CAN communication system with fail-safe mechanism and vehicle
By introducing a fault indication module into the CAN communication system to monitor the status of the power supply and main control module in real time, and controlling the CAN transceiver to enter sleep mode when a fault occurs, the problem of erroneous message propagation caused by main control or power supply failure is solved, and safe and reliable communication of the whole vehicle network is realized.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-10
- Publication Date
- 2026-03-10
AI Technical Summary
In existing technologies, when the main control chip or power module of an in-vehicle CAN communication system fails, the CAN transceiver cannot enter sleep mode, resulting in the propagation of erroneous messages and failing to meet functional safety requirements.
A CAN communication system with a fail-safe mechanism was designed. The fault indication module monitors the status of the power module and the main control module in real time. In case of a fault, the CAN transceiver is controlled to enter a sleep/mute mode, including the logic level toggling and mode control of the power fault indication signal and the main control fault indication signal.
It effectively prevents the propagation of erroneous messages on the bus, ensuring the reliability and security of the vehicle network communication and meeting functional safety requirements.
Smart Images
Figure CN121644266A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of automotive electronics technology, and more particularly to a CAN communication system and vehicle with a fail-safe mechanism. Background Technology
[0002] In the existing technology, the CAN communication scheme of the vehicle controller usually consists of a main control chip, a CAN transceiver and related power modules, and the main control chip directly controls the CAN transceiver through GPIO pins.
[0003] However, when the main control chip or power module experiences a specific fault (such as a program crash in the main control chip or abnormal power output), the main control chip may fail to correctly output the signal to control the CAN transceiver to enter sleep mode. This will cause the CAN transceiver to continue operating on the bus, potentially sending erroneous messages, disrupting bus communication, and failing to meet functional safety requirements. Summary of the Invention
[0004] This invention provides a CAN communication system with a fail-safe mechanism, which solves the problem that the CAN transceiver cannot go into sleep mode when the main control or power supply fails in traditional vehicle CAN solutions.
[0005] In a first aspect, embodiments of the present invention provide a CAN communication system with a fail-safe mechanism, including a main control module, a CAN transceiver, a fault indication module, and a power supply module;
[0006] The power module is electrically connected to the main control module, CAN transceiver and fault indication module respectively. When the power module fails, it outputs a power failure indication signal to the fault indication module.
[0007] When the main control module fails, it outputs a main control fault indication signal to the fault indication module.
[0008] The fault indication module is electrically connected to the main control module and the CAN transceiver respectively. The fault indication module is used to control the CAN transceiver to enter sleep / mute mode when it receives a power failure indication signal and / or a main control failure indication signal.
[0009] Optionally, the main control module is also used to output an active sleep signal to the fault indication module;
[0010] The fault indication module is also used to control the CAN transceiver to enter sleep / mute mode when an active sleep signal is received.
[0011] Optionally, the fault indication module includes:
[0012] The fault integration unit is used to receive power failure indication signals and main control failure indication signals, and generate a fault enable signal when the power failure indication signal and / or the main control failure indication signal is received.
[0013] The mode control unit is electrically connected to the fault integration unit and the main control module respectively. It is used to receive the fault enable signal generated by the fault integration unit and the active sleep signal sent by the main control module. When it receives the fault enable signal and / or the active sleep signal, it controls the CAN transceiver to enter the sleep / mute mode.
[0014] Optionally, the fault indication module may also include a logic level toggling unit;
[0015] The logic level inversion unit is located before the signal input terminal of the fault synthesis unit, and / or, is located before the signal input terminal of the mode control unit;
[0016] The logic level switching unit is used to perform logic level conversion on at least one of the power failure indication signal, the main control failure indication signal, the fault enable signal, and / or the active sleep signal, so that the power failure indication signal and the main control failure indication signal, the fault enable signal, and the active sleep signal are logically aligned.
[0017] Optionally, the fault synthesis unit includes AND gate logic circuitry, and / or the mode control unit includes AND gate logic circuitry;
[0018] The logic level flipping unit is used to convert non-active-low logic signals in the power failure indication signal, master control failure indication signal and active sleep signal input to the AND gate logic circuit into active-low logic signals.
