Communication fault diagnosis method, communication system and storage medium

Abstract

The invention provides a communication fault diagnosis method, a communication system and a storage medium, the communication fault diagnosis method is applied to the communication system, the communication system comprises a first communication bus and a second communication bus, and the communication fault diagnosis method comprises the following steps: obtaining a first voltage of the first communication bus and a second voltage of the second communication bus; and determining a fault state of the first communication bus and / or the second communication bus according to the first voltage and the second voltage. According to the method and the device, the fault of the first communication bus and / or the second communication bus in the communication system can be quickly positioned, so that the troubleshooting difficulty when the first communication bus and the second communication bus of the communication system have faults can be reduced.

Description

Technical Field

[0001] The present application relates to the field of communication technologies, and in particular, to a communication fault diagnosis method, a communication system, and a storage medium. Background Art

[0002] Currently, Controller Area Network (CAN) communication is a serial communication protocol that enables efficient data transmission among multiple nodes through differential signals. Due to its advantages such as strong anti-interference ability, low cost, and simple implementation, it is widely used in fields such as automotive electronics and industrial control.

[0003] In the related art, CAN communication usually uses twisted pair wires (CANH and CANL) to transmit differential signals. Since the differential signals transmitted by the twisted pair wires are two signals with equal values but opposite polarities, and environmental noise or interference signals are usually common-mode interferences (i.e., environmental noise or interference signals act on both signals simultaneously), these noises will be canceled out at the receiving end. Therefore, the influence of noise on the signals can be reduced, thereby avoiding the phenomenon of a large number of error codes formed due to interference signals. However, currently, the CAN communication system cannot diagnose whether there are faults (such as short circuits, open circuits, etc.) in the twisted pair wires, which increases the difficulty of troubleshooting when faults occur in the twisted pair wires of the CAN communication system. Summary of the Invention

[0004] The present application provides a communication fault diagnosis method, a communication system, and a storage medium, aiming to solve the above technical problems.

[0005] In a first aspect, the present application provides a communication fault diagnosis method. The communication fault diagnosis method is applied to a communication system. The communication system includes a first communication bus and a second communication bus. The communication fault diagnosis method includes:

[0006] Obtain a first voltage of the first communication bus and a second voltage of the second communication bus;

[0007] Determine the fault status of the first communication bus and / or the second communication bus according to the first voltage and the second voltage.

[0008] In some embodiments, the step of determining the fault status of the first communication bus and / or the second communication bus according to the first voltage and the second voltage includes:

[0009] When the first voltage is less than or equal to a first preset value, determine that the fault status of the first communication bus is a short circuit to ground; or

[0010] When the second voltage is less than or equal to the first preset value, determine that the fault status of the second communication bus is a short circuit to ground; or

[0011] When both the first voltage and the second voltage are less than or equal to a first preset value, determine that the fault states of the first communication bus and the second communication bus are short - circuits to the ground.

[0012] In some embodiments, the steps of determining the fault state of the first communication bus and / or the second communication bus according to the first voltage and the second voltage include:

[0013] When the first voltage is greater than or equal to a second preset value, determine that the fault state of the first communication bus is a short - circuit to the power supply; or

[0014] When the second voltage is greater than or equal to a second preset value, determine that the fault state of the second communication bus is a short - circuit to the power supply; or

[0015] When the first voltage and the second voltage are greater than or equal to a second preset value, determine that the fault states of the first communication bus and the second communication bus are short - circuits to the power supply.

[0016] In some embodiments, the steps of determining the fault state of the first communication bus and / or the second communication bus according to the first voltage and the second voltage include:

[0017] When the voltage difference between the first voltage and the second voltage is less than or equal to a preset threshold, determine that the fault states of the first communication bus and the second communication bus are short - circuits to each other.

[0018] In some embodiments, the communication system further includes a first terminal resistor and a second terminal resistor. The first end of the first terminal resistor is connected to the first communication bus, the second end of the first terminal resistor is connected to the second communication bus, the first end of the second terminal resistor is connected to the first communication bus, and the second end of the second terminal resistor is connected to the second communication bus;

[0019] Before the step of obtaining the first voltage of the first communication bus and the second voltage of the second communication bus, the communication fault diagnosis method further includes:

[0020] Control the first end of the first terminal resistor to access a standard current source, and control the second end of the first terminal resistor to be grounded.

[0021] In some embodiments, the steps of obtaining the first voltage of the first communication bus and the second voltage of the second communication bus include:

[0022] Obtain the voltage of the first end of the first terminal resistor and the voltage of the second end of the first terminal resistor, and / or the voltage of the first end of the second terminal resistor and the voltage of the second end of the second terminal resistor;

[0023] The steps of determining the fault state of the first communication bus and / or the second communication bus according to the first voltage and the second voltage include:

[0024] Determine the fault status of the first communication bus and / or the second communication bus according to the first terminal voltage and the second terminal voltage of the first terminal resistor, and / or the first terminal voltage and the second terminal voltage of the second terminal resistor.

[0025] In some embodiments, the step of obtaining the first terminal voltage and the second terminal voltage of the first terminal resistor, and / or the first terminal voltage and the second terminal voltage of the second terminal resistor includes:

[0026] Obtain the first terminal voltage and the second terminal voltage of the first terminal resistor;

[0027] The step of determining the fault status of the first communication bus and / or the second communication bus according to the first terminal voltage and the second terminal voltage of the first terminal resistor, and / or the first terminal voltage and the second terminal voltage of the second terminal resistor includes:

[0028] When the voltage difference between the first terminal voltage and the second terminal voltage of the first terminal resistor is greater than or equal to a first preset threshold, determine that the fault status of the first communication bus and the second communication bus is an open circuit.

[0029] In some embodiments, the step of obtaining the first terminal voltage and the second terminal voltage of the first terminal resistor, and / or the first terminal voltage and the second terminal voltage of the second terminal resistor includes:

[0030] Obtain the first terminal voltage and the second terminal voltage of the second terminal resistor;

[0031] The step of determining the fault status of the first communication bus and / or the second communication bus according to the first terminal voltage and the second terminal voltage of the first terminal resistor, and / or the first terminal voltage and the second terminal voltage of the second terminal resistor includes:

[0032] When the voltage difference between the first terminal voltage and the second terminal voltage of the second terminal resistor is less than or equal to a second preset threshold, determine that the fault status of the first communication bus and the second communication bus is an open circuit.

