Communication device, communication system, and failure sign diagnosis method

Abstract

This communication device carries out transmission of data signals, and comprises a setpoint data variation diagnosis unit that uses first setpoint data, which is for adjusting a transmission waveform when data signals are exchanged with an external device through a transmission line, and second setpoint data, which is for adjusting the transmission waveform when data signals are looped back between a transmission circuit and a reception circuit within the transmission device, to determine, on the basis of a prescribed determination condition, a variation in the first setpoint data when data signals are exchanged via the external device and the transmission line, and a variation in the second setpoint data when data signals are looped back between the transmission circuit and the reception circuit, and that diagnoses a failure sign in the communication device and the transmission line on the basis of the determination result.

Description

[Technical Field]

[0001] The present invention relates to a communication device, a communication system, and a method for predictive failure diagnosis, each of which has a function for performing predictive failure diagnosis in data communication via an in-vehicle network, for example. [Background technology]

[0002] In recent years, data communications have become indispensable in the infrastructure of industry and life, and it is desirable to be able to detect signs of failure before communication equipment actually breaks down. For example, with the spread of autonomous driving and car sharing services, it will become more difficult to ensure the long-term reliability of semiconductor components installed in automobiles as automobile operating rates increase significantly. For this reason, it is expected that in the future, maintaining the functionality of semiconductor components through part replacement will become the norm. Since semiconductors used in communication devices that communicate data with on-board sensors and cameras are deeply involved in safety control, it is necessary to establish a diagnostic method that focuses on diagnosing signs of failure.

[0003] Patent Document 1 discloses a method for diagnosing a failure sign by comparing setting value data for adjusting a transmission waveform during communication with diagnostic reference information. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-129969 Summary of the Invention [Problem to be solved by the invention]

[0005] For example, when the technology of Patent Document 1 is used to detect a failure sign in a communication path connecting a first communication device and a second communication device via a transmission line, it is possible to determine that the diagnosed communication path is in a failure sign state. However, it is not possible to identify whether the failure sign is in the first communication device, the second communication device, or the transmission line. This requires maintenance work to identify the actual failure sign location, and if the failure sign location cannot be identified, it may be necessary to preventively replace suspect parts or communication devices more than necessary, resulting in increased costs.

[0006] In view of the above circumstances, there has been a demand for a method that can at least determine whether or not a communication device to be diagnosed is in a state where a failure is predicted. [Means for solving the problem]

[0007] In order to solve the above problem, one embodiment of the present invention provides a communication device that transmits data signals, and includes a transmission circuit that transmits the data signals, a receiving circuit that receives the data signals, and a setting value data fluctuation diagnosis unit that uses first setting value data that adjusts the transmission waveform when the data signal is transmitted and received via a transmission line with an external device, and second setting value data that adjusts the transmission waveform when the data signal is looped back between the transmission circuit and the receiving circuit, to determine, based on predetermined determination conditions, the fluctuation of the first setting value data when the data signal is transmitted and received via the transmission line with an external device, and the fluctuation of the second setting value data when the data signal is looped back between the transmission circuit and the receiving circuit, and diagnoses signs of failure in the communication device and the transmission line based on the determination results. [Effects of the Invention]

[0008] According to at least one aspect of the present invention, by adding a failure prediction diagnosis when looped back to the diagnosis when transmitting and receiving with an external device via a transmission line, self-diagnosis by the communication device itself becomes possible, and it becomes possible to determine whether the communication device being diagnosed is in a failure prediction state. Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a block diagram showing an example of the internal configuration of a communication device that constitutes a communication system according to a first embodiment of the present invention. [Figure 2] 5 is a diagram showing an example of fluctuation over time of setting value data for transmission waveform adjustment according to the first embodiment of the present invention. FIG. [Figure 3] FIG. 4 is a diagram showing a table in which the results of failure sign diagnosis for a single communication device according to the first embodiment of the present invention are classified into cases. [Figure 4] FIG. 4 is a diagram showing a table showing the results of failure sign diagnosis for two communication devices according to the first embodiment of the present invention, divided into cases. [Figure 5] 1 is a block diagram showing an example of the internal configuration of a communication device according to a first embodiment of the present invention, when the communication device includes a temperature detection unit. [Figure 6] 1 is a block diagram showing an example of the internal configuration of a communication device according to a first embodiment of the present invention, when the communication device includes a power supply voltage detection unit. [Figure 7] 1 is a diagram showing an example of a configuration in which information on the results of failure sign diagnosis is collected in a higher-level device and the higher-level device identifies the location of the failure sign in a communication system according to a first embodiment of the present invention. [Figure 8] FIG. 10 is a diagram showing an example of a configuration for identifying a failure symptom location by a communication device without using a higher-level device in a communication system according to a second embodiment of the present invention. [Figure 9] FIG. 10 is a diagram showing an example of a configuration for changing a determination threshold used in a failure sign diagnosis of a communication device in response to an instruction from an external device in a communication system according to a third embodiment of the present invention. [Figure 10] FIG. 10 is a diagram showing an example of a configuration in which an instruction from an external device is transmitted and received via wireless communication between two communication devices in a communication system according to a third embodiment of the present invention. [Figure 11] 1 is a block diagram showing an example of the hardware configuration of a communication device, a microcomputer, and a computer included in a server according to a first embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, examples of modes for carrying out the present invention (hereinafter referred to as "embodiments") will be described with reference to the accompanying drawings. In this specification and the accompanying drawings, identical components or components having substantially the same functions will be assigned the same reference numerals, and redundant explanations will be omitted. Furthermore, when there are multiple components having the same or similar functions, they may be described using the same reference numerals with different subscripts. Furthermore, when it is not necessary to distinguish between these multiple components, the subscripts may be omitted in the description.

[0011] First Embodiment First, a communication device according to a first embodiment of the present invention and a communication system using the communication device will be described. Fig. 1 is a block diagram showing an example of the internal configuration of a communication device constituting a communication system according to a first embodiment. In the example shown in Fig. 1, communication device 1 and communication device 2 are connected by a single transmission line 10. In the case of in-vehicle Ethernet (registered trademark), the transmission line 10 is a pair of twisted pair cables (differential transmission line). Full-duplex communication can be performed between communication device 1 and communication device 2 using the twisted pair cables. For example, communication device 1 and communication device 2 are used as in-vehicle Ethernet switches.

[0012] [Configuration of communication device 1] In the communication device 1, the transmission circuit is made up of a transmission processing circuit 101, an emphasis circuit 102, and a transmission output circuit 103, and the reception circuit is made up of a reception input circuit 104, an equalizer circuit 105, an error detection unit 106, and a reception processing circuit 107. In addition to these, the communication device 1 is also provided with an input / output unit 108 and a setting value data fluctuation diagnosis unit 109, the details of which will be described later, that diagnoses fluctuations in the setting value data for adjusting the transmission waveform.

[0013] The transmission processing circuit 101 converts data (e.g., IP packets) output from the input / output unit 108 into a signal suitable for transmission (referred to as a "data signal"), and outputs the data signal to the emphasis circuit 102 via a signal line 11. In the drawing, the transmission processing circuit 101 is indicated as "TX."

[0014] Emphasis circuit 102 amplifies the high frequency band of the data signal input from transmission processing circuit 101 in accordance with the high frequency attenuation characteristics specific to the transmission path, and outputs the amplified signal to transmission output circuit 103. This improves the frequency characteristics of the data signal received by communication device 2 on the receiving side. Emphasis circuit 102 also outputs setting value data 1 for transmission waveform adjustment (which is an index of the tap coefficient values ​​that adjust the transmission waveform), which will be described later, to setting value data fluctuation diagnosis section 109 via signal line 12. Emphasis circuit 102 is generally realized by a compensation circuit that uses a frequency filter or the like that adjusts the frequency characteristics of the data signal to optimize them.