[0019] Optionally, the CAN communication system also includes an output level toggling unit; the CAN transceiver also includes a normal operating mode;
[0020] The output level switching unit is located between the fault indication module and the CAN transceiver;
[0021] The output level toggling unit is used to toggle the logic level output by the fault indication module so that the CAN transceiver enters normal operation mode when it receives the first level and enters sleep / mute mode when it receives the second level; the first level and the second level are different.
[0022] Optionally, the output level switching unit includes a transistor switching circuit;
[0023] The transistor switching circuit turns on when no sleep / mute signal is received, and outputs the first level to the CAN transceiver so that the CAN transceiver enters normal working mode.
[0024] When the transistor switching circuit receives a sleep / mute signal, or when the main control module loses power before the CAN transceiver, it outputs a second level to enable the CAN transceiver to enter sleep / mute mode.
[0025] Optionally, the transistor switching circuit includes: a PNP transistor and a first resistor;
[0026] The collector of the PNP transistor is electrically connected to the power supply terminal via the first resistor, and the collector of the PNP transistor is also electrically connected to the CAN transceiver.
[0027] The base of the PNP transistor is electrically connected to the fault indication module;
[0028] The emitter of a PNP transistor is grounded.
[0029] Optionally, the output level inversion unit includes a logic gate circuit, which is used to invert the logic level output by the fault indication module.
[0030] Secondly, embodiments of the present invention also provide a vehicle, characterized in that it includes a CAN communication system with a fail-safe mechanism as described in any of the first aspects.
[0031] This invention provides a CAN communication system with a fail-safe mechanism, including a main control module, a CAN transceiver, a fault indication module, and a power supply module. The power supply module is electrically connected to the main control module, the CAN transceiver, and the fault indication module. When the power supply module fails, it outputs a power failure indication signal to the fault indication module to proactively report the abnormal power status, thereby controlling the CAN transceiver to enter a sleep / mute mode. When the main control module fails, it outputs a main control failure indication signal to the fault indication module to proactively report the abnormal status of the main control module, thereby controlling the CAN transceiver to enter a sleep / mute mode, preventing erroneous control of the CAN transceiver due to program crashes or logic errors. The fault indication module is electrically connected to both the main control module and the CAN transceiver. Upon receiving a power failure indication signal and / or a main control failure indication signal, the fault indication module controls the CAN transceiver to enter a sleep / mute mode, directly cutting off the CAN transceiver's bus drive capability through hardware, fundamentally preventing the propagation of erroneous messages on the bus. This invention provides a solution to the problem that the CAN transceiver cannot enter sleep / mute mode when either the power module or the main control module fails, by using a fault indication module to monitor the fault status of the power module and the main control module in real time. Attached Figure Description
[0032] Figure 1 A schematic diagram of a CAN communication system with a fail-safe mechanism provided in an embodiment of the present invention;
[0033] Figure 2 A schematic diagram of another CAN communication system with a fail-safe mechanism provided in an embodiment of the present invention;
[0034] Figure 3 This is a partial structural diagram of a CAN communication system with a fail-safe mechanism provided in an embodiment of the present invention. Detailed Implementation
[0035] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.
[0036] Figure 1 This is a schematic diagram of a CAN communication system with a fail-safe mechanism provided in an embodiment of the present invention. Figure 2 A schematic diagram of another CAN communication system with a fail-safe mechanism provided in an embodiment of the present invention. (Refer to...) Figures 1-2 This invention provides a CAN communication system with a fail-safe mechanism, characterized in that it includes a main control module 10, a CAN transceiver 20, a fault indication module 30, and a power supply module 40.
[0037] The power module 40 is electrically connected to the main control module 10, the CAN transceiver 20 and the fault indication module 30 respectively. When the power module 40 fails, it outputs a power fault indication signal to the fault indication module 30.
[0038] When the main control module 10 fails, it outputs a main control fault indication signal to the fault indication module 30.
[0039] The fault indication module 30 is electrically connected to the main control module 10 and the CAN transceiver 20 respectively. The fault indication module 30 is used to control the CAN transceiver 20 to enter the sleep / mute mode when it receives a power failure indication signal and / or a main control failure indication signal.
