo-Emitter Coupled Logic (PECL) level and send it to the SFP optical module. The SFP optical module is used to convert the PECL level into an optical signal for transmission on an optical fiber.

[0032] Among them, the first sampling data is a Transistor-Transistor Logic (TTL) level converted by the RS485 interface chip based on the RS485 interface level. The private frame structure is a private communication frame structure constructed by the programmable logic device based on the first sampling data, the second sampling data, and the third sampling data. The first sampling data includes the first path of RS485 interface data and the second path of RS485 interface data. The second sampling data includes the data line data and the clock line data of the synchronous, half-duplex Inter-Integrated Circuit (I2C) bus obtained by the programmable logic device. The third sampling data includes the configuration information of the optical fiber access device.

[0033] In the embodiments of the present application, the RS485 interface chip can implement the conversion function of two-way RS485 interface levels, that is, it can convert the interface levels corresponding to the collected first-way RS485 interface data and the second-way RS485 interface data into TTL levels to obtain the first sampling data, and send the first sampling data to the programmable logic device for further processing by the programmable logic device. The docking of the RS485 interface chip and the programmable logic device is realized. In addition, the programmable logic device can also sample the data on the data line and the clock line of the I2C bus to obtain the second sampling data; sample the configuration information (for example, Bill of Materials (BOM) version; Printed Circuit Board (PCB) version; Charge Injection Device (CID) device type, etc.) to obtain the third sampling data. The programmable logic device constructs a private frame structure based on the first sampling data, the second sampling data, and the third sampling data, and converts the private frame structure into PECL levels and sends them to the SFP optical module, so that the SFP optical module can convert the PECL levels into optical signals for transmission on the optical fiber. In this way, by using fiber optic communication technology, the limitation of the connection distance of traditional RS485 cables is successfully broken through, and long-distance (for example, 0 - 40 km) transparent transmission of RS485 communication interfaces can be achieved.

[0034] Among them, an RS485 interface is connected to the RS485 interface chip. After the two-way RS485 interface levels (A+, A-; B+, B-) are converted into TTL levels by the RS485 interface chip, they are sent to the programmable logic device. A communication connection is established between the programmable logic device and the SFP optical module to realize the transmission of Transmit Data (TXD), Receive Data (RXD), Serial Clock (SCK) signals, and Serial Data (SDA) signals.

[0035] Among them, before converting the first sampling data and the second sampling data into PECL levels and sending them to the SFP optical module, the programmable logic device can perform multiplexing processing on the sampled data to optimize resource utilization and realize multi-signal concurrent transmission; perform framing processing on the sampled data to ensure clear data boundaries and support synchronization, error correction, and protocol parsing; perform scrambling processing on the sampled data to improve signal reliability and security and avoid physical layer transmission problems.

[0036] Optionally, each private frame in the private frame structure includes a first time slot, a second time slot, a third time slot, a fourth time slot, and a fifth time slot. The first time slot is used to transmit framing bytes and overhead information. The framing bytes are used for frame synchronization, and the overhead information is used for device management. The second time slot is used to transmit the data of the first RS485 interface. The third time slot is used to transmit the data of the second RS485 interface. The fourth time slot is used to transmit the clock line data of the I2C bus. The fifth time slot is used to transmit the data line data of the I2C bus.

[0037] In this embodiment, the private frame structure may include multiple private frames. Each private frame is set to include 5 bits (bit), and each bit is a transmission time slot. In other words, each private frame in the private frame structure includes a first time slot, a second time slot, a third time slot, a fourth time slot, and a fifth time slot. The first time slot may be named FSA, the second time slot may be named TS1, the third time slot may be named TS2, the fourth time slot may be named SCL, and the fifth time slot may be named SDA, as Figure 2 shown. The first time slot FSA is used to transmit framing bytes and overhead information. The framing bytes are used for frame synchronization, and the overhead information is used for device management. The second time slot TS1 is used to transmit the data of the first RS485 interface. The third time slot TS2 is used to transmit the data of the second RS485 interface. The fourth time slot SCL is used to transmit the clock line data of the I2C bus. The fifth time slot SDA is used to transmit the data line data of the I2C bus.