[0015] The transmission output circuit 103 amplifies the data signal input from the emphasis circuit 102 with a preset gain, and outputs the data signal to the input / output unit 108 via the signal line 13 .

[0016] The input / output unit 108 performs processing to output a data signal input from the transmission output circuit 103 to the transmission line 10 (solid line). Furthermore, a data signal is input to the input / output unit 108 from the communication device 2 via the transmission line 10 (dashed line). Furthermore, the input / output unit 108 outputs the data signal input from the transmission output circuit 103 during loopback to the reception input circuit 104 via signal line 14 (chain double-dashed line). Similarly, in the communication device 2, the input / output unit 208 outputs the data signal input from the transmission output circuit 203 during loopback to the reception input circuit 204 via signal line 24 (chain double-dashed line).

[0017] The receiving input circuit 104 amplifies the data signal input from the input / output unit 108 with a preset gain, and outputs the data signal to the equalizer circuit 105 .

[0018] After receiving a data signal from the receiving input circuit 104, the equalizer circuit 105 adjusts the frequency characteristics of the data signal to restore or minimize changes in the signal waveform that have been caused by the characteristics of the transmission path, and outputs the data signal to the error detection unit 106. The equalizer circuit 105 also outputs setting value data 2 for transmission waveform adjustment (which is an index of the tap coefficient values ​​that adjust the transmission waveform), which will be described later, to the setting value data fluctuation diagnosis unit 109 via signal line 15. The equalizer circuit 105 is realized by a compensation circuit that uses a frequency filter or the like that adjusts the frequency characteristics of the data signal to optimize them. In many cases, the high-frequency band of the signal sent from the transmission path is amplified to compensate for lost high-frequency components.

[0019] The error detection unit 106 compares the data signal input from the equalizer circuit 105 with a predetermined data signal to detect an error, and outputs the error detection result to the reception processing circuit 107 together with the data signal.

[0020] The reception processing circuit 107 receives the data signal and the error detection result, and converts the data signal into data suitable for use in a subsequent processing block or device (not shown). In the figure, the reception processing circuit 107 is indicated as "RX."

[0021] The set value data fluctuation diagnostic unit 109 monitors fluctuations in the set value data 1 for transmission waveform adjustment acquired from the emphasis circuit 102 and the set value data 2 for transmission waveform adjustment acquired from the equalizer circuit 105, and diagnoses signs of failure in the communication device and the transmission line. The set value data fluctuation diagnostic unit 109 outputs the diagnosis result of the signs of failure to a device external to the communication device 1 via the signal line 16.

[0022] [Configuration of communication device 2] In the communication device 2, the transmission circuit is made up of a transmission processing circuit 201, an emphasis circuit 202, and a transmission output circuit 203, and the reception circuit is made up of a reception input circuit 204, an equalizer circuit 205, an error detection unit 206, and a reception processing circuit 207. In addition to these, the communication device 2 is also provided with an input / output unit 208 and a setting value data fluctuation diagnosis unit 209, the details of which will be described later.

[0023] The transmission processing circuit 201, emphasis circuit 202, and transmission output circuit 203 constituting the transmission circuit have the same configuration as the transmission processing circuit 101, emphasis circuit 102, and transmission output circuit 103 of the communication device 1. Furthermore, the reception input circuit 204, equalizer circuit 205, error detection unit 206, and reception processing circuit 207 constituting the reception circuit have the same configuration as the reception input circuit 104, equalizer circuit 105, error detection unit 106, and reception processing circuit 107 of the communication device 1. Furthermore, the input / output unit 208 and setting value data fluctuation diagnosis unit 209 have the same configuration as the input / output unit 108 and setting value data fluctuation diagnosis unit 109 of the communication device 1. Description of these processing blocks of the communication device 2 will be omitted. Furthermore, signal lines 21 to 26 correspond to signal lines 11 to 16 of the communication device 1.

[0024] When transmitting and receiving data signals, communication device 1 and communication device 2 adjust the transmission waveform because they are affected by the frequency characteristics of transmission line 10. The circuits that perform this adjustment function are emphasis circuits 102 and 202 on the transmitting side and equalizer circuits 105 and 205 on the receiving side.

[0025] The emphasis circuits 102 and 202 are, for example, Finite Impulse Response (FIR) type digital filters (frequency filters). In an FIR type digital filter (hereinafter referred to as an "FIR filter"), if the number of taps in the transfer function is three, for example, the transmission waveform can be adjusted using three tap coefficients. Hereinafter, the tap coefficients will also be simply referred to as "coefficients."

[0026] The equalizer circuits 105 and 205 are, for example, decision feedback equalizers (DFEs) that use digital filters (frequency filters). In a DFE, for example, if the number of taps in a transfer function is three, the transmission waveform can be adjusted using three tap coefficients.

[0027] In the emphasis circuits 102, 202 and the equalizer circuits 105, 205, the values ​​obtained by indexing the tap coefficients used to adjust the transmission waveforms are referred to as "setting value data for transmission waveform adjustment." However, "setting value data for transmission waveform adjustment" may also be abbreviated to "setting value data." In this embodiment, changes in at least either the setting value data for the emphasis circuit or the setting value data for the equalizer circuit are monitored to detect signs of failure.

[0028] Since both FIR filters and DFEs are digital filters, an example of an FIR filter will be described here. The formula for the transfer function of an FIR filter is H(z)=a0+(a1×Z -1 )+(a2×Z -2 ) where the three coefficients in the formula are a0, a1, and a2. For example, the rate of change from the initial value for each of the three coefficients a0, a1, and a2 is calculated, and the maximum value among these is used as an index to determine the setting value data for the transmission waveform adjustment.

[0029] As an example, if the initial state values ​​are "a0=-0.20, a1=+0.70, a2=-0.10" and the subsequent state is "a0=-0.30, a1=+0.90, a2=-0.10", the percentage change from the initial state values ​​will be a0=-50.0[%], a1=+28.6[%], a2=0.0[%].

[0030] The absolute value of the rate of change from the initial value is greatest when coefficient a0 is -50.0[%], and the maximum value is 50[%]. In this case, the indexed value is -50. Here, as an example, the percentage value is normalized between 0 and 100. The setting value data for adjusting the transmission waveform (indexed values ​​of the tap coefficients for adjusting the transmission waveform) tends to change more from the initial value as the deterioration of the communication devices 1, 2 and the transmission line 10 progresses. Therefore, the setting value data fluctuation diagnosis unit 109 can diagnose signs of failure by monitoring fluctuations in the setting value data for adjusting the transmission waveform.

[0031] In the above example, attention is focused on the maximum value of the change rate of the three coefficients, but it is also possible to index each of the three coefficients and perform failure sign diagnosis individually. Alternatively, the allowable ranges of the three coefficients may be determined, and the margin to the allowable range may be an indexed value of the minimum value of the three coefficients, or an indexed value of each of the three coefficients. Furthermore, among the three coefficients, a0 and a2 generate an undershoot waveform and play an important role in adjusting the transmission waveform, so the coefficients may be weighted and used as an index. For example, in the above example, if "a0 = -0.2" changes to "a0 = -0.3," and the coefficient weight is increased by 1.2, the change rate will change from -50% to -60%. On the other hand, if a margin is used as an index by defining an allowable range, the margin may be reduced to 0.8 times. As described in Patent Document 1, it is also possible to focus only on the changes in coefficients a0 and a2.