[0040] Among them, the power supply fault indication signal can be understood as a logic level signal sent to the fault indication module to indicate its abnormal state when the power module fails to supply power normally due to abnormalities such as overvoltage, undervoltage, or overheating, in order to trigger the safety response mechanism; the master control fault indication signal can be understood as a logic level signal sent to the fault indication module to indicate its abnormal state when the master control module experiences hardware or software failures such as internal program crashes or timeouts; the sleep / mute mode can be understood as the CAN transceiver being forced into a low-power or high-impedance operating state. In this mode, it stops driving any differential signals to the CAN bus. Its core function is to ensure that the bus is not interfered with by erroneous messages from a physical level when the system is abnormal, thereby ensuring the safety and integrity of the vehicle network communication.
[0041] Specifically, during system implementation, the power module 40 and the main control module 10 continuously monitor their own status. If the power module 40 fails, it will output a power failure indication signal to the fault indication module 30; if the main control module 10 fails, it will output a main control failure indication signal. After receiving any fault signal, the fault indication module 30 will generate a mode control signal and send it to the CAN transceiver 20 to force the CAN transceiver 20 to switch to sleep / mute mode, thereby cutting off the drive capability of the CAN transceiver 20. This ultimately achieves the purpose of preventing erroneous messages from propagating on the bus when the power supply or main control chip fails, thereby ensuring the reliability and security of the vehicle network communication.
[0042] This invention provides a CAN communication system with a fail-safe mechanism, including a main control module, a CAN transceiver, a fault indication module, and a power supply module. The power supply module is electrically connected to the main control module, the CAN transceiver, and the fault indication module. When the power supply module fails, it outputs a power failure indication signal to the fault indication module to proactively report the abnormal power status, thereby controlling the CAN transceiver to enter a sleep / mute mode. When the main control module fails, it outputs a main control failure indication signal to the fault indication module to proactively report the abnormal status of the main control module, thereby controlling the CAN transceiver to enter a sleep / mute mode, preventing erroneous control of the CAN transceiver due to program crashes or logic errors. The fault indication module is electrically connected to both the main control module and the CAN transceiver. Upon receiving a power failure indication signal and / or a main control failure indication signal, the fault indication module controls the CAN transceiver to enter a sleep / mute mode, directly cutting off the CAN transceiver's bus drive capability through hardware, fundamentally preventing the propagation of erroneous messages on the bus. This invention provides a solution to the problem that the CAN transceiver cannot enter sleep / mute mode when either the power module or the main control module fails, by using a fault indication module to monitor the fault status of the power module and the main control module in real time.
[0043] Continue to refer to Figure 1 and Figure 2 In an optional embodiment, the main control module 10 is also used to output an active sleep signal to the fault indication module 30;
[0044] The fault indication module 30 is also used to control the CAN transceiver 20 to enter sleep / mute mode when it receives an active sleep signal.
[0045] The active sleep signal can be understood as a logical control signal actively issued by the main control module 10 according to the vehicle network management strategy (such as the vehicle entering sleep mode) when the system is working normally. Its function is to notify the downstream unit system that it is about to enter a low power state and require the CAN transceiver to enter sleep mode as planned.
[0046] Specifically, when the vehicle needs the CAN transceiver 20 to enter a low-power state, the main control module 10 will actively send an active sleep signal to the fault indication module 30. After receiving the active sleep signal, the fault indication module 30 will generate a corresponding mode control signal and send it to the CAN transceiver 20 in a similar manner to the fault signal, thereby causing the CAN transceiver 20 to switch to sleep / mute mode.
[0047] Continue to refer to Figure 1 and Figure 2 In an optional embodiment, the fault indication module 30 includes:
[0048] The fault integration unit 31 is used to receive power failure indication signal and main control failure indication signal, and generate a fault enable signal when the power failure indication signal and / or the main control failure indication signal are received.
[0049] The mode control unit 32 is electrically connected to the fault integration unit 31 and the main control module 10 respectively. It is used to receive the fault enable signal generated by the fault integration unit 31 and the active sleep signal sent by the main control module 10. When it receives the fault enable signal and / or the active sleep signal, it controls the CAN transceiver 20 to enter the sleep / mute mode.
[0050] The fault enable signal can be understood as a logic level signal output by the fault integration unit 31 after detecting at least one fault, which is used to notify the mode control unit 32 that there is a fault in the system.
