Electronic control devices, in-vehicle network systems, communication methods, communication programs

Abstract

The present invention provides an electronic control device that can activate a communication unit compatible with the second communication standard only when performing communication according to the second communication standard. [Solution] The electronic control devices (21, 22, 25, 26) constituting the in-vehicle network system 100 include a first communication unit and a second communication unit. The first communication unit is capable of communication according to a first communication standard using a first communication bus 51 and a second communication bus 52. The second communication unit is capable of communication according to a second communication standard using a third communication bus 53. When the electronic control devices (21, 22, 25, 26) receive a first operation notification through communication according to the first communication standard, they switch the first communication unit to an operational state. When the first device 21 communicates with another electronic control device, the fifth device 25, according to the second communication standard, it transmits a second operation notification to the fifth device 25 through communication according to the first communication standard, requesting the operation of the second communication unit.

Description

Technical Field

[0001] This invention relates to an electronic control device, an in-vehicle network system, a communication method, and a communication program.

Background Art

[0002] Patent Document 1 describes an in-vehicle network system. This in-vehicle network system is composed of a plurality of electronic control units (ECUs: Electronic Control Unit). Hereinafter, the electronic control device will be referred to as an ECU.

[0003] In this in-vehicle network system, an ECU communicates with other ECUs using CAN (Controller Area Network) as a communication standard. An ECU includes a communication unit for communicating with other ECUs via CAN. The communication unit has a standby state in which communication with other ECUs is restricted to reduce power consumption, and an operating state in which the restriction is released.

[0004] An ECU in an in-vehicle network system has a network management function. When an ECU having a network management function receives a message requesting operation from another ECU through communication using CAN, it shifts the communication unit from the standby state to the operating state.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In in-vehicle network systems, ECUs may employ CAN and Ethernet (registered trademark) as communication standards for communicating with other ECUs. In this case, the ECU has two types of communication units: one for CAN communication and another for Ethernet communication. The Ethernet communication unit, like the CAN communication unit, has both a standby state and an active state.

[0007] An ECU with network management functionality may, upon receiving a message requesting operation via CAN communication, activate both the communication unit for CAN communication and the communication unit for Ethernet communication. Ideally, the electronic control unit should only activate the communication unit for Ethernet communication when Ethernet communication is required. [Means for solving the problem]

[0008] To solve the above problems, an electronic control device comprises a first communication unit and a second communication unit, which are communication devices capable of switching between a standby state in which communication functions are restricted and an operational state in which the restrictions on communication functions are lifted. The first communication unit is capable of communication according to a first communication standard. The second communication unit is capable of communication according to a second communication standard, which is a communication standard different from the first communication standard. This electronic control device has a network management function that, upon receiving a first operational notification, which is a message requesting the operation of the first communication unit, via communication according to the first communication standard, transitions the first communication unit from the standby state to the operational state. This electronic control device constitutes an in-vehicle network system. When this electronic control device communicates with other electronic control devices according to the second communication standard, it transmits a second operational notification, which is a message requesting the operation of the second communication unit of the other electronic control device, to the other electronic control device via communication according to the first communication standard.

[0009] An electronic control device for solving the above problems comprises a first communication unit and a second communication unit, which are communication devices capable of switching between a standby state in which communication functions are restricted and an operational state in which the restrictions on communication functions are lifted. The first communication unit is capable of communication according to a first communication standard. The second communication unit is capable of communication according to a second communication standard, which is a communication standard different from the first communication standard. This electronic control device has a network management function that, upon receiving a first operational notification, which is a message requesting the operation of the first communication unit, via communication according to the first communication standard, transitions the first communication unit from the standby state to the operational state. This electronic control device constitutes an in-vehicle network system. This electronic control device is an electronic control device that can communicate with other electronic control devices in the in-vehicle network system. When this electronic control device receives a second operational notification, which is a message requesting the operation of the second communication unit, from another electronic control device via communication according to the first communication standard, it transitions the second communication unit from the standby state to the operational state.

[0010] The in-vehicle network system for solving the above problems is an in-vehicle network system comprising multiple electronic control units. In this in-vehicle network system, the electronic control unit comprises a first communication unit and a second communication unit as communication devices capable of switching between a standby state in which communication functions are restricted and an operational state in which the restrictions on communication functions are lifted. The first communication unit is capable of communication according to a first communication standard. The second communication unit is capable of communication according to a second communication standard, which is a communication standard different from the first communication standard. In this in-vehicle network system, the electronic control unit is an electronic control unit having a network management function that transitions the first communication unit from the standby state to the operational state when it receives a first operational notification, which is a message requesting the operation of the first communication unit, through communication according to the first communication standard. In this in-vehicle network system, when a specific electronic control unit in the plurality of electronic control units communicates with other electronic control units in the plurality of electronic control units according to the second communication standard, it transmits a second operational notification, which is a message requesting the operation of the second communication unit, through communication according to the first communication standard. In this in-vehicle network system, when another electronic control unit receives the second operation notification through communication according to the first communication standard, it transitions the second communication unit from the standby state to the operational state.

[0011] A communication method for solving the above problems is a communication method for an in-vehicle network system. The in-vehicle network system comprises a plurality of electronic control units. The plurality of electronic control units include a first communication unit and a second communication unit as communication devices that can switch between a standby state in which communication functions are restricted and an operational state in which the restrictions on communication functions are lifted. The first communication unit is capable of communication according to a first communication standard. The second communication unit is capable of communication according to a second communication standard, which is a communication standard different from the first communication standard. The plurality of electronic control units have a network management function that causes the first communication unit to transition from the standby state to the operational state when it receives a first operational notification, which is a message requesting the operation of the first communication unit, through communication according to the first communication standard. This communication method includes the step that when a specific electronic control unit in the plurality of electronic control units communicates with other electronic control units in the plurality of electronic control units according to the second communication standard, the specific electronic control unit transmits a second operational notification, which is a message requesting the operation of the second communication unit, through communication according to the first communication standard. This communication method includes the step of transitioning the second communication unit from the standby state to the operating state when another electronic control unit receives the second operation notification through communication according to the first communication standard.

[0012] The communication program for solving the above problems is a communication program executed by the processing circuit of an electronic control unit. The electronic control unit includes a first communication unit and a second communication unit as a communication device that can switch between a standby state in which communication functions are restricted and an operating state in which the restrictions on communication functions are lifted. The first communication unit is capable of communication according to a first communication standard. The second communication unit is capable of communication according to a second communication standard, which is a communication standard different from the first communication standard. The electronic control unit has a network management function that, when it receives a first operation notification, which is a message requesting the operation of the first communication unit, through communication according to the first communication standard, it transitions the first communication unit from the standby state to the operating state. The electronic control unit constitutes an in-vehicle network system. This communication program causes the processing circuit to execute a second operation notification, which is a message requesting the operation of the second communication unit of the other electronic control unit, to the other electronic control unit when the electronic control unit communicates with the other electronic control unit according to the second communication standard, through communication according to the first communication standard.

[0013] The communication program for solving the above problems is a communication program executed by the processing circuit of an electronic control unit. The electronic control unit includes a first communication unit and a second communication unit as a communication device that can switch between a standby state in which communication functions are restricted and an operating state in which the restrictions on communication functions are lifted. The first communication unit is capable of communication according to a first communication standard. The second communication unit is capable of communication according to a second communication standard, which is a communication standard different from the first communication standard. The electronic control unit has a network management function that, when it receives a first operation notification, which is a message requesting the operation of the first communication unit, through communication according to the first communication standard, transitions the first communication unit from the standby state to the operating state. The electronic control unit constitutes an in-vehicle network system. The electronic control unit can communicate with other electronic control units in the in-vehicle network system. This communication program causes the processing circuit to transition the second communication unit from the standby state to the operating state when the electronic control unit receives a second operation notification, which is a message requesting the operation of the second communication unit, from another electronic control unit through communication according to the first communication standard. [Effects of the Invention]

[0014] According to the above-described electronic control unit, in-vehicle network system, communication method, and communication program, the communication unit corresponding to the second communication standard can be operated only when communication is performed using Ethernet (registered trademark), which is the second communication standard. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1 is a schematic diagram showing the configuration of an in-vehicle network system according to one embodiment. [Figure 2] Figure 2 is a schematic diagram showing the configuration of the first, second, fifth, and sixth devices shown in Figure 1. [Figure 3] Figure 3 is a schematic diagram showing the configuration of the third device shown in Figure 1. [Figure 4]FIG. 4 is a sequence diagram showing a mode in which the PN device shown in FIG. 1 transmits a message to another PN device. [Figure 5] FIG. 5 is a sequence diagram showing a mode in which the NM device shown in FIG. 1 transmits a message to the PN device. [Figure 6] FIG. 6 is a sequence diagram showing a mode in which the NM device shown in FIG. 1 transmits a message to another NM device. [Figure 7] FIG. 7 is a sequence diagram showing a mode in which the PN device shown in FIG. 1 transmits a message to the NM device. [Figure 8] FIG. 8 is a table summarizing, for each type of electronic control device, a mode in which the electronic control device operates the second communication unit or the relay unit in a conventional in-vehicle network system. [Figure 9] FIG. 9 is a table summarizing, for each type of electronic control device, a mode in which the electronic control device operates the second communication unit or the relay unit in another conventional in-vehicle network system different from FIG. 8. [Figure 10] FIG. 10 is a sequence diagram showing a mode in which the first device shown in FIG. 1 communicates with the second device. [Figure 11] FIG. 11 is a sequence diagram showing a mode in which the first device shown in FIG. 1 communicates with the third device. [Figure 12] FIG. 12 is an explanatory diagram showing an example of an operation request signal transmitted by the electronic control device shown in FIG. 1. [Figure 13] FIG. 13 is a flowchart showing a series of processes executed when the electronic control device shown in FIG. 1 transmits an operation request signal to another electronic control device. [Figure 14] FIG. 14 is a flowchart showing a series of processes executed when the electronic control device shown in FIG. 1 receives an operation request signal from another electronic control device. [Figure 15] FIG. 15 is a flowchart showing a series of processes executed when the electronic control device shown in FIG. 1 turns off the operation flag. [Figure 16]FIG. 16 is a flowchart showing a mode in which the electronic control device shown in FIG. 1 switches the state of the second communication unit or the relay unit according to the operation flag. [Figure 17] FIG. 17 is a schematic diagram showing a mode in which the first device shown in FIG. 1 transmits a first message to another electronic control device. [Figure 18] FIG. 18 is a schematic diagram showing a mode in which the first device shown in FIG. 1 transmits an operation request signal to another electronic control device. [Figure 19] FIG. 19 is a schematic diagram showing an example of an operation request signal transmitted by the first device shown in FIG. 1 for communication with another electronic control device by a second communication method. [Figure 20] FIG. 20 is a schematic diagram showing an example of an operation request signal transmitted when the first device shown in FIG. 1 no longer needs to communicate with another electronic control device by a second communication method.

MODE FOR CARRYING OUT THE INVENTION

[0016] Hereinafter, an embodiment of the in-vehicle network system will be described with reference to FIGS. 1 to 20. <Configuration of In-Vehicle Network System 100> As shown in FIG. 1, the in-vehicle network system 100 is composed of a plurality of electronic control units (ECUs: Electronic Control Unit). Hereinafter, the electronic control unit will be referred to as an ECU.

