Cable tester

Abstract

The invention relates to the technical field of aircraft component testing, in particular to a cable tester, which comprises a test interface, a cable testing module and a cable testing module, wherein the test interface is used for connecting a to-be-tested cable; the test circuit is used for connecting a to-be-tested cable through the test interface to carry out a cable connectivity test, and the test circuit comprises a first micro-control unit, a second micro-control unit and a dynamic relay matrix; the first micro-control unit is used for being connected with a first group of pins of a to-be-tested cable through the test interface, and the second micro-control unit is used for being connected with a second group of pins of the to-be-tested cable through the test interface; the dynamic relay matrix at least comprises a first relay and a second relay and is used for controlling connection between the first micro-control unit and the test interface and connection between the second micro-control unit and the test interface by closing the first relay and the second relay, so that the cable tester enters a cable connectivity test mode; and a power module. The cable connectivity detection device is specially designed for a flexible cable assembly in a CDSS hinge assembly, and automatic detection of cable connectivity can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft component testing, and in particular to a cable tester. Background Art

[0002] The civil aviation system has extremely high requirements for the stability of aircraft components. Any minor fault may trigger a chain reaction and threaten flight safety. Therefore, regular inspection is a key link to ensure its continuous reliability and safety. The Airbus cockpit door surveillance system (CDSS) is a key system to ensure cockpit safety, and the connectivity of the flexible cable assembly in its hinge assembly is one of the important contents that need to be detected.

[0003] Most existing cable testers adopt a single-core microcontroller unit (MCU), which needs to process tasks such as data acquisition, logical judgment, and display in sequence, resulting in a long test cycle. The test time per frame is usually ≥ 1.5 seconds, making it difficult to meet the requirements of rapid detection of aircraft components. Moreover, most existing cable testers can only test cables with a fixed number of cores, and are unable to flexibly adjust to different requirements in the face of complex multi-channel test scenarios such as 47-core cables. In addition, the mode switching of existing cable testers is rigid, the relay control logic lacks flexibility, and it does not have the function of self-recovery diode detection, and the functions are relatively single. Summary of the Invention

[0004] To solve one of the above-mentioned problems of the prior art, the present invention provides a cable tester.

[0005] To achieve the above object, the present invention provides a cable tester, including: a test interface, a test circuit, and a power supply module; The test interface is used to connect the cable to be tested, and the cable to be tested includes: a flexible cable configured for the hinge assembly of the Airbus cockpit door surveillance system; The test circuit is used to connect the cable to be tested through the test interface for cable connectivity testing. The test circuit includes a first microcontroller unit, a second microcontroller unit, and a dynamic relay matrix; The first microcontroller unit and the second microcontroller unit are respectively connected to the test interface through the dynamic relay matrix. The first microcontroller unit is used to connect the first set of pins of the cable to be tested through the test interface, and the second microcontroller unit is used to connect the second set of pins of the cable to be tested through the test interface, where the first set of pins is a part of the pins of the cable to be tested, and the second set of pins is another part of the pins of the cable to be tested; The dynamic relay matrix includes at least a first relay and a second relay, and is used to control the connection between the first microcontroller unit and the second microcontroller unit and the test interface by closing the first relay and the second relay, so that the cable tester enters the cable connectivity test mode; The power supply module is used to supply power to the cable tester.

[0006] The beneficial effects of the present invention are reflected in providing a cable detector, which is specifically designed for the 47-core flexible cable assembly in the CDSS hinge assembly, and can realize the automatic detection of cable connectivity and the performance of self-recovery diodes. By applying the dual-MCU parallel processing technology, the dynamic relay matrix structure and the high-precision impedance voltage division algorithm, the cable detector improves the test efficiency by 40% and controls the false detection rate at ≤0.05%, greatly reducing the need for manual intervention. Description of the Drawings