[0032] The FIR filter and DFE mentioned above are examples of emphasis circuits and equalizer circuits used to adjust the transmission waveform, and are not limited to these circuit types, but also include analog signal processing circuits, etc. Also, the number of taps is not limited to three, and if the number of taps is N, the transmission waveform can be adjusted using N coefficients.

[0033] Typically, the set value data for adjusting the transmission waveform is determined before transmitting and receiving a data signal. For example, communication device 1 and communication device 2 repeatedly transmit and receive a predetermined signal pattern, and the set value data for adjusting the transmission waveform is determined to achieve optimal conditions that result in zero errors in error detection units 106 and 206. A method for predictively diagnosing a communication path failure using the set value data for adjusting the transmission waveform during normal transmission and reception is known from Patent Document 1.

[0034] The present invention performs failure sign diagnosis using setting value data 1 for adjusting the transmission waveform during normal transmission and reception (referred to as "setting value data 1" to distinguish it from setting value data 1) and setting value data 2 for adjusting the transmission waveform during loopback from the transmitting circuit to the receiving circuit within the same communication device (referred to as "setting value data 2" to distinguish it from setting value data 1). In addition to being able to self-diagnose whether the communication device itself is normal or abnormal, the present invention makes it possible to identify the location of the failure sign (communication device 1, communication device 2, or transmission line 10) by using the diagnosis results of transmission and reception between communication device 1 and communication device 2.

[0035] For example, if a failure sign diagnosis during normal transmission and reception determines that there is a failure sign in the "communication device 2 transmission" → "transmission line 10" → "communication device 1 reception" path, it is possible to determine that there is an abnormality in this communication path, but it is not possible to identify the location of the failure sign. Therefore, in the present invention, by adding a failure sign diagnosis during loopback, information on the self-diagnosis results can be obtained for each of communication device 1 and communication device 2, making it possible to identify the location of the failure sign. If there is a response of normal reception from the communication device at the transmission destination (e.g., communication device 1), it can be confirmed that the communication is normal. Whether or not there is a response from the communication partner is confirmed by the communication device that sent the data signal or by a higher-level device, which will be described later.

[0036] The signal path when looping back within the same communication device is, for example, in the case of communication device 1, "transmission processing circuit 101" → "emphasis circuit 102" → "transmission output circuit 103" → "signal line 13" → "input / output unit 108" → "signal line 14" → "reception input circuit 104" → "equalizer circuit 105" → "error detection unit 106".

[0037] As with normal transmission and reception, the setting value data 2 for adjusting the transmission waveform is determined to achieve the optimum conditions for zero errors in the error detection unit 106 of the communication device 1. The same applies to the communication device 2, so a description thereof will be omitted.

[0038] During loopback, the communication path does not include the transmission line 10, so distortion of the transmission waveform is small. For this reason, it is more effective to adjust the transmission waveform in the emphasis circuit 102 and the equalizer circuit 105 under different setting conditions than those used during normal transmission and reception. For example, the tap coefficients of the transfer function in the emphasis circuit 102 are set to reduce the signal amplitude. Alternatively, the gain for the entire signal in the transmission output circuit 103 or the gain for the entire signal in the reception input circuit 104 can be adjusted to reduce the signal amplitude.

[0039] Furthermore, when examining the optimum conditions, a diagnostic pattern that is prone to errors, such as a single Hi level during successive Lo levels, or conversely, a single Lo level during successive Hi levels, is considered to be more suitable for capturing changes as a failure sign diagnosis. In a diagnostic pattern that is prone to errors, errors are more likely to be detected by the error detection unit 106. Another diagnostic pattern that is prone to errors is one in which the signal frequency is increased and the interval on the time axis is narrowed.

[0040] Although not shown in the present embodiment, in the case of a configuration in which full-duplex communication is performed using a single transmission line (for example, using different bands), an echo canceller circuit (not shown) is installed to remove the transmission signal included in the reception signal. If this echo canceller function works during loopback and removes the looped-back signal, it is necessary to take measures such as disabling the echo canceller function. For example, a circuit for disabling the echo canceller function is provided at least before the equalizer circuit 105, such as between the input / output unit 108 and the reception input circuit 104.

[0041] Also, when the communication device 1 is in loopback, it may be affected by the reflection of electrical signals by the connected transmission line 10 or the data signals arriving from the communication device 2. In such a case, for example, the input / output unit 108 may be provided with a function to cut off the connection with the transmission line 10 using a switch circuit or the like, and a method of performing a fault prediction diagnosis during loopback in a state where the transmission line 10 is cut off is also conceivable.

[0042] Note that the fault prediction diagnosis needs to be performed at a timing that does not interfere with normal communication. For example, the timing at which the set value data fluctuation diagnosis unit 109 performs the fault prediction diagnosis is preferably at the start (during communication training) or end of the communication device.

[0043] The set value data fluctuation diagnosis unit 109 for transmission waveform adjustment performs a fault prediction diagnosis using the set value data 1 and set value data 2 of the transmission waveform adjustment obtained by indexing the tap coefficients of the transfer functions of the emphasis circuit 102 and the equalizer circuit 105.

[0044] Next, the time-variation of the set value data of the transmission waveform adjustment will be described using FIG. 2. FIG. 2 is a diagram showing an example of the time-variation of the set value data of the transmission waveform adjustment according to the present embodiment. FIG. 2 is an example in the case of determining with a plurality of thresholds, with the horizontal axis being time and the vertical axis being the set value data of the transmission waveform adjustment. [[ID=1,6]]

[0045] The set value data fluctuation diagnosis unit 109 determines the fluctuation (fault prediction) of the set value data based on the relationship between the set value data of the transmission waveform adjustment and the thresholds (TH-U1, TH-U2, TH-U3, TH-D1, TH-D2, TH-D3). The magnitude relationship of the upper thresholds is TH-U1 < TH-U2 < TH-U3, and the magnitude relationship of the lower thresholds is TH-D1 > TH-D2 > TH-D3.

[0046] In this example, the value of the set value data for the transmission waveform adjustment fluctuates upward over time. Here, the simplest diagnostic method, in which exceeding the upper threshold TH-U3 is determined to be a sign of failure, would be to simply determine that a sign of failure exists when the value of the set value data for the transmission waveform adjustment exceeds threshold TH-U3. Note that a sign of failure is also determined when the value of the set value data for the transmission waveform adjustment falls below the lower threshold TH-D3.

[0047] Additionally, the time until a failure sign (here, threshold value TH-U3) is reached can be predicted based on the time when the threshold value TH-U1 or TH-U2 is exceeded. That is, the time when the setting value data for the transmission waveform adjustment reaches threshold value TH-U3 can be determined from the time elapsed from when the setting value data exceeds threshold value TH-U1 until when the setting value data exceeds threshold value TH-U2. Furthermore, the state of a failure sign (the rate at which component deterioration progresses) can be estimated from the time elapsed from threshold value TH-U1 to threshold value TH-U3 or from threshold value TH-U2 to threshold value TH-U3. The state of a failure sign may be estimated by comparing the time elapsed from threshold value TH-U1 to threshold value TH-U3 with the time elapsed from threshold value TH-U2 to threshold value TH-U3.

[0048] Furthermore, it is possible to predict the time until a failure symptom occurs by acquiring transmission waveform adjustment setting value data in a time series without using multiple thresholds. In this case, it is assumed that at least one threshold (e.g., threshold TH-U3) is set. For example, the time when threshold TH-U3 is reached can be estimated from the slope or degree of the rising curve of data (time series data) acquired in a time series of transmission waveform adjustment setting value data. In this way, it is possible to diagnose a failure symptom by capturing temporal fluctuations using time series data. Note that a judgment using multiple thresholds has the advantage of requiring less data than a judgment using time series data.