[0017] The in-vehicle network system 100 includes, as ECUs, a first device 21, a second device 22, a third device 23, a fourth device 24, a fifth device 25, and a sixth device 26. In the in-vehicle network system 100, each ECU is connected so as to be able to communicate with each other. In other words, in the in-vehicle network system 100, each ECU is connected so as to be able to exchange messages.

[0018] The in-vehicle network system 100 includes, as communication buses, a first communication bus 51, a second communication bus 52, and a third communication bus 53. The first communication bus 51 and the second communication bus 52 relay communication between ECUs according to the first communication standard. The first communication standard is CAN (Controller Area Network).

[0019] As shown in Figure 1, in the in-vehicle network system 100, the first device 21, the second device 22, the third device 23, and the fourth device 24 are connected via the first communication bus 51. ECUs connected to the first communication bus 51 can communicate with other ECUs via the first communication bus 51 using the first communication standard. For example, the first device 21 can send and receive messages by communicating with other ECUs via the first communication bus 51 using the first communication standard.

[0020] As shown in Figure 1, in the in-vehicle network system 100, the fourth device 24, the fifth device 25, and the sixth device 26 are connected via the second communication bus 52. ECUs connected to the second communication bus 52 can communicate with other ECUs via the second communication bus 52 using the first communication standard. For example, the fifth device 25 can send and receive messages by communicating with other ECUs via the second communication bus 52 using the first communication standard.

[0021] As shown in Figure 1, the fourth device 24 is connected to both the first communication bus 51 and the second communication bus 52. When the fourth device 24 receives a message via the first communication bus 51, it transmits the received message to the ECU connected to the second communication bus 52. For example, if the first device 21 transmits a message to the fifth device 25 via communication according to the first communication standard, the first device 21 transmits the message to the fourth device 24 via the first communication bus 51. Then, the fourth device 24 transmits the message received from the first device 21 to the fifth device 25 via the second communication bus 52.

[0022] When the fourth device 24 receives a message via the second communication bus 52, it transmits the received message to the ECU connected to the first communication bus 51. For example, when the fifth device 25 transmits a message to the first device 21 via communication according to the first communication standard, the fifth device 25 transmits the message to the fourth device 24 via the second communication bus 52. Then, the fourth device 24 transmits the message received from the fifth device 25 to the first device 21 via the first communication bus 51.

[0023] In this way, the fourth device 24 relays messages exchanged between the first communication bus 51 and the second communication bus 52. At this time, the fourth device 24 checks the received message and relays the message only if it determines that it is necessary to send the received message to the other communication bus.

[0024] The third communication bus 53 relays communication between ECUs using the second communication standard. The second communication standard is a communication standard different from the first communication standard. Specifically, the second communication standard is Ethernet (registered trademark).

[0025] As shown in Figure 1, in the in-vehicle network system 100, the first device 21, the second device 22, the third device 23, the fifth device 25, and the sixth device 26 are connected via the third communication bus 53. ECUs connected to the third communication bus 53 can communicate with other ECUs via the third communication bus 53 using the second communication standard. For example, the first device 21 can send and receive messages by communicating with other ECUs via the third communication bus 53 using the second communication standard.

[0026] As shown in Figure 1, the third device 23 includes a relay unit 71. The relay unit 71 is an Ethernet switch. As shown in FIG. 1, in the third communication bus 53, the first device 21 and the second device 22 are connected to the fifth device 25 via the relay unit 71. As shown in FIG. 1, in the third communication bus 53, the first device 21 and the second device 22 are connected to the sixth device 26 via the relay unit 71. As shown in FIG. 1, in the third communication bus 53, the fifth device 25 is connected to the sixth device 26 via the relay unit 71.

[0027] The third device 23 has the role of a relay device. A relay device is a device that relays communication according to the second communication standard executed by ECUs through the relay unit 71. For example, when the first device 21 transmits a message to the fifth device 25 through communication according to the second communication standard, the first device 21 transmits the message to the third device 23 through the third communication bus 53. The third device 23 receives the message from the first device 21 by the relay unit 71. The third device 23 transmits the message received from the first device 21 to the fifth device 25 through the third communication bus 53 from the relay unit 71. At this time, the third device 23 confirms that the message received from the first device 21 is the message transmitted to the fifth device 25 and does not relay the message to the sixth device 26. That is, after confirming the destination of the received message, the third device 23 transmits the message toward the destination of the message.

[0028] As shown in FIG. 1, in the third communication bus 53, the first device 21 and the second device 22 are directly connected without passing through the relay unit 71, so communication according to the second communication standard can be performed without the third device 23 relaying.

[0029] <Configuration of ECU> FIG. 2 shows the configurations of the first device 21, the second device 22, the fifth device 25, and the sixth device 26. As shown in FIG. 2, the first device 21, the second device 22, the fifth device 25, and the sixth device 26 include a processing circuit 11 and a storage device 12.

[0030] The processing circuit 11 executes various processes by running the program stored in the memory device 12. The processing circuit 11 includes a processor. As shown in Figure 2, the storage device 12 stores the communication program PC. The communication program PC is executed by the processing circuit 11, causing the processing circuit 11 to communicate with other ECUs.

[0031] The ECU is equipped with a communication device for communicating with other ECUs. The communication device has a standby state in which its ability to communicate with other ECUs is restricted, and an operational state in which this restriction is lifted. When the communication device is in the operational state, the ECU can send messages to other ECUs. As shown in Figure 2, the first device 21, the second device 22, the fifth device 25, and the sixth device 26 are equipped with a first communication unit 13 and a second communication unit 14 as communication devices.

[0032] The first communication unit 13 is a communication device capable of communication according to the first communication standard. The first device 21, the second device 22, the fifth device 25, and the sixth device 26 can communicate with other ECUs according to the first communication standard when the first communication unit 13 is operational.

[0033] The second communication unit 14 is a communication device capable of communication according to the second communication standard. The first device 21, the second device 22, the fifth device 25, and the sixth device 26 can communicate with other ECUs according to the second communication standard when the second communication unit 14 is operational.

[0034] The configuration of the fourth device 24 is the same as that of the ECU shown in Figure 2, except that it does not include the second communication unit 14. Figure 3 shows the configuration of the third device 23. As shown in Figure 3, the third device 23 includes a processing circuit 11 and a storage device 12, similar to the ECU shown in Figure 2. The third device 23 stores the communication program PC in the storage device 12, similar to the ECU shown in Figure 2.

[0035] As shown in Figure 3, the third device 23 includes a first communication unit 13 and a relay unit 71 as a communication device. As mentioned above, the third device 23 relays communication according to the second communication standard by using the relay unit 71. The third device 23 can communicate with other ECUs according to the second communication standard by using the relay unit 71. In other words, the relay unit 71 has the function of relaying communication according to the second communication standard between ECUs and the function of a second communication unit 14.

[0036] The third device 23 can communicate with other ECUs using the first communication standard when the first communication unit 13 is operational. The third device 23 can communicate with other ECUs using the second communication standard when the relay unit 71 is operational. The third device 23 can relay communication between ECUs using the second communication standard when the relay unit 71 is operational.

[0037] <Types of messages exchanged in the in-vehicle network system 100> An ECU capable of communication according to the first communication standard has a network management function. Hereinafter, the network management function will be referred to as the NM function. When the first communication unit 13 is in a standby state, an ECU with the NM function receives a first operation notification, which is a message requesting the operation of the first communication unit 13, via communication according to the first communication standard, and switches the first communication unit 13 to an operational state. Furthermore, as long as the ECU with the NM function periodically receives the first operation notification, it maintains the first communication unit 13 in an operational state.

[0038] An ECU with NM functionality activates its own and the other ECU's first communication unit 13 when attempting to communicate with another ECU with NM functionality using the first communication standard. Activating a communication device means transitioning from a standby state to an operational state, or maintaining an operational state if the communication device is already operational.

[0039] An ECU that attempts to communicate with other ECUs according to the first communication standard activates its own first communication unit 13. Then, the ECU that has activated its own first communication unit 13 transmits a first activation notification to the ECU on the other side of the communication according to the first communication standard, thereby activating the first communication unit 13 included in the ECU on the other side of the communication. After activating its own first communication unit 13 and the first communication unit 13 of the ECU on the other side of the communication, the ECU having the NM function starts communication according to the first communication standard.

[0040] As shown in FIG. 1, in the in-vehicle network system 100, messages exchanged by the ECU through communication according to the first communication standard include a first message 61 and a second message 62.

[0041] The first message 61 is a message that requests the activation of the first communication unit 13. That is, the first message 61 is synonymous with the first activation notification. The ECU activates the first communication unit 13 based on the first message 61.

[0042] The second message 62 is a general term for messages other than the first message 61 among the messages transmitted by the ECU through the first communication standard. For example, the ECU transmits information indicating the traveling speed of the vehicle equipped with the in-vehicle network system 100 as the second message 62. The ECU can exchange the second message 62 when the first communication unit 13 is in an operating state.

[0043] As shown in FIG. 1, the ECU in the in-vehicle network system 100 transmits a third message 63 through communication according to the second communication standard. The ECU can exchange the third message 63 when the second communication unit 14 is in an operating state.

[0044] <Classification of ECU with NM function> Among the ECUs having the NM function, there are ECUs having a partial network function and ECUs not having a partial network function. Hereinafter, the partial network function is referred to as the PN function.

[0045] In the in - vehicle network system 100 shown in FIG. 1, the first device 21, the second device 22, the third device 23, and the fourth device 24 are PN devices 30. The PN device 30 is an ECU having a PN function among the ECUs having an NM function.

[0046] The PN device 30 transmits a PN message as the first operation notification. The PN message includes an identifier indicating the identification information of the destination ECU of the PN message. The PN device 30 transmits a PN message with the ECU for which it wants to operate the first communication unit 13 as the destination. The PN device 30 periodically transmits a PN message while communication according to the first communication standard is required.

[0047] In the in - vehicle network system 100 shown in FIG. 1, the fifth device 25 and the sixth device 26 are NM devices 40. The NM device 40 is an ECU having an NM function but not having a PN function among the ECUs having an NM function.

[0048] The NM device 40 transmits an NM message as the first operation notification. The NM message does not include an identifier indicating the identification information of the destination ECU of the NM message. The NM device 40 periodically transmits an NM message while communication according to the first communication standard is required.

[0049] Hereinafter, referring to FIGS. 4 to 7, the differences between the PN device 30 and the NM device 40 will be described. <Features of the PN device 30> FIG. 4 shows a mode in which the PN device 30 executes processing when receiving a PN message from another PN device 30. In FIG. 4, the first communication unit 13 of the PN device 30 on the receiving side of the PN message receives the PN message in a standby state.

[0050] As shown in the upper part of FIG. 4, the PN device 30 that has received a PN message from another PN device 30 confirms the destination of the received PN message. At this time, the PN device 30 confirms the identifier included in the PN message.

[0051] As shown in the middle section of Figure 4, if the PN device 30 that receives a PN message does not have the received PN message addressed to itself, it maintains the standby state of the first communication unit 13. On the other hand, as shown in the lower part of Figure 4, when the PN device 30 receives a PN message, if the received PN message is addressed to itself, it switches the first communication unit 13 from standby to operational.

[0052] Thus, when the PN device 30 receives a PN message, if the PN message is addressed to itself, it switches the first communication unit 13 from standby to operational. After receiving a PN message, the PN device 30 switches the first communication unit 13 to operational and maintains the operational state of the first communication unit 13 for a certain period of time.

[0053] As shown in the lower part of Figure 4, the PN device 30, after receiving a PN message addressed to itself, switches the first communication unit 13 from the operational state to the standby state if it does not receive a PN message addressed to itself for a certain period of time or longer.

