A physical isolation type multi-network port time synchronization device and a synchronization method
Patent Information
- Application Number
- CN202611411445.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-09-11
- Publication Date
- 2026-10-16
AI Technical Summary
[0005]本发明实施例提供了一种物理隔离型多网口时间同步设备及同步方法，以解决现有技术中的上述技术的问题
[0020] Each of the NTP modules performs time synchronization based on the received system time synchronization signal and independently provides NTP services to the outside world;
Smart Images
Figure CN122932879A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of network time service technology, and in particular to a physically isolated multi-port time synchronization device and synchronization method. Background Technology
[0002] The HJ260-N network time server, developed by Beijing Taifute Electronic Technology Co., Ltd., is a high-precision, high-reliability rubidium atomic clock network time server. This product effectively combines a high-precision rubidium atomic clock with BeiDou, high-precision time synchronization, network time synchronization, and time synchronization technologies. This ensures the rubidium atomic clock's output frequency is disciplined and synchronized with the BeiDou satellite cesium atomic clock signal, improving the long-term stability and accuracy of the frequency signal and providing a high-precision time and frequency standard at the cesium clock level. The HJ260-N network time server has multiple network ports providing NTP network time synchronization and centralized management and control of these ports.
[0003] For centralized management and control, most NTP network time servers on the market use logical isolation between network ports rather than physical isolation. This approach has the following drawbacks: (1) Logical isolation is easily breached, resulting in a high risk of lateral penetration; (2) Traffic eavesdropping and man-in-the-middle attacks; (3) Risk of mixed transmission between high and low security domains; (4) Bandwidth resource contention, making traffic interference easy; (5) Broadcast storms spread throughout the entire domain, paralyzing the entire device; (6) Uncontrollable latency and jitter, failing to meet the requirements of high-precision services; (7) Fault linkage, with a single network port failure affecting all network ports; (8) High maintenance difficulty: fault location is difficult, and repair or replacement is not easy; (9) Does not meet the mandatory compliance requirements of the security level protection and industrial control security industries. For example, network security protection level protection, power industrial control 386, rail transit, and financial regulations clearly require that production control networks, office networks, and external networks must be physically isolated, and logical isolation alone will not pass the security level protection assessment.
[0004] To address these issues in the market, the HJ260-N network time server, through innovative design, achieves both physical isolation of network ports and centralized management of each port. Summary of the Invention
[0005] This invention provides a physically isolated multi-port time synchronization device and synchronization method to solve the problems mentioned above in the prior art.
[0006] According to a first aspect of the present invention, a physically isolated multi-port time synchronization device is provided.
[0007] In one embodiment, the physically isolated multi-port time synchronization device includes:
[0008] The satellite receiver is used to receive satellite signals and output the first timing signal to the main control module;
[0009] The main control module, connected to the satellite receiver, is used to generate system time based on the first timing signal and output the system timing signal to the serial port transmission module; the system timing signal includes the system 1PPS signal and the system TOD signal.
[0010] The serial port transmission module, connected to the main control module, is used to distribute the system timing signal into multiple outputs and to adjust the delay of each output system 1PPS signal;
[0011] Multiple NTP modules, each of which is connected to one output of the serial port transmitting module, are used to complete time synchronization based on the received system timing signal and independently provide NTP services to the outside world;
[0012] A serial port receiving module is connected to each of the NTP modules and is used to receive status data reported by each of the NTP modules.
[0013] The main control module is also connected to the serial port receiving module to receive status data forwarded by the serial port receiving module and to centrally manage each NTP module based on the status data.
[0014] According to a second aspect of the present invention, a physically isolated multi-port time synchronization method is provided.
[0015] In one embodiment, the physically isolated multi-port time synchronization method includes:
[0016] A physically isolated multi-port time synchronization method includes:
[0017] The satellite receiver receives satellite signals and outputs a first timing signal to the main control module. The first timing signal includes a first 1PPS signal and a first TOD signal.
[0018] The main control module generates the system time based on the first timing signal and outputs the system timing signal to the serial port transmission module; the system timing signal includes the system 1PPS signal and the system TOD signal;
[0019] The serial port transmission module distributes the system timing signal into multiple outputs, and after delaying and adjusting the system 1PPS signal of each output, it outputs them to multiple physically isolated NTP modules respectively.