[0033] In some embodiments, the step of obtaining the first terminal voltage and the second terminal voltage of the first terminal resistor, and / or the first terminal voltage and the second terminal voltage of the second terminal resistor includes:

[0034] Obtain the first-end voltage and the second-end voltage of the first terminal resistor, as well as the first-end voltage and the second-end voltage of the second terminal resistor;

[0035] The steps of determining the fault status of the first communication bus and / or the second communication bus according to the first-end voltage and the second-end voltage of the first terminal resistor, and / or the first-end voltage and the second-end voltage of the second terminal resistor include:

[0036] When the voltage difference between the first-end voltage of the first terminal resistor and the first-end voltage of the second terminal resistor is greater than or equal to a third preset threshold, determine that the fault status of the first communication bus is an open circuit;

[0037] When the voltage difference between the second-end voltage of the first terminal resistor and the second-end voltage of the second terminal resistor is greater than or equal to a fourth preset threshold, determine that the fault status of the second communication bus is an open circuit.

[0038] In a second aspect, the present application provides a communication system, including:

[0039] A first communication bus and a second communication bus;

[0040] A communication transceiver configured to convert the received communication level signal into a differential communication signal so that the first communication bus and the second communication bus transmit the differential communication signal;

[0041] A fault diagnosis unit configured to detect the first voltage of the first communication bus and the second voltage of the second communication bus;

[0042] A controller and a memory, in which a computer program is stored. When the computer program is executed by the controller, the controller is caused to execute the steps of the communication fault diagnosis method according to any one of claims 1 to 9.

[0043] In some embodiments, the communication system further includes a first terminal resistor and a second terminal resistor;

[0044] The first end of the first terminal resistor is connected to the first communication bus, and the second end of the first terminal resistor is connected to the second communication bus;

[0045] The first end of the second terminal resistor is connected to the first communication bus, and the second end of the second terminal resistor is connected to the second communication bus.

[0046] In some embodiments, the fault diagnosis unit includes a signal processing circuit;

[0047] The signal processing circuit is connected to the first end of the first terminal resistor and the second end of the first terminal resistor to detect the voltage at the first end and the voltage at the second end of the first terminal resistor; and / or

[0048] The signal processing circuit is connected to the first end of the second terminal resistor and the second end of the second terminal resistor to detect the voltage at the first end and the voltage at the second end of the second terminal resistor.

[0049] In some embodiments, the fault diagnosis unit further includes a standard current source, a first switch, and a second switch;

[0050] The first end of the first switch is connected to the standard current source, and the second end of the first switch is connected to the first end of the first terminal resistor;

[0051] The first end of the second switch is connected to the second end of the first terminal resistor, and the second end of the second switch is connected to the ground terminal.

[0052] In a third aspect, the present application provides a storage medium storing multiple instructions suitable for being loaded by a controller to execute the steps of the communication fault diagnosis method as described in the first aspect.

[0053] The present application obtains the first voltage of the first communication bus and the second voltage of the second communication bus. Based on the first voltage and the second voltage, the fault status of the first communication bus and / or the second communication bus can be determined. For example, whether the first communication bus is short-circuited to the ground, short-circuited to the power supply, or open-circuited; or whether the second communication bus is short-circuited to the ground, short-circuited to the power supply, or open-circuited. That is to say, the present application can achieve rapid positioning of faults in the first communication bus and / or the second communication bus in the communication system, thereby facilitating the reduction of the troubleshooting difficulty when faults occur in the first communication bus and the second communication bus of the communication system. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0055] Figure 1 Shows a schematic diagram of a communication system in an embodiment of the present application;

[0056] Figure 2 Shows another schematic diagram of a communication system in an embodiment of the present application;

[0057] Figure 3Shows a schematic flowchart of a communication fault diagnosis method in an embodiment of the present application;

[0058] Figure 4 Shows a schematic diagram of a communication system in a fault state in an embodiment of the present application;

[0059] Figure 5 Shows another schematic diagram of a communication system in a fault state in an embodiment of the present application;

[0060] Figure 6 Shows another schematic diagram of a communication system in a fault state in an embodiment of the present application;

[0061] Figure 7 Shows a schematic diagram of a communication system in a detected fault state in an embodiment of the present application;

[0062] Figure 8 Shows another schematic diagram of a communication system in an embodiment of the present application;

[0063] Figure 9 Shows another schematic diagram of a communication system in an embodiment of the present application;

[0064] Figure 10 Shows another schematic diagram of a communication system in an embodiment of the present application;

[0065] Figure 11 Shows another schematic diagram of a communication system in an embodiment of the present application.

[0066] Among them, 101 - single-chip microcomputer, 1011 - controller, 1012 - memory, 102 - communication transceiver, 103 - fault diagnosis unit, 1031 - signal processing circuit;

[0067] The first communication bus - CANH, the second communication bus - CANL, the first terminal resistor - R1, the second terminal resistor - R2, the standard current source - IS, the first switch - S1, the second switch - S2. Detailed implementation manners

[0068] 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 only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present invention.

[0069] In the description of the present invention, the term "exemplary" is used to mean "serving as an example, illustration, or explanation". Any embodiment described as "exemplary" in this application is not necessarily to be construed as more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the present invention. In the following description, details are set forth for purposes of explanation. It should be understood that the present invention can be practiced without these specific details. In other instances, well-known structures and processes are not elaborated in detail to avoid obscuring the description of the present invention with unnecessary details. Therefore, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed in this application.

[0070] Embodiments of this application provide a communication fault diagnosis method, a communication system, and a storage medium, which will be described in detail below.

[0071] First, before introducing the communication fault diagnosis method of this application, a communication system to which the communication fault diagnosis method of this application is applied will be introduced. Refer to Figure 1 , Figure 1 which shows a schematic diagram of a communication system in an embodiment of this application. In the communication system, there are a first communication bus CANH, a second communication bus CANL, a communication transceiver 102, a controller 1011, and a memory 1012.

[0072] Specifically, the first communication bus CANH and the second communication bus CANL are connected to the communication transceiver 102. The first communication bus CANH and the second communication bus CANL can transmit differential communication signals output by the communication transceiver 102 to improve the anti-interference ability during signal transmission.