[0007] Figure 1 Schematic diagram of the cable tester structure provided by Embodiment 1 of the present invention; Figure 2 Schematic diagram of the connection between the cable tester provided by Embodiment 1 of the present invention and the cable to be tested; Figure 3 A design example diagram of the connector circuit of the test interface provided by Embodiment 1 of the present invention; Figure 4 Another design example diagram of the connector circuit of the test interface provided by Embodiment 1 of the present invention; Figure 5 A design example diagram of the dual-MCU circuit provided by Embodiment 1 of the present invention; Figure 6 A design example diagram of JT1 in the dynamic relay matrix circuit provided by Embodiment 1 of the present invention; Figure 7 A design example diagram of JT2 in the dynamic relay matrix circuit provided by Embodiment 1 of the present invention; Figure 8 A specific implementation circuit design example diagram of the self-recovery test unit and JT3 provided by Embodiment 1 of the present invention; Figure 9 A flowchart of a specific test example of the self-recovery diode test provided by Embodiment 1 of the present invention. Detailed Description of the Invention

[0008] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0009] Embodiment 1 This embodiment provides a cable tester, which is specifically designed to adapt to the 47-core flexible cable assembly in the CDSS hinge assembly, and can realize the automatic detection of cable connectivity and the performance of self-recovery diodes. The flexible cable assembly is generally a PMA (Parts Manufacturer Approval) part. PMA refers to an aviation replacement part produced by a non-third-party manufacturer approved by airworthiness authorities such as FAA / EASA. The flexible cable assembly is installed on the hinge assembly and is a sub-component of the hinge assembly. The flexible cable assembly can be fixed on the hinge assembly or embedded in the hinge assembly.

[0010] As Figure 1 shown, the cable tester provided in this embodiment includes: a test interface, a test circuit, and a power supply module.

[0011] In an alternative embodiment, the specific structure of the cable tester may include: a chassis, a chassis cover, a front panel, a display screen, an aviation plug interface, a test circuit board, and a power supply module. The test interface in this embodiment can be set on the aviation plug interface, and the test circuit can be set on the test circuit board.

[0012] The test interface is used to connect the cable to be tested. The cable to be tested includes: a flexible cable configured for the hinge assembly of the Airbus cockpit door monitoring system. Specifically, the test interface can be set on the housing of the cable tester, or an interface with a data cable can be set outside the housing to flexibly insert the cable to be tested. The test interface should be adapted to match the flexible cable to be tested. For example, if the flexible cable is a 47-core pin cable, the test interface should include at least 47 core pins and be able to adapt to the positions of the 47 core pins.

[0013] In an alternative embodiment, the cable to be tested may have two ports J1 and J2, then the test interface should also have two connectors, and the two ends of the cable to be tested can be respectively connected through the two connectors to form a test loop. Figure 2 Shows a possible connection method.

[0014] In an alternative embodiment, the test interface can be as Figure 3 and 4The connectors shown, each connector having 50 wire pins.

[0015] A test circuit for performing cable connectivity testing by connecting a cable to be tested through a test interface. The test circuit includes a first microcontroller unit, a second microcontroller unit, and a dynamic relay matrix. Specifically, the test circuit can adopt a dual-MCU collaborative architecture to execute division of labor tasks, and the two can achieve real-time data synchronization through an interface (such as a UART serial port with a baud rate of 115200).

[0016] The first microcontroller unit and the second microcontroller unit are respectively connected to the test interface through the dynamic relay matrix. The first microcontroller unit is used to connect the first set of pins of the cable to be tested through the test interface, and the second microcontroller unit is used to connect the second set of pins of the cable to be tested through the test interface. Among them, the first set of pins is a part of the pins of the cable to be tested, and the second set of pins is another part of the pins of the cable to be tested. Specifically, the first microcontroller unit and the second microcontroller unit respectively have a corresponding number of pins to connect the pins of the cable to be tested through the pins of the test interface, and the number of pins they have depends on the model of the microcontroller unit used. For example, the first microcontroller unit and the second microcontroller unit can adopt the STC15F2K60S2 model. In this embodiment, only the necessary pins need to be connected, and the redundant pins can be left unconnected. The dynamic relay matrix can be connected between the pins of the test interface and the pins of the first microcontroller unit and the second microcontroller unit to control the paths between the test interface and the first microcontroller unit and the second microcontroller unit.

[0017] In an alternative embodiment, the cable to be tested can be a 47-core flexible cable. The first set of pins is the first 24 cores of the cable to be tested, and the second set of pins is the last 23 cores of the cable to be tested. Then, the first microcontroller unit should have at least 24 pins to connect the first 24 cores of the cable to be tested through the test interface correspondingly; the second microcontroller unit should have at least 23 pins to connect the last 23 cores of the cable to be tested through the test interface correspondingly. By connecting and testing the cable to be tested in groups, it is not only possible to more flexibly adapt to complex cables such as the 47-core flexible cable assembly of the CDSS articulated component, but also to improve the detection efficiency through parallel processing.

