JP6471613B2 - Relay device and communication system - Google Patents

Description

  The present invention relates to a relay device that transmits data to a plurality of communication devices connected to one of a plurality of communication lines, and a communication system including the relay device.

  As a communication system mounted on a vehicle, a communication system in which a plurality of communication devices connected to one of a plurality of communication lines communicate with each other has been proposed. Each of the plurality of communication devices is an ECU (Electronic Control Unit) that controls an electric device mounted on the vehicle. In this communication system, a control process for interlocking a plurality of electrical devices is realized by communication between a plurality of communication devices.

  In a communication system in which a plurality of communication devices are connected to one of a plurality of communication lines, each of the plurality of communication lines is connected to a relay device, and the relay device relays communication between the plurality of communication devices. . In such a communication system, for example, there may be a case where the relay apparatus should transmit simultaneously to two communication apparatuses connected to two communication lines.

  In communication via each of a plurality of communication lines, when transmission priority is provided for each data, since the communication status differs for each communication line, the relay device is connected to each of the two communication lines. It is difficult to simultaneously transmit data to two communication devices.

  As a communication system that solves this problem, Patent Document 1 discloses a communication in which the priority of data transmission performed by a relay device is higher than the priority of data transmission performed by a plurality of communication devices in communication via a plurality of communication lines. A system is disclosed. In this communication system, since the priority of data transmission performed by the relay device is high, the probability that data is simultaneously transmitted from the relay device to the plurality of communication devices connected to the plurality of communication lines is high.

JP 2008-172362 A

  However, when the relay device of the communication system described in Patent Document 1 transmits data, when other data is being transmitted / received via the communication line used for data transmission, the relay device Regardless of the priority of data transmission, the end of transmission / reception of other data must be waited.

Thus, for example, when the relay device transmits data to two communication devices connected to two communication lines, when one communication line is used and the other communication line is not used, The relay device transmits data first to a communication device connected to another communication line.
For this reason, the communication system described in Patent Document 1 has a problem that the relay apparatus cannot reliably perform simultaneous transmission of data via each of the plurality of communication lines.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a relay device capable of reliably performing simultaneous transmission of data via each of a plurality of communication lines, and the relay device. A communication system is provided.

The relay device according to the present invention is connected to one of N (N: integer greater than or equal to 2) communication lines, and transmits data to a plurality of communication devices that transmit and receive data via the communication line. In the relay device, the prohibition transmission unit that transmits prohibition information indicating transmission prohibition to all the communication devices connected to K (K: an integer not less than 2 and not more than N) communication lines, and the prohibition transmission unit While the transmission of the prohibition information to all of the communication devices is successful and the transmission of all of the communication devices is prohibited , the common to all the communication devices via each of the K communication lines And a data transmission unit that performs simultaneous transmission for transmitting data.

In the present invention, each of the plurality of communication devices is connected to one of the N communication lines, and transmits and receives data via the communication line. Data is transmitted to these communication devices.
For example, if it is necessary to transmit data simultaneously to K communication devices connected to K communication lines, prohibit transmission in advance for all communication devices connected to K communication lines. Send prohibited information to indicate. Accordingly, since all of the transmission of the communication equipment that is connected to the K communication line is inhibited, it is possible to reliably perform the simultaneous transmission of data via the people the K communication lines husband.

Further , while transmission performed by all communication devices connected to the K communication lines is prohibited, common data is transmitted via each of the K communication lines. This realizes simultaneous reception of common data via each of the K communication lines.

  The relay device according to the present invention includes a data receiving unit that receives specific data via one of the N communication lines, and the prohibited transmission unit receives the specific data by the data receiving unit. In this case, the prohibition information is transmitted.

  In the present invention, when specific data is received via one of N communication lines, the prohibition information is transmitted to a plurality of communication devices connected to the K communication lines. Thereafter, for example, the received specific data is simultaneously transmitted.

  A communication system according to the present invention includes the relay device described above and a plurality of the communication devices that receive data from the relay device, and each of the plurality of communication devices receives the prohibition information transmitted by the prohibition transmission unit. A prohibition receiving unit configured to stop data transmission when the prohibition reception unit receives the prohibition information.