[0054] Figure 5 shows how the PN device 30 performs processing when it receives an NM message from the NM device 40. In Figure 5, the first communication unit 13 of the PN device 30 is in a standby state and has received an NM message.

[0055] As shown in the upper part of Figure 5, the PN device 30, upon receiving an NM message from the NM device 40, confirms the destination of the received NM message. At this time, the PN device 30 attempts to confirm the identifier contained in the NM message.

[0056] As mentioned above, NM messages do not contain an identifier indicating the ECU to which the NM message is addressed. When the PN device 30 receives a first operational notification, it determines that the NM message is not addressed to itself if the NM message does not contain an identifier.

[0057] As shown in the lower part of FIG. 5, when the PN device 30 receives an NM message, it maintains the standby state of the first communication unit 13 in the same manner as when it receives a PN message not addressed to itself.

[0058] In this way, when the PN device 30 receives the first operation notification, if the message is a PN message addressed to itself, it operates the first communication unit 13. On the other hand, when the received first operation notification is a PN message not addressed to itself, the PN device 30 does not operate the first communication unit 13. The PN device 30 also does not operate the first communication unit 13 when the received first operation notification is an NM message.

[0059] <Features of the NM device 40> FIG. 6 shows a mode in which the NM device 40 executes processing when receiving an NM message from another NM device 40. In FIG. 6, the first communication unit 13 of the NM device 40 on the receiving side of the NM message receives the NM message in the standby state.

[0060] As shown in the upper part of FIG. 6, the NM device 40 that has received an NM message from another NM device 40 shifts the first communication unit 13 from the standby state to the operating state without confirming the destination of the received NM message.

[0061] After shifting the first communication unit 13 to the operating state, the NM device 40 maintains the operating state of the first communication unit 13 for a certain period of time. As shown in the lower part of FIG. 6, after receiving an NM message, when the NM device 40 does not receive an NM message for a certain period of time or more, it shifts the first communication unit 13 from the operating state to the standby state.

[0062] FIG. 7 shows a mode in which the NM device 40 executes processing when receiving a PN message from the PN device 30. In FIG. 7, the first communication unit 13 of the NM device 40 receives the PN message in the standby state.

[0063] As shown in the upper part of Figure 7, when the NM device 40 receives a PN message from the PN device 30, it switches the first communication unit 13 from standby to operational without confirming the destination of the received PN message.

[0064] The NM device 40 transitions the first communication unit 13 to an operational state and then maintains the operational state of the first communication unit 13 for a certain period of time. As shown in the lower part of Figure 7, the NM device 40 switches the first communication unit 13 from the operational state to the standby state when it does not receive a PN message for a certain period of time after receiving a PN message.

[0065] Thus, when the NM device 40 receives the first operation notification, it does not check the identifier included in the first operation notification. Therefore, when the NM device 40 receives the first operation notification, it activates the first communication unit 13 regardless of whether the message is addressed to itself or not. Furthermore, when the NM device 40 receives the first operation notification, it activates the first communication unit 13 regardless of whether the received message is a PN message or an NM message.

[0066] In the following, with reference to Figures 8 and 9, we will describe how the ECU operates the second communication unit 14 or the relay unit 71 in a conventional in-vehicle network system 100.

[0067] Figure 8 is a table summarizing the types of ECUs that receive the first operation notification in the conventional in-vehicle network system 100, the types of first operation notifications received, and the manner in which the communication device is operated in response to the first operation notification.

[0068] As shown in Figure 8, when the PN device 30 receives a PN message addressed to itself, the PN device 30 activates the first communication unit 13. Then, as shown in Figure 8, when the PN device 30 receives a PN message addressed to itself, the PN device 30 activates the second communication unit 14 or the relay unit 71 together with the first communication unit 13.

[0069] In other words, if the in-vehicle network system 100 shown in Figure 1 employs the configuration shown in Figure 8, the first device 21 and the second device 22, which are PN devices 30, activate the second communication unit 14 when they receive a PN message addressed to themselves. More specifically, when the second communication unit 14 is in a standby state and the first device 21 and the second device 22 receive a PN message addressed to themselves, they switch the second communication unit 14 to an active state. After switching the second communication unit 14 to an active state, the first device 21 and the second device 22 maintain the active state of the second communication unit 14 for a certain period of time. Then, after receiving a PN message addressed to themselves, if the first device 21 and the second device 22 do not receive a PN message addressed to themselves for a certain period of time or longer, they switch the second communication unit 14 from an active state to a standby state.

[0070] Furthermore, if the in-vehicle network system 100 shown in Figure 1 employs the configuration shown in Figure 8, the third device 23, which is the PN device 30, activates the relay unit 71 when it receives a PN message addressed to itself. More specifically, if the third device 23 receives a PN message addressed to itself while the relay unit 71 is in standby mode, it switches the relay unit 71 to the active state. After switching the relay unit 71 to the active state, the third device 23 maintains the active state of the relay unit 71 for a certain period of time. Then, if the third device 23 does not receive a PN message addressed to itself for a certain period of time or longer after receiving a PN message addressed to itself, it switches the relay unit 71 from the active state to the standby state.

[0071] As shown in Figure 8, if the PN device 30 receives a PN message or NM message that is not addressed to itself, the PN device 30 does not activate the first communication unit 13. Furthermore, as shown in Figure 8, if the PN device 30 receives a PN message or NM message that is not addressed to itself, the PN device 30 does not activate the second communication unit 14 or the relay unit 71.

[0072] In other words, if the in-vehicle network system 100 shown in Figure 1 adopts the configuration shown in Figure 8, the first device 21 and the second device 22, which are PN devices 30, will not activate the second communication unit 14 when they receive a PN message that is not addressed to themselves. Also, if the in-vehicle network system 100 shown in Figure 1 adopts the configuration shown in Figure 8, the first device 21 and the second device 22, which are PN devices 30, will not activate the second communication unit 14 when they receive an NM message.

[0073] Furthermore, if the in-vehicle network system 100 shown in Figure 1 adopts the configuration shown in Figure 8, the third device 23, which is the PN device 30, will not activate the relay unit 71 when it receives a PN message that is not addressed to itself. If the in-vehicle network system 100 shown in Figure 1 adopts the configuration shown in Figure 8, the third device 23, which is the PN device 30, will also not activate the relay unit 71 when it receives an NM message.

[0074] As shown in Figure 8, when the NM device 40 receives a PN message or an NM message, the NM device 40 activates the first communication unit 13. Then, as shown in Figure 8, when the NM device 40 receives a PN message or an NM message, the NM device 40 activates the second communication unit 14 or the relay unit 71.

[0075] If the in-vehicle network system 100 shown in Figure 1 employs the configuration shown in Figure 8, the fifth device 25 and the sixth device 26, which are NM devices 40, activate the second communication unit 14 when they receive a PN message or an NM message. More specifically, when the second communication unit 14 is in a standby state and the fifth device 25 and the sixth device 26 receive a PN message or an NM message, they switch the second communication unit 14 to an active state. After switching the second communication unit 14 to an active state, the fifth device 25 and the sixth device 26 maintain the active state of the second communication unit 14 for a certain period of time. Then, if the fifth device 25 and the sixth device 26 do not receive a PN message or an NM message for a certain period of time or longer after receiving a PN message or an NM message, they switch the second communication unit 14 from an active state to a standby state.

[0076] As shown in Figure 1, the in-vehicle network system 100 does not have an NM device 40 equipped with a relay unit 71, but an NM device 40 may be equipped with a relay unit 71. In this case, an NM device 40 equipped with a relay unit 71 activates the relay unit 71 when it receives an NM message or a PN message.

[0077] In the example described above with reference to Figure 8, the PN device 30 transmits a PN message that includes an identifier indicating the ECU to which the PN message is destined. When the PN device 30 receives a PN message, it determines, based on the identifier, whether or not the PN message is destined for itself.

[0078] On the other hand, it is also possible that the PN device 30 transmits a PN message with an identifier that includes information indicating whether or not to request the operation of the second communication unit 14 or the relay unit 71, in addition to information indicating the destination ECU of the PN message.

[0079] Figure 9 is a table summarizing the types of ECUs that receive the first operation notification, the types of first operation notifications received, and the manner in which the communication device is operated in response to the first operation notification, when the ECU adopts such a configuration.

[0080] As shown in Figure 9, when the PN device 30 receives a PN message addressed to itself, it activates the first communication unit 13. Then, as shown in Figure 9, when the PN device 30 receives a PN message addressed to itself, it determines, based on the identifier, whether or not the activation of the second communication unit 14 or the relay unit 71 is requested.

[0081] When PN device 30 receives a PN message addressed to itself, if it determines, based on the identifier, that it is being requested to operate the second communication unit 14 or the relay unit 71, it operates the second communication unit 14 or the relay unit 71. In other words, if the in-vehicle network system 100 shown in Figure 1 employs the configuration shown in Figure 9, the first device 21 and the second device 22 will operate the second communication unit 14 if they determine, based on the identifier, that it is being requested to operate the second communication unit 14. Also, if the in-vehicle network system 100 shown in Figure 1 employs the configuration shown in Figure 9, the third device 23 will operate the relay unit 71 if it determines, based on the identifier, that it is being requested to operate the relay unit 71.

[0082] In Figure 9, the behavior when the PN device 30 receives a PN message or NM message that is not addressed to itself is the same as the behavior shown in Figure 8. Also, in Figure 9, the behavior when the NM device 40 receives a PN message or NM message is the same as the behavior shown in Figure 8.

[0083] <Problems with conventional ECUs> If the ECU in the in-vehicle network system 100 adopts the configuration shown in Figure 8, the ECU will activate the second communication unit 14 or the relay unit 71 when it activates the first communication unit 13. In this case, even if the ECU does not need to communicate with other ECUs using the second communication standard, it will activate the second communication unit 14 or the relay unit 71 while the first communication unit 13 is operating.

[0084] Furthermore, if the ECU in the in-vehicle network system 100 adopts the configuration shown in Figure 9, the PN device 30 can determine whether or not to operate the second communication unit 14 or the relay unit 71 based on the identifier. Therefore, the PN device 30 can operate the first communication unit 13 while not operating the second communication unit 14 or the relay unit 71 when it is not necessary.

[0085] However, even if the ECU in the in-vehicle network system 100 adopts the configuration shown in Figure 9, the NM device 40 will also activate the second communication unit 14 when the first communication unit 13 is activated. Therefore, the NM device 40 will activate the second communication unit 14 while the first communication unit 13 is operating, even if it does not need to communicate with other ECUs using the second communication standard.

[0086] Thus, an ECU employing a conventional configuration will activate the second communication unit 14 or the relay unit 71 even when it is not necessary. In particular, since the NM device 40 cannot verify the identifier, it will activate the second communication unit 14 when it is not necessary, regardless of which configuration is adopted from Figures 8 and 9.

[0087] To solve the above problems, the ECU according to this embodiment controls the operation of the second communication unit 14 and the relay unit 71 using the second message 62. The following describes how the ECU according to this embodiment controls the operation of the second communication unit 14 and the relay unit 71 using the second message 62, with reference to Figures 10 and 11.

[0088] <Activation of the Second Communications Unit 14 following the Second Operation Notification> Figure 10 shows how the first device 21 controls the operation of the second communication unit 14 of the second device 22 in order to communicate with the second device 22 according to the second communication standard. In Figure 10, before receiving a message from the first device 21, the second device 22 has the first communication unit 13 and the second communication unit 14 in standby mode.