[0073] Generally, the first communication bus CANH and the second communication bus CANL may refer to two cables corresponding to twisted pairs. It can be understood that the first communication bus CANH and the second communication bus CANL may also refer to other communication cables capable of realizing differential signal transmission. For example, the first communication bus CANH and the second communication bus CANL may also refer to two coaxial cables.

[0074] In some embodiments, the communication system may further include a first terminal resistor R1 and a second terminal resistor R2. The first end of the first terminal resistor R1 is connected to the first communication bus CANH, and the second end of the first terminal resistor R1 is connected to the second communication bus CANL. The first end of the second terminal resistor R2 is connected to the first communication bus CANH, and the second end of the second terminal resistor R2 is connected to the second communication bus CANL. The first terminal resistor R1 and the second terminal resistor R2 can achieve impedance matching between the first communication bus CANH and the second communication bus CANL, thereby effectively reducing signal reflection at both ends of the bus and ensuring clear and stable signal transmission on the bus.

[0075] The communication transceiver 102 is connected to the controller 1011. The communication transceiver 102 can convert the level signal input by the controller 1011 into a differential signal to transmit differential communication signals to devices 1, 2... n using the first communication bus CANH and the second communication bus CANL. At the same time, the communication transceiver 102 can also convert the differential signals transmitted back by the first communication bus CANH and the second communication bus CANL into level signals so that the controller 1011 can receive the signals returned by devices 1, 2... n.

[0076] Exemplarily, the communication transceiver 102 can be, but is not limited to, an automotive-grade CAN transceiver, an industrial-grade CAN transceiver, an agricultural machinery-grade CAN transceiver, or a space-grade CAN transceiver.

[0077] The controller 1011 is the control center of the communication system. By running or executing software programs and / or modules stored in the memory 1012, and calling programs stored in the memory 1012, it performs data processing of the communication system to achieve communication functions and bus diagnostic functions. For example, the controller 1011 can achieve data exchange and issue control instructions. For another example, the controller 1011 can parse the received instructions into digital signals and output level signals to the communication transceiver 102. For yet another example, the controller 1011 can convert the level signals returned by the communication transceiver 102 into digital signals.

[0078] Exemplarily, the controller 1011 may include one or more processing cores; the controller 1011 may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0079] The memory 1012 can be used to store software programs and modules. The controller 1011 executes various functional applications and data processing by running the software programs and modules stored in the memory 1012. The memory 1012 mainly includes a program storage area and a data storage area. Among them, the program storage area can store an operating system, application programs required for at least one function, etc.; the data storage area can store data created according to the use of the light sensing module, etc. In addition, the memory 1012 may include high-speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other volatile solid-state storage devices. Correspondingly, the memory 1012 may also include a memory controller 1011 to provide the controller 1011 with access to the memory 1012.

[0080] It should be noted that the above description of the communication system is only for convenience of description and does not limit the present application to the scope of the examples given. It can be understood that for those skilled in the art, after understanding the principle of the system, they may, without departing from this principle, make any combination of the various modules, or form a subsystem and connect it with other modules. For example, Figure 1 the controller 1011 and the communication transceiver 102 disclosed in [reference] may be different modules in a system, or a module may implement the functions of two or more of the above modules. For example, refer to Figure 2 , Figure 2 shows another schematic diagram of the communication system in the embodiment of the present application. Among them, the controller 1011 and the controller 1011 are both integrated in the single-chip microcomputer 101 (MCU, Single-Chip Microcomputer), that is, the single-chip microcomputer 101 simultaneously realizes the control function of the controller 1011 and the software program storage function of the memory 1012 in the communication system.

[0081] Meanwhile, it can be understood that the communication fault diagnosis method of the present application is not limited to being applied only to the CAN communication system. The communication fault diagnosis method can also be applied to other communication systems using differential signal transmission methods. For example, the communication fault diagnosis method of the present application can also be applied to an LVDS (Low-Voltage Differential Signaling) communication system.

[0082] Next, the communication fault diagnosis method of the present application will be introduced. The communication fault diagnosis method of the present application is applied to a communication system, and the communication system includes a first communication bus CANH and a second communication bus CANL. It should be noted that the execution subject of the communication fault diagnosis method of the present application can be the controller 1011 as shown in Figure 1 or other processing devices (such as a host computer, a cloud server), etc. The present application does not make specific limitations.

[0083] Referring to Figure 3 , Figure 3 shows a schematic flowchart of a communication fault diagnosis method in an embodiment of the present application. Among them, the communication fault diagnosis method includes:

[0084] Step S301, obtaining a first voltage of the first communication bus CANH and a second voltage of the second communication bus CANL;

[0085] Specifically, the first voltage of the first communication bus CANH may refer to the voltage at any position or a specific position of the first communication bus CANH, and the second voltage of the second communication bus CANL may refer to the voltage at any position or a specific position of the second communication bus CANL.

[0086] For example, taking Figure 1 as an example, the first voltage of the first communication bus CANH may refer to the voltage at the first end of the first terminal resistor R1, and the second voltage of the second communication bus CANL may refer to the voltage at the first end of the second terminal resistor R2; or, the first voltage of the first communication bus CANH may also refer to the voltage at the first end of the second terminal resistor R2, and the second voltage of the second communication bus CANL may also refer to the voltage at the second end of the second terminal resistor R2; or, the first voltage of the first communication bus CANH may further refer to the voltage at any node between the first end of the first terminal resistor R1 and the first end of the second terminal resistor R2 of the first communication bus CANH, and the second voltage of the second communication bus CANL may further refer to the voltage at any node between the second end of the first terminal resistor R1 and the second end of the second terminal resistor R2 of the second communication bus CANL.

[0087] It should be noted that the first voltage of the first communication bus CANH and the second voltage of the second communication bus CANL can be measured by an analog-to-digital converter. The analog-to-digital converter converts the first voltage of the first communication bus CANH and the second voltage of the second communication bus CANL into digital signals, so that the controller 1011 can determine the fault status of the first communication bus CANH and / or the second communication bus CANL according to the digital signals.

[0088] Step S302: Determine the fault status of the first communication bus CANH and / or the second communication bus CANL according to the first voltage and the second voltage.