[0049] Furthermore, the acquired setting value data for the transmission waveform adjustment can be used to diagnose signs of failure using statistical techniques or machine learning.

[0050] Next, the procedure for failure sign diagnosis in the setting value data variation diagnosis unit 109 will be described. For example, a case where failure sign diagnosis is performed at startup in the communication device 1 will be described as an example. First, the communication device 1 performs failure sign diagnosis during loopback, and checks through self-diagnosis whether there is a problem with the communication device 1 itself. Next, the communication device 1 performs failure sign diagnosis during normal transmission and reception. For example, in the communication device 1, the setting value data variation diagnosis unit 109 acquires the following four patterns of setting value data for adjusting the transmission waveform: (1) Setting value data 2 for adjusting the transmission waveform of the emphasis circuit 102 during loopback (2) Setting value data 2 for adjusting the transmission waveform of the equalizer circuit 105 during loopback (3) Setting value data 1 of the transmission waveform adjustment of the emphasis circuit 102 during normal transmission and reception (4) Setting value data 1 of the transmission waveform adjustment of the equalizer circuit 105 during normal transmission and reception

[0051] Then, the set value data variation diagnosis unit 109 performs a failure sign diagnosis on the set value data for each of the transmission waveform adjustments (1) to (4) above, based on predetermined judgment conditions. If the set value data variation diagnosis unit 109 determines that a failure sign exists, it outputs a failure sign signal from the signal line 16 to a device external to the communication device 1.

[0052] Next, the classification of the failure sign diagnosis results for the communication device alone according to this embodiment will be described with reference to FIG. Fig. 3 is a diagram showing a table that categorizes the results of failure sign diagnosis for communication device 1 alone. Table 3 for categorizing cases shown in Fig. 3 has the following items: "No.", "Communication device 1 → 2 (normal)", "Communication device 1 (loopback)", "Communication device 2 → 1 (normal)", and "Failure sign location".

[0053] "No." is an identifier (for example, a number) for uniquely identifying a row (record) in a table. "Communication device 1 → 2 (normal)" indicates the normal communication state when a data signal is transmitted from communication device 1 to communication device 2. In the figure, "○" indicates normal, and "×" indicates a failure prediction state. "Communication device 1 (loopback)" indicates the communication state when communication device 1 performs loopback. "Communication device 2 → 1 (normal)" indicates the normal communication state when a data signal is transmitted from communication device 2 to communication device 1. In the figure, "○" indicates normal, and "×" indicates a failure prediction state. The "failure symptom location" indicates the failure symptom location identified from the communication states shown as "communication device 1 → 2 (normal)", "communication device 1 (loopback)", and "communication device 2 → 1 (normal)".

[0054] By adding a loopback diagnosis to the normal diagnosis during transmission and reception, it is possible to determine whether the communication device 1 itself is normal or in a pre-failure state. However, since the pre-failure state of the communication device 2 is unknown, there are cases where it is not possible to identify the location of the pre-failure (No. 3, No. 4, No. 7 in Figure 3).

[0055] For example, in the data of No. 3, "communication device 1 → 2 (normal)" is in a pre-failure state, "communication device 1 (loopback)" is normal, and "communication device 2 → 1 (normal)" is in a pre-failure state. In addition, in the data of No. 4, "communication device 1 → 2 (normal)" is in a pre-failure state, "communication device 1 (loopback)" is normal, and "communication device 2 → 1 (normal)" is normal. Furthermore, in the data of No. 7, "communication device 1 → 2 (normal)" is normal, "communication device 1 (loopback)" is normal, and "communication device 2 → 1 (normal)" is in a pre-failure state. In the cases of any of the data of No. 3, No. 4, and No. 7, the location of the pre-failure symptom is likely to be "communication device 1" or "transmission line 10."

[0056] In this embodiment, by adding a diagnosis during loopback to the diagnosis during normal transmission and reception, it may be possible to infer whether a fault sign is occurring in the transmission circuit or the reception circuit of the communication device 1. For example, in the data No. 2, "communication device 1 → 2 (normal)" is in a fault sign state, "communication device 1 (loopback)" is in a fault sign state, and "communication device 2 → 1 (normal)" is normal. In this combination, since "communication device 1 (loopback)" is in a fault sign state and "communication device 2 → 1 (normal)" is normal, it can be determined that a fault sign is occurring in the transmission circuit of the communication device 1.

[0057] Similarly, in data No. 5, "communication device 1 → 2 (normal)" is normal, "communication device 1 (loopback)" is in a pre-failure state, and "communication device 2 → 1 (normal)" is in a pre-failure state. In this combination, since "communication device 1 (loopback)" is in a pre-failure state and "communication device 1 → 2 (normal)" is normal, it can be determined that there is a pre-failure sign in the receiving circuit of communication device 1. In this way, being able to infer whether a pre-failure sign is occurring in the transmitting circuit or the receiving circuit within the communication device contributes to fault analysis of the circuit board mounted in the communication device or the communication device itself.

[0058] It is advisable to start the diagnosis of the communication status, i.e., the diagnosis of signs of failure, from "communication device 1 (loopback)." If "communication device 1 (loopback)" is in a state of signs of failure, it can be determined that there are signs of failure in communication device 1 regardless of the diagnosis results of "communication device 1 → 2 (normal)" and "communication device 2 → 1 (normal)" (see No. 1, No. 2, No. 5, No. 6). In this way, the diagnosis of "communication device 1 → 2 (normal)" and "communication device 2 → 1 (normal)" can be omitted.

[0059] As described above, the communication device (e.g., communication device 1) according to this embodiment is a communication device that transmits data signals, and includes a transmission circuit (transmission processing circuit 101 to transmission output circuit 103) that transmits the data signals, a reception circuit (reception input circuit 104 to reception processing circuit 107) that receives the data signals, and a setting value data fluctuation diagnosis unit (setting value data fluctuation diagnosis unit 109). The setting value data variation diagnosis unit is configured to use first setting value data that adjusts the transmission waveform when a data signal is transmitted and received with an external device (e.g., communication device 2) via a transmission line (communication device 1 → 2 (normal), communication device 2 → 1 (normal)), and second setting value data that adjusts the transmission waveform when a data signal is looped back between a transmitting circuit and a receiving circuit (communication device 1 (loopback)), to determine, based on predetermined determination conditions, the variation of the first setting value data when a data signal is transmitted and received with an external device via a transmission line and the variation of the second setting value data when a data signal is looped back between a transmitting circuit and a receiving circuit, and to diagnose signs of failure in the communication device and the transmission line based on the determination results.

[0060] According to the communication device (e.g., communication device 1) of the above-described embodiment, by adding a loopback diagnosis to the diagnosis when transmitting and receiving with an external device (e.g., communication device 2) via a transmission line, it is possible to diagnose signs of failure based on the setting value data for adjusting the transmission waveform under different conditions. This enables the communication device to perform self-diagnosis itself, improving the accuracy of the signs of failure diagnosis. In this embodiment, it is possible to determine whether the communication device to be diagnosed (e.g., communication device 1) is in a signs of failure state.

[0061] In this way, it is possible to identify communication devices (components) that are showing signs of failure, so that, for example, only the parts that need to be replaced can be replaced or maintenance can be performed, thereby reducing component costs and maintenance man-hours.