[0089] As shown in the upper part of Figure 10, the first device 21 transmits a first operation notification to the second device 22 via communication according to the first communication standard. Since both the first device 21 and the second device 22 are PN devices 30, the first device 21 transmits a PN message addressed to the second device 22 as the first operation notification.

[0090] As shown in the upper part of Figure 10, upon receiving the first operation notification, the second device 22 switches the first communication unit 13 from standby to operational. At this time, the second device 22 confirms that the received first operation notification is a PN message addressed to itself before switching the first communication unit 13 to operational.

[0091] From this point forward, the first device 21 periodically transmits the first operation notification during the period in which it communicates with the second device 22 using the second communication standard. Then, after the second device 22 has switched the first communication unit 13 to the operational state, it maintains the first communication unit 13 in the operational state while it periodically receives the first operation notification.

[0092] As shown in the middle section of Figure 10, the first device 21 activates the first communication unit 13 of the second device 22 and then transmits a second activation notification. The second activation notification is a message requesting the activation of the second communication unit 14 of the communication partner under the second communication standard. The second activation notification is the second message 62. In other words, the second activation notification is transmitted through communication under the first communication standard.

[0093] As shown in the middle section of Figure 10, upon receiving the second operation notification, the second device 22 switches the second communication unit 14 from standby to operational. From this point onward, the first device 21 continues to periodically transmit the second operation notification using the first communication standard while communicating according to the second communication standard. Then, after the second device 22 has switched the second communication unit 14 to the operational state, it maintains the second communication unit 14 in the operational state while periodically receiving the second operation notification.

[0094] In this way, the ECU in the in-vehicle network system 100 activates the first communication unit 13 of the other ECU using the first message 61, which is a first operation notification, in order to communicate with the other ECU according to the second communication standard. The ECU then activates the second communication unit 14 of the other ECU by transmitting the second message 62, which is a second operation notification, through communication according to the first communication standard. As a result, the ECU can communicate with the other ECU according to the second communication standard.

[0095] The first device 21 stops sending the second operation notification when it is no longer necessary to communicate using the second communication standard. As shown in the lower part of Figure 10, the second device 22 switches the second communication unit 14 from the operational state to the standby state if it does not receive another second operation notification for a certain period of time after receiving the second operation notification.

[0096] Thus, the ECU in the in-vehicle network system 100 periodically sends a second operational notification while communication using the second communication standard is required. The ECU then stops periodically sending the second operational notification when it stops communicating using the second communication standard.

[0097] <Activation of relay unit 71 based on the third operational notification> Figure 11 shows an embodiment in which the first device 21 controls the operation of the relay unit 71 provided in the third device 23.

[0098] In the in-vehicle network system 100, the ECU requests the operation of the relay unit 71 provided by the third device 23 when communicating with the third device 23 using the second communication standard. Also, when communicating with other ECUs using the second communication standard, the ECU requests the operation of the relay unit 71 if relaying by the relay unit 71 is necessary. For example, when the first device 21 communicates with the fifth device 25 using the second communication standard, it requests the operation of the second communication unit 14 provided by the fifth device 25, as well as the operation of the relay unit 71 provided by the third device 23.

[0099] In Figure 11, before receiving a message from the first device 21, the third device 23 has the first communication unit 13 and the relay unit 71 in standby mode. As shown in the upper part of Figure 11, the first device 21 transmits a first operation notification to the third device 23 via communication according to the first communication standard. Since both the first device 21 and the third device 23 are PN devices 30, the first device 21 transmits a PN message addressed to the third device 23 as the first operation notification.

[0100] As shown in the upper part of Figure 11, upon receiving the first operation notification, the third device 23 switches the first communication unit 13 from standby to operational. At this time, the third device 23 confirms that the received first operation notification is a PN message addressed to itself before switching the first communication unit 13 to operational.

[0101] From this point onward, the first device 21 periodically transmits the first operation notification for the period during which it requests the operation of the relay unit 71. Then, after the third device 23 has brought the first communication unit 13 into the operational state, it maintains the first communication unit 13 in the operational state while it periodically receives the first operation notification.

[0102] As shown in the middle section of Figure 11, the first device 21 activates the first communication unit 13 of the third device 23 and then transmits a third operation notification. The third operation notification is a message requesting the activation of the relay unit 71. The third operation notification is the second message 62. In other words, the third operation notification is transmitted via communication according to the first communication standard.

[0103] As shown in the middle section of Figure 11, upon receiving the third operation notification, the third device 23 switches the relay unit 71 from standby to operational. From this point onward, the first device 21 continues to periodically transmit third operation notifications using communication according to the first communication standard while requesting the operation of the relay unit 71. Then, after the third device 23 has brought the relay unit 71 into the operational state, it maintains the relay unit 71 in the operational state while periodically receiving third operation notifications.

[0104] Thus, in the in-vehicle network system 100, the ECU activates the first communication unit 13 of the ECU acting as a relay device using the first message 61, which is a first operation notification, to request the operation of the relay unit 71. The ECU then activates the relay unit 71 of the ECU acting as a relay device by transmitting the second message 62, which is a third operation notification, through communication according to the first communication standard. As a result, the ECU can communicate with the ECU acting as a relay device according to the second communication standard. Furthermore, in order for the ECU to communicate with other ECUs according to the second communication standard, the ECU can have the ECU acting as a relay device relay communications according to the second communication standard.

[0105] The first device 21 stops transmitting the third operation notification when it is no longer necessary to operate the relay unit 71. As shown in the lower part of Figure 11, the third device 23 switches the relay unit 71 from the operating state to the standby state after receiving the third operation notification and if it does not receive another third operation notification for a certain period of time or longer.

[0106] In this manner, the ECU in the in-vehicle network system 100 periodically sends a third operation notification while the relay unit 71 is operational. The ECU then stops sending the third operation notification when it is no longer necessary to operate the relay unit 71.

[0107] In Figure 10, the first device 21 and the second device 22 are PN devices 30. Figure 10 shows how a PN device 30 transmits a first operation notification and a second operation notification in order to communicate with other PN devices 30 according to the second communication standard.

[0108] Even when PN device 30 attempts to communicate with NM device 40 using the second communication standard, as shown in Figure 10, by sending a first operation notification and a second operation notification, communication between PN device 30 and NM device 40 using the second communication standard becomes possible. Similarly, when NM device 40 attempts to communicate with another NM device 40 using the second communication standard, as shown in Figure 10, by sending a first operation notification and a second operation notification, communication between NM devices 40 using the second communication standard becomes possible.

[0109] As shown in Figure 5, the NM device 40 cannot activate the first communication unit 13 of the PN device 30. Therefore, even if the NM device 40 attempts to communicate with the PN device 30 using the second communication standard, it cannot activate the second communication unit 14 of the PN device 30 by sending the first and second operation notifications as shown in Figure 10.

[0110] In Figure 11, the first device 21 and the third device 23 are PN devices 30. Figure 11 shows how PN device 30 transmits a first operation notification and a third operation notification in order to activate a relay unit 71 of another PN device 30.

[0111] As mentioned above, it is also possible that the NM device 40 is equipped with a relay unit 71. Even when the PN device 30 tries to activate the relay unit 71 of the NM device 40, as shown in Figure 11, the PN device 30 can activate the relay unit 71 of the NM device 40 by sending a first operation notification and a third operation notification. Similarly, when the NM device 40 tries to activate the relay unit 71 of another NM device 40, as shown in Figure 11, the NM device 40 can activate the relay unit 71 of the NM device 40 by sending a first operation notification and a third operation notification.

[0112] As shown in Figure 5, the NM device 40 cannot activate the first communication unit 13 of the PN device 30. Therefore, the NM device 40 cannot activate the relay unit 71 of the PN device 30 by transmitting the first operation notification and the third operation notification as shown in Figure 11.

[0113] <Pattern of operation request signal 64> As illustrated in Figure 10, the ECU in the in-vehicle network system 100 transmits a second operation notification to activate the second communication unit 14 of another ECU. On the other hand, as illustrated in Figure 11, the ECU in the in-vehicle network system 100 transmits a third operation notification to activate the relay unit 71 of an ECU that acts as a relay device.

[0114] Figure 12 shows an example of an operation request signal 64. The operation request signal 64 is a message that serves as both a second operation notification and a third operation notification. The operation request signal 64 is the second message 62. In other words, the ECU in the in-vehicle network system 100 sends and receives the operation request signal 64 through communication according to the first communication standard.

[0115] Each ECU in the in-vehicle network system 100 periodically transmits an operation request signal 64. However, since the fourth device 24 does not have a second communication unit 14 and a relay unit 71, it does not communicate according to the second communication standard, nor does it relay communications according to the second communication standard. Therefore, the fourth device 24 does not transmit an operation request signal 64.

[0116] As shown in Figure 12, the operation request signal 64 has slots corresponding to each ECU in the in-vehicle network system 100. Since the fourth device 24 does not need to receive the operation request signal 64, the operation request signal 64 shown in Figure 12 does not have a slot corresponding to the fourth device 24.

[0117] In the in-vehicle network system 100, the slots corresponding to the ECUs equipped with the second communication unit 14 are input to "zero" or "1". In other words, the slots corresponding to the first device 21, the second device 22, the fifth device 25, and the sixth device 26 are input to "zero" or "1".

[0118] When an ECU transmits the operation request signal 64, if there is another ECU that wants to request the operation of the second communication unit 14, the ECU inputs "1" into the slot corresponding to that ECU. For example, if the first device 21 wants to activate the second communication unit 14 of the sixth device 26, it inputs "1" into the slot corresponding to the sixth device 26 and transmits the operation request signal 64, as shown in Figure 12.

[0119] An ECU equipped with a second communication unit 14 activates the second communication unit 14 when it receives an operation request signal 64 and the corresponding slot is set to "1". In this way, an ECU in the in-vehicle network system 100 transmits an operation request signal 64 with a "1" input to the slot corresponding to the ECU in which it wants to activate the second communication unit 14, as a second operation notification to that ECU.

[0120] When an ECU transmits an operation request signal 64, if it does not need to request the operation of the second communication unit 14 for an ECU equipped with the second communication unit 14, it inputs "zero" into the slot corresponding to that ECU. For example, if the first device 21 does not need to operate the second communication unit 14 of the second device 22, it inputs "zero" into the slot corresponding to the second device 22 and transmits the operation request signal 64, as shown in Figure 12.

[0121] When an ECU equipped with a second communication unit 14 receives an operation request signal 64, if "0" is input to the slot corresponding to itself, the second communication unit 14 will not be activated. Thus, in the in-vehicle network system 100, when an ECU inputs "1" into a slot corresponding to an ECU equipped with a second communication unit 14 and transmits an operation request signal 64, only the ECU corresponding to that slot will activate the second communication unit 14. In other words, when an ECU in the in-vehicle network system 100 communicates with another ECU using the second communication standard, it specifies the communication partner from among multiple ECUs and transmits an operation request signal 64 including a second operation notification. An ECU that receives an operation request signal 64 will not activate the second communication unit 14 if the received operation request signal 64 does not include a second operation notification specifying itself.

[0122] As mentioned above, the ECU in the in-vehicle network system 100 periodically sends an operation request signal 64 with "1" input to the slot corresponding to the other ECU while requesting the operation of the second communication unit 14 of the other ECU. Then, when the ECU no longer needs to request the operation of the second communication unit 14 of the other ECU, it sends an operation request signal 64 with "0" input to the slot corresponding to the other ECU.