[0089] After determining the first voltage of the first communication bus CANH and the second voltage of the second communication bus CANL, the fault status of the first communication bus CANH and / or the second communication bus CANL can be determined according to the first voltage and the second voltage.

[0090] Among them, the fault status of the first communication bus CANH and the second communication bus CANL may include a short circuit fault or an open circuit fault. For example, whether there is a fault of short circuit to ground in the first communication bus CANH and the second communication bus CANL; for another example, whether there is a fault of short circuit to power supply in the first communication bus CANH and the second communication bus CANL; for another example, whether there is a fault of short circuit between the first communication bus CANH and the second communication bus CANL; for still another example, whether there is an open circuit fault in the first communication bus CANH and the second communication bus CANL.

[0091] In the embodiments of the present application, the present application obtains the first voltage of the first communication bus CANH and the second voltage of the second communication bus CANL, and can determine the fault status of the first communication bus CANH and / or the second communication bus CANL according to the first voltage and the second voltage. For example, whether the first communication bus CANH is short-circuited to ground, short-circuited to power supply or open-circuited; for another example, whether the second communication bus CANL is short-circuited to ground, short-circuited to power supply or open-circuited. That is to say, the present application can realize the rapid positioning of faults in the first communication bus CANH and / or the second communication bus CANL in the communication system, which is beneficial to reducing the troubleshooting difficulty when faults occur in the first communication bus CANH and the second communication bus CANL of the communication system.

[0092] In some embodiments of the present application, the step of determining the fault status of the first communication bus CANH and / or the second communication bus CANL according to the first voltage and the second voltage includes:

[0093] When the first voltage is less than or equal to the first preset value, determine that the fault state of the first communication bus CANH is a short circuit to ground; or, when the second voltage is less than or equal to the first preset value, determine that the fault state of the second communication bus CANL is a short circuit to ground; or, when the first voltage and the second voltage are less than or equal to the first preset value, determine that the fault states of the first communication bus CANH and the second communication bus CANL are short circuits to ground.

[0094] For example, referring to Figure 4 , Figure 4 shows a schematic diagram of the communication system in a fault state in an embodiment of the present application. Among them, the first communication bus CANH is short-circuited to ground, and the second communication bus CANL is short-circuited to ground. Then, the first voltage of the first communication bus CANH is close to 0, and the second voltage of the second communication bus CANL is close to 0. Therefore, it can be determined that the first communication bus CANH is short-circuited to ground when the first voltage is less than or equal to the first preset value (such as 0.1V), and it can be determined that the second communication bus CANL is short-circuited to ground when the second voltage is less than or equal to the first preset value.

[0095] It can be understood that when only the first voltage of the first communication bus CANH is close to 0, it can be determined that the first communication bus CANH is short-circuited to ground; or, when only the second voltage of the second communication bus CANL is close to 0, it can be determined that the second communication bus CANL is short-circuited to ground.

[0096] In some embodiments of the present application, the step of determining the fault state of the first communication bus CANH and / or the second communication bus CANL according to the first voltage and the second voltage includes:

[0097] When the first voltage is greater than or equal to the second preset value, determine that the fault state of the first communication bus CANH is a short circuit to the power supply; or, when the second voltage is greater than or equal to the second preset value, determine that the fault state of the second communication bus CANL is a short circuit to the power supply; or, when the first voltage and the second voltage are greater than or equal to the second preset value, determine that the fault states of the first communication bus CANH and the second communication bus CANL are short circuits to the power supply.

[0098] For example, referring to Figure 5 , Figure 5Another schematic diagram showing the communication system in a fault state in an embodiment of the present application is shown. Among them, the first communication bus CANH is short-circuited to the power supply VBAT, and the second communication bus CANL is short-circuited to the power supply VBAT. Then, the first voltage of the first communication bus CANH is close to the power supply voltage, and the second voltage of the second communication bus CANL is close to the power supply voltage. Therefore, it can be determined that the first communication bus CANH is short-circuited to the power supply VBAT when the first voltage is greater than or equal to a second preset value (for example, 10V), and it can be determined that the second communication bus CANL is short-circuited to the power supply VBAT when the second voltage is greater than or equal to the second preset value.

[0099] It should be noted that the second preset value can be less than or equal to the voltage of the power supply VBAT. For example, when the voltage of the power supply VBAT is 15V, the second preset value can be set to 15V; or, when the voltage of the power supply VBAT is 15V, the second preset value can be 10V. Those skilled in the art can set the size of the second preset value according to actual needs, and the present application does not make specific limitations. At the same time, it can be understood that when only the first voltage of the first communication bus CANH is close to the power supply VBAT, it can be determined that the first communication bus CANH is short-circuited to the power supply VBAT; or, when only the second voltage of the second communication bus CANL is close to the power supply VBAT, it can be determined that the second communication bus CANL is short-circuited to the power supply VBAT.

[0100] In some embodiments of the present application, the steps of determining the fault state of the first communication bus CANH and / or the second communication bus CANL according to the first voltage and the second voltage include:

[0101] When the voltage difference between the first voltage and the second voltage is less than or equal to a preset threshold, it is determined that the fault states of the first communication bus CANH and the second communication bus CANL are short-circuited to each other.

[0102] For example, refer to Figure 6 , Figure 6 Another schematic diagram showing the communication system in a fault state in an embodiment of the present application is shown. Among them, the first communication bus CANH and the second communication bus CANL are short-circuited to each other. Then, the first voltage of the first communication bus CANH is basically equal to the second voltage of the second communication bus CANL. Therefore, it can be determined that the first communication bus CANH and the second communication bus CANL are short-circuited to each other when the voltage difference between the first voltage and the second voltage is less than or equal to a preset threshold (for example, 0.1V).

[0103] In some embodiments of the present application, for example, in the embodiments where the communication system further includes a first terminal resistor R1 and a second terminal resistor R2, before the step of obtaining the first voltage of the first communication bus CANH and the second voltage of the second communication bus CANL, the communication fault diagnosis method further includes:

[0104] Control the first end of the first terminal resistor R1 to be connected to a standard current source IS, and control the second end of the first terminal resistor R1 to be grounded.