  In the present invention, the plurality of communication devices receive data from the relay device. Each of the plurality of communication devices stops data transmission when the prohibition information is received from the relay device. Thereby, transmission of each of a plurality of communication devices is prohibited.

  The communication system according to the present invention is characterized in that the communication device resumes data transmission after a predetermined period has elapsed since the prohibition receiving unit received the prohibition information.

  In the present invention, the communication apparatus resumes data transmission after a predetermined time has elapsed since the prohibition information was received. As a result, data transmission can be permitted with a simple configuration.

In the communication system according to the present invention, the relay device includes a permission transmission unit that transmits permission information indicating transmission permission to the plurality of communication devices connected to the K communication lines, and the plurality of the communication devices Each device has a permission receiving unit that receives permission information transmitted by the permission transmitting unit, and when the permission receiving unit receives the permission information , transmission of data is resumed.

  In the present invention, the relay device transmits prohibition information to a plurality of communication devices connected to K communication lines, and transmission of these communication devices is prohibited. Thereafter, the relay device transmits permission information to a plurality of communication devices connected to the K communication lines. Each of the plurality of communication devices connected to the K communication lines stops data transmission when the prohibition information is received, and resumes data transmission when the permission information is received. For this reason, simultaneous transmission of data can be performed in a state where transmission of data through each of the K communication lines is reliably prohibited.

A communication system according to the present invention includes the relay device described above and a plurality of the communication devices that receive data from the relay device, and the relay device transmits the common data after the data transmission unit transmits the common data. A permission transmission unit that transmits permission information indicating transmission permission to the plurality of communication devices connected to the K communication lines, and each of the plurality of communication devices includes prohibition information transmitted by the prohibition transmission unit. And a permission receiving unit that receives permission information transmitted by the permission transmitting unit. When the prohibition receiving unit receives the prohibition information, the transmission of data is stopped, and the permission is received. When the receiving unit receives the permission information, transmission of data is resumed.

  In the present invention, the plurality of communication devices receive data from the relay device. The relay device transmits prohibition information to a plurality of communication devices connected to the K communication lines. When receiving the prohibition information, the communication device stops data transmission. The relay device transmits common data via each of the K communication lines while transmission of the plurality of communication devices connected to the K communication lines is prohibited. Thereafter, the relay device transmits permission information indicating transmission permission to a plurality of communication devices connected to the K communication lines. When receiving the permission information, these communication devices resume data transmission.

  According to the present invention, since data transmission is prohibited to a plurality of communication devices connected to K communication lines, simultaneous transmission of data via each of the K communication lines can be reliably performed.

1 is a block diagram showing a main part configuration of a communication system according to Embodiment 1. FIG. It is explanatory drawing of a structure of a message. It is a block diagram which shows the principal part structure of a communication apparatus. It is a flowchart which shows the procedure of the transmission control process which the control part of a communication apparatus performs. It is a flowchart which shows the procedure of the transmission process which the communication part of a communication apparatus performs. It is a flowchart which shows the procedure of the reception process which the communication part of a communication apparatus performs. It is a block diagram which shows the principal part structure of a relay apparatus. It is a chart which shows the contents of a message correspondence table. It is a flowchart which shows the procedure of the transmission control process which the control part of a relay apparatus performs. It is a flowchart which shows the procedure of the transmission control process which the control part of a relay apparatus performs. It is a flowchart which shows the procedure of the transmission process which the communication part of a relay apparatus performs. It is a flowchart which shows the procedure of the reception process which the communication part of a relay apparatus performs. 10 is a flowchart illustrating a procedure of transmission control processing executed by a control unit of the communication device according to Embodiment 2. It is a flowchart which shows the procedure of the reception process which the communication part of a communication apparatus performs. It is a flowchart which shows the procedure of the transmission control process which the control part of a relay apparatus performs. It is a flowchart which shows the procedure of the transmission control process which the control part of a relay apparatus performs.

Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof.
(Embodiment 1)
FIG. 1 is a block diagram illustrating a main configuration of a communication system 1 according to the first embodiment. The communication system 1 is suitably mounted on a vehicle and includes a relay device 2, N (= 3) communication lines 3, 4, 5 and six communication devices 30, 31, 40, 41, 50, 51. The relay device 2 is connected to N (= 3) communication lines 3, 4, and 5.

Two communication devices 30 and 31 are connected to the communication line 3 separately. Two communication devices 40 and 41 are connected to the communication line 4 separately. Two communication devices 50 and 51 are connected to the communication line 5.
In this way, each of the six communication devices 30, 31, 40, 41, 50, 51 is connected to one of N (= 3) communication lines 3, 4, 5.

  Each of the six communication devices 30, 31, 40, 41, 50, 51 is an ECU that controls an electric device (not shown) mounted on the vehicle. The six communication devices 30, 31, 40, 41, 50, 51 communicate with each other, and a control process for interlocking a plurality of electrical devices is realized by communication of the communication devices 30, 31, 40, 41, 50, 51. . The relay device 2 relays communication between the six communication devices 30, 31, 40, 41, 50, and 51.

  The relay device 2 and the communication devices 30 and 31 transmit and receive messages, so-called data frames, to each other via the communication line 3. The relay device 2 and the communication devices 40 and 41 transmit and receive messages to and from each other via the communication line 4. The relay device 2 and the communication devices 50 and 51 transmit and receive messages to and from each other via the communication line 5. The relay device 2 relays communication of a plurality of communication devices connected to different communication lines among the communication lines 3, 4, and 5.

  Each of the six communication devices 30, 31, 40, 41, 50, 51 receives a message from the relay device 2 and transmits a message to the relay device 2. The relay device 2 receives messages from the six communication devices 30, 31, 40, 41, 50, 51 and transmits messages to the six communication devices 30, 31, 40, 41, 50, 51. For example, the relay device 2 transmits a message transmitted by the communication device 30 via the communication line 3 to the communication device 40 connected to the communication line 4 and the communication device 50 connected to the communication line 5. .

  The relay device 2 transmits a message indicating transmission prohibition to each of the six communication devices 30, 31, 40, 41, 50, and 51. When each of the six communication devices 30, 31, 40, 41, 50, 51 receives a message indicating that transmission is prohibited, it stops transmitting the message. A message indicating prohibition of transmission corresponds to prohibition information.

  Each of the communication lines 3, 4, 5 is a so-called twisted pair line, and is constituted by two conductors (not shown) twisted together. The message is composed of a plurality of bits of data, and 1-bit data is represented by “0” (dominant) or “1” (recessive).

  Each of the communication devices 30 and 31 transmits 1-bit data by applying a voltage to the two conductors constituting the communication line 3. Specifically, each of the communication devices 30 and 31 applies a voltage to each of the two conductors such that the voltage difference between the two conductors is a constant voltage equal to or higher than a predetermined voltage, for example, 2V. As a result, data “0” is transmitted. Further, each of the communication devices 30 and 31 applies a voltage to each of the two conductors so that the voltage difference between the two conductors becomes a constant voltage less than a predetermined voltage, for example, 0V. As a result, data “1” is transmitted. The predetermined voltage is 1 V, for example.

  Further, each of the communication devices 30 and 31 receives 1-bit data “0” or “1” by detecting a voltage difference between two conductors constituting the communication line 3. Each of the communication devices 30 and 31 receives data “0” when the detected voltage difference is greater than or equal to the predetermined voltage, and receives data “1” when the detected voltage difference is less than the predetermined voltage.

  When data “0” and “1” are transmitted to the communication line 3 at the same time, the voltage difference between the two conductors constituting the communication line 3 becomes a predetermined voltage or more, and the data “0” is received.