[0123] In other words, while the ECU periodically transmits an operation request signal 64 with "1" input to the slot corresponding to the other ECU having the second communication unit 14, it can be said that the ECU periodically transmits a second operation notification to the other ECU. Subsequently, when the ECU begins to periodically transmit an operation request signal 64 with "0" input to the slot corresponding to the ECU having the second communication unit 14, it can be said that the periodic transmission of the second operation notification to that ECU has stopped.

[0124] In the in-vehicle network system 100, either "zero" or "1" is input to the slot corresponding to the ECU equipped with the relay unit 71. In other words, either "zero" or "1" is input to the slot corresponding to the third device 23.

[0125] When an ECU sends an operation request signal 64, if it wants to request the operation of the relay unit 71 of an ECU that acts as a relay device, it inputs "1" into the slot corresponding to that ECU. For example, if the first device 21 wants to operate the relay unit 71 of the third device 23, it inputs "1" into the slot corresponding to the third device 23 and sends the operation request signal 64, as shown in Figure 12.

[0126] The ECU, which acts as a relay device, activates the relay unit 71 when it receives the operation request signal 64 and the corresponding slot is set to "1". In this way, the ECU in the in-vehicle network system 100 transmits the operation request signal 64, in which the slot corresponding to the ECU acting as a relay device is set to "1", as a third operation notification.

[0127] When an ECU transmits an operation request signal 64, if it does not need to request the operation of the relay unit 71 for an ECU acting as a relay device, it inputs "zero" into the slot corresponding to that ECU.

[0128] The ECU, which acts as a relay device, will not activate the relay unit 71 if it receives the operation request signal 64 and the corresponding slot has a "0" input. As mentioned above, in the in-vehicle network system 100, the ECU periodically sends an operation request signal 64 with "1" input to the slot corresponding to the other ECU while requesting the operation of the relay unit 71 of the ECU acting as a relay device. Then, when the ECU no longer needs to request the operation of the relay unit 71 of the ECU acting as a relay device, it sends an operation request signal 64 with "0" input to the slot corresponding to the other ECU.

[0129] In other words, while the ECU periodically transmits an operation request signal 64 with "1" input to the slot corresponding to the ECU acting as a relay device, it can be said that it periodically transmits a third operation notification to that ECU. Subsequently, when the ECU begins to periodically transmit an operation request signal 64 with "0" input to the slot corresponding to the ECU acting as a relay device, it can be said that it has stopped periodically transmitting the third operation notification to that ECU.

[0130] <Processing performed to send the operation request signal 64> Figure 13 shows a series of processes performed by the ECU in the in-vehicle network system 100 when it transmits an operation request signal 64. The series of processes shown in Figure 13 are performed by the processing circuits 11 of the first device 21, the second device 22, the third device 23, the fifth device 25, and the sixth device 26 executing the communication program PC.

[0131] As mentioned earlier, the operation request signal 64 is transmitted periodically. The process shown in Figure 13 is performed periodically by each ECU while each ECU has the first communication unit 13 in operation.

[0132] As shown in Figure 13, each ECU starts executing input processing in step S11. Input processing is the process of determining whether it needs to request the operation of the second communication unit 14 or relay unit 71 of another ECU, and then generating the operation request signal 64 by inputting "zero" or "1" into the slot of the operation request signal 64 based on the result of the determination.

[0133] The input processing is repeatedly performed for all ECUs to which the operation request signal 64 is sent, until the input to the corresponding slot is completed (see step S17). In other words, during the input processing, steps S12 to S16 are performed for all ECUs to which the operation request signal 64 is sent.

[0134] The ECU to which the operation request signal 64 is transmitted is an ECU in the in-vehicle network system 100 that has a second communication unit 14 or a relay unit 71. For example, when the first device 21 performs input processing, the first device 21 repeatedly performs input processing until the inputs to the slots corresponding to the second device 22, the third device 23, the fifth device 25, and the sixth device 26 are completed.

[0135] When input processing begins, the ECU executes the process in step S12. In the process in step S12, the ECU determines whether it is necessary to request the operation of the second communication unit 14 or relay unit 71 of another ECU.

[0136] When the ECU is performing input processing with an ECU equipped with the second communication unit 14 as the transmission target, it determines that it is necessary to request the operation of the second communication unit 14 if it is necessary to communicate with the transmission target using the second communication standard. On the other hand, when the ECU is performing input processing with an ECU equipped with the second communication unit 14 as the transmission target, it determines that it is not necessary to request the operation of the second communication unit 14 if it is not necessary to communicate with the transmission target using the second communication standard. For example, when the first device 21 is performing input processing for the second device 22, the fifth device 25, or the sixth device 26, it determines whether it is necessary to request the operation of the second communication unit 14 based on whether it is necessary to communicate with those ECUs using the second communication standard.

[0137] When the ECU is performing input processing with an ECU equipped with a relay unit 71 as the transmission target, it determines that it is necessary to request the operation of the relay unit 71 if it is necessary to communicate with the said transmission target using the second communication standard. When the ECU is performing input processing with an ECU equipped with a relay unit 71 as the transmission target, it also determines that it is necessary to request the operation of the relay unit 71 if it is necessary to have the ECU equipped with the relay unit 71 relay the communication using the second communication standard. On the other hand, when the ECU is performing input processing with an ECU equipped with a relay unit 71 as the transmission target, it determines that it is not necessary to request the operation of the relay unit 71 if it is not necessary to communicate with the said transmission target using the second communication standard, nor is it necessary to have the said transmission target relay the communication. For example, when the first device 21 performs input processing for the third device 23, it determines whether it is necessary to request the operation of the relay unit 71 based on whether it is necessary to communicate with the third device 23 using the second communication standard, and whether it is necessary to have the third device 23 relay the communication.

[0138] If the ECU determines that it does not need to request the operation of the second communication unit 14 or relay unit 71 of another ECU (step S12: NO), it proceeds to step S16. In step S16, the ECU inputs "zero" to the slot corresponding to the ECU that does not need to request the operation of the second communication unit 14 or relay unit 71 for the operation request signal 64. After that, the ECU terminates the input processing for the ECU that determined whether or not it needed to request the operation of the second communication unit 14 or relay unit 71.

[0139] On the other hand, if the ECU determines that it needs to request the operation of the second communication unit 14 or relay unit 71 owned by another ECU (step S12: YES), it proceeds to step S13. In step S13, the ECU inputs "1" to the slot corresponding to the ECU that needs to request the operation of the second communication unit 14 or relay unit 71 in response to the operation request signal 64. After that, the ECU proceeds to step S14.

[0140] In step S14, the ECU determines whether its operational flag is off or off. An ECU having a second communication unit 14 or relay unit 71 manages an operational flag. The operational flag is a flag that manages whether the second communication unit 14 or relay unit 71 it has is in an operational state or a standby state. When the operational flag is on, it indicates that the second communication unit 14 or relay unit 71 needs to be in an operational state. When the operational flag is off, it indicates that the second communication unit 14 or relay unit 71 needs to be in a standby state.

[0141] The ECU determines that the operation flag it manages is off if it is in the off state. If the ECU determines that its operation flag is off (step S14: YES), it proceeds to step S15. In step S15, the ECU switches the operation flag it manages from off to on. After that, the ECU terminates the input processing for the ECU that determined whether or not an operation request from the second communication unit 14 or the relay unit 71 is necessary.

[0142] The ECU determines that the operation flag it manages is not off if the operation flag is in the ON state. If the ECU determines that its own operation flag is not off (step S14: NO), it terminates the input processing for the ECU that determined whether or not an operation request from the second communication unit 14 or the relay unit 71 is necessary.

[0143] When input is complete for all slots corresponding to the ECUs to which the operation request signal 64 will be sent, the ECU proceeds to step S17. The operation request signal 64 is generated when input is complete for all slots corresponding to the ECUs to which the operation request signal 64 will be sent. In the process of step S17, the ECU terminates the input processing.

[0144] Once the input processing is complete, the ECU proceeds to step S18. In step S18, the ECU transmits the operation request signal 64 generated through the input processing. After transmitting the operation request signal 64, the ECU terminates the series of processes shown in Figure 13.

[0145] <Processing performed by the ECU upon receiving the operation request signal 64> Figure 14 shows a series of processes performed by the ECU in the in-vehicle network system 100 when it receives an operation request signal 64. The series of processes shown in Figure 14 are performed by the processing circuits 11 of the first device 21, the second device 22, the third device 23, the fifth device 25, and the sixth device 26 executing the communication program PC.

[0146] In step S21, the ECU checks whether the slot corresponding to itself is "1" in the received operation request signal 64. If the ECU receives an operation request signal 64 and the corresponding slot is set to "zero", it determines that the corresponding slot is not set to "1". If the ECU determines that the corresponding slot is not set to "1" in the received operation request signal 64 (step S21: NO), it terminates the series of processes shown in Figure 14.

[0147] If the ECU receives an operation request signal 64 and the input for the slot corresponding to it is "1", it determines that the slot corresponding to it is "1" in the received operation request signal 64. If the ECU determines that the slot corresponding to it is "1" in the received operation request signal 64 (step S21: YES), it proceeds to step S22.

[0148] In step S22, the ECU determines whether the operational flag is off or not. When the operation flag managed by the ECU is off, the ECU determines that the operation flag is off. When the ECU determines that its own operation flag is off (step S22: YES), the process proceeds to step S23. In the process of step S23, the ECU switches the operation flag it manages from off to on. After that, the ECU ends the series of processes shown in FIG. 14.

[0149] When the operation flag managed by the ECU is on, the ECU determines that the operation flag is not off. When the ECU determines that its own operation flag is not off (step S22: NO), it ends the series of processes shown in FIG. 14.

[0150] <The process executed by the ECU to turn off the operation flag> FIG. 15 shows the process executed by the ECU in the in-vehicle network system 100 to turn off the operation flag. The series of processes shown in FIG. 15 are executed by the processing circuits 11 of the first device 21, the second device 22, the third device 23, the fifth device 25, and the sixth device 26 when they execute the communication program PC.

[0151] The ECU that manages the operation flag executes the series of processes shown in FIG. 15 when a certain period of time has elapsed after receiving an operation request signal 64 that requests the operation of its own second communication unit 14 or relay unit 71. That is, the ECU having the second communication unit 14 or the relay unit 71 executes the series of processes shown in FIG. 15 when a certain period of time has elapsed after receiving the operation request signal 64 in which "1" is input to the slot corresponding to itself.

[0152] Also, the ECU that manages the operation flag executes the series of processes shown in FIG. 15 when a certain period of time has elapsed after transmitting an operation request signal 64 that requests the operation of the second communication unit 14 or the relay unit 71 of another ECU.

[0153] Note that when the series of processes shown in Figure 15 begins, the operational flag in the ECU executing the process is in the ON state. In step S31, the ECU determines whether it has received a second operation notification or a third operation notification within a certain period of time. The certain period of time here refers to the time from when an ECU receives an operation request signal 64 requesting the operation of its own second communication unit 14 or relay unit 71 and performs the series of processes shown in Figure 15, until it starts the series of processes shown in Figure 15. The certain period of time here also refers to the time from when an ECU sends an operation request signal 64 requesting the operation of another ECU's second communication unit 14 or relay unit 71 and performs the series of processes shown in Figure 15, until it starts the series of processes shown in Figure 15.