[0105] It should be noted that referring to Figure 7 , Figure 7 shows a schematic diagram of the communication system in the detection fault state in the embodiments of the present application. After the first end of the first terminal resistor R1 is connected to the standard current source IS and the second end of the first terminal resistor R1 is grounded, assuming that the resistance values of the first terminal resistor R1 and the second terminal resistor R2 are equal, if there is no open circuit in the first communication bus CANH and the second communication bus CANL, then the voltages at the first end of the first terminal resistor R1, the second end of the first terminal resistor R1, the first end of the second terminal resistor R2, and the second end of the second terminal resistor R2 are respectively:

[0106] VR11 = 1 / 2 * I0 * R0

[0107] VR12 = 0

[0108] VR21 = 1 / 2 * I0 * R0

[0109] VR22 = 0

[0110] Wherein, VR11 is the voltage at the first end of the first terminal resistor R1, VR12 is the voltage at the second end of the first terminal resistor R1, VR21 is the voltage at the first end of the second terminal resistor R2, VR22 is the voltage at the second end of the second terminal resistor R2, I0 is the constant current output by the standard current source IS, and R0 is the resistance value of the first terminal resistor R1 and the second terminal resistor R2.

[0111] On the contrary, if there is an open circuit in the first communication bus CANH and the second communication bus CANL, then the voltages at the first end of the first terminal resistor R1, the second end of the first terminal resistor R1, the first end of the second terminal resistor R2, and the second end of the second terminal resistor R2 are respectively:

[0112] VR11 = I0 * R0

[0113] VR12 = 0

[0114] VR21 = 0

[0115] VR22 = 0

[0116] It can be seen that in the two cases where there is an open circuit in the first communication bus CANH and the second communication bus CANL, the voltage at the first end of the first terminal resistor R1, the voltage at the second end of the first terminal resistor R1, the voltage at the first end of the second terminal resistor R2, and the voltage at the second end of the second terminal resistor R2 are different. Therefore, the steps of obtaining the first voltage of the first communication bus CANH and the second voltage of the second communication bus CANL in this application may include: obtaining the voltage at the first end of the first terminal resistor R1 and the voltage at the second end of the first terminal resistor R1, and / or the voltage at the first end of the second terminal resistor R2 and the voltage at the second end of the second terminal resistor R2.

[0117] The steps of determining the fault status of the first communication bus CANH and / or the second communication bus CANL according to the first voltage and the second voltage may include: determining the fault status of the first communication bus CANH and / or the second communication bus CANL according to the voltage at the first end of the first terminal resistor R1 and the voltage at the second end of the first terminal resistor R1, and / or the voltage at the first end of the second terminal resistor R2 and the voltage at the second end of the second terminal resistor R2.

[0118] That is to say, after controlling the first end of the first terminal resistor R1 to be connected to the standard current source IS and controlling the second end of the first terminal resistor R1 to be grounded, this application can determine the fault status of the first communication bus CANH and / or the second communication bus CANL according to the voltage at the first end of the first terminal resistor R1 and the voltage at the second end of the first terminal resistor R1, and / or the voltage at the first end of the second terminal resistor R2 and the voltage at the second end of the second terminal resistor R2.

[0119] In some embodiments of this application, the steps of obtaining the voltage at the first end of the first terminal resistor R1 and the voltage at the second end of the first terminal resistor R1, and / or the voltage at the first end of the second terminal resistor R2 and the voltage at the second end of the second terminal resistor R2 include:

[0120] Obtaining the voltage at the first end of the first terminal resistor R1 and the voltage at the second end of the first terminal resistor R1.

[0121] The steps of determining the fault status of the first communication bus CANH and / or the second communication bus CANL according to the voltage at the first end of the first terminal resistor R1 and the voltage at the second end of the first terminal resistor R1, and / or the voltage at the first end of the second terminal resistor R2 and the voltage at the second end of the second terminal resistor R2 include:

[0122] When the voltage difference between the voltage at the first end and the voltage at the second end of the first terminal resistor R1 is greater than or equal to the first preset threshold, it is determined that the fault status of the first communication bus CANH and the second communication bus CANL is an open circuit.

[0123] For example, continuing to refer to Figure 7 , if there is an open circuit in the first communication bus CANH and the second communication bus CANL, then the voltage difference between the first terminal voltage and the second terminal voltage of the first terminal resistor R1 should be greater than 0.5*I0*R0 and close to I0*R0. Therefore, when the voltage difference between the first terminal voltage and the second terminal voltage of the first terminal resistor R1 is greater than or equal to the first preset threshold (for example, 0.8*I0*R0), it can be determined that there is an open circuit in the first communication bus CANH and the second communication bus CANL.

[0124] In some embodiments of the present application, the steps of obtaining the first terminal voltage of the first terminal resistor R1 and the second terminal voltage of the first terminal resistor R1, and / or the first terminal voltage of the second terminal resistor R2 and the second terminal voltage of the second terminal resistor R2 include:

[0125] Obtaining the first terminal voltage of the second terminal resistor R2 and the second terminal voltage of the second terminal resistor R2.

[0126] The steps of determining the fault state of the first communication bus CANH and / or the second communication bus CANL according to the first terminal voltage of the first terminal resistor R1 and the second terminal voltage of the first terminal resistor R1, and / or the first terminal voltage of the second terminal resistor R2 and the second terminal voltage of the second terminal resistor R2 include:

[0127] When the voltage difference between the first terminal voltage and the second terminal voltage of the second terminal resistor R2 is less than or equal to the second preset threshold, it can be determined that the fault state of the first communication bus CANH and the second communication bus CANL is an open circuit.

[0128] For example, continuing to refer to Figure 7 , if there is an open circuit in the first communication bus CANH and the second communication bus CANL, then the voltage difference between the first terminal voltage and the second terminal voltage of the second terminal resistor R2 should be less than 0.5*I0*R0 and close to 0. Therefore, when the voltage difference between the first terminal voltage and the second terminal voltage of the second terminal resistor R2 is less than or equal to the second preset threshold (for example, 0.1*I0*R0), it can be determined that there is an open circuit in the first communication bus CANH and the second communication bus CANL.

[0129] In some embodiments of the present application, the steps of obtaining the first terminal voltage of the first terminal resistor R1 and the second terminal voltage of the first terminal resistor R1, and / or the first terminal voltage of the second terminal resistor R2 and the second terminal voltage of the second terminal resistor R2 include:

[0130] Obtain the voltage at the first end of the first terminal resistor R1 and the voltage at the second end of the first terminal resistor R1, as well as the voltage at the first end of the second terminal resistor R2 and the voltage at the second end of the second terminal resistor R2.