[0051] Specifically, the fault integration unit 31 receives and continuously monitors the power fault indication signal from the power module 40 and the main control fault indication signal from the main control module 10. When either signal is valid, the fault integration unit 31 generates a fault enable signal and sends it to the mode control unit 32. At the same time, the mode control unit 32 also receives the active sleep signal from the main control module 10. When the mode control unit 32 receives either the fault enable signal from the fault integration unit 31 and / or the active sleep signal from the main control module 10, it immediately generates a final mode control signal and sends it to the CAN transceiver 20, thereby driving the CAN transceiver 20 into sleep / mute mode. Ultimately, this ensures that the CAN bus output can be reliably shut down through a unified path regardless of whether it is a system fault or a normal sleep command, thus ensuring bus safety.
[0052] Continue to refer to Figure 1 and Figure 2 In an optional embodiment, the fault indication module 30 further includes a logic level toggling unit 33;
[0053] The logic level switching unit 33 is located before the signal input terminal of the fault integration unit 31, and / or, is located before the signal input terminal of the mode control unit 32;
[0054] The logic level switching unit 33 is used to perform logic level conversion on at least one of the power failure indication signal, the main control failure indication signal, the fault enable signal, and / or the active sleep signal, so that the power failure indication signal, the main control failure indication signal, the fault enable signal, and the active sleep signal are logically aligned.
[0055] Specifically, the logic level inversion unit 33 is configured before the input terminal of the fault synthesis unit 31 and / or the input terminal of the mode control unit 32; it is used to invert the level of these fault signals when the main control fault signal and / or power fault indication signal do not match the input logic required by the fault synthesis unit 31, so that the fault synthesis unit 31 can correctly identify them; similarly, when the level logic of the active sleep signal does not match the triggering requirements of the mode control unit 32, the logic level inversion unit 33 is used to perform level conversion on the active sleep signal, thereby ensuring that chips with different logic specifications can work together in this system, improving the flexibility and compatibility of the solution.
[0056] Continue to refer to Figure 1 and Figure 2 In an optional embodiment, the fault synthesis unit 31 includes AND gate logic circuitry, and / or the mode control unit 32 includes AND gate logic circuitry.
[0057] The logic level switching unit 33 is used to convert the non-active logic signals in the power failure indication signal, main control failure indication signal and active sleep signal input to the AND gate logic circuit into active logic signals.
[0058] Specifically, the fault integration unit 31 and / or the mode control unit 32 employ AND gate logic circuits, i.e., active low. In this case, the logic level toggling unit 33 is located at the input of the AND gate logic circuit, used to convert the power fault indication signal, the main control fault indication signal, and / or the active sleep signal, which are active high signals, to active low signals; thereby ensuring that the AND gate outputs a low-level fault enable signal when any fault or sleep signal is input.
[0059] Continue to refer to Figure 1 and Figure 2 In an optional embodiment, the CAN communication system further includes an output level toggling unit 50; the CAN transceiver 20 also includes a normal operating mode;
[0060] The output level switching unit 50 is located between the fault indication module 30 and the CAN transceiver 20;
[0061] The output level toggling unit 50 is used to toggle the logic level output by the fault indication module 30 so that the CAN transceiver 20 enters normal operation mode when it receives the first level and enters sleep / mute mode when it receives the second level; wherein the first level and the second level are different.
[0062] The normal working mode can be understood as the standard working state in which the CAN transceiver 20 can normally transmit and receive CAN bus differential signals.
[0063] Specifically, the output level toggling unit 50 is located between the fault indication module 30 and the CAN transceiver 20. When the fault indication module 30 outputs a logic level (e.g., high level) indicating normal system operation, the output level toggling unit 50 toggles this level to a first level (e.g., low level) and sends it to the enable pin of the CAN transceiver 20, so that the CAN transceiver 20 enters normal operation mode when it receives the first level (low level). Similarly, when the fault indication module 30 outputs a logic level (e.g., low level) indicating "system abnormality" due to detecting a fault or a sleep request, the output level toggles unit 50 toggles this level to a second level (high level) and sends it to the CAN transceiver 20, so that the CAN transceiver 20 enters sleep / mute mode.
[0064] In one specific embodiment, the output level toggle unit 50 is an optional level conversion circuit. Its core function is to adapt the output logic of the fault indication module 30 to the level requirements of the CAN transceiver enable pin. If an AND gate logic circuit is used and the enable pin of the CAN transceiver 20 is configured to a high-level active sleep / mute mode, then the output level toggle unit 50 needs to be configured. Conversely, if an AND gate logic circuit is used and the enable pin of the CAN transceiver 20 is configured to a low-level sleep mode, then this unit does not need to be configured.