Each of the communication devices 40 and 41 transmits and receives 1-bit data in the same manner as the communication devices 30 and 31. In the description of the transmission / reception of the communication devices 30 and 31, the transmission / reception of the communication devices 40 and 41 can be described by replacing the communication line 3 and the communication devices 30 and 31 with the communication line 4 and the communication devices 40 and 41, respectively.
Similarly, the communication devices 50 and 51 transmit and receive 1-bit data in the same manner as the communication devices 30 and 31. In the description of the transmission / reception of the communication devices 30 and 31, the transmission / reception of the communication devices 50 and 51 can be described by replacing the communication line 3 and the communication devices 30 and 31 with the communication line 5 and the communication devices 50 and 51, respectively.

  FIG. 2 is an explanatory diagram of the structure of the message. Communication via the communication lines 3, 4, 5, that is, transmission / reception of messages is performed according to a CAN (Controller Area Network) protocol. As shown in FIG. 2, the message used in the CAN communication includes SOF (Start Of Frame), arbitration field, control field, data field, CRC (Cyclic Redundancy Check) field, ACK (Acknowledge), and EOF (End of Frame). Of Frame).

The SOF is composed of one bit, and the data of this bit is “0” (dominant). SOF indicates the start of the message.
Arbitration (arbitration) is performed when a plurality of messages are transmitted simultaneously on each of the communication lines 3, 4, 5. The arbitration field includes a message ID (Identification Data) indicating a message type and an RTR (Remote Transmission Request) bit. The message ID is used for arbitration.

  Data included in the control field indicates the length of the data field. The data field forms the core of the message, and the data included in the data field indicates the specific content of the message. The CRC field is composed of a plurality of bits of data. Data included in the CRC field indicates a code and a CRC boundary. For example, the code is represented by 15-bit data, and the CRC boundary is represented by 1-bit data.

  The ACK is composed of 1-bit data, and is used to check whether the message has been correctly received. Data contained in the EOF indicates the end of the message. The EOF is composed of 7-bit data, each of which is “1” (recessive), for example.

  Arbitration performed in communication via the communication line 3 will be described. Each of the relay device 2 and the communication devices 30 and 31 transmits 1-bit data in order from the SOF of the message. Here, each of the relay device 2 and the communication devices 30 and 31 also detects a voltage difference between two conductors constituting the communication line 3.

  While each of the relay device 2 and the communication devices 30 and 31 is transmitting data included in the arbitration field, it is determined whether or not the transmitted data matches the data transmitted via the communication line 3. judge. As described above, when data “0” (dominant) and “1” (recessive) are simultaneously transmitted to the communication line 3, the data “0” is transmitted via the communication line 3. The relay device 2 and the communication devices 30 and 31 stop transmitting data when the data “0” is transmitted via the communication line 3 even though the data “1” is transmitted. In this way, arbitration is performed.

  In the communication line 3, a plurality of messages having the same message ID are not transmitted from the relay device 2 and the communication devices 30 and 31. Among the relay device 2 and the communication devices 30 and 31, one device that has completed transmission of data included in the arbitration field acquires a transmission right to transmit a message, and the other device until the transmission of this message is completed. Never send a message.

  Arbitration performed by communication via the communication lines 4 and 5 is also performed in the same manner as arbitration performed by communication via the communication line 3. In the explanation of arbitration performed by communication via the communication line 3, the communication line 3 and the communication devices 30 and 31 are replaced with the communication line 4 and the communication devices 40 and 41, thereby performing the communication via the communication line 4. Explain arbitration. Similarly, in the explanation of the arbitration performed by communication via the communication line 3, the communication line 3 and the communication devices 30 and 31 are replaced with the communication line 5 and the communication devices 50 and 51, whereby communication via the communication line 5 is performed. Can explain the arbitration performed in

  FIG. 3 is a block diagram showing a main configuration of the communication device 30. The communication device 30 includes a control unit 60, a communication unit 61, an input unit 62, an output unit 63, a storage unit 64, and a timer 65. These are connected to the bus 66. The communication unit 61 is connected to the communication line 3 in addition to the bus 66.