[0131] The steps of determining the fault status of the first communication bus CANH and / or the second communication bus CANL according to the voltage at the first end of the first terminal resistor R1 and the voltage at the second end of the first terminal resistor R1, and / or the voltage at the first end of the second terminal resistor R2 and the voltage at the second end of the second terminal resistor R2 include:

[0132] When the voltage difference between the voltage at the first end of the first terminal resistor R1 and the voltage at the first end of the second terminal resistor R2 is greater than or equal to a third preset threshold, determine that the fault status of the first communication bus CANH is an open circuit; when the voltage difference between the voltage at the second end of the first terminal resistor R1 and the voltage at the second end of the second terminal resistor R2 is greater than or equal to a fourth preset threshold, determine that the fault status of the second communication bus CANL is an open circuit.

[0133] For example, continue to refer to Figure 7 , if there is an open circuit in the first communication bus CANH, then the voltage at the first end of the first terminal resistor R1 is close to I0*R0, and the voltage at the first end of the second terminal resistor R2 is close to 0. Therefore, when the voltage difference between the voltage at the first end of the first terminal resistor R1 and the voltage at the first end of the second terminal resistor R2 is greater than or equal to a third preset threshold (such as 0.5*I0*R0), it can be determined that the first communication bus CANH is open.

[0134] Similarly, if there is an open circuit in the second communication bus CANL, then the voltage at the second end of the first terminal resistor R1 is close to 0, and the voltage at the second end of the second terminal resistor R2 is close to I0*R0. Therefore, when the voltage difference between the voltage at the second end of the first terminal resistor R1 and the voltage at the second end of the second terminal resistor R2 is greater than or equal to a fourth preset threshold (such as 0.5*I0*R0), it can be determined that the second communication bus CANL is open.

[0135] It can be seen that through the above embodiments, by obtaining the voltage at the first end of the first terminal resistor R1 and the voltage at the second end of the first terminal resistor R1, as well as the voltage at the first end of the second terminal resistor R2 and the voltage at the second end of the second terminal resistor R2, it is possible to specifically determine whether the first communication bus CANH and the second communication bus CANL are open circuits respectively, which is conducive to further reducing the difficulty of troubleshooting when open circuit faults occur in the first communication bus CANH and the second communication bus CANL of the communication system.

[0136] It should be noted that the above content regarding the communication fault diagnosis method is intended to clearly illustrate the implementation verification process of this application. Those skilled in the art can make equivalent modified designs under the guidance of this application. For example, when detecting an open - circuit fault, the first end of the second terminal resistor R2 can also be connected to the standard current source IS, and the second end of the second terminal resistor R2 can be grounded. By obtaining the voltage at the first end and the voltage at the second end of the first terminal resistor R1, and / or the voltage at the first end and the voltage at the second end of the second terminal resistor R2, the fault state of the first communication bus CANH and / or the second communication bus CANL is determined.

[0137] Furthermore, in order to better implement the communication fault diagnosis method in the embodiments of this application, based on the communication fault diagnosis method, this application also provides a communication system. Refer to Figure 8 , Figure 8 which shows another schematic diagram of the communication system in the embodiments of this application. Among them, the communication system includes:

[0138] The first communication bus CANH and the second communication bus CANL;

[0139] A communication transceiver 102, which is configured to convert the received communication level signal into a differential communication signal so that the first communication bus CANH and the second communication bus CANL transmit differential communication signals;

[0140] A fault diagnosis unit 103, which is configured to detect the first voltage of the first communication bus CANH and the second voltage of the second communication bus CANL;

[0141] A controller 1011 and a memory 1012. A computer program is stored in the controller 1011. When the computer program is executed by the controller 1011, the controller 1011 is caused to execute the steps of the communication fault diagnosis method as described in any of the above embodiments.

[0142] In the embodiments of this application, this application detects the first voltage of the first communication bus CANH and the second voltage of the second communication bus CANL through the fault diagnosis unit 103. The controller 1011 can determine the fault state of the first communication bus CANH and / or the second communication bus CANL according to the first voltage and the second voltage, and can achieve rapid positioning of the faults of the first communication bus CANH and / or the second communication bus CANL of the communication system, thereby facilitating the reduction of the troubleshooting difficulty when faults occur in the first communication bus CANH and the second communication bus CANL of the communication system.

[0143] In some embodiments of this application, refer to Figure 9 , Figure 9Another schematic diagram of the communication system in the embodiment of the present application is shown. The communication system further includes a first terminal resistor R1 and a second terminal resistor R2. The first end of the first terminal resistor R1 is connected to the first communication bus CANH, and the second end of the first terminal resistor R1 is connected to the second communication bus CANL. The first end of the second terminal resistor R2 is connected to the first communication bus CANH, and the second end of the second terminal resistor R2 is connected to the second communication bus CANL.

[0144] Among them, the fault diagnosis unit 103 includes a signal processing circuit 1031. The signal processing circuit 1031 is connected to the first end of the first terminal resistor R1 and the second end of the first terminal resistor R1 to detect the voltage at the first end and the voltage at the second end of the first terminal resistor R1. That is to say, the voltage at the first end of the first terminal resistor R1 can be used as the first voltage of the first communication bus CANH, and the voltage at the second end of the first terminal resistor R1 can be used as the second voltage of the second communication bus CANL, so that the controller 1011 can perform communication fault diagnosis based on the first voltage and the second voltage.

[0145] In some embodiments of the present application, refer to Figure 10 , Figure 10 Another schematic diagram of the communication system in the embodiment of the present application is shown. Among them, the signal processing circuit 1031 is connected to the first end of the second terminal resistor R2 and the second end of the second terminal resistor R2 to detect the voltage at the first end and the voltage at the second end of the second terminal resistor R2. The voltage at the first end of the second terminal resistor R2 can be used as the first voltage of the first communication bus CANH, and the voltage at the second end of the second terminal resistor R2 can be used as the second voltage of the second communication bus CANL, so that the controller 1011 can perform communication fault diagnosis based on the first voltage and the second voltage.