[0020] Each of the NTP modules performs time synchronization based on the received system time synchronization signal and independently provides NTP services to the outside world;
[0021] Each NTP module reports its status data to the serial port receiving module via the serial port;
[0022] The main control module obtains the status data from the serial port receiving module and centrally manages each of the NTP modules.
[0023] The technical solution provided by the embodiments of the present invention can include the following beneficial effects: Through a physical isolation architecture with independent PCBs for each NTP module and no direct electrical connection, and with independent serial port reporting and sending channels to achieve centralized management, while ensuring that the NTP services of each network port are completely independent, single-path faults do not propagate, and broadcast storms are limited to a single module, the independent delay adjustment of each 1PPS through the serial port sending module ensures the consistency of multi-path time synchronization accuracy, and the real-time linkage across modules through blacklists achieves full-domain security protection, fundamentally eliminating the inherent defects of logical isolation schemes in terms of security, reliability, accuracy assurance, and operation and maintenance efficiency, and can directly meet the mandatory physical isolation compliance requirements of industries such as power, rail transit, and finance.
[0024] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description
[0025] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.
[0026] Figure 1 This is a system module architecture diagram of a physically isolated multi-port time synchronization device according to an exemplary embodiment;
[0027] Figure 2 This is a structural diagram of an NTP module according to an exemplary embodiment;
[0028] Figure 3 This is a schematic diagram of NTP module power supply according to an exemplary embodiment;
[0029] Figure 4 This is a flowchart illustrating a physically isolated multi-port time synchronization method according to an exemplary embodiment;
[0030] Figure 5 This is a circuit schematic diagram of a satellite receiver module according to an exemplary embodiment;
[0031] Figure 6 This is a circuit schematic diagram of the main control module according to an exemplary embodiment;
[0032] Figure 7 This is a circuit schematic diagram of a serial port receiving module according to an exemplary embodiment;
[0033] Figure 8This is a circuit schematic diagram of a serial port transmission module according to an exemplary embodiment;
[0034] Figure 9 This is a circuit schematic diagram of the pin circuit of an ARM core board according to an exemplary embodiment;
[0035] Figure 10 This is a circuit schematic diagram of a DC-DC power module circuit according to an exemplary embodiment;
[0036] Figure 11 This is a circuit schematic diagram of peripheral circuits such as a PHY chip, according to an exemplary embodiment.
[0037] Figure 12 This is a circuit diagram of the peripheral circuit of the RJ45 network port of the internal supporting network transformer, according to an exemplary embodiment.
[0038] Figure 13 This is a circuit schematic diagram of an RJ45 debugging interface and a level conversion chip, according to an exemplary embodiment. Detailed Implementation
[0039] The following description and accompanying drawings fully illustrate specific embodiments described herein to enable those skilled in the art to practice them. Some portions and features of certain embodiments may be included in or replace portions and features of other embodiments. The scope of the embodiments herein includes the entire scope of the claims and all available equivalents thereof. The various embodiments described herein are presented in a progressive manner, with each embodiment focusing on its differences from other embodiments; similar or identical parts between embodiments can be referred to interchangeably.
[0040] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.
[0041] Figure 1 An embodiment of a physically isolated multi-port time synchronization device of the present invention is shown.
[0042] In this optional embodiment, the physically isolated multi-port time synchronization device includes:
[0043] The satellite receiver is used to receive satellite signals and output the first timing signal to the main control module;
[0044] The main control module, connected to the satellite receiver, is used to generate the system time based on the first timing signal and output the system timing signal to the serial port transmission module; the system timing signal includes the system 1PPS signal and the system TOD signal.
[0045] The serial port transmission module, connected to the main control module, is used to distribute the system timing signal into multiple outputs and adjust the delay of each output system 1PPS signal;
[0046] Multiple NTP modules, each connected to one output of the serial port transmitting module, are used to synchronize time based on the received system timing signal and independently provide NTP services to the outside world;
[0047] The serial port receiving module is connected to each NTP module and is used to receive the status data reported by each NTP module.
[0048] The main control module is also connected to the serial port receiving module to receive status data forwarded by the serial port receiving module and to centrally manage each NTP module based on the status data.
[0049] In this optional embodiment, the first timing signal includes a first 1PPS signal and a first TOD signal; the main control module performs validity verification on the first TOD signal, and when all validity verifications pass, the main control module updates the system time according to the first TOD signal; the validity verification includes XOR check comparison, time validity judgment and time continuity judgment.