[0018] Such as Figure 5Shown is an optional circuit design example of the first microcontroller IC1 and the second microcontroller IC2. Among them, the pins P01 - P24 of IC1 can correspond to the wires 1 - 1 to 1 - 24 of the connector, which are used to connect the first 24 cores of the cable to be tested; the pins P25 - P47 of IC2 can correspond to the wires 1 - 25 to 1 - 47 of the connector, where the 36th / 37th / 43rd cores are not enabled, and are used to connect the latter 23 - core cable and the self - recovery diode test channel. It can be seen that IC1 mainly undertakes the on - off test task of the first 24 - core cable, and IC2 is mainly responsible for the test tasks of the latter 23 - core cable and the self - recovery diode mentioned later.

[0019] It should be noted that Figure 3 and Figure 4 the connectors of Figure 5 and the pin markings in the microcontroller unit are only the naming of the pins, which can assist in understanding the interconnection relationship between the connector and the microcontroller unit pins, rather than the limitation of the pins. In the specific implementation, the connection can be made according to the actual circuit relationship. Figure 3 、 Figure 4 and Figure 5 There may be some unused pins in both the connectors and the microcontroller units of

[0020] The dynamic relay matrix includes at least a first relay and a second relay, which are used to control the connection between the first microcontroller unit and the second microcontroller unit and the test interface by closing the first relay and the second relay, so that the cable tester enters the cable connectivity test mode. Figure 6 and 7 give optional specific circuit design examples of the dynamic relay matrix. Figure 6 and 7 are the first relay JT1 and the second relay JT2, and the connection relationship between the first relay JT1 and the second relay JT2 and the test interface can be referred to Figure 3 、 Figure 4 and Figure 5 .

[0021] In the specific implementation, in the non - powered or standby state, the contacts of JT1 / JT2 are in the normally open (disconnected) state. The trigger condition for the relay state switch can be jointly controlled by the power mode and / or the control button. For example, a button TEST1 (which can be a physical button, a soft button or a virtual button) for controlling the opening and closing of the relay JT1 / JT2 can be set on the cable tester. The specific logic is as follows: after turning on the AC power supply of the whole machine, pressing the TEST1 button, the JT1 / JT2 relay is attracted (closed), and the moving contact (such as JT1 - K1 / JT2 - K1) automatically connects the cable test circuit, thereby controlling the cable tester to enter the cable connectivity test mode.

[0022] The power supply module is used to provide power for the cable tester. Specifically, the power supply module can operate within the voltage range of 100V - 240V / 50 - 60Hz alternating current, and can output power such as DC 12V / 3A and 5V / 2A to supply power to various parts of the cable tester. The power supply module can adopt the GA46 - 2DB model power supply, and the power supply module can be integrated with a heat dissipation module and a temperature compensation function module to improve the reliability of test results in extreme temperature environments.

[0023] The cable tester provided in this embodiment is based on the collaborative control of a dual micro - control unit (MCU) and a dynamic relay, and is designed specifically to adapt to the flexible cable assembly in the hinge assembly of the Airbus cockpit door monitoring system (CDSS), and can realize the automated detection of cable connectivity. By applying the dual - MCU parallel processing technology and the dynamic relay matrix structure, the tester has increased the test efficiency by 40%, greatly reducing the need for manual intervention.

[0024] In an optional implementation manner, after the cable tester enters the cable connectivity test mode, the first micro - control unit is used to scan the level value of each pin in the first group of pins, judge the on - off state information of the first group of pins according to the level value of each pin in the first group of pins, generate real - time synchronization data according to the on - off state information of the first group of pins, and send the real - time synchronization data to the second micro - control unit through a preset communication protocol format. Specifically, the first micro - control unit is mainly responsible for the on - off test of the first 24 - core cable (P01 - P24 pins), and then sends the on - path / off - path state to the second micro - control unit through the UART serial port. The first micro - control unit may not directly output externally, but only be responsible for transmitting the original data. Of course, the first micro - control unit can also directly output externally in real - time, which can be determined according to the specific design scenario requirements. The judgment threshold for the on - off test can be determined according to the actual situation of the circuit. A low level is recognized as an open circuit, and a high level is recognized as a closed circuit. For example, the judgment threshold for the on - off test can be set as low level ≤ 0.8V and high level ≥ 2.0V. By having the first micro - control unit share the test process, the connectivity (on / off) of the cable conductors can be quickly detected and the cable open circuit can be located, improving the detection efficiency.