[0154] As mentioned above, the ECU sends an operation request signal 64 with "1" input to the slot corresponding to the ECU having the second communication unit 14 as a second operation notification. If the ECU having the second communication unit 14 receives an operation request signal 64 with "1" input to the slot corresponding to itself within a certain period of time, it determines that it has received the second operation notification. If the ECU having the second communication unit 14 does not receive an operation request signal 64 with "1" input to the slot corresponding to itself within a certain period of time, it determines that it has not received the second operation notification.

[0155] As mentioned above, the ECU sends an operation request signal 64 with "1" input to the slot corresponding to the ECU having the relay unit 71 as a third operation notification. If the ECU having the relay unit 71 receives an operation request signal 64 with "1" input to the slot corresponding to it within a certain period of time, it determines that it has received a third operation notification. If the ECU having the relay unit 71 does not receive an operation request signal 64 with "1" input to the slot corresponding to it within a certain period of time, it determines that it has not received a third operation notification.

[0156] If the ECU determines that it has not received a second operation notification or a third operation notification within a certain period of time (step S31: NO), it proceeds to step S32. In step S32, the ECU determines whether or not it needs to communicate with other ECUs using the second communication standard.

[0157] If the ECU determines that it does not need to communicate with other ECUs using the second communication standard (step S32: NO), it proceeds to step S33. In step S33, the ECU turns off the operation flag. After that, the ECU terminates the series of processes shown in Figure 15.

[0158] If the ECU determines that it has received a second or third operation notification within a certain period of time (step S31: YES), it terminates the series of processes shown in Figure 15 without turning off the operation flag. If the ECU determines that it needs to communicate with other ECUs using the second communication standard (step S32: YES), it also terminates the series of processes shown in Figure 15 without turning off the operation flag.

[0159] Thus, an ECU turns off the operation flag when it has not been requested by another ECU to operate the second communication unit 14 or the relay unit 71, and when it does not need to communicate with other ECUs using the second communication standard. On the other hand, an ECU keeps the operation flag on when it has been requested by another ECU to operate the second communication unit 14 or the relay unit 71, or when it needs to communicate with other ECUs using the second communication standard.

[0160] <Processing to control the state of the second communication unit 14 or relay unit 71> Figure 16 shows the process that the ECU in the in-vehicle network system 100 performs when controlling the state of the second communication unit 14 or the relay unit 71 based on the operation flag. The series of processes shown in Figure 16 are performed by the processing circuits 11 of the first device 21, the second device 22, the third device 23, the fifth device 25, and the sixth device 26 executing the communication program PC.

[0161] The first device 21, the second device 22, the third device 23, the fifth device 25, and the sixth device 26 execute the series of processes shown in Figure 16 when the state of the operation flag they manage changes. In other words, the ECU having the second communication unit 14 or relay unit 71 executes the series of processes shown in Figure 16 when the operation flag it manages changes from an off state to an on state, or from an on state to an off state.

[0162] In step S41, the ECU determines whether its operational flag is in the ON state. At this time, the ECU determines whether the operational flag remains ON after the state has been switched.

[0163] The ECU determines that its own operation flag is on when the operation flag after the switch is on. If the ECU determines that its own operation flag is on (step S41: YES), it proceeds to step S42.

[0164] When the operation flag switches from the off state to the on state, the second communication unit 14 or relay unit 71 is in a standby state at the time of the state switch. In the process of step S42, the ECU transitions the second communication unit 14 or relay unit 71 from the standby state to the operational state. The first device 21, the second device 22, the fifth device 25, and the sixth device 26 transition the second communication unit 14 from the standby state to the operational state in the process of step S42. The third device 23 transitions the relay unit 71 from the standby state to the operational state in the process of step S42. After that, the ECU completes the series of processes shown in Figure 16.

[0165] The ECU determines that its own operating flag is not on when the operating flag after the switch is off. If the ECU determines that its own operating flag is not on (step S41: NO), it proceeds to step S43.

[0166] When the operation flag switches from the ON state to the OFF state, the second communication unit 14 or the relay unit 71 is in the operating state at the time when the state of the operation flag switches. In the process of step S43, the ECU causes the second communication unit 14 or the relay unit 71 to shift from the operating state to the standby state. The first device 21, the second device 22, the fifth device 25, and the sixth device 26 cause the second communication unit 14 to shift from the operating state to the standby state in the process of step S43. The third device 23 causes the relay unit 71 to shift from the operating state to the standby state in the process of step S43. Then, the ECU ends the series of processes shown in FIG. 16.

[0167] <Specific Example of the Mode in Which the ECU Controls the Second Communication Unit 14 and the Relay Unit 71> Hereinafter, referring to FIGS. 17 to 20, a mode in which the ECU in the in-vehicle network system 100 controls the second communication unit 14 and the relay unit 71 included in other ECUs in order to perform communication according to the second communication standard will be specifically shown. In FIGS. 17 to 20, a communication mode implemented in the in-vehicle network system 100 when the first device 21 performs communication with the fifth device 25 according to the second communication standard is shown.

[0168] FIG. 17 shows a mode in which the first device 21 transmits a first message 61 which is a first operation notification. The dashed-dotted arrow shown in FIG. 17 is connected to the ECU that receives the first message 61 and operates the first communication unit 13.

[0169] As described with reference to FIG. 10, when the ECU performs communication with another ECU according to the second communication standard, the ECU transmits a first operation notification to the ECU that is the communication partner of the communication. As shown in FIG. 17, the first device 21 transmits the first message 61 toward the fifth device 25 via the fourth device 24. In order for the first device 21 to have the fourth device 24 relay the first message 61 directed to the fifth device 25, it is necessary to operate the first communication unit 13 included in the fourth device 24.

[0170] Therefore, the first device 21 transmits a PN message as the first message 61, which includes an identifier indicating the fifth device 25 and an identifier indicating the fourth device 24, via the first communication bus 51.

[0171] In Figure 17, the fourth device 24, having received a PN message addressed to itself via the first communication bus 51, activates the first communication unit 13 and relays the first message 61 to the second communication bus 52. In Figure 17, the fifth device 25, having received a PN message addressed to itself via the second communication bus 52, is an NM device 40, and therefore activates the first communication unit 13 without confirming the destination.

[0172] As explained with reference to Figure 1, when the first device 21 communicates with the fifth device 25 via communication according to the second communication standard, the third device 23 is required to act as a relay. As explained with reference to Figure 11, the ECU sends a first operation notification to the ECU having the relay unit 71 when relaying by the relay unit 71 is required.

[0173] Therefore, as shown in Figure 17, the first device 21 also transmits the first message 61 to the third device 23. Thus, the first message 61 transmitted from the first device 21 via the first communication bus 51 is a PN message that also includes an identifier indicating the third device 23.

[0174] In Figure 17, the third device 23, upon receiving a PM message addressed to itself via the first communication bus 51, activates the first communication unit 13. When the first device 21 sends a first operation notification, the second device 22 receives the first operation notification via the first communication bus 51. In Figure 17, the second device 22, which has received the PN message from the first device 21, is a PN device 30, and therefore confirms that the PN message is not addressed to itself and does not activate the first communication unit 13.

[0175] When the fourth device 24 relays the first operation notification received via the first communication bus 51 to the second communication bus 52, the sixth device 26 receives the first operation notification via the second communication bus 52. In Figure 17, the sixth device 26, which has received the PN message via the second communication bus 52, is the NM device 40, and therefore activates the first communication unit 13 regardless of whether it has been requested to activate the first communication unit 13 or not.

[0176] Figure 18 shows a configuration in which, after communication in the manner shown in Figure 17 is performed, the first device 21 transmits an operation request signal 64 through communication according to the first communication standard using the first communication bus 51 and the second communication bus 52. The dashed arrows in Figure 18 are connected to an ECU that receives the operation request signal 64 and activates the second communication unit 14 or the relay unit 71.

[0177] As illustrated in Figure 10, the ECU sends a first operation notification to the ECU of the other party communicating according to the second communication standard, and then sends a second operation notification. As shown in Figure 18, the first device 21 transmits an operation request signal 64 via the fourth device 24 to the second communication bus 52 to which the fifth device 25 is connected, through communication according to the first communication standard using the first communication bus 51 and the second communication bus 52.

[0178] Figure 19 shows the operation request signal 64 that the first device 21 transmits to the fifth device 25 in order to communicate with it according to the second communication standard. In the operation request signal 64 shown in Figure 19, the slot corresponding to the fifth device 25 is input with "1". Therefore, the operation request signal 64 shown in Figure 19 functions as a second operation notification to the fifth device 25.

[0179] In Figure 18, the fifth device 25, having received the operation request signal 64 relayed by the fourth device 24, recognizes that "1" has been input to the slot corresponding to itself and activates the second communication unit 14.

[0180] As shown and explained in Figure 11, the ECU sends a first operation notification to the ECU having the relay unit 71, and then sends a third operation notification. As shown in Figure 18, the first device 21 sends an operation request signal 64 to the first communication bus 51 to which the third device 23 is connected, via communication according to the first communication standard.

[0181] In the operation request signal 64 shown in Figure 19, the slot corresponding to the third device 23 has a "1" input. Therefore, the operation request signal 64 shown in Figure 19 functions as a third operation notification to the third device 23.

[0182] In Figure 18, the third device 23, upon receiving the operation request signal 64, recognizes that "1" has been input to the slot corresponding to itself and activates the relay unit 71. In the operation request signal 64 shown in Figure 19, "0" is input to the corresponding slot for ECUs other than the third device 23 and the fifth device 25. Therefore, the second device 22 and the sixth device 26 do not activate the second communication unit 14.

[0183] In Figure 19, the operation request signal 64 has a slot corresponding to the first device 21, but the contents of this slot do not affect the second communication unit 14 of the first device 21. The operation request signal 64 does not need to have a slot corresponding to the ECU that transmits the signal, and it may always be "zero" or "1".

[0184] In Figure 18, when the first device 21 transmits an operation request signal 64 as shown in Figure 19, the second communication unit 14 of the fifth device 25 and the relay unit 71 of the third device 23 become operational in the in-vehicle network system 100. As a result, the first device 21 can communicate with the fifth device 25 via the third communication bus 53 using the second communication standard.

[0185] On the other hand, in Figure 18, even if the first device 21 transmits an operation request signal 64 as shown in Figure 19, the second communication unit 14 of the second device 22 and the second communication unit 14 of the sixth device 26 will not be activated by the operation request signal 64. In this way, the in-vehicle network system 100 can prevent the second communication unit 14 from being activated for ECUs whose corresponding slot in the operation request signal 64 is "0" and which did not include a second operation notification. This effect is particularly effective for the NM device 40, which cannot confirm the identifier indicating the destination.

[0186] Figure 20 shows the operation request signal 64 that the first device 21 transmits when it stops communicating with the fifth device 25 according to the second communication standard. In Figure 20, "zero" is input to the slots corresponding to the third device 23 and the fifth device 25.

[0187] The operation request signal 64 shown in Figure 20 is transmitted in the same manner as the operation request signal 64 shown in Figure 19, as shown in Figure 18. The fifth device 25, which was operating the second communication unit 14, switches the second communication unit 14 to standby mode when it stops receiving the operation request signal 64 shown in Figure 20 and when it stops receiving the operation request signal 64 with "1" entered in the slot corresponding to itself. The fifth device 25, which was operating the relay unit 71, switches the relay unit 71 to standby mode when it stops receiving the operation request signal 64 shown in Figure 20 and when it stops receiving the operation request signal 64 with "1" entered in the slot corresponding to itself.