[0050] Specifically, the high-precision timing satellite receiver receives satellite signals through the BeiDou satellite antenna. After the receiver system locks, it outputs high-precision first 1PPS and first TOD signals to the main control module. The main control module performs judgment processing on the first TOD signal output by the receiver, including XOR check comparison, time validity judgment and time continuity judgment. After confirming that the first TOD signal of the receiver meets the above judgment processing, it synchronizes the system time of the main control module.
[0051] In this optional embodiment, the main control module includes a rubidium atomic clock, a second difference measurement chip, and a digital-to-analog converter chip; wherein, the second difference measurement chip is used to measure the second difference between the local 1PPS signal and the first 1PPS signal of the rubidium atomic clock, and after filtering and fitting the second difference measurement result, the main control module converts it into a control voltage through the digital-to-analog converter chip to tame the output frequency of the rubidium atomic clock.
[0052] Specifically, the main control module uses a TDC (Transmission of Dips) chip to measure the difference in seconds between the local 1PPS signal of the rubidium atomic clock and the first 1PPS signal output by the receiver. The measurement result is processed using algorithms such as Kalman filtering and least squares, and then converted into a 0-5V voltage via a digital-to-analog converter chip. This voltage-controlled discipline of the rubidium atomic clock ensures that the local 1PPS signal of the rubidium atomic clock and the first 1PPS signal of the receiver remain in phase. The main control module uses the local 1PPS signal of the rubidium atomic clock as an interrupt. When an interrupt occurs, it sends TOD (Time of Observation) information, including system time and system status, to the serial port transmission module via the serial port. Finally, the main control module outputs a system TOD+1PPS signal to the serial port transmission module, completing the allocation and output of the system TOD and 1PPS signals.
[0053] In this alternative embodiment, such as Figure 2 and Figure 3 As shown, each NTP module is an independent PCB board, containing an independent ARM core board, an independent PHY chip, an independent network transformer, an independent RJ45 network port, a power module, and a level conversion chip.
[0054] Specifically, the device consists of multiple independent NTP modules, each with its own independent PCB and wiring. Each NTP module mainly includes one RJ45 network port, one RJ45 debugging interface, one 5V power input, one 1PPS input, and one TOD input interface. Each NTP module comprises an independent ARM core board, an independent PHY chip, an independent network transformer, an independent RJ45 network port, a DC-DC power supply module, and a TOD to 1PPS level conversion chip. There is no direct electrical connection between the NTP modules, thus achieving physical isolation of the network ports.
[0055] In this optional embodiment, the NTP module filters the received system TOD signal. Only after all filtering processes have passed does the NTP module complete time synchronization based on the system TOD signal. The filtering process includes format judgment, XOR check comparison, time continuity judgment, and time validity judgment.
[0056] Specifically, the NTP module receives the system TOD and 1PPS signals sent by the main control module through the serial port transmission module, and performs format judgment, XOR check comparison, and time continuity and validity filtering on the system TOD signal.
[0057] In this optional embodiment, the NTP module performs validity checks on the received system 1PPS signal. Only when all validity checks pass will the NTP module use the system 1PPS signal to trigger time synchronization. The validity checks include edge detection, jitter detection, and pulse width detection.
[0058] Specifically, the NTP module performs edge detection, jitter detection, and pulse width detection on the received system 1PPS signal. Finally, it uses the detected system TOD and 1PPS signal to complete the system time synchronization of the ARM core board and provides NTP services to the outside world.
[0059] In this optional embodiment, the NTP module is also used to monitor the NTP request frequency of external clients. When the request frequency of the same IP client exceeds a preset threshold, the IP client is added to the blacklist. The NTP module reports the IP information in the blacklist to the main control module through the serial port receiving module. The main control module sends the IP information to all NTP modules through the serial port sending module. Each NTP module updates its local blacklist synchronously according to the received IP information.
[0060] Specifically, during operation, the NTP module continuously monitors the frequency of NTP requests from external clients. When it detects a short-term high-frequency abnormal request from a client—that is, when the number of requests per second from the same IP client reaches 80% of the total requests—it triggers the NTP self-protection mechanism, classifying this client as high-risk and adding it to the blacklist, preventing further reception of network packets from this IP. Additionally, this NTP module reports the abnormal IP information via serial port to the serial port receiving module. The serial port receiving module performs format judgment and verification comparison on the information before sending it to the main control module. The main control module decodes and reassembles the information before sending it to the serial port sending module. The serial port sending module distributes the data and sends it to each NTP module. Each NTP module synchronously adds the received IP information to its local blacklist.