[0025] In an alternative embodiment, the second microcontroller unit is configured to scan the level values of each pin in the second set of pins, determine the on / off status information of the second set of pins according to the level values of each pin in the second set of pins, receive real-time synchronization data, obtain the on / off status information of the first set of pins in the real-time synchronization data, and integrate and output the on / off status information of the first set of pins and the second set of pins. Specifically, the second microcontroller unit needs to scan pins P25 - P47 (including P25 - P28), rather than relying solely on the data of the first microcontroller unit. P25 - P28 are the test channels of the second microcontroller unit, which are directly connected to the 23-core cable at the back and need to scan their level status independently. Therefore, the task of the second microcontroller unit is to receive the real-time synchronization data from the first microcontroller unit, simultaneously scan the level of the 23-core cable at the back for on / off judgment testing, and uniformly integrate the test results of all 47 cores (the first 24 cores come from the first microcontroller unit, and the last 23 cores come from its own scan), and control the output of the test results according to the integrated data. The test results can be output in various ways such as text display, image display, voice broadcast, etc. For example, if the cable tester is equipped with a display screen, the shape of the cable and the pins can be simulated on the display screen, and the on / off of the pins can be identified by green / red markings, so that users can directly read the test results. By using the second microcontroller unit for centralized control, signal conflicts or asynchronous refreshing caused by the simultaneous operation of two MCUs on the display screen can be avoided. As the control core, the second microcontroller unit can ensure that all test results are rendered at one time, maintain data integrity, and improve the user experience.

[0026] In an alternative embodiment, the real-time synchronization data at least includes: a frame header, a data segment, and a check code, and the on / off status information of the first set of pins is stored in the data segment. Specifically, the format of the real-time synchronization data can be determined according to needs, and its key information is stored in the data segment. Table 1 shows a specific example of the format of real-time synchronization data. In addition to the frame header, the data segment, and the check code, it may also include functional fields such as a function code for defining the operation type and a field for defining the data length.

[0027] Table 1 Example of the format of real-time synchronization data

[0028] In an alternative embodiment, the first microcontroller unit and the second microcontroller unit are respectively connected to the test interface through impedance voltage division circuits. As can be seen from Figure 3 and Figure 4 each pin end of the connector circuit is connected with a resistor, and the pins of the first microcontroller unit and the second microcontroller unit can be connected to the pins of the connector through series resistors. By using the series resistor network to collect the cable loop voltage in real time, the detection accuracy can be improved, and the detection accuracy can reach ±0.1%.

[0029] In an alternative embodiment, the test circuit further includes: a self - recovery test unit; the dynamic relay matrix further includes a third relay, and the third relay remains closed when the cable tester is in the cable connectivity test mode; the self - recovery test unit is connected to the second micro - control unit through the third relay; the second micro - control unit is further configured to connect to a self - recovery diode in the cable to be tested through a test interface; the dynamic relay matrix is further configured to disconnect the first relay and the second relay, and switch the third relay from the closed state to the open state to control the connection between the self - recovery test unit and the second micro - control unit to be conducted, so that the cable tester enters the self - recovery test mode. Specifically, the self - recovery diode is located on the flexible cable assembly and is used for over - current protection and self - recovery of the flexible cable to ensure the performance stability of the flexible cable. The cable detector of the present invention can also detect the self - recovery diode. To ensure the normal operation of the two detection modes, the dynamic relay matrix can be used to switch between the two detection modes of cable connectivity test and self - recovery test respectively. By regularly detecting the performance of the self - recovery diode in the flexible cable, the holding current, tripping current and self - recovery performance of the self - recovery diode can be verified in time, the diode failure problem can be found, and the maintenance efficiency can be improved.