[0038] In this way, the data of the two RS485 interfaces, the I2C clock line data, and the I2C data line data are respectively allocated to independent time slots to avoid signal interference. Through fixed time slot allocation, a complex bus arbitration mechanism is not required, reducing the hardware design complexity. Among them, the second time slot TS1 and the third time slot TS2 can match the baud rate through the time slot period to achieve asynchronous data synchronization; the fourth time slot SCL and the fifth time slot SDA can retain the original clock synchronization characteristics to ensure that the receiving end can completely restore the I2C waveform (such as start bit, stop bit, acknowledgment bit). In addition, the framing bytes transmitted in the first time slot FSA can quickly achieve frame synchronization through a fixed mode (such as 0xFF) to avoid parsing errors caused by misalignment; through the overhead information transmitted in the first time slot FSA, a lightweight but efficient device management mechanism can be implemented, facilitating network maintenance personnel to timely understand the status of the optical fiber access device and the remote device, and improving the remote management efficiency.

[0039] Among them, for the framing bytes and overhead information transmitted in the first time slot FSA, please refer to the following description:

[0040] Optionally, the data structure formed by the framing byte and the overhead information is a matrix data of 8 rows * 16 columns, with a total of 256 bytes. It has good information capacity, reliability, and scalability.

[0041] Optionally, the matrix data includes:

[0042] A first field, which is used to indicate the framing byte and is not scrambled.

[0043] A second field, which is a multi-frame indication.

[0044] A third field, which is used to indicate the alarm information of the remote device connected to the RS485 interface chip.

[0045] A fourth field, which is used to indicate the alarm information of the optical path connected to the SFP optical module.

[0046] A fifth field, which is used to indicate transmission error information.

[0047] A sixth field, which is used to indicate the configuration information.

[0048] A seventh field, which is used to indicate reserved information.

[0049] An eighth field, which is used to indicate the check code of the first field.

[0050] In this embodiment, as Figure 3 shown, the matrix data of 8 rows * 16 columns may include:

[0051] A first field, namely the FSA_OH field. The FSA_OH field is used to indicate the framing byte and can be composed of 6 fixed bytes, which are fixed as: 0xF6, 0xF6, 0xF6, 0x28, 0x28, 0x28; and the FSA_OH field is not scrambled, which can avoid the scrambling code from destroying the synchronization code feature and ensure that the receiver can quickly capture the frame header through the sliding window detection.

[0052] A second field, namely the MFI field. The MFI field is a multi-frame indication and is used to indicate which sub-frame the current frame belongs to. The value ranges from 0 to 255, supporting time-division multiplexing of multi-frame combinations.

[0053] A third field, namely the PRD field. The PRD field is used to indicate the alarm information of the remote device connected to the RS485 interface chip. If the remote device loses power, this field is 1, and if the power supply is normal, it is 0, realizing the power-off alarm of the remote device, so that the remote device can be remotely managed.

[0054] The fourth field, namely the ALM field, is used to indicate the alarm information of the optical path connected to the SFP optical module. If there is an alarm in the optical path, this field is 1; if there is no alarm, it is 0. This realizes the optical path alarm of the SFP optical module, enabling remote management of the SFP optical module.

[0055] The fifth field, namely the ERR field, is used to indicate transmission error information. If the previous frame check fails, this field is 1; if it passes, it is 0.

[0056] The sixth field is used to indicate configuration information and can include at least one of the following fields:

[0057] The CID field is used to transmit device type information, with values ranging from 0 to 255, encoded according to the device type. For example, 0 = optical module, 1 = switch, 2 = sensor;

[0058] The PCB field is used to transmit PCB version information, recording the circuit board version (e.g., V1.2 → 0x12), with values ranging from 0 to 255;

[0059] The BOM field is used to transmit BOM version information, recording the bill of materials version (e.g., Rev.C → 0x03), with values ranging from 0 to 255;

[0060] The MOD field is used to transmit module type information. For example, 1 indicates that the transmission module type is remote, and 0 indicates that the transmission module type is local, enabling network hierarchical management;

[0061] The LP field is used to transmit loopback configuration information. For example, 1 indicates loopback configuration, and 0 indicates loopback cancellation;

[0062] The PWR field is used to transmit power supply type information. For example, 1 indicates that the power supply type is AC, and 0 indicates that the power supply type is DC.