  The communication unit 61 is a so-called CAN driver and has a CPU (Central Processing Unit) (not shown). The communication unit 61 performs a transmission process for transmitting a message via the communication line 3 and a reception process for receiving a message via the communication line 3. In the reception process, the message received by the communication unit 61 includes a message indicating that transmission is prohibited. In the reception process, the communication unit 61 notifies the control unit 60 of the received message when the received message does not indicate message transmission prohibition via the communication line 3. When the received message indicates that the transmission of the message via the communication line 3 is prohibited, that is, when the message indicating that the transmission is prohibited is received from the relay device 2, the communication unit 61 instructs the control unit 60 to prohibit the transmission of the message. Notice. The communication unit 61 functions as a prohibited reception unit.

The input unit 62 is supplied with signals indicating output results of various sensors (not shown) mounted on the vehicle, or on / off of operation switches provided on the vehicle. The input unit 62 notifies the control unit 60 of the content of the input signal.
The output unit 63 is connected to an electric device mounted on the vehicle, and outputs a signal for controlling the operation to the electric device in accordance with an instruction from the control unit 60. The electric device operates or stops according to the signal output from the output unit 63.

The timer 65 starts and ends timing in accordance with instructions from the control unit 60. The time measured by the timer 65 is read from the timer 65 by the control unit 60.
The storage unit 64 is a non-volatile memory, and the storage unit 64 stores a control program. The storage unit 64 is further provided with a transmission data area in which data to be transmitted by the communication unit 61 via the communication line 3 is stored. Reading and writing of the contents stored in the storage unit 64 is performed by the control unit 60.

  The control unit 60 executes various processes by executing the control program stored in the storage unit 64. Specifically, the control unit 60 causes the output unit 63 to output a control signal based on the data received by the communication unit 61 and / or the content input to the input unit 62, and is connected to the output unit 63. Control the operation of the electrical equipment that is.

Further, the control unit 60 generates data to be transmitted by the communication unit 61 via the communication line 3 according to the content input to the input unit 62 and stores the generated data in the transmission data area of the storage unit 64. To do.
Further, the control unit 60 executes a transmission control process for controlling the transmission of the communication unit 61.

  FIG. 4 is a flowchart illustrating a procedure of transmission control processing executed by the control unit 60 of the communication device 30. The control unit 60 periodically executes transmission control processing. First, the control unit 60 determines whether or not a message transmission prohibition is notified from the communication unit 61 (step S1). When it is determined that the transmission prohibition is notified (S1: YES), the control unit 60 instructs the timer 65 to start measuring time (step S2), and the time measured by the timer 65 is equal to or longer than the waiting time. Is determined (step S3). The standby time is constant and is stored in the storage unit 64 in advance. The waiting time is, for example, 300 to 500 microseconds.

  When it is determined that the timed time is less than the standby time (S3: NO), the control unit 60 executes Step S3 again and waits until the timed time becomes equal to or longer than the standby time. When it is determined that the measured time is equal to or longer than the standby time (S3: YES), the control unit 60 instructs the timer 65 to end the time measurement (step S4).

  When it is determined that the transmission prohibition is not notified (S1: NO), or after step S4 is executed, the control unit 60 determines whether data to be transmitted is stored in the transmission data area of the storage unit 64. Is determined (step S5). When it is determined that the data to be transmitted is not stored (S5: NO), the control unit 60 ends the transmission control process. In this case, the control unit 60 resumes the transmission control process when the next cycle arrives.

When it is determined that data to be transmitted is stored (S5: YES), the control unit 60 instructs the communication unit 61 to transmit a data to instruct transmission of data stored in the transmission data area of the storage unit 64. Output (step S6).
The communication unit 61 executes transmission processing when a data transmission instruction is input from the control unit 60. The communication unit 61 notifies the control unit 60 of success and failure of data transmission in the transmission process.

  After executing step S6, the control unit 60 determines whether or not a data transmission failure is notified from the communication unit 61 (step S7). When it is determined that the transmission failure is not notified (step S7: NO), the control unit 60 determines whether the data transmission success is notified from the communication unit 61 (step S8).