[0061] In this optional embodiment, the NTP module is also used to monitor the synchronization deviation of external clients and generate alarm information when the synchronization deviation exceeds a preset threshold.
[0062] Specifically, during operation, the NTP module continuously monitors the synchronization deviation of external clients. When it detects that the client deviation exceeds the limit (default 20ms), it will issue an alarm on the web monitoring interface and send an email notification.
[0063] In this optional embodiment, the NTP module reports status data to the serial port receiving module through an independent serial port channel. The serial port receiving module performs format judgment and verification comparison on the status data and then forwards it to the main control module. The main control module outputs the status data to the screen or WEB interface for display.
[0064] Specifically, the NTP module reports IP information and status data via an independent serial port channel to the serial port receiving module. The serial port receiving module performs filtering processes such as format judgment and verification comparison on the data, then parses the data and displays the IP information and status data in the data information through the screen and the WEB interface respectively, thus completing the centralized management of the NTP module.
[0065] Figure 4 An embodiment of a physically isolated multi-port time synchronization method of the present invention is shown.
[0066] In this optional embodiment, the physically isolated multi-port time synchronization method includes:
[0067] Step S101: The satellite receiver receives the satellite signal and outputs the first timing signal to the main control module. The first timing signal includes the first 1PPS signal and the first TOD signal.
[0068] Step S102: The main control module generates the system time based on the first timing signal and outputs the system timing signal to the serial port transmission module; the system timing signal includes the system 1PPS signal and the system TOD signal;
[0069] Step S103: The serial port sending module distributes the system timing signal into multiple outputs, and after delaying and adjusting the system 1PPS signal of each output, it outputs them to multiple physically isolated NTP modules respectively.
[0070] Step S104: Each NTP module completes time synchronization according to the received system timing signal and independently provides NTP service to the outside world;
[0071] Step S105: Each NTP module reports its status data to the serial port receiving module via the serial port.
[0072] Step S106: The main control module obtains the status data from the serial port receiving module and centrally manages each of the NTP modules.
[0073] To facilitate understanding of the above technical solutions of the present invention, the following further explains the above technical solutions of the present invention from the perspective of architecture and principle, as follows:
[0074] like Figure 5 As shown, the main functions of the satellite receiver module circuit are: (1) antenna signal input interface (2) satellite receiver power supply (3) satellite receiver 1PPS+TOD signal output; the satellite receiver module mainly completes the function of receiving Beidou satellite signals and outputting TOD+1PPS signal after the receiver is locked.
[0075] like Figure 6 As shown, the main control module circuit mainly performs functions such as receiver TOD+1PPS signal input, system TOD+1PPS signal output, TDC second difference measurement, digital-to-analog chip control of voltage rubidium clock, and rubidium clock 10MHz signal level conversion.
[0076] like Figure 7 As shown, the serial port receiving module receives data from NTP that includes IP information and status information. After filtering the data, it displays it on the screen and uploads it to the web monitoring system.
[0077] like Figure 8 As shown, the main function of the serial port transmitting module circuit is to receive TOD+1PPS sent by the main control module, and then distribute and output it.
[0078] like Figures 9-13 As shown, the NTP module mainly consists of an ARM core board, a DC-DC power supply module, a PHY chip, a network transformer, an RJ45 network port, an RJ45 debug port, and a level conversion chip. The main function of the NTP module is to parse the TOD+1PPS sent by the main control module, complete system time synchronization, and provide NTP time synchronization.
[0079] Specifically Figure 9 It is the pin circuit of the ARM core board. The main function of the circuit is to support TOD and 1PPS signal input and level conversion.
[0080] Figure 10 It is a DC-DC power module circuit. The main function of the circuit is to provide power to peripheral circuits such as the ARM core board and PHY chip.
[0081] Figure 11 These are peripheral circuits such as the PHY chip. The main functions of the circuit are signal encoding and decoding, level conversion, transmit and receive driving, and analog-to-digital signal conversion.
[0082] Figure 12 It is the peripheral circuit of the RJ45 network port of the internal network transformer. The main functions of the circuit are to provide electrical isolation, differential signal coupling transmission, impedance matching, surge / lightning protection, and ultimately realize Ethernet physical layer access.
[0083] Figure 13 It is an RJ45 debugging interface and level conversion chip. The main function of the circuit is to convert the debugging serial port of the ARM core board from LVTTL level to RS232 level and then connect it to the RJ45 debugging interface, so that it can be easily debugged directly using a USB to RJ45 serial cable.