[0065] Figure 3 This is a partial structural diagram of a CAN communication system with a fail-safe mechanism provided in an embodiment of the present invention, with reference to... Figure 3 In an optional embodiment, the output level switching unit 50 includes a transistor switching circuit;
[0066] When the transistor switching circuit does not receive a sleep / mute signal, it turns on and outputs the first level to the CAN transceiver 20 so that the CAN transceiver 20 enters the normal working mode.
[0067] When the transistor switching circuit receives a sleep / mute signal, or when the main control module 10 is powered off before the CAN transceiver 20, it outputs a second level to enable the CAN transceiver 20 to enter sleep / mute mode.
[0068] Specifically, the transistor switching circuit is configured as a common-emitter switching circuit. When the base receives a valid sleep / mute signal from the fault indication module 30, the transistor is in the off state, and its collector output is pulled up to the second level by the pull-up resistor. This second level (high level) causes the CAN transceiver 20 to enter the sleep / mute mode. When the base does not receive a valid sleep / mute signal, the transistor enters the saturation conduction state, and the collector output voltage is pulled down to the first level. The first level (low level) causes the CAN transceiver 20 to enter the normal operation mode. When the main control module 10 fails to power down, the output pin of the main control module 10 is in a high-impedance state. The fault indication module 30, due to the loss of effective drive, defaults to outputting a low-level sleep control signal, causing the transistor to be cut off and output a high level, thereby forcing the CAN transceiver 20 to enter the safe mode. Conversely, if the logic specification of the target CAN transceiver is low-level sleep and high-level operation, logic matching can be achieved by adjusting the transistor type or circuit structure to ensure reliable adaptation.
[0069] In one specific embodiment, if the main control module 10 (such as the Chipown E3106 chip) loses power before the CAN transceiver 20, its TXD pin enters a high-impedance state with a low equivalent impedance (approximately 56kΩ). At this time, if the CAN transceiver 20 is still powered by a constant VIO (3.3V) and its internal TXD pin has a pull-up resistor (approximately 100kΩ), the two will form a series voltage divider circuit. According to the voltage divider formula, the voltage at the main control chip's TXD pin will be pulled down to approximately 1.185V. This level is recognized as a logic low by the CAN transceiver, causing the bus to continuously output a dominant level, triggering a communication error. To solve this problem, in this embodiment, the output level toggle unit 50 uses a transistor switching circuit. When the main control module 10 loses power, causing its output to be in a high-impedance state, the fault indication module 30 can default to output a sleep control signal (such as a low level) because its input is floating or invalid, thereby driving the transistor switching circuit to operate and forcing the CAN transceiver 20 into sleep / mute mode.
[0070] Continue to refer to Figure 1 and Figure 2 In an optional embodiment, the transistor switching circuit includes: a PNP transistor and a first resistor R1;
[0071] The collector of the PNP transistor is electrically connected to the power supply terminal via the first resistor R1, and the collector of the PNP transistor is also electrically connected to the CAN transceiver 20.
[0072] The base of the PNP transistor is electrically connected to the fault indication module 30;
[0073] The emitter of a PNP transistor is grounded.
[0074] Specifically, the PNP transistor switching circuit is configured with its emitter grounded. When the fault indication module 30 does not output a valid sleep / mute signal (including when the main control module 10 loses power and its output is in a high-impedance state), the base is at a low level, the PNP transistor meets the conduction condition and conducts, and its collector output voltage is pulled down to a near-ground level. The low level causes the CAN transceiver 20 to enter normal operating mode. When the fault indication module 30 outputs a sleep signal, the base is at a high level, the PNP transistor is cut off, and its collector output is pulled up to a high level by the first resistor R1. The high level causes the CAN transceiver 20 to enter sleep / mute mode.
[0075] Continue to refer to Figure 1 and Figure 2 In an optional embodiment, the output level inversion unit 50 includes a logic gate circuit for inverting the logic level output by the fault indication module 30.
[0076] Specifically, the output level inversion unit 50 includes a logic gate circuit. The logic gate circuit (NOT gate) is set between the output terminal of the fault indication module 30 and the mode control pin of the CAN transceiver 20. When the fault indication module 30 outputs a logic level indicating "system normal", such as a high level, the logic gate circuit inverts this high level to a low level and sends it to the CAN transceiver 20, so that the CAN transceiver 20 receives the low level and enters the normal operation mode. When the fault indication module 30 outputs a logic level indicating "system abnormality", such as a low level, due to detecting a fault or a sleep request, the logic gate circuit inverts this low level to a high level and sends it to the CAN transceiver 20, so that the CAN transceiver 20 receives the high level and enters the sleep / mute mode.