[0062] Next, the case classification of the failure sign diagnosis results in the two communication devices according to this embodiment will be described with reference to FIG. FIG. 4 is a diagram showing a table in which the results of failure sign diagnosis for two communication devices 1 and 2 are classified into cases. The example in FIG. 4 is an example of a case in which the location of a failure sign is identified using the results of failure sign diagnosis for communication device 1 alone and communication device 2 alone. In table 3 for case classification shown in FIG. 3, an item for "communication device 2 (loopback)" is added to table 4 for case classification shown in FIG. 4. In other words, table 4 for case classification has the items "No.", "communication device 1 → 2 (normal)", "communication device 1 (loopback)", "communication device 2 → 1 (normal)", "communication device 2 (loopback)", and "location of failure sign".

[0063] In this embodiment, it is assumed that a failure sign of the internal circuits of the communication device 1 and the communication device 2 can be detected by a failure sign diagnosis during loopback. Table 4 showing the case divisions shown in Fig. 4 shows how one or more failure sign locations can be identified in the communication device 1, the communication device 2, and the transmission line 10 by adding a diagnosis during loopback to a diagnosis during normal transmission and reception.

[0064] For example, the failure sign diagnosis result for "No. 3" in Table 3 shown in FIG. 3 corresponds to the failure sign diagnosis results for "No. 5" and "No. 6" in Table 4 in FIG. 4. In "No. 5" in Table 4, if "communication device 1 → 2 (normal)" is in a failure sign state, "communication device 1 (loopback)" is normal, and "communication device 2 → 1 (normal)" is in a failure sign state, and "communication device 2 (loopback)" is in a failure sign state, then communication device 2 can be identified as the failure sign location. Similarly, in "No. 6" in Table 4, if "communication device 1 → 2 (normal)" is in a failure sign state, "communication device 1 (loopback)" is normal, and "communication device 2 → 1 (normal)" is in a failure sign state, and "communication device 2 (loopback)" is normal, then transmission line 10 can be identified as the failure sign location.

[0065] 3 corresponds to the failure sign diagnosis results of "No. 7" and "No. 8" in Table 4 of FIG. 4. In "No. 7" in Table 4, if "communication device 1 → 2 (normal)" is in a failure sign state, "communication device 1 (loopback)" is normal, and "communication device 2 → 1 (normal)" is normal, and "communication device 2 (loopback)" is in a failure sign state, communication device 2 can be identified as the failure sign location. Similarly, in "No. 8" in Table 4, if "communication device 1 → 2 (normal)" is in a failure sign state, "communication device 1 (loopback)" is normal, and "communication device 2 → 1 (normal)" is normal, and "communication device 2 (loopback)" is normal, and transmission line 10 can be identified as the failure sign location.

[0066] Furthermore, for example, the failure sign diagnosis result for "No. 7" in Table 3 shown in FIG. 3 corresponds to the failure sign diagnosis results for "No. 13" and "No. 14" in Table 4 in FIG. 4. In "No. 13" in Table 4, if "communication device 1 → 2 (normal)" is normal, "communication device 1 (loopback)" is normal, and "communication device 2 → 1 (normal)" is in a failure sign state, and "communication device 2 (loopback)" is in a failure sign state, then communication device 2 can be identified as the failure sign location. Similarly, in "No. 14" in Table 4, if "communication device 1 → 2 (normal)" is normal, "communication device 1 (loopback)" is normal, and "communication device 2 → 1 (normal)" is in a failure sign state, and "communication device 2 (loopback)" is normal, then transmission line 10 can be identified as the failure sign location.

[0067] As shown in FIG. 4, even when diagnosing "communication device 2 (loopback)" in addition to "communication device 1 → 2 (normal)," "communication device 1 (loopback)," and "communication device 2 → 1 (normal)," for the reasons explained in FIG. 3, it is preferable to perform diagnosis of the communication status, i.e., diagnosis of signs of failure, from "communication device 1 (loopback)" and "communication device 2 (loopback)."

[0068] As described above, the communication system according to this embodiment is a communication system including a first communication device (for example, communication device 1) and a second communication device (for example, communication device 2) that transmit data signals. Each of the first communication device and the second communication device includes a transmission circuit (transmission processing circuit 101 to transmission output circuit 103, transmission processing circuit 201 to transmission output circuit 203) that transmits the data signals, a reception circuit (reception input circuit 104 to reception processing circuit 107, reception input circuit 204 to reception processing circuit 207) that receives the data signals, and a setting value data fluctuation diagnosis unit (setting value data fluctuation diagnosis unit 109, 209). The set value data fluctuation diagnosis unit uses first set value data for adjusting a transmission waveform when a data signal is transmitted and received between the first communication device and the second communication device via a transmission line (communication device 1 → 2 (normal), communication device 2 → 1 (normal)), second set value data for adjusting a transmission waveform when a loopback is performed between a transmission circuit and a reception circuit in the first communication device (communication device 1 (loopback)), and third set value data for adjusting a transmission waveform when a loopback is performed between a transmission circuit and a reception circuit in the second communication device (communication device 2 (loopback)). The system is configured to determine, based on predetermined determination conditions, a variation in first setting value data when a data signal is transmitted and received between a first communication device and a second communication device via a transmission line, a variation in second setting value data when a loopback is performed between a transmitting circuit and a receiving circuit in the first communication device, and a variation in third setting value data when a loopback is performed between a transmitting circuit and a receiving circuit in the second communication device, and to diagnose signs of failure in the first communication device, the second communication device, and the transmission line based on the determination results, and identify locations having signs of failure.

[0069] According to the communication system (including, for example, communication devices 1 and 2) of the present embodiment described above, by performing a failure sign diagnosis by adding a diagnosis when looping back in each communication device to a diagnosis when transmitting and receiving between two communication devices (for example, communication devices 1 and 2) via a transmission line, it becomes possible to identify which communication device or transmission line is the location of the failure sign.

[0070] In this way, it is possible to identify communication devices (components) that are showing signs of failure, so that, for example, only the parts that need to be replaced can be replaced or maintenance can be performed, thereby reducing component costs and maintenance man-hours.

[0071] [Modification (1) of the first embodiment] Next, a modified example (1) of the communication device according to this embodiment will be described with reference to FIG. 5 is a block diagram showing an example of the internal configuration of a communication device according to this embodiment, which includes a temperature detection unit (temperature detection circuit). This example is an example in which the influence of the temperature of the communication device is taken into consideration in failure sign diagnosis.

[0072] The communication device 1 and the communication device 2 shown in FIG. 1 are provided with temperature detection units 111 and 211, respectively, for detecting the temperature inside the communication device. The setting value data variation diagnosis units 109 and 209 change the judgment threshold for failure sign diagnosis in accordance with the temperatures inside the communication device 1 and 2 detected by the temperature detection units 111 and 211. This prevents the setting value data that adjusts the transmission waveform of the data signal from being erroneously determined to be a failure sign state when it changes due to the influence of temperature. One possible method for changing the threshold in accordance with temperature is to measure the temperature dependency of the setting value data during product shipping inspection and store threshold information corresponding to the temperature inside the communication device.

[0073] [Modification (2) of the first embodiment] Next, a modified example (2) of the communication device according to this embodiment will be described with reference to FIG. 6 is a block diagram showing an example of the internal configuration of a communication device according to this embodiment when the device includes a power supply voltage detection unit (power supply voltage detection circuit). This example is an example in which the influence of the power supply voltage of the communication device is taken into consideration in failure sign diagnosis.

[0074] The communication device 1 and the communication device 2 shown in FIG. 1 each include a power supply voltage detection unit 112 and a power supply voltage detection unit 212. The setting value data variation diagnosis units 109 and 209 change the judgment threshold for failure sign diagnosis in accordance with the power supply voltage supplied to the communication devices 1 and 2 detected by the power supply voltage detection units 112 and 212. This prevents the setting value data that adjusts the transmission waveform of a data signal from being erroneously determined to be a failure sign state when it changes due to the influence of the power supply voltage. One possible method for changing the threshold in accordance with the power supply voltage is to measure the power supply voltage dependency of the setting value data during product shipping inspection and store threshold information corresponding to the power supply voltage.