[0188] In this way, when the first device 21 stops communication according to the second communication standard, it puts the second communication unit 14 of the ECU of the communication partner and the relay unit 71 that was relaying the communication into a standby state.

[0189] In this way, the ECU in the in-vehicle network system 100 can activate the second communication unit 14 and the relay unit 71 only when necessary by transmitting the second operation notification and the third operation notification through communication according to the first communication standard. This effect is particularly effective in the NM device 40, where the identifier cannot be confirmed.

[0190] <Operation of this embodiment> The first device 21, the second device 22, the third device 23, the fifth device 25, and the sixth device 26, when communicating according to the second communication standard, request the other party to communicate to activate the second communication unit 14 through communication according to the first communication standard.

[0191] <Effects of this embodiment> (1) As a result, the first device 21, the second device 22, the third device 23, the fifth device 25, and the sixth device 26 can operate the second communication unit 14, which is a communication unit that corresponds to the second communication standard, only when communicating according to the second communication standard.

[0192] (2) The first device 21, the second device 22, the third device 23, the fifth device 25, and the sixth device 26 are capable of communicating with multiple other ECUs in the in-vehicle network system 100 using the second communication standard. When the first device 21, the second device 22, the third device 23, the fifth device 25, and the sixth device 26 communicate using the second communication standard, they specify the communication partner from among the multiple other ECUs and send a second operation notification.

[0193] The first device 21, the second device 22, the third device 23, the fifth device 25, and the sixth device 26 specify which of the multiple ECUs will communicate with using the second communication standard when transmitting the second operation notification. This allows the first device 21, the second device 22, the third device 23, the fifth device 25, and the sixth device 26 to operate only the second communication unit 14 of a specific ECU.

[0194] (3) The in-vehicle network system 100 includes a relay unit 71 and a first communication unit 13 as communication devices that relay communication between the ECU and other ECUs according to the second communication standard, and a third device 23 which is a relay device having a network management function. The first device 21, the second device 22, the fifth device 25, and the sixth device 26, when communicating with other ECUs according to the second communication standard, send a third operation notification, which is a message requesting the operation of the relay unit 71, to the third device 23 via communication according to the first communication standard.

[0195] When the first device 21, the second device 22, the fifth device 25, and the sixth device 26 communicate with other ECUs using the second communication standard via the relay unit 71 provided by the third device 23, they request the operation of the relay unit 71 through communication using the first communication standard. This allows the first device 21, the second device 22, the fifth device 25, and the sixth device 26 to operate the relay unit 71 only when necessary.

[0196] (4) The first device 21, the second device 22, the fifth device 25, and the sixth device 26 determine whether or not to operate the second communication unit 14 based on whether or not they have received a second operation notification received through communication according to the first communication standard. As a result, the first device 21, the second device 22, the fifth device 25, and the sixth device 26 can operate the second communication unit 14, which is a communication unit corresponding to the second communication standard, only when they are performing communication according to the second communication standard.

[0197] (5) The first device 21, the second device 22, the fifth device 25, and the sixth device 26 maintain the second communication unit 14 in an operational state during the period in which they periodically receive the second operation notification. If the first device 21, the second device 22, the fifth device 25, and the sixth device 26 do not receive the second operation notification for a certain period of time or longer, they switch the second communication unit 14 from the operational state to the standby state.

[0198] The first device 21, the second device 22, the fifth device 25, and the sixth device 26 switch the second communication unit 14 to a standby state when they stop receiving the second operation notification. This allows the first device 21, the second device 22, the fifth device 25, and the sixth device 26 to switch the second communication unit 14 to a standby state when communication according to the second communication standard is no longer required.

[0199] (6) The first device 21, the second device 22, the third device 23, the fifth device 25, and the sixth device 26 periodically send second operation notifications to other ECUs during periods when communication with other ECUs using the second communication standard is required. The first device 21, the second device 22, the third device 23, the fifth device 25, and the sixth device 26 cease periodically sending second operation notifications to other ECUs when they stop communicating with other ECUs using the second communication standard.

[0200] The first device 21, the second device 22, the third device 23, the fifth device 25, and the sixth device 26 stop transmitting the second operation notification when there is no longer a need for communication according to the second communication standard. As a result, the first device 21, the second device 22, the third device 23, the fifth device 25, and the sixth device 26 can put the second communication unit 14 of the ECU of the communication partner into standby mode when there is no longer a need for communication according to the second communication standard.

[0201] (7) In the in-vehicle network system 100, an ECU that intends to communicate using the second communication standard activates the second communication unit 14 of the ECU that is communicating with the other party using the second communication standard by communicating using the first communication standard. As a result, the in-vehicle network system 100 can activate the second communication unit 14, which is a communication unit that corresponds to the second communication standard, only when the ECU is communicating using the second communication standard.

[0202] (8) A specific ECU in the in-vehicle network system 100 periodically sends a second operational notification to other ECUs during the period when communication with other ECUs using the second communication standard is required. When a specific ECU in the in-vehicle network system 100 stops communicating with other ECUs using the second communication standard, it stops periodically sending the second operational notification to other ECUs. Other ECUs in the in-vehicle network system 100 maintain the second communication unit 14 in an operational state during the period when they periodically receive the second operational notification. If other ECUs in the in-vehicle network system 100 do not receive the second operational notification for a certain period of time or longer, they switch the second communication unit 14 from an operational state to a standby state.

[0203] In the in-vehicle network system 100, the ECU that sent the second operation notification stops sending the second operation notification when it no longer needs to communicate using the second communication standard. Furthermore, in the in-vehicle network system 100, the ECU that was receiving the second operation notification switches the second communication unit 14 to a standby state when it no longer receives the second operation notification. This allows the in-vehicle network system 100 to switch the second communication unit 14 to a standby state when it no longer needs to communicate using the second communication standard.

[0204] (9) The in-vehicle network system 100 includes a relay unit 71 and a first communication unit 13 as communication devices that relay communication between a specific ECU and other ECUs according to a second communication standard, and a third device 23 which is a relay device having a network management function. In the in-vehicle network system 100, when a specific electronic control unit communicates with other ECUs according to the second communication standard, it sends a third operation notification, which is a message requesting the operation of the relay unit 71, to the third device 23 via communication according to the first communication standard. In the in-vehicle network system 100, when the third device 23 receives the third operation notification, it switches the relay unit 71 from a standby state to an operational state.

[0205] In the in-vehicle network system 100, when ECUs communicate with each other using the second communication standard via the relay unit 71 provided by the third device 23, the third device 23 activates the relay unit 71 based on the third operation notification. This allows the in-vehicle network system 100 to activate the relay unit 71 only when necessary.

[0206] (10) In the above communication method, an ECU that intends to communicate according to the second communication standard activates the second communication unit 14 of the ECU that is communicating with the other party according to the second communication standard by communicating according to the first communication standard. As a result, the above communication method can activate the second communication unit 14, which is a communication unit corresponding to the second communication standard, only when the ECU is communicating according to the second communication standard.

[0207] (11) When the ECU communicates using the second communication standard, the communication program PC instructs the ECU to request the other party to communicate using the first communication standard to activate the second communication unit 14. As a result, the communication program PC can activate the second communication unit 14, which is a communication unit corresponding to the second communication standard, only when the ECU communicates using the second communication standard.

[0208] (12) The communication program PC instructs the ECU to determine whether or not to operate the second communication unit 14 based on whether or not it has received a second operation notification received through communication according to the first communication standard. As a result, the communication program PC can operate the second communication unit 14, which is a communication unit corresponding to the second communication standard, only when communication according to the second communication standard is performed.

[0209] <Example of changes> This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0210] The in-vehicle network system 100 is not limited to the configuration shown in Figure 1. For example, the number of ECUs in the in-vehicle network system 100 is not limited to the configuration shown in Figure 1.

[0211] Furthermore, the ratio of the number of PN devices 30 and NM devices 40 in the in-vehicle network system 100 is not limited to the above embodiment. The in-vehicle network system 100 may consist only of PN devices 30, or it may consist only of NM devices 40.

[0212] The topology of the in-vehicle network system 100 is not limited to the embodiments described above. Furthermore, the in-vehicle network system 100 does not need to include an ECU that acts as a relay device. In this case, the ECU does not need to transmit the third operation notification.

[0213] In the above-described in-vehicle network system 100, the first communication standard is CAN. The first communication standard does not have to be CAN. For example, the first communication standard may be Ethernet. For example, the first communication standard may be CAN FD (CAN with Flexible Data Rate).

[0214] In the above-described in-vehicle network system 100, the second communication standard is Ethernet. The second communication standard does not have to be Ethernet. For example, the second communication standard may be CAN. The second communication standard may be CAN FD.

[0215] In the above-described in-vehicle network system 100, the fourth device 24 checks the received message and relays the message only if it determines that it is necessary to send the received message to another communication bus. Alternatively, the fourth device 24 may adopt a configuration in which it relays the message without checking whether or not it is necessary to relay the received message.

[0216] In the above-described in-vehicle network system 100, the third device 23 confirms the destination of the received message when relaying communication according to the second communication standard. The third device 23 then uses the relay unit 71 to transmit the received message to the destination of the message. On the other hand, the third device 23 may transmit the message to all ECUs connected to the relay unit 71 without confirming the destination of the message when relaying communication according to the second communication standard.

[0217] In the above-described in-vehicle network system 100, the relay unit 71 has the function of relaying communication between ECUs according to the second communication standard, and the function of a second communication unit 14. The relay unit 71 does not necessarily have to have the function of a second communication unit 14.

[0218] In the above-described in-vehicle network system 100, even if the NM device 40 attempts to communicate with the PN device 30 using the second communication standard, it cannot activate the second communication unit 14 by sending the first operation notification and the second operation notification, as shown in Figure 10.

[0219] The PN device 30 may adopt a configuration in which it activates the first communication unit 13 when it receives an NM message. In this case, the NM device 40 can activate the second communication unit 14 of the PN device 30 by sending a first activation notification and a second activation notification, as shown in Figure 10.

[0220] Furthermore, in the above-described in-vehicle network system 100, the NM device 40 cannot activate the relay unit 71 of the PN device 30 by transmitting the first operation notification and the second operation notification as shown in Figure 11.

[0221] If the PN device 30 is configured to activate the first communication unit 13 when it receives an NM message, the NM device 40 can activate the relay unit 71 of the PN device 30 by sending a first operation notification and a second operation notification, as shown in Figure 11.

[0222] In Figure 17, the first device 21 sends a PN message to the fifth device 25 as the first message 61, which includes an identifier indicating the fifth device 25. In other words, the PN device 30 sends a PN message when it sends the first operation notification to the NM device 40. The PN device 30 may also adopt a configuration in which it sends an NM message when it sends the first operation notification to the NM device 40.

[0223] In the above-described in-vehicle network system 100, the ECU that transmits the operation request signal 64 specifies the ECU that requests the operation of the second communication unit 14 or relay unit 71 by using a slot corresponding to the ECU that requests the operation of the second communication unit 14 or relay unit 71. The manner in which the ECU specifies the ECU that requests the operation of the second communication unit 14 or relay unit 71 is not limited to the above embodiment. For example, the ECU may specify the ECU that requests the operation of the second communication unit 14 or relay unit 71 by transmitting a second operation notification that includes an identifier indicating the identification information of the destination of the signal, such as a PN message.