[0077] This invention also provides a vehicle that includes the CAN communication system with a fail-safe mechanism described in the above embodiments. This CAN communication system is used to realize data interaction between on-board controller nodes. Therefore, this vehicle also possesses all the technical effects achieved by the aforementioned CAN communication system.
[0078] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, combinations, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.
Claims
1. A CAN communication system with a fail-safe mechanism, characterized in that The CAN communication system comprises a main control module, a CAN transceiver, a fault indication module and a power module; The power module is electrically connected with the main control module, the CAN transceiver and the fault indication module respectively, and outputs a power failure indication signal to the fault indication module when the power module fails; The main control module outputs a main control failure indication signal to the fault indication module when the main control module fails; The fault indication module is electrically connected with the main control module and the CAN transceiver respectively, and controls the CAN transceiver to enter a sleep / mute mode when the power failure indication signal and / or the main control failure indication signal is received.
2. The CAN communication system according to claim 1, characterized by, The main control module is further configured to output an active sleep signal to the fault indication module; The fault indication module is further configured to control the CAN transceiver to enter the sleep / mute mode when the active sleep signal is received.
3. The CAN communication system according to claim 2, characterized by The fault indication module comprises: a fault synthesis unit configured to receive the power failure indication signal and the main control failure indication signal, and generate a fault enable signal when the power failure indication signal and / or the main control failure indication signal is received; a mode control unit electrically connected with the fault synthesis unit and the main control module, configured to receive the fault enable signal generated by the fault synthesis unit and the active sleep signal sent by the main control module, and control the CAN transceiver to enter the sleep / mute mode when the fault enable signal and / or the active sleep signal is received.
4. The CAN communication system according to claim 3, characterized by The fault indication module further comprises a logic level inversion unit; The logic level inversion unit is arranged in front of the signal input end of the fault synthesis unit and / or in front of the signal input end of the mode control unit; The logic level inversion unit is configured to perform logic level conversion on at least one of the power failure indication signal, the main control failure indication signal, the fault enable signal and / or the active sleep signal, so that the power failure indication signal, the main control failure indication signal, the fault enable signal and the active sleep signal are logically aligned.
5. The CAN communication system according to claim 4, characterized by The fault synthesis unit comprises an AND gate logic circuit, and / or the mode control unit comprises an AND gate logic circuit; The logic level inversion unit is configured to convert a non-low-level valid logic signal among the power failure indication signal, the main control failure indication signal and the active sleep signal input into the AND gate logic circuit into a low-level valid logic signal.
6. The CAN communication system of claim 1, wherein, The CAN communication system further comprises an output level inversion unit, and the CAN transceiver further comprises a normal working mode; The output level inversion unit is arranged between the fault indication module and the CAN transceiver; The output level inversion unit is configured to invert the logic level output by the fault indication module, so that the CAN transceiver enters the normal working mode when a first level is received and enters the sleep / mute mode when a second level is received; wherein the first level and the second level are different.
7. The CAN communication system according to claim 6, characterized by The output level inversion unit comprises a transistor switching circuit. The triode switch circuit is turned on when the sleep / mute signal is not received, outputs the first level to the CAN transceiver, and makes the CAN transceiver enter the normal working mode; The triode switch circuit is turned off when the sleep / mute signal is received, or when the master module is powered off earlier than the CAN transceiver, outputs the second level, and makes the CAN transceiver enter the sleep / mute mode.
8. The CAN communication system according to claim 7, characterized by The triode switch circuit comprises a PNP triode and a first resistor. The collector of the PNP triode is electrically connected to a power supply end through the first resistor, and the collector of the PNP triode is also electrically connected to the CAN transceiver. The base of the PNP triode is electrically connected to the fault indication module. The emitter of the PNP triode is grounded.
9. The CAN communication system of claim 6, wherein, The output level reversing unit comprises a logic gate circuit, which is used to invert the logic level output by the fault indication module.
10. A vehicle characterized by comprising: A CAN communication system with a fault safety mechanism as claimed in any one of claims 1-9.