  When it is determined that the transmission success is not notified (S8: NO), the control unit 60 executes step S7 and waits until the communication unit 61 notifies the transmission success or the transmission failure. When the transmission failure is notified (S7: YES), the control unit 60 ends the transmission control process. Also in this case, the control unit 60 resumes the transmission control process when the next cycle arrives. In the resumed transmission control process, the data that failed to be transmitted in the previous transmission control process has not been deleted from the transmission data area of the storage unit 64, so the control unit 60 causes the communication unit 61 to transmit the same data.

  When it is determined that the transmission success has been notified (S8: YES), the control unit 60 deletes the data transmitted by the communication unit 61 from the transmission data area of the storage unit 64 (step S9), and ends the transmission control process. Also in this case, the control unit 60 resumes the transmission control process when the next cycle arrives. In the resumed transmission control process, since the data successfully transmitted in the previous transmission control process is deleted from the transmission data area of the storage unit 64, the control unit 60 is stored in the transmission data area of the storage unit 64. New data is transmitted to the communication unit 61.

  FIG. 5 is a flowchart showing a procedure of transmission processing executed by the communication unit 61 of the communication device 30. As described above, the communication unit 61 executes transmission processing when a data transmission instruction is input from the control unit 60. The communication unit 61 does not execute the transmission process unless a data transmission instruction is input from the control unit 60.

  The communication unit 61 determines whether a message can be transmitted via the communication line 3 (step S11). The communication unit 61 determines whether the message can be transmitted based on whether the message is transmitted through the communication line 3. In the case where the EOF of the message is composed of 7-bit data, each of which is “1” (recessive), the communication unit 61 detects data “1” continuously for 7 bits or more. It is determined that the message can be transmitted. In the same case, the communication unit 61 determines that message transmission is impossible when data “1” is not detected continuously for 7 bits or more. When the EOF is composed of 7-bit data, each of which is “1” (recessive), the data transmitted / received in the communication system 1 does not indicate data “1” continuously for 7 bits.

  When the communication unit 61 determines that the message can be transmitted (S11: YES), the communication unit 61 generates a message in which the data stored in the transmission data area of the storage unit 64 is included in the data field (step S12). ). Next, the communication unit 61 transmits 1-bit data of the message generated in step S12 (step S13). In the transmission process, the communication unit 61 repeatedly executes step S13, and sequentially transmits message data from 1-bit data constituting the SOF of the message.

  Next, the communication unit 61 determines whether or not to stop the message transmission (step S14). As described in the explanation of arbitration, the communication unit 61 transmits a message when data “0” (dominant) is transmitted via the communication line 3 even though data “1” (recessive) is transmitted. Is determined to be stopped. If the transmitted data matches the data transmitted via the communication line 3, the communication unit 61 determines that the message transmission should not be stopped.

  If the communication unit 61 determines that the message transmission is impossible (S11: NO) or determines that the message transmission should be stopped (S14: YES), the communication unit 61 controls the message transmission failure. The notification is sent to the unit 60 (step S15), and the transmission process is terminated.

  When determining that the message transmission should not be stopped (S14: NO), the communication unit 61 determines whether or not the message transmission right has been acquired (step S16). As described in the explanation of arbitration, the communication unit 61 determines that the transmission right of the message has been acquired when the transmission of the data included in the arbitration field of the message is completed. The communication unit 61 determines that the message transmission right has not been acquired when the transmission of the data included in the arbitration field has not been completed.

  When it is determined that the message transmission right has not been acquired (S16: NO), the communication unit 61 executes step S13 and determines that the message transmission should be stopped or acquires the message transmission right. The message data is transmitted bit by bit until it is determined that it has been completed.

  When it is determined that the message transmission right has been acquired (S16: YES), the communication unit 61 transmits the 1-bit data of the message generated in step S12 as in step S13 (step S17). The communication unit 61 repeatedly executes step S17 as in step S13. The data transmitted by the communication unit 61 in step S17 is message data included after the arbitration field.

  After executing Step S17, the communication unit 61 determines whether or not the message transmission is completed (Step S18). When it is determined that the message transmission has not been completed (S18: NO), the communication unit 61 executes step S17, and transmits message data bit by bit until the message transmission is completed. If the communication unit 61 determines that the message transmission is completed (S18: YES), the communication unit 61 notifies the control unit 60 of the successful message transmission (step S19), and ends the transmission process.