[0146] It can be understood that the signal processing circuit 1031 can also be simultaneously connected to the first end of the first terminal resistor R1, the second end of the first terminal resistor R1, the first end of the second terminal resistor R2, and the second end of the second terminal resistor R2. In this way, the voltage at the first end of the first terminal resistor R1 and the voltage at the first end of the second terminal resistor R2 can be used as the first voltage of the first communication bus CANH, and the voltage at the second end of the first terminal resistor R1 and the voltage at the second end of the second terminal resistor R2 can be used as the second voltage of the second communication bus CANL.

[0147] In some embodiments of the present application, refer to Figure 11 , Figure 11Another schematic diagram of the communication system in the embodiment of the present application is shown. Among them, the fault diagnosis unit 103 further includes a standard current source IS, a first switch S1, and a second switch S2; the first end of the first switch S1 is connected to the standard current source IS, and the second end of the first switch S1 is connected to the first end of the first terminal resistor R1; the first end of the second switch S2 is connected to the second end of the first terminal resistor R1, and the second end of the second switch S2 is connected to the ground terminal.

[0148] It should be noted that when detecting whether there is a short circuit fault (such as short circuit to ground, short circuit to power supply, etc.) in the first communication bus CANH and the second communication bus CANL, the first switch S1 and the second switch S2 are disconnected, and the current of the standard current source IS will not flow into the first communication bus CANH and the second communication bus CANL. Therefore, it will not affect the short circuit fault diagnosis of the first communication bus CANH and the second communication bus CANL. When detecting whether there is an open circuit fault in the first communication bus CANH and the second communication bus CANL, the controller 1011 controls the first switch S1 and the second switch S2 to close, and controls the communication transceiver 102 to stop working (sleep). At this time, the current of the standard current source IS can flow into the first communication bus CANH and the second communication bus CANL, thereby changing the voltage across the first terminal resistor R1 and the second terminal resistor R2. By detecting the voltage across the first terminal resistor R1 and the second terminal resistor R2, it is possible to identify whether there is an open circuit fault in the first communication bus CANH and the second communication bus CANL. Regarding how to identify whether there is an open circuit fault in the first communication bus CANH and the second communication bus CANL according to the voltage across the first terminal resistor R1 and the second terminal resistor R2, reference can be made to the foregoing content, and the present application will not elaborate herein.

[0149] Specifically, in this embodiment, the controller 1011 in the communication system will load the executable files corresponding to the processes of one or more application programs into the controller 1011 according to the following instructions, and the controller 1011 will run the application programs stored in the memory 1012 to implement various functions as follows:

[0150] Obtain the first voltage of the first communication bus CANH and the second voltage of the second communication bus CANL;

[0151] Determine the fault status of the first communication bus CANH and / or the second communication bus CANL according to the first voltage and the second voltage.

[0152] Those of ordinary skill in the art can understand that all or part of the steps in the above-mentioned various methods can be completed by instructions, or by controlling relevant hardware through instructions. The instructions can be stored in a computer-readable storage medium and loaded and executed by the controller 1011.

[0153] To this end, an embodiment of the present invention provides a computer-readable storage medium, which may include: a read-only memory 1012 (ROM), a random access memory 1012 (RAM), a magnetic disk or an optical disc, etc. A computer program is stored thereon, and the computer program is loaded by a controller 1011 to execute the steps in any one of the communication fault diagnosis methods provided by the embodiments of the present invention. For example, when the computer program is loaded by the controller 1011, the following steps may be executed:

[0154] Obtain a first voltage of a first communication bus CANH and a second voltage of a second communication bus CANL;

[0155] Determine the fault status of the first communication bus CANH and / or the second communication bus CANL according to the first voltage and the second voltage.

[0156] In the above embodiments, the descriptions of the respective embodiments have their own emphases. For parts not detailed in a certain embodiment, reference may be made to the detailed descriptions of other embodiments above, which will not be elaborated here.

[0157] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only an example and does not constitute a limitation to this application. Although not explicitly stated here, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are proposed in this application, so such modifications, improvements, and corrections still fall within the spirit and scope of the exemplary embodiments of this application.

[0158] At the same time, specific terms are used in this application to describe the embodiments of this application. Such as "one embodiment", "an embodiment", and / or "some embodiments" mean a certain feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that the "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more at different positions in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application can be appropriately combined.

[0159] Similarly, it should be noted that, in order to simplify the expression of the disclosure of this application and thus help the understanding of one or more inventive embodiments, in the foregoing description of the embodiments of this application, sometimes multiple features are merged into one embodiment, drawing, or description thereof. However, this disclosure method does not mean that the features required by the subject matter of this application are more than those mentioned in the claims. In fact, the features of the embodiment are less than all the features of the single embodiment disclosed above.

[0160] The above has introduced in detail a communication fault diagnosis method, a communication system, and a storage medium provided by the embodiments of the present application. Specific examples are used herein to elaborate on the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A communication fault diagnosis method, characterized in that: The communication fault diagnosis method is applied to a communication system, the communication system includes a first communication bus and a second communication bus, and the communication fault diagnosis method includes: Acquire a first voltage of the first communication bus and a second voltage of the second communication bus; A fault state of the first communication bus and / or the second communication bus is determined according to the first voltage and the second voltage.

2. The communication fault diagnosis method according to claim 1, characterized in that: The step of determining the fault state of the first communication bus and / or the second communication bus according to the first voltage and the second voltage comprises: When the first voltage is less than or equal to a first preset value, determining that the fault state of the first communication bus is a short circuit to ground; or When the second voltage is less than or equal to a first preset value, determining that the fault state of the second communication bus is a short circuit to ground; or When the first voltage and the second voltage are both less than or equal to a first preset value, it is determined that the fault state of the first communication bus and the second communication bus is a short circuit to ground.

3. The communication fault diagnosis method according to claim 1, characterized in that: The step of determining the fault state of the first communication bus and / or the second communication bus according to the first voltage and the second voltage comprises: In a case where the first voltage is greater than or equal to a second preset value, determining that the fault state of the first communication bus is a short circuit to the power supply; or In a case where the second voltage is greater than or equal to a second preset value, determining that the fault state of the second communication bus is a short circuit to the power supply; or When the first voltage and the second voltage are greater than or equal to a second preset value, it is determined that the fault state of the first communication bus and the second communication bus is a short circuit to the power supply.