[0030] In a specific embodiment, the self - recovery test unit can be connected to the power supply module and the second micro - control unit, obtain power supply through the power supply module, and implement self - recovery test through the second micro - control unit. And the dynamic relay matrix can further include a third relay JT3. The specific implementation of the self - recovery test unit and JT3 can be as Figure 8 shown in the circuit. In the non - powered or standby state, the contact of JT3 is in the normally - closed / closed state. The trigger condition for the state switching of the JT3 relay can be controlled by a button. For example, a control button TEST2 (which can be a physical button, a soft button or a virtual button) for controlling the opening and closing of the JT3 relay can be set on the cable tester. The specific logic is as follows: when an external test power supply is connected, the TEST2 button is triggered, the JT3 relay is attracted (the normally - closed contact is disconnected), and the power supply to the MCU and the cable continuity test circuit is cut off. The JT1 / JT2 relays are released (remain in the normally - open state), and the static contacts are connected to the self - recovery diode test circuit. In addition, there can be multiple channels for self - recovery test, such as Figure 8 the F1 - F4 ports in represent 4 self - recovery test channels, and the self - recovery test can be completed separately or simultaneously.

[0031] In an alternative embodiment, when the cable tester enters the self - recovery test mode, the power supply module is used to supply working current to the self - recovery diode through the self - recovery test unit; the self - recovery test unit is used to detect the on - or - off state of the self - recovery diode under the working current. If the self - recovery diode is in the on state, the power supply module is controlled to supply a step current to the self - recovery diode, and the on - or - off state of the self - recovery diode under the step current is detected, where the step current is greater than the working current. Specifically, the working current can be adjusted within the range of 0 - 3.2 A by an external power supply. In a specific test example, the working current can be set to 0.25 A and the step current can be set to 0.4 A. Verifying the diode performance through a current step can test whether the diode has an over - current protection function.

[0032] In an alternative embodiment, after detecting that the self - recovery diode enters the off state, the power supply module is further used to supply working current to the self - recovery diode through the self - recovery test unit again; the self - recovery test unit is further used to detect whether the self - recovery diode resumes the on state. After the diode trips and disconnects due to over - current protection, verifying the diode performance by applying the normal working current can test whether the diode has a self - recovery function.

[0033] Figure 9 It is a flowchart of a specific test example for the self - recovery diode test, which can intuitively show the specific process of the self - recovery diode test.

[0034] Embodiment 2 This embodiment gives an example and data verification of using the cable tester of the present invention to detect the connectivity of a 47 - core cable, as follows: 1. Test conditions Cable model: 47 - core cable dedicated for the CDSS hinge assembly.

[0035] Ambient temperature: 25 °C.

[0036] 2. Test process (1) Connect the 47 - core cable dedicated for the CDSS hinge assembly to the J1 interface and the J2 interface, and start the cable connectivity test mode; (2) The cable tester device completes the scanning of all core wires within 1 second and marks 2 red open - circuit points on the display screen; (3) Export the detection report, and after calculation, the false detection rate is 0.03%.

[0037] 3. Comparison of test results

[0038] Embodiment 3 This embodiment presents an example and data verification of using the cable tester of the present invention to detect the performance of self - recovery diodes for a 47 - core cable, as follows: 1. Test conditions Cable model: 47 - core cable dedicated to CDSS hinge assembly.

[0039] Ambient temperature: - 20°C.

[0040] External power supply: 0 - 32V adjustable DC power supply.

[0041] 2. Test process (1) Connect the 47 - core cable in an environment of - 20°C.

[0042] (2) Inject a current of 0.40A into the external power supply, observe the ammeter, and record the tripping time as 1.8 seconds.

[0043] (3) After power - off, restart the device, adjust the current to 0.25A, verify that the diode resumes conduction, and record the recovery time as 4.5 seconds.

[0044] 3. Comparison of test results

[0045] In the description of the embodiments of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "center", "top", "bottom", "top part", "bottom part", "inner", "outer", "inner side", "outer side", etc. are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of the present invention. Among them, the "inner side" refers to the internal or enclosed area or space. The "periphery" refers to the area around a specific component or a specific area.

[0046] In the description of the embodiments of the present invention, the terms "first", "second", "third", "fourth" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", "third", "fourth" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0047] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection", "linkage", and "assembly" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a direct connection, or an indirect connection through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0048] In the description of the embodiments of the present invention, specific features, structures, materials, or characteristics may be combined in a suitable manner in any one or more embodiments or examples.