[0084] This invention is not limited to the structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this invention is limited only by the appended claims.
Claims
1. A physically isolated multi-port time synchronization device, characterized in that, include: The satellite receiver is used to receive satellite signals and output the first timing signal to the main control module; The main control module, connected to the satellite receiver, is used to generate system time based on the first timing signal and output the system timing signal to the serial port transmission module; the system timing signal includes the system 1PPS signal and the system TOD signal. The serial port transmission module, connected to the main control module, is used to distribute the system timing signal into multiple outputs and to adjust the delay of each output system 1PPS signal; Multiple NTP modules, each of which is connected to one output of the serial port transmitting module, are used to complete time synchronization based on the received system timing signal and independently provide NTP services to the outside world; A serial port receiving module is connected to each of the NTP modules and is used to receive status data reported by each of the NTP modules. The main control module is also connected to the serial port receiving module to receive status data forwarded by the serial port receiving module and to centrally manage each NTP module based on the status data.
2. The physically isolated multi-port time synchronization device according to claim 1, characterized in that, The first timing signal includes a first 1PPS signal and a first TOD signal; The main control module performs validity verification on the first TOD signal. When all validity verifications pass, the main control module updates the system time based on the first TOD signal. The validity verification includes XOR check comparison, time validity judgment, and time continuity judgment.
3. The physically isolated multi-port time synchronization device according to claim 2, characterized in that, The main control module includes a rubidium atomic clock, a parity measurement chip, and a digital-to-analog converter chip; The second difference measurement chip is used to measure the second difference between the local 1PPS signal and the first 1PPS signal of the rubidium atomic clock. After filtering and fitting the second difference measurement result, the main control module converts it into a control voltage through the digital-to-analog converter chip to tame the output frequency of the rubidium atomic clock.
4. The physically isolated multi-port time synchronization device according to claim 1, characterized in that, Each NTP module is an independent PCB board, containing an independent ARM core board, an independent PHY chip, an independent network transformer, an independent RJ45 network port, a power module, and a level conversion chip.
5. The physically isolated multi-port time synchronization device according to claim 4, characterized in that, The NTP module filters the received system TOD signal. Only after all filtering processes have passed can the NTP module complete time synchronization based on the system TOD signal. The filtering process includes format judgment, XOR check comparison, time continuity judgment, and time validity judgment.
6. The physically isolated multi-port time synchronization device according to claim 4, characterized in that, The NTP module performs validity checks on the received system 1PPS signal. Only when all validity checks pass will the NTP module use the system 1PPS signal to trigger time synchronization. The validity checks include edge detection, jitter detection, and pulse width detection.
7. The physically isolated multi-port time synchronization device according to claim 4, characterized in that, The NTP module is also used to monitor the NTP request frequency of external clients. When the request frequency of the same IP client exceeds a preset threshold, the IP client is blacklisted. The NTP module reports the IP information in the blacklist to the main control module through the serial port receiving module. The main control module then sends the IP information to all NTP modules through the serial port sending module. Each NTP module updates its local blacklist synchronously based on the received IP information.
8. The physically isolated multi-port time synchronization device according to claim 4, characterized in that, The NTP module is also used to monitor the synchronization deviation of external clients, and generates an alarm message when the synchronization deviation exceeds a preset threshold.
9. The physically isolated multi-port time synchronization device according to claim 8, characterized in that, The NTP module reports status data to the serial port receiving module through an independent serial port channel. The serial port receiving module performs format judgment and verification comparison on the status data and then forwards it to the main control module. The main control module outputs the status data to the screen or WEB interface for display.
10. A physically isolated multi-port time synchronization method, characterized in that, include: The satellite receiver receives satellite signals and outputs a first timing signal to the main control module. The first timing signal includes a first 1PPS signal and a first TOD signal. The main control module generates the system time based on the first timing signal and outputs the system timing signal to the serial port transmission module; the system timing signal includes the system 1PPS signal and the system TOD signal; The serial port transmission module distributes the system timing signal into multiple outputs, and after delaying and adjusting the system 1PPS signal of each output, it outputs them to multiple physically isolated NTP modules respectively. Each of the NTP modules performs time synchronization based on the received system time synchronization signal and independently provides NTP services to the outside world; Each NTP module reports its status data to the serial port receiving module via the serial port; The main control module obtains the status data from the serial port receiving module and centrally manages each of the NTP modules.