[0063] The seventh field, namely the RSV field, is used to indicate reserved information and can be used for later extended functions, such as encryption keys, IPv6 address extensions, etc.

[0064] The eighth field, namely the FCS field, is used to indicate the checksum of the first field. A cyclic redundancy check is performed on the entire FAS frame to ensure data integrity.

[0065] In this way, the private frame structure achieves fast synchronization through the FSA_OH framing symbol and avoids scrambling interference. The MFI multiframe indication supports 256-level time-division multiplexing. The three-bit linkage of PRD / ALM / ERR enables millisecond-level fault diagnosis. The CID / PCB / BOM fields support the traceability of the entire device life cycle. The LP / PWR fields optimize testing and power management. The RSV reserves expansion space. Combining the 256-byte matrix architecture with CRC32 checksum, in the scenario of transparent transmission of the long-distance RS485 communication interface using optical fiber communication, the real-time performance, reliability, and scalability of the optical fiber access device are significantly improved.

[0066] Optionally, the transmission rate of each of the first time slot, the second time slot, the third time slot, the fourth time slot, and the fifth time slot is 2.5 Mbps. This enables each time slot to transmit a large amount of data in a short time. For example, in the scenario of transparent transmission of the long-distance RS485 communication interface using optical fiber communication, a large amount of data (such as temperature, pressure, flow, etc.) collected by sensors can be quickly uploaded in a timely manner, reducing data transmission delay and improving the real-time response ability of the optical fiber access device.

[0067] Optionally, the frame period of the first time slot is 819.2 us. This provides a stable time reference for the entire optical fiber access device. In the scenario of transparent transmission of the long-distance RS485 communication interface using optical fiber communication, the local device and the remote device can perform precise synchronization according to this fixed frame period, ensuring the accurate transmission and reception of data and improving the reliability and stability of communication.

[0068] Optionally, the frame rate of the private frame structure is 12.5 Mbps. This ensures that the entire frame structure can transmit data at a high speed.

[0069] Optionally, the private frame structure is a private communication frame structure using bit-interleaved multiplexing.

[0070] In this example, a private communication frame structure is adopted with a rate of 12.5 Mbps. Every 5 bits of data in the frame structure form 1 private frame, and each bit is 1 transmission time slot with a rate of 2.5 Mbps, which are respectively used to transmit 2-way RS485 data and the I2C interface management information of the SFP optical module. The 5 time slots are multiplexed into a 12.5M private communication frame in a bit-interleaved manner. The private frame structure using bit-interleaved multiplexing improves the spectral efficiency within the frame period through dynamic interleaving of multi-service bit streams, enhances the anti-burst interference ability, and at the same time ensures the real-time performance of data transmission.

[0071] Optionally, it further includes a power supply drop detection module, and an energy storage capacitor is provided in the power supply drop detection module, and the energy storage capacitor is electrically connected to the programmable logic device.

[0072] In this example, the power supply dropout detection module monitors the input power supply voltage in real time. When the detected voltage is lower than the threshold value, the programmable logic device immediately triggers the energy storage capacitor to supply power, ensuring that a power-down alarm is sent to the local end through the PRD field in the private frame structure at the moment of power supply dropout. At the same time, it maintains power supply to the key modules for 30 ms to complete the last data sampling and transmission, achieving millisecond-level fault response, data integrity protection, and industrial-grade wide-temperature reliability. It is particularly suitable for the transparent transmission scenario of long-distance RS485 communication interfaces using fiber optic communication.

[0073] Optionally, it further includes a crystal oscillator, which is used to send the working clock information of 25Mhz to the programmable logic device.

[0074] In this example, the 25MHz reference clock provided by the crystal oscillator provides an accurate timing reference for the programmable logic device, ensuring nanosecond-level synchronization of the 12.5Mbps frame rate and the 2.5Mbps time slot rate, and improving the synchronization, reliability, and anti-interference ability of the fiber optic access device.