  FIG. 6 is a flowchart illustrating a procedure of reception processing executed by the communication unit 61 of the communication device 30. The communication unit 61 executes the reception process when detecting the SOF of the message or when determining that the transmission should be stopped by the transmission process.

  The communication unit 61 receives 1-bit data of the message (step S21), and determines whether or not the message has been received (step S22). If the communication unit 61 determines that the message reception has not been completed (S22: NO), the communication unit 61 executes the process in step S21 and sequentially receives 1-bit data until the message reception is completed.

  If it is determined that the message has been received (S22: YES), the communication unit 61 determines whether or not the received message indicates message transmission prohibition (step S23). When the communication unit 61 determines that the received message indicates transmission prohibition (S23: YES), the communication unit 61 notifies the control unit 60 of message transmission prohibition (step S24).

  When it is determined that the received message does not indicate message transmission prohibition (S23: NO), or after executing step S24, the communication unit 61 ends the reception process.

  If the message received in the reception process does not indicate transmission prohibition, the communication unit 61 determines whether each received message is a message transmitted to the communication device 30 based on the message ID. . If the communication unit 61 determines that the message is not a message transmitted to the communication device 30, the communication unit 61 discards this message. When determining that the message is a message transmitted to the communication device 30, the communication unit 61 notifies the control unit 70 of data included in the message, and the control unit 70 receives the communication unit 61 as described above. Based on the data, a control signal is output to the output unit 63, and the operation of the electrical device connected to the output unit 63 is controlled.

  Each of the communication devices 31, 40, 41, 50, 51 is configured similarly to the communication device 30, and includes a control unit 60, a communication unit 61, an input unit 62, an output unit 63, a storage unit 64, and a timer 65. In the description of the configuration of the communication device 30, the configuration of the communication device 31 can be described by replacing the communication device 30 with the communication device 31. In the description of the configuration of the communication device 30, the configuration of the communication device 40 or the communication device 41 is described by replacing the communication line 3 with the communication line 4 and replacing the communication device 30 with the communication device 40 or the communication device 41. Can do. In the description of the configuration of the communication device 30, the configuration of the communication device 50 or the communication device 51 will be described by replacing the communication line 3 with the communication line 5 and replacing the communication device 30 with the communication device 50 or the communication device 51. Can do.

  As described above, when the communication unit 61 of each of the communication devices 30, 31, 40, 41, 50, 51 receives a message indicating transmission prohibition in the reception process, the control unit 60 performs communication in the transmission control process. The unit 61 does not output a data transmission instruction to the communication unit 61 until the standby time elapses after receiving a message indicating that transmission is prohibited. For this reason, the communication unit 61 stops the message transmission until the standby time elapses after the message indicating the transmission prohibition is received. When the communication unit 61 stores data to be transmitted in the transmission data area of the storage unit 64 after the standby time has elapsed since the communication unit 61 received the message indicating that transmission is prohibited, the control unit 60 instructs the data transmission. Is output to the communication unit 61, and the communication unit 61 resumes message transmission.

  FIG. 7 is a block diagram showing a main configuration of the relay device 2. The relay apparatus 2 includes a control unit 70, N (= 3) communication units 71, 72, 73 and a storage unit 74. These are connected to the bus 75. Each of the communication units 71, 72, 73 is connected to communication lines 3, 4, 5 in addition to the bus 75.

Similar to the communication unit 61, the communication unit 71 is a so-called CAN driver and includes a CPU (not shown). The communication unit 71 performs a transmission process for transmitting a message via the communication line 3 and a reception process for receiving a message via the communication line 3.
Each of the communication units 72 and 73 operates in the same manner as the communication unit 71. In the description of the operation of the communication unit 71, the operation of the communication unit 72 can be described by replacing the communication line 3 and the communication unit 71 with the communication line 4 and the communication unit 72. In the description of the operation of the communication unit 71, the operation of the communication unit 73 can be described by replacing the communication line 3 and the communication unit 71 with the communication line 5 and the communication unit 73.