[0075] [Communication system including host device] Next, a configuration for collecting information on the results of failure sign diagnosis in the upper device and identifying the location of the failure sign in the upper device in the communication system according to this embodiment will be described with reference to FIG.

[0076] Fig. 7 is a diagram showing an example of a configuration in a communication system in which information on the results of failure sign diagnosis is collected in a higher-level device and the higher-level device identifies the location of the failure sign. Fig. 7 shows an example of a configuration in which information on the results of failure sign diagnosis by the setting value data variation diagnosis units 109, 209 of the communication devices 1 and 2 is collected in the higher-level device 300 and the higher-level device 300 identifies the communication devices and transmission lines having the location of the failure sign.

[0077] In this example, the electronic control device 100 equipped with communication device 1 further includes communication device 3, and the electronic control device 200 equipped with communication device 2 further includes communication device 5. In the electronic control device 100, communication device 1 and communication device 3 are connected via signal line 16. Similarly, in the electronic control device 200, communication device 2 and communication device 5 are connected via signal line 26. Communication device 3 may have the same configuration as communication device 1, or may have a configuration that does not include the setting value data fluctuation diagnosis unit 109 of communication device 1. Similarly, communication device 5 may have the same configuration as communication device 2, or may have a configuration that does not include the setting value data fluctuation diagnosis unit 209 of communication device 2.

[0078] The higher-level device 300 includes a communication device 4, a communication device 6, and a microcomputer 310 that identifies a failure sign location based on the failure sign diagnosis result. The communication device 3 of the electronic control device 100 and the communication device 4 of the higher-level device 300 are connected by a transmission line 30. The communication device 5 of the electronic control device 200 and the communication device 6 of the higher-level device 300 are connected by a transmission line 50. The communication device 4 may have the same configuration as the communication device 1, or may have a configuration that does not include the setting value data variation diagnosis unit 109 of the communication device 1. Similarly, the communication device 6 may have the same configuration as the communication device 2, or may have a configuration that does not include the setting value data variation diagnosis unit 209 of the communication device 2.

[0079] The failure sign diagnosis result of the communication device 1 is sent from the signal line 16 to the microcomputer 310 via the communication device 3, the transmission line 30, and the communication device 4. That is, the failure sign diagnosis result of the communication device 1 is sent from the set value data variation diagnosis unit 109 to the transmission processing circuit 101 of the communication device 3 via the signal line 16. Then, by normal data communication, the failure sign diagnosis result is sent from the input / output unit 108 of the communication device 3 to the input / output unit 108 of the communication device 4 via the transmission line 30. Furthermore, the failure sign diagnosis result is sent from the reception processing circuit 107 of the communication device 4 to the microcomputer 310.

[0080] Similarly, the failure sign diagnosis result of communication device 2 is sent from signal line 26 to microcomputer 310 via communication device 5, transmission line 50, and communication device 6. The specific communication path by which this failure sign diagnosis result of communication device 2 is sent to microcomputer 310 from signal line 26 via communication device 5, transmission line 50, and communication device 6 is the same as the communication path for the failure sign diagnosis result of communication device 1 described above, and therefore a detailed description thereof will be omitted.

[0081] Then, the microcomputer 310 identifies the locations of the signs of failure in the communication device 1, the communication device 2, and the transmission line 10 based on the results of the signs of failure diagnosis for the communication device 1 and the communication device 2.

[0082] Note that instead of the failure sign diagnosis result, the setting value data for adjusting the transmission waveforms of the emphasis circuit 102 and the equalizer circuit 105 of the communication device 1 and the setting value data for adjusting the transmission waveforms of the emphasis circuit 202 and the equalizer circuit 205 of the communication device 2 may be transmitted to the higher-level device 300. The microcomputer 310 of the higher-level device 300 can also aggregate the setting value data for each circuit transmitted by the communication device 1 and the setting value data for each circuit transmitted by the communication device 2, and perform failure sign diagnosis and identify the location of the failure sign.

[0083] For example, consider a case where a vehicle is equipped with multiple communication devices 1 to 6. If there are ECUs (Electronic Control Units) including communication devices 1 and 3, and ECUs including communication devices 2 and 5, then the higher-level device 300 corresponds to an integrated ECU that controls these ECUs in an integrated manner.

[0084] As described above, the communication system of this embodiment is a communication system including a first communication device (e.g., communication device 1) and a second communication device (e.g., communication device 2) that transmit data signals, and an information processing device (higher-level device 300). Each of the first communication device and the second communication device includes a transmission circuit (transmission processing circuit 101 to transmission output circuit 103, transmission processing circuit 201 to transmission output circuit 203) for transmitting a data signal; The device includes receiving circuits (receiving input circuit 104 to receiving processing circuit 107, receiving input circuit 204 to receiving processing circuit 207) that receive data signals, and setting value data fluctuation diagnostic units (setting value data fluctuation diagnostic units 109, 209). The set value data fluctuation diagnosis unit includes first set value data for adjusting a transmission waveform when a data signal is transmitted and received between the first communication device and the second communication device via a transmission line (communication device 1 → 2 (normal), communication device 2 → 1 (normal)), second set value data for adjusting a transmission waveform when a loopback is performed between a transmission circuit and a reception circuit in the first communication device (communication device 1 (loopback)), and third set value data for adjusting a transmission waveform when a loopback is performed between a transmission circuit and a reception circuit in the second communication device (communication device 2 (loopback)). and a data set, based on a predetermined determination condition, determine a variation in first setting value data when a data signal is transmitted and received between a first communication device and a second communication device via a transmission line, a variation in second setting value data when a loopback is performed between a transmitting circuit and a receiving circuit in the first communication device, and a variation in third setting value data when a loopback is performed between a transmitting circuit and a receiving circuit in the second communication device, and diagnoses signs of failure in the first communication device, the second communication device, and the transmission line based on the determination results. The information processing device is configured to acquire the failure sign diagnosis results of the setting value data variation diagnosis section from the first communication device and the second communication device, and to identify a location having a failure sign.

[0085] According to the communication system (including, for example, the communication devices 1 and 2 and the higher-level device 300) of the present embodiment described above, the results of failure sign diagnoses from multiple communication devices can be aggregated in an external information processing device, and the information processing device can identify the location of the failure sign. Therefore, the location of the failure sign can be identified by the information processing device, which has a higher data processing capacity than the communication devices.

[0086] <Second embodiment> The second embodiment is an example in which a communication device identifies a location of a failure sign without using a higher-level device in the communication system according to the first embodiment (see FIG. 7). The second embodiment will be described with reference to FIG.

[0087] 8 is a diagram showing an example of a configuration in which a communication device identifies a failure symptom location without using a higher-level device in a communication system according to this embodiment. In this embodiment, a signal line 17 connecting a transmission processing circuit 101 and a setting value data variation diagnosis unit 109, and a signal line 18 connecting a reception processing circuit 107 and a setting value data variation diagnosis unit 109 are added to the communication device 1 (see FIG. 1). Similarly, a signal line 27 connecting a transmission processing circuit 201 and a setting value data variation diagnosis unit 209, and a signal line 28 connecting a reception processing circuit 207 and a setting value data variation diagnosis unit 209 are added to the communication device 2. In order to distinguish from the communication devices 1 and 2 described above, these devices will be referred to as communication device 1A and communication device 2A in this embodiment.