4. The communication fault diagnosis method according to claim 1, characterized in that: The step of determining the fault state of the first communication bus and / or the second communication bus according to the first voltage and the second voltage comprises: When the voltage difference between the first voltage and the second voltage is less than or equal to a preset threshold, it is determined that the fault state of the first communication bus and the second communication bus is a mutual short circuit.

5. The communication fault diagnosis method according to claim 1, characterized in that: The communication system further includes a first terminal resistor and a second terminal resistor, wherein a first end of the first terminal resistor is connected to the first communication bus, a second end of the first terminal resistor is connected to the second communication bus, a first end of the second terminal resistor is connected to the first communication bus, and a second end of the second terminal resistor is connected to the second communication bus; Before the step of obtaining the first voltage of the first communication bus and the second voltage of the second communication bus, the communication fault diagnosis method further includes: The first end of the first terminal resistor is controlled to be connected to a standard current source, and the second end of the first terminal resistor is controlled to be grounded.

6. The communication fault diagnosis method according to claim 5, characterized in that: The step of obtaining a first voltage of the first communication bus and a second voltage of the second communication bus comprises: Acquire a first terminal voltage of the first terminal resistor and a second terminal voltage of the first terminal resistor, and / or a first terminal voltage of the second terminal resistor and a second terminal voltage of the second terminal resistor; The step of determining the fault state of the first communication bus and / or the second communication bus according to the first voltage and the second voltage comprises: The fault state of the first communication bus and / or the second communication bus is determined according to the first terminal voltage of the first terminal resistor and the second terminal voltage of the first terminal resistor, and / or the first terminal voltage of the second terminal resistor and the second terminal voltage of the second terminal resistor.

7. The communication fault diagnosis method according to claim 6, characterized in that: The step of obtaining the first terminal voltage of the first terminal resistor and the second terminal voltage of the first terminal resistor, and / or the first terminal voltage of the second terminal resistor and the second terminal voltage of the second terminal resistor comprises: Acquire a first terminal voltage of the first terminal resistor and a second terminal voltage of the first terminal resistor; The step of determining the fault state of the first communication bus and / or the second communication bus according to the first terminal voltage of the first terminal resistor and the second terminal voltage of the first terminal resistor, and / or the first terminal voltage of the second terminal resistor and the second terminal voltage of the second terminal resistor comprises: When the voltage difference between the first terminal voltage and the second terminal voltage of the first terminal resistor is greater than or equal to a first preset threshold, it is determined that the fault state of the first communication bus and the second communication bus is open circuit.

8. The communication fault diagnosis method according to claim 6, characterized in that: The step of obtaining the first terminal voltage of the first terminal resistor and the second terminal voltage of the first terminal resistor, and / or the first terminal voltage of the second terminal resistor and the second terminal voltage of the second terminal resistor comprises: Acquire a first terminal voltage of the second terminal resistor and a second terminal voltage of the second terminal resistor; The step of determining the fault state of the first communication bus and / or the second communication bus according to the first terminal voltage of the first terminal resistor and the second terminal voltage of the first terminal resistor, and / or the first terminal voltage of the second terminal resistor and the second terminal voltage of the second terminal resistor comprises: When the voltage difference between the first terminal voltage and the second terminal voltage of the second terminal resistor is less than or equal to a second preset threshold, it is determined that the fault state of the first communication bus and the second communication bus is open circuit.

9. The communication fault diagnosis method according to claim 6, characterized in that: The step of obtaining the first terminal voltage of the first terminal resistor and the second terminal voltage of the first terminal resistor, and / or the first terminal voltage of the second terminal resistor and the second terminal voltage of the second terminal resistor comprises: Acquire a first terminal voltage of the first terminal resistor and a second terminal voltage of the first terminal resistor, and a first terminal voltage of the second terminal resistor and a second terminal voltage of the second terminal resistor; The step of determining the fault state of the first communication bus and / or the second communication bus according to the first terminal voltage of the first terminal resistor and the second terminal voltage of the first terminal resistor, and / or the first terminal voltage of the second terminal resistor and the second terminal voltage of the second terminal resistor comprises: When a voltage difference between a first terminal voltage of the first terminal resistor and a first terminal voltage of the second terminal resistor is greater than or equal to a third preset threshold, determining that the fault state of the first communication bus is a circuit break; When a voltage difference between a second terminal voltage of the first terminal resistor and a second terminal voltage of the second terminal resistor is greater than or equal to a fourth preset threshold, it is determined that the fault state of the second communication bus is open circuit.

10. A communication system, characterized in that: include: A first communication bus and a second communication bus; a communication transceiver, the communication transceiver being configured to convert a received communication level signal into a differential communication signal, so that the first communication bus and the second communication bus transmit the differential communication signal; a fault diagnosis unit, the fault diagnosis unit being configured to detect a first voltage of the first communication bus and a second voltage of the second communication bus; A controller and a memory, wherein a computer program is stored in the memory, and when the computer program is executed by the controller, the controller executes the steps of the communication fault diagnosis method as described in any one of claims 1 to 9.

11. The communication system according to claim 10, characterized in that The communication system also includes a first terminal resistor and a second terminal resistor; A first end of the first terminal resistor is connected to the first communication bus, and a second end of the first terminal resistor is connected to the second communication bus; A first end of the second terminal resistor is connected to the first communication bus, and a second end of the second terminal resistor is connected to the second communication bus.

12. The communication system according to claim 11, characterized in that The fault diagnosis unit includes a signal processing circuit; The signal processing circuit is connected to the first end of the first terminal resistor, and the signal processing circuit is connected to the second end of the first terminal resistor to detect the first terminal voltage and the second terminal voltage of the first terminal resistor; and / or The signal processing circuit is connected to a first end of the second terminal resistor, and the signal processing circuit is connected to a second end of the second terminal resistor to detect a first end voltage and a second end voltage of the second terminal resistor.

13. The communication system according to claim 12, characterized in that The fault diagnosis unit also includes a standard current source, a first switch and a second switch; A first end of the first switch is connected to the standard current source, and a second end of the first switch is connected to a first end of the first terminal resistor; The first end of the second switch is connected to the second end of the first terminal resistor, and the second end of the second switch is connected to the ground.

14. A storage medium, characterized in that: The storage medium stores a plurality of instructions, and the instructions are suitable for being loaded by a controller to execute the steps of the communication fault diagnosis method according to any one of claims 1 to 9.

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