[0224] In the above-described in-vehicle network system 100, the ECU that transmits the operation request signal 64 specifies the ECU that requests the operation of the second communication unit 14 or the relay unit 71. The ECU does not have to specify the ECU that requests the operation of the second communication unit 14 or the relay unit 71. In this case, when the ECU having the second communication unit 14 receives a message requesting the operation of the second communication unit 14 from any ECU via communication according to the first communication standard, it receives the message as a second operation notification and activates the second communication unit 14. In this case, when the ECU having the relay unit 71 receives a message requesting the operation of the relay unit 71 from any ECU via communication according to the first communication standard, it receives the message as a third operation notification and activates the relay unit 71.

[0225] In the above-described in-vehicle network system 100, the ECU periodically sends a second operation notification as long as it requests the operation of the second communication unit 14. Alternatively, instead of periodically sending the second operation notification, the ECU may, after sending the second operation notification once, send a message requesting that the second communication unit 14 be moved to a standby state when it is no longer necessary to request the operation of the second communication unit 14.

[0226] In the above-described in-vehicle network system 100, the ECU periodically sends a third operation notification as long as it requests the operation of the relay unit 71. Alternatively, instead of periodically sending a third operation notification, the ECU may send a message requesting that the relay unit 71 be put into standby mode once it has sent a third operation notification and no longer needs to request the operation of the relay unit 71.

[0227] <Note> The technical concepts that can be understood from the above embodiments and modified examples are described below. [Note 1] An electronic control device that constitutes an in-vehicle network system, comprising a first communication unit capable of communication according to a first communication standard and a second communication unit capable of communication according to a second communication standard which is a different communication standard from the first communication standard, as a communication device that can switch between a standby state in which communication functions are restricted and an operating state in which the restrictions on communication functions are lifted, and having a network management function that transitions the first communication unit from the standby state to the operating state when it receives a first operation notification, which is a message requesting the operation of the first communication unit, through communication according to the first communication standard, and an electronic control device that, when communicating with other electronic control devices according to the second communication standard, transmits a second operation notification, which is a message requesting the operation of the second communication unit provided by the other electronic control device, to the other electronic control device through communication according to the first communication standard.

[0228] [Note 2] The electronic control unit described in Note 1, which is capable of communicating with a plurality of other electronic control units in the in-vehicle network system using the second communication standard, and which, when communicating using the second communication standard, specifies the communication partner from among the plurality of other electronic control units and transmits the second operation notification.

[0229] [Note 3] The in-vehicle network system comprises a relay unit and a first communication unit as the communication device, which relay communication performed by the electronic control unit and other electronic control units according to the second communication standard, and includes a relay unit having a network management function, and when communicating with other electronic control units according to the second communication standard, transmits a third operation notification, which is a message requesting the relay unit to operate, to the relay unit via communication according to the first communication standard, as described in Note 1 or Note 2.

[0230] [Note 4] An electronic control device that constitutes an in-vehicle network system, comprising a first communication unit capable of communication according to a first communication standard, and a second communication unit capable of communication according to a second communication standard which is a different communication standard from the first communication standard, as a communication device that can switch between a standby state in which communication functions are restricted and an operating state in which the restrictions are lifted, and having a network management function that transitions the first communication unit from the standby state to the operating state when it receives a first operation notification, which is a message requesting the operation of the first communication unit, via communication according to the first communication standard, and being an electronic control device that can communicate with other electronic control devices in the in-vehicle network system, and is an electronic control device that transitions the second communication unit from the standby state to the operating state when it receives a second operation notification, which is a message requesting the operation of the second communication unit, from another electronic control device via communication according to the first communication standard.

[0231] [Note 5] An electronic control device according to any one of Notes 1 to 4, which maintains the second communication unit in the operating state during the period in which the second operation notification is received periodically, and transitions the second communication unit from the operating state to the standby state if the second operation notification is not received for a certain period of time or longer.

[0232] [Note 6] The electronic control device described in Note 5, which periodically transmits the second operation notification to other electronic control devices during periods when communication with other electronic control devices according to the second communication standard is required, and stops periodically transmitting the second operation notification to other electronic control devices when communication with other electronic control devices according to the second communication standard is stopped. [Explanation of Symbols]

[0233] 11…Processing circuit 12...Storage device 13…First Communications Department 14…Second Communications Department 21...First device 22…Second device 23...Third device 24…Fourth device 25…Fifth device 26…6th device 30...PN device 40...NM device 51...1st Communications Bus 52...Second Communications Bus 53...Third Communications Bus 61…First Message 62…Second Message 63…Third Message 64... Operation request signal 71…Relay section 100…In-vehicle network systems PC...communication program

Claims

1. As a communication device capable of switching between a standby state with restricted communication functions and an operational state with the restrictions on communication functions removed, A first communication unit capable of communication according to the first communication standard, A second communication unit capable of communication using a second communication standard, which is a different communication standard from the first communication standard, Equipped with, An electronic control device constituting an in-vehicle network system has a network management function that, upon receiving a first operation notification, which is a message requesting the operation of the first communication unit, through communication according to the first communication standard, transitions the first communication unit from the standby state to the operational state. When communicating with other electronic control devices using the second communication standard, a second operation notification, which is a message requesting the other electronic control device to operate the second communication unit, is transmitted to the other electronic control device via communication using the first communication standard. Electronic control unit.

2. In the aforementioned in-vehicle network system, communication with multiple other electronic control devices is possible using the second communication standard. When communicating using the second communication standard, the second operation notification is transmitted by specifying the recipient of the communication from among the multiple other electronic control devices. The electronic control device according to claim 1.

3. The in-vehicle network system includes, as a communication device, a relay unit and a first communication unit that relay communications performed by the electronic control unit and other electronic control units according to the second communication standard, and includes a relay device having a network management function. When communicating with other electronic control devices using the second communication standard, a third operation notification, which is a message requesting the relay unit to operate, is transmitted to the relay device via communication using the first communication standard. The electronic control device according to claim 1 or claim 2.

4. As a communication device capable of switching between a standby state with restricted communication functions and an operational state with the restrictions on communication functions removed, A first communication unit capable of communication according to the first communication standard, A second communication unit capable of communication using a second communication standard, which is a different communication standard from the first communication standard, Equipped with, An electronic control device constituting an in-vehicle network system has a network management function that, upon receiving a first operation notification, which is a message requesting the operation of the first communication unit, through communication according to the first communication standard, transitions the first communication unit from the standby state to the operational state. In the aforementioned in-vehicle network system, the electronic control unit is capable of communicating with other electronic control units, When the second communication unit receives a second operation notification, which is a message requesting the operation of the second communication unit, from another electronic control unit via communication according to the first communication standard, the second communication unit is switched from the standby state to the operational state. Electronic control unit.

5. During the period in which the second operational notification is periodically received, the second communication unit is kept in the operational state. If the second operation notification is not received for a certain period of time or longer, the second communication unit is switched from the operating state to the standby state. The electronic control device according to claim 1 or claim 4.

6. During the period when communication with other electronic control devices is required according to the second communication standard, the second operation notification is periodically sent to the other electronic control devices. When communication with other electronic control devices according to the second communication standard is stopped, the periodic transmission of the second operation notification to the other electronic control devices is stopped. The electronic control device according to claim 5.

7. It is an in-vehicle network system equipped with multiple electronic control devices, The aforementioned electronic control device is A communication device capable of switching between a standby state with restricted communication functions and an operational state with the restrictions on communication functions removed comprises a first communication unit capable of communication according to a first communication standard, and a second communication unit capable of communication according to a second communication standard, which is a communication standard different from the first communication standard. An electronic control device having a network management function that, upon receiving a first operation notification, which is a message requesting the operation of the first communication unit, through communication according to the first communication standard, transitions the first communication unit from the standby state to the operational state. A specific electronic control unit in the plurality of electronic control units, When communicating with other electronic control units in multiple electronic control units using the second communication standard, a second operation notification, which is a message requesting the operation of the second communication unit, is transmitted through communication using the first communication standard. Other electronic control devices, When the second operation notification is received through communication according to the first communication standard, the second communication unit is switched from the standby state to the operating state. In-vehicle network system.

8. The aforementioned specific electronic control device is During the period when communication with other electronic control devices is required according to the second communication standard, the second operation notification is periodically sent to the other electronic control devices. When communication with other electronic control devices according to the second communication standard is stopped, the periodic transmission of the second operation notification to the other electronic control devices is stopped. Other electronic control devices include: During the period in which the second operational notification is periodically received, the second communication unit is kept in the operational state. If the second operation notification is not received for a certain period of time or longer, the second communication unit is switched from the operating state to the standby state. The in-vehicle network system according to claim 7.

9. The communication device includes a relay unit and a first communication unit that relay communication according to the second communication standard performed by the specific electronic control unit and other electronic control units, and also includes a relay device having a network management function. The aforementioned specific electronic control device, When communicating with other electronic control devices according to the second communication standard, a third operation notification, which is a message requesting the operation of the relay unit, is transmitted to the relay device via communication according to the first communication standard. The relay device, When the third operational notification is received, the relay unit is switched from the standby state to the operational state. The in-vehicle network system according to claim 7 or claim 8.

10. A communication device capable of switching between a standby state with restricted communication functions and an operational state with the restrictions on communication functions removed comprises a first communication unit capable of communication according to a first communication standard, and a second communication unit capable of communication according to a second communication standard, which is a communication standard different from the first communication standard. A communication method in an in-vehicle network system comprising a plurality of electronic control devices having a network management function that transitions the first communication unit from the standby state to the operating state when it receives a first operation notification, which is a message requesting the operation of the first communication unit, through communication according to the first communication standard, When a specific electronic control unit in the plurality of electronic control units communicates with other electronic control units in the plurality of electronic control units according to the second communication standard, the specific electronic control unit transmits a second operation notification, which is a message requesting the operation of the second communication unit, through communication according to the first communication standard. The other electronic control unit includes the step of transitioning the second communication unit from the standby state to the operating state when it receives the second operation notification through communication according to the first communication standard. Communication method.

11. A communication device capable of switching between a standby state with restricted communication functions and an operational state with the restrictions on communication functions removed comprises a first communication unit capable of communication according to a first communication standard, and a second communication unit capable of communication according to a second communication standard, which is a communication standard different from the first communication standard. A communication program executed by a processing circuit of an electronic control unit constituting an in-vehicle network system, which has a network management function that transitions the first communication unit from the standby state to the operational state when it receives a first operation notification, which is a message requesting the operation of the first communication unit, through communication according to the first communication standard, When the aforementioned electronic control unit communicates with another aforementioned electronic control unit according to the second communication standard, the processing circuit causes the other aforementioned electronic control unit to transmit a second operation notification, which is a message requesting the other aforementioned electronic control unit to operate its second communication unit, via communication according to the first communication standard. Communication program.

12. A communication device capable of switching between a standby state with restricted communication functions and an operational state with the restrictions on communication functions removed comprises a first communication unit capable of communication according to a first communication standard, and a second communication unit capable of communication according to a second communication standard, which is a communication standard different from the first communication standard. An electronic control device constituting an in-vehicle network system has a network management function that, upon receiving a first operation notification, which is a message requesting the operation of the first communication unit, through communication according to the first communication standard, transitions the first communication unit from the standby state to the operational state, In the aforementioned in-vehicle network system, a communication program is executed by the processing circuit of the electronic control unit, which is capable of communicating with other electronic control units. When the aforementioned electronic control unit receives a second operation notification, which is a message requesting the operation of the second communication unit, from another aforementioned electronic control unit via communication according to the first communication standard, it causes the processing circuit to transition the second communication unit from the standby state to the operational state. Communication program.

Images