[0088] In communication device 1A, the failure sign diagnosis result of set value data variation diagnosis unit 109 is sent to transmission processing circuit 101 via signal line 17, and is then transmitted to communication device 2A by normal data communication. The failure sign diagnosis result of communication device 1A that has arrived at communication device 2A is sent from reception processing circuit 207 to set value data variation diagnosis unit 209 via signal line 28. Since the failure sign diagnosis results of communication device 1A and communication device 2A are aggregated in set value data variation diagnosis unit 209, it is possible to identify the location of the failure sign in communication device 1A, communication device 2A, and transmission line 10.

[0089] Conversely, in communication device 2A, the failure sign diagnosis result of set value data variation diagnosis unit 209 is sent to transmission processing circuit 201 via signal line 27, and is then transmitted to communication device 1A via normal data communication. The failure sign diagnosis result of communication device 2A that has arrived at communication device 1A is sent from reception processing circuit 107 to set value data variation diagnosis unit 109 via signal line 18. The failure sign diagnosis results of communication device 1A and communication device 2A are aggregated in set value data variation diagnosis unit 109, making it possible to identify the location of a failure sign in communication device 1A, communication device 2A, and transmission line 10. The result of identifying the failure sign location in communication device 1A is output to a device external to communication device 1A via signal line 16. Similarly, the result of identifying the failure sign location in communication device 2A is output to a device external to communication device 2A via signal line 26.

[0090] <Third embodiment> The third embodiment is an example in which a determination threshold used in failure sign diagnosis of a communication device is changed in response to an instruction from an external device.

[0091] FIG. 9 is a diagram showing an example of a configuration for changing a determination threshold used in a failure sign diagnosis of a communication device in response to an instruction from an external device in the communication system according to this embodiment. FIG. 10 is a diagram showing an example of a configuration in which instructions from an external device are transmitted and received between two communication devices via wireless communication in a communication system according to this embodiment.

[0092] 9, a communication device 1B according to this embodiment is the same as the communication device 1A (see FIG. 8) except that it includes a signal line T1 that connects the transmission processing circuit 101 to an external device and a signal line R1 that connects the reception processing circuit 107 to the external device. Similarly, a communication device 2B is the same as the communication device 2A except that it includes a signal line T2 that connects the transmission processing circuit 201 to an external device and a signal line R2 that connects the reception processing circuit 207 to the external device.

[0093] Furthermore, in communication device 1B, signal line 16, which was present in communication device 1A and which outputs a failure sign diagnosis result from set value data variation diagnosis unit 109, is deleted, and the failure sign diagnosis result is output from signal line R1 via signal line 18 and reception processing circuit 107. Similarly, in communication device 2B, signal line 26, which was present in communication device 2A and which outputs a failure sign diagnosis result from set value data variation diagnosis unit 209, is deleted, and the failure sign diagnosis result is output from signal line R2 via signal line 28 and reception processing circuit 207.

[0094] An example of a method for changing the judgment thresholds for failure sign diagnosis of communication device 1B and communication device 2B in response to an instruction from an external device will be described with reference to Fig. 10. In Fig. 10, electronic control device 100B can transmit and receive data signals to and from electronic control device 200B via transmission line 10. Furthermore, electronic control device 100B can transmit and receive data signals to and from server 400 (an example of an external device) using wireless communication. Electronic control device 200B has a wired communication function, but may have the same configuration as electronic control device 100B having a wireless communication function.

[0095] For example, when wireless communication is used, instruction data from an external device (e.g., a server 400) is received by an antenna 130 installed in the electronic control device 100B and sent to the microcomputer 110, which controls the electronic control device 100B, via the wireless communication module 120. The instruction data from the external device includes information for changing the judgment threshold for the failure sign diagnosis. Furthermore, the instruction data from the external device is sent from the microcomputer 110 to the transmission processing circuit 101 of the communication device 1B via a signal line T1. Within the communication device 1B, the instruction data is delivered from the transmission processing circuit 101 to the set value data variation diagnosis unit 109 via a signal line 17. Therefore, the set value data variation diagnosis unit 109 can change the judgment threshold for the failure sign diagnosis in response to an instruction from the external device.

[0096] Meanwhile, in the communication device 2B mounted on the electronic control device 200B, instruction data from an external device is delivered to the set value data variation diagnosis unit 209 via the communication device 1B, the transmission line 10, the receiving circuit from the input / output unit 208 to the receiving processing circuit 207, and the signal line 28. Therefore, the set value data variation diagnosis unit 209 can change the determination threshold for the failure sign diagnosis in response to an instruction from the external device.

[0097] In this way, the set value data variation diagnosis unit 109, 209 can receive instructions from an external device via a wireless communication network and change the threshold value for failure sign diagnosis based on the instruction from the external device. For example, in the case of an in-vehicle communication device, the set value data variation diagnosis unit 109, 209 in the communication device can receive information on failure occurrence status of the same vehicle model as an instruction from the external device, and change the judgment conditions based on the information on the failure occurrence status to improve the accuracy of failure sign diagnosis. For example, changing the judgment conditions means changing the threshold value as shown in FIG. 2. As an example, if you want to detect failure signs of a certain part early based on the failure occurrence status of the same vehicle model, you can consider reducing the value of threshold value TH-U3 to bring it closer to threshold value TH-U2.

[0098] 10, conversely, the failure sign diagnosis results of communication device 1B and communication device 2B and the set value data for transmission waveform adjustment can be transmitted to a device external to communication device 1 and communication device 2, such as a server 400, via wireless communication. The server 400 can perform failure sign diagnosis using the transmitted failure sign diagnosis results and the set value data for transmission waveform adjustment. The server 400 can also transmit the obtained failure sign diagnosis results to electronic control devices 100B, 200B (communication devices 1B, 2B) via wireless communication. For example, in the case of an in-vehicle system, the wireless communication formed by the wireless communication module 120 and the antenna 130 corresponds to OTA (Over the Air).

[0099] The external device may be a maintenance terminal used by a mechanic for maintenance. By connecting the maintenance terminal to a connector connected to the in-vehicle Ethernet, the maintenance terminal and the electronic control devices 100B, 200B are communicatively connected. The mechanic operates the maintenance terminal to send an instruction to change the threshold value for the failure sign diagnosis to the communication devices 1B, 2B of the electronic control devices 100B, 200B.

[0100] [Computer hardware configuration] Next, the hardware configuration of the communication device, the microcomputer, and the computer provided in the server in each of the above-described embodiments will be described with reference to FIG.

[0101] 11 is a block diagram showing an example of the hardware configuration of a computer provided in a communication device, a microcomputer, and a server according to each embodiment of the present invention. A calculator 500 shown in FIG. 11 is hardware used as a so-called computer.

[0102] The computer 500 includes a CPU (Central Processing Unit) 501, a ROM (Read Only Memory) 502, a RAM (Random Access Memory) 503, a non-volatile storage 506, and a network interface 507, which are all connected to a bus.

[0103] The CPU 501 is an example of a processor as a computing device. The ROM 502 and RAM 503 are examples of memories.

[0104] The nonvolatile storage 506 is a nonvolatile storage element with a larger capacity than a memory. A program that realizes the functions of the communication device according to each embodiment of the present invention is stored in the nonvolatile storage 506. The nonvolatile storage 506 is an example of a computer-readable non-transitory recording medium. The program may be stored in the ROM 502. When at least the functions of the setting value data variation diagnosis units 109 and 209 are realized by software, the CPU 501 executes a program stored in the ROM 502 or the nonvolatile storage 506 to realize the functions of the setting value data variation diagnosis unit.