[0075] This application adopts fiber optic communication technology and a private communication frame structure, and can realize the fiber optic transmission of 2-way RS485 data interfaces. The fiber optic rate is 12.5Mbps, which supports transparent transmission of RS485 data interface communication signals. The RS485 data interface rate range can reach 4800bps to 200kbps. At the same time, it can realize the fiber optic transmission of the I2C management bus, support transparent transmission of the clock and data of the I2C bus, so as to realize the management of the SFP module of the remote device, and support reporting management functions such as power-down alarm, optical interface alarm, and device information of the remote device to the local end. In addition, a programmable logic device is used to implement private communication framing and frame synchronization, multiplexing and demultiplexing, scrambling and descrambling, etc. The programmable logic device is peripherally connected to circuits such as an RS485 interface chip, a power supply dropout detection circuit, an SFP optical module data, and an I2C management interface. It successfully breaks through the limitation of the traditional RS485 cable connection distance and can realize an increase in the transparent transmission distance of the RS485 communication interface.

[0076] It should be noted that in this text, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising such element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order discussed, but may also include performing functions in a substantially simultaneous manner or in a reverse order according to the functions involved. For example, the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. Additionally, the features described with reference to certain examples may be combined in other examples.

[0077] From the description of the above embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions for causing a terminal (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of the present application.

[0078] The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Those of ordinary skill in the art, under the inspiration of the present application and without departing from the spirit and scope protected by the claims of the present application, can still make many forms, all of which fall within the protection scope of the present application.

Claims

1. An optical fiber access device, characterized in that: It includes a programmable logic device, an RS485 interface chip and a small pluggable SFP optical module, wherein the RS485 interface chip is connected to the SFP optical module through the programmable logic device, the RS485 interface chip is used to send the first sampling data to the programmable logic device, the programmable logic device is used to convert the private frame structure into a positive emitter coupled logic PECL level and send it to the SFP optical module, and the SFP optical module is used to convert the PECL level into an optical signal for transmission on an optical fiber; Among them, the first sampling data is the transistor-transistor logic TTL level converted by the RS485 interface chip based on the RS485 interface level, the private frame structure is a private communication frame structure constructed by the programmable logic device based on the first sampling data, the second sampling data and the third sampling data, the first sampling data includes the first RS485 interface data and the second RS485 interface data, the second sampling data includes the data line data and the clock line data of the synchronous, half-duplex communication I2C bus acquired by the programmable logic device; the third sampling data includes the configuration information of the optical fiber access device.

2. The optical fiber access device according to claim 1, characterized in that: Each private frame in the private frame structure includes a first time slot, a second time slot, a third time slot, a fourth time slot and a fifth time slot. The first time slot is used to transmit framing bytes and overhead information, the framing bytes are used for frame synchronization, and the overhead information is used for device management. The second time slot is used to transmit the first RS485 interface data, the third time slot is used to transmit the second RS485 interface data, the fourth time slot is used to transmit the clock line data of the I2C bus, and the fifth time slot is used to transmit the data line data of the I2C bus.

3. The optical fiber access device according to claim 2, characterized in that: The data structure formed by the framing bytes and the overhead information is matrix data of 8 rows*16 columns.

4. The optical fiber access device according to claim 3, characterized in that: The matrix data includes: A first field, the first field is used to indicate the framing byte, and the first field is not scrambled; A second field, wherein the second field is a multiframe indication; A third field, the third field is used to indicate the alarm information of the remote device connected to the RS485 interface chip; A fourth field, the fourth field is used to indicate alarm information of the optical path connected to the SFP optical module; A fifth field, the fifth field is used to indicate transmission error information; A sixth field, the sixth field is used to indicate the configuration information; A seventh field, the seventh field is used to indicate reserved information; An eighth field, wherein the eighth field is used to indicate a check code of the first field.

5. The optical fiber access device according to claim 2, characterized in that: The frame period of the first time slot is 819.2us.

6. The optical fiber access device according to claim 2, characterized in that: The transmission rate of each of the first time slot, the second time slot, the third time slot, the fourth time slot and the fifth time slot is 2.5 Mbps.

7. The optical fiber access device according to claim 1, characterized in that: The frame rate of the private frame structure is 12.5 Mbps.

8. The optical fiber access device according to claim 1, characterized in that: The private frame structure is a private communication frame structure using bit interleaving multiplexing.

9. The optical fiber access device according to claim 1, characterized in that: It also includes a power drop detection module, in which an energy storage capacitor is arranged, and the energy storage capacitor is electrically connected to the programmable logic device.

10. The optical fiber access device according to claim 1, characterized in that: It also includes a crystal oscillator, which is used to send 25Mhz working clock information to the programmable logic device.

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