[0049] In the description of the embodiments of the present invention, it should be understood that "-" and "~" represent the range between two numerical values, and this range includes the endpoints. For example, "A - B" represents the range greater than or equal to A and less than or equal to B. "A ~ B" represents the range greater than or equal to A and less than or equal to B.

[0050] In the description of the embodiments of the present invention, the term "and / or" herein is merely a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after.

[0051] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A cable tester, characterized in that: include: Test interface, test circuit and power supply module; The test interface is used to connect the cable to be tested, and the cable to be tested includes: a flexible cable configured for the hinge assembly of the cockpit door monitoring system of Airbus aircraft; The test circuit is used to connect the cable to be tested through the test interface to perform a cable connectivity test, and the test circuit includes a first micro control unit, a second micro control unit and a dynamic relay matrix; The first micro control unit and the second micro control unit are connected to the test interface through the dynamic relay matrix respectively, the first micro control unit is used to connect a first group of pins of the cable to be tested through the test interface, and the second micro control unit is used to connect a second group of pins of the cable to be tested through the test interface, wherein the first group of pins is a part of the pins of the cable to be tested, and the second group of pins is another part of the pins of the cable to be tested; The dynamic relay matrix comprises at least a first relay and a second relay, and is used to control the connection between the first micro control unit and the second micro control unit and the test interface by closing the first relay and the second relay, so that the cable tester enters a cable connectivity test mode; The power supply module is used to provide power to the cable tester.

2. The cable tester according to claim 1, characterized in that: The cable to be tested is a 47-core flexible cable, the first group of pins are the first 24 core pins of the cable to be tested, and the second group of pins are the last 23 core pins of the cable to be tested.

3. The cable tester according to claim 2, characterized in that: The first micro control unit has at least 24 pins, which are used to connect to the first 24 pins of the cable to be tested through the test interface; The second micro control unit has at least 23 pins, which are used to be connected to the rear 23 pins of the cable to be tested via the test interface.

4. The cable tester according to claim 1, characterized in that: When the cable tester enters the cable connectivity test mode, the first microcontroller unit is used to scan the level value of each pin in the first group of pins, determine the on-off status information of the first group of pins according to the level value of each pin in the first group of pins, and generate real-time synchronization data according to the on-off status information of the first group of pins, and send the real-time synchronization data to the second microcontroller unit through a preset communication protocol format.

5. The cable tester according to claim 4, characterized in that: The second microcontroller unit is used to scan the level value of each pin in the second group of pins, determine the on-off status information of the second group of pins according to the level value of each pin in the second group of pins, receive the real-time synchronization data, obtain the on-off status information of the first group of pins in the real-time synchronization data, and integrate and output the on-off status information of the first group of pins and the second group of pins.

6. The cable tester according to claim 4, characterized in that: The real-time synchronization data at least includes: a frame header, a data segment and a check code, and the on-off status information of the first group of pins is stored in the data segment.

7. The cable tester according to claim 1, characterized in that: The first micro control unit and the second micro control unit are respectively connected to each pin of the test interface through an impedance voltage divider circuit.

8. The cable tester according to any one of claims 1 to 7, characterized in that: The test circuit also includes: a self-recovery test unit; The dynamic relay matrix further includes a third relay, wherein the third relay remains in a closed state when the cable tester is in the cable continuity test mode; The self-recovery test unit is connected to the second micro control unit via the third relay; The second micro control unit is also used to connect the self-recovery diode in the cable to be tested through the test interface; The dynamic relay matrix is ​​also used to disconnect the first relay and the second relay, and switch the third relay from a closed state to an open state to control the connection between the self-recovery test unit and the second micro control unit, so that the cable tester enters a self-recovery test mode.

9. The cable tester according to claim 8, characterized in that: When the cable tester enters the self-recovery test mode, the power supply module is used to connect the working current to the self-recovery diode through the self-recovery test unit; The self-recovery test unit is used to detect the on or off state of the self-recovery diode under the working current. If the self-recovery diode is in the on state, the power supply module is controlled to connect a step current to the self-recovery diode to detect the on or off state of the self-recovery diode under the step current, wherein the step current is greater than the working current.

10. The cable tester according to claim 9, characterized in that: When it is detected that the self-recovery diode enters the disconnected state, the power supply module is further used to reconnect the working current to the self-recovery diode through the self-recovery test unit; The self-recovery test unit is also used to detect whether the self-recovery diode recovers to a conducting state.

Images