[0105] In addition, the non-volatile storage 506 may store the judgment threshold for failure sign diagnosis (Figure 2) used by the setting value data fluctuation diagnosis unit 109, 209 in the communication device, case classification of failure sign diagnosis results (Figures 3, 4), and data obtained in chronological order of setting value data for transmission waveform adjustment (Figure 2), etc.

[0106] Furthermore, if the microcomputer 310 of the higher-level device 300 in FIG. 7 or the server 400 in FIG. 10 is to have a function for diagnosing signs of failure and a function for identifying the location of the signs of failure, a program that realizes the same function as the setting value data fluctuation diagnosis unit 109, 209 is recorded in the ROM 502 or non-volatile storage 506 provided in the microcomputer 310 and the server 400.

[0107] The network interface 507 is configured by a communication device or the like that controls communication with other devices (for example, ECUs) via a network such as a communication line or an in-vehicle Ethernet. For example, the input / output units 108 and 208 of the communication device are realized by the network interface 507. The wireless communication module 120 in the electronic control device 100B in FIG. 10 is an example of the network interface 507.

[0108] Furthermore, the present invention is not limited to the above-described embodiments, and various other applications and modifications are possible without departing from the spirit of the present invention as defined in the claims. For example, the above-described embodiments have been described in detail and specifically to clearly explain the present invention, and are not necessarily limited to those including all of the components described. Furthermore, it is possible to replace part of the configuration of one embodiment with a component of another embodiment. It is also possible to add a component of another embodiment to the configuration of one embodiment. It is also possible to add, replace, or delete other components from part of the configuration of each embodiment.

[0109] Furthermore, the above-described configurations, functions, processing units, etc. may be partly or entirely implemented in hardware, for example, by designing them as integrated circuits. Broadly defined processor devices such as FPGAs (Field Programmable Gate Arrays) and ASICs (Application Specific Integrated Circuits) may also be used as hardware. The above-described configurations, functions, processing units, etc. may also be implemented in software, with a processor in a computer interpreting and executing a program that implements each function.

[0110] In the above-described embodiment, the control lines and information lines are those that are considered necessary for the explanation, and not all control lines and information lines in the product are necessarily shown. In reality, it can be considered that almost all components are connected to each other. [Explanation of symbols]

[0111] 1 to 6... communication device, 1A, 2A... communication device, 1B, 2B... communication device, 10, 30, 50... transmission line, 101, 201... transmission processing circuit, 102, 202... emphasis circuit, 103, 203... transmission output circuit, 104, 204... reception input circuit, 105, 205... equalizer circuit, 106, 206... error detection unit, 107, 207... reception processing circuit, 108, 208... input / output unit, 109, 209... setting value data fluctuation adjustment unit, 100, 200... electronic control device, 100B, 200B... electronic control device, 111, 211... temperature detection unit, 112, 212... power supply voltage detection unit, 300... upper device, 110, 310... microcomputer

Claims

1. A communication device for transmitting a data signal, a transmitter circuit for transmitting a data signal; a receiving circuit for receiving a data signal; first setting value data for adjusting a transmission waveform when a data signal is transmitted and received via a transmission line to and from an external device; and second setting value data for adjusting a transmission waveform when a data signal is looped back between the transmitting circuit and the receiving circuit, and a set value data fluctuation diagnosis unit that determines, based on predetermined determination conditions, a fluctuation in the first set value data when the data signal is transmitted and received with the external device via the transmission line, and a fluctuation in the second set value data when the data signal is looped back between the transmitting circuit and the receiving circuit, and diagnoses a failure sign in the communication device and the transmission line based on the determination results. Communication equipment.

2. The first set value data and the second set value data for adjusting the transmission waveform are set values ​​of tap coefficients of the transfer function of an emphasis circuit or set values ​​of tap coefficients of the transfer function of an equalizer circuit. The communication device according to claim 1 .

3. The timing when the setting value data fluctuation diagnosis unit performs the diagnosis of a failure sign is when the communication device is started up or shut down. The communication device according to claim 1 .

4. a temperature detection circuit for detecting a temperature inside the communication device; The set value data fluctuation diagnosis unit changes the determination condition in accordance with the temperature detected by the temperature detection circuit. The communication device according to claim 1 .

5. a power supply voltage detection circuit for detecting a power supply voltage supplied to the communication device; The set value data fluctuation diagnosis unit changes the determination condition in accordance with the power supply voltage detected by the power supply voltage detection circuit. The communication device according to claim 1 .

6. The set value data fluctuation diagnosis unit changes the determination condition based on an instruction from an external device of the communication device. The communication device according to claim 1 .

7. The set value data fluctuation diagnosis unit diagnoses the failure sign based on a plurality of thresholds or a temporal fluctuation of the time series data of the first set value data and the second set value data. The communication device according to claim 1 .

8. A communication system including a first communication device and a second communication device that transmit data signals, Each of the first communication device and the second communication device a transmitter circuit for transmitting a data signal; a receiving circuit for receiving a data signal; first setting value data for adjusting a transmission waveform when a data signal is transmitted and received between the first communication device and the second communication device via a transmission line; second setting value data for adjusting a transmission waveform when looped back between the transmitting circuit and the receiving circuit in the first communication device; and third setting value data for adjusting a transmission waveform when looped back between the transmitting circuit and the receiving circuit in the second communication device, a set value data variation diagnosis unit that determines, based on predetermined determination conditions, a variation in the first set value data when a data signal is transmitted and received between the first communication device and the second communication device via a transmission line, a variation in the second set value data when a loopback is performed between the transmitting circuit and the receiving circuit in the first communication device, and a variation in the third set value data when a loopback is performed between the transmitting circuit and the receiving circuit in the second communication device, and that diagnoses a failure sign in the first communication device, the second communication device, and the transmission line based on the determination results, and identifies a location having the failure sign. Communication system.

9. A communication system including a first communication device and a second communication device that transmit data signals, and an information processing device, Each of the first communication device and the second communication device a transmitter circuit for transmitting a data signal; a receiving circuit for receiving a data signal; first setting value data for adjusting a transmission waveform when a data signal is transmitted and received between the first communication device and the second communication device via a transmission line; second setting value data for adjusting a transmission waveform when looped back between the transmitting circuit and the receiving circuit in the first communication device; and third setting value data for adjusting a transmission waveform when looped back between the transmitting circuit and the receiving circuit in the second communication device, a set value data fluctuation diagnosis unit that determines, based on predetermined determination conditions, a fluctuation in the first set value data when a data signal is transmitted and received between the first communication device and the second communication device via a transmission line, a fluctuation in the second set value data when a loopback is performed between the transmitting circuit and the receiving circuit in the first communication device, and a fluctuation in the third set value data when a loopback is performed between the transmitting circuit and the receiving circuit in the second communication device, and diagnoses a fault sign in the first communication device, the second communication device, and the transmission line based on the determination results; The information processing device includes: A failure sign diagnosis result of the setting value data variation diagnosis unit is obtained from the first communication device and the second communication device, and a location having the failure sign is identified. Communication system.

10. A failure sign diagnosis method executed by a communication device that transmits and receives data signals using a transmission circuit and a reception circuit, comprising: a process of using first set value data for adjusting a transmission waveform when a data signal is transmitted and received with an external device via a transmission line, and second set value data for adjusting a transmission waveform when the data signal is looped back between the transmitting circuit and the receiving circuit, and determining, based on predetermined determination conditions, a fluctuation in the first set value data when the data signal is transmitted and received with the external device via the transmission line, and a fluctuation in the second set value data when the data signal is looped back between the transmitting circuit and the receiving circuit; and diagnosing a failure sign in the communication device and the transmission line based on the determination result. A method for diagnosing signs of failure.

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