  The storage unit 74 is a nonvolatile memory. The storage unit 74 stores a control program. In addition, the storage unit 74 is provided with a transmission message area in which messages to be transmitted by the communication units 71, 72, and 73 via the communication lines 3, 4, and 5 are stored. Messages received by the communication units 71, 72, 73 in the reception process are stored in the transmission message area of the storage unit 74. Reading and writing of the contents stored in the storage unit 74 is performed by the control unit 60.

  The control unit 70 executes a transmission control process that controls transmission of the communication units 71, 72, and 73 by executing a control program stored in the storage unit 74. In order for the control unit 70 to execute the transmission control process, the storage unit 74 stores a message correspondence table indicating the correspondence between the message ID and the communication lines 3, 4, 5 used for message transmission.

  FIG. 8 is a table showing the contents of the message correspondence table. In the message correspondence table, communication lines used for message transmission among the communication lines 3, 4, and 5 are shown for each message ID. “O” indicates that the message is used for message transmission. "-" Indicates that the message is not used for transmission. In addition, when the number of communication lines used for message transmission among the communication lines 3, 4, 5 is 2 or more, it is indicated whether simultaneous transmission of messages is necessary or unnecessary.

  For a message having a message ID “A1”, the two communication lines 3 and 4 are used for message transmission, and it is not necessary to transmit the message simultaneously via the communication lines 3 and 4. For a message with the message ID “A2”, the two communication lines 4 and 5 are used for message transmission, and it is necessary to transmit the messages simultaneously via the communication lines 4 and 5 respectively. For a message whose message ID is “A3”, one communication line 5 is used for message transmission.

  FIG. 9 and FIG. 10 are flowcharts showing the procedure of the transmission control process executed by the control unit 70 of the relay apparatus 2. The control unit 70 periodically executes transmission control processing. The control unit 60 determines whether a message to be transmitted is stored in the transmission message area of the storage unit 74 (step S31). When it is determined that a message to be transmitted is stored (S31: YES), the control unit 60 determines a communication line for outputting a message based on the message ID of the message to be transmitted and the message correspondence table ( Step S32). For example, when the message ID is “A2”, the communication lines 4 and 5 are determined as communication lines to output the message.

  Next, based on the message ID of the message to be transmitted and the message correspondence table, the control unit 70 determines whether the messages should be transmitted simultaneously (step S33). For example, when the message ID is “A1” or “A3”, the control unit 70 determines that the messages should not be transmitted simultaneously. For example, when the message ID is “A2”, the control unit 70 determines that the messages should be transmitted simultaneously.

  When determining that the messages should not be transmitted simultaneously (S33: NO), the control unit 70 determines a message transmission instruction for instructing transmission of the message stored in the transmission message area of the storage unit 74 in step S32. Is output to the communication unit connected to the communication line (step S34). For example, when the communication line 5 is determined as the communication line 5 in step S <b> 32, the control unit 70 outputs a message transmission instruction to the communication unit 73.

  Each of the communication units 71, 72, and 73 executes transmission processing when a message transmission instruction is input from the control unit 70. Each of the communication units 71, 72, and 73 notifies the control unit 70 of the success and failure of message transmission in the transmission process.

  The control unit 70 determines whether or not a transmission failure has been notified from at least one of the communication units that are executing message transmission processing among the communication units 71, 72, and 73 (step S35). When it is determined that the transmission failure has been notified from at least one of the communication units that are executing the transmission process (S35: YES), the control unit 70 transmits a message transmission instruction in the communication units 71, 72, and 73. It outputs to the communication part which notified failure (step S36). Thereafter, the control unit 70 executes Step S35 again.

  If the transmission failure has not been notified (S35: NO), the control unit 70 has received a successful transmission notification from all the communication units executing the message transmission process in the communication units 71, 72, 73. Is determined (step S37). When it is determined that the transmission success has not been notified from all the communication units (S37: NO), the control unit 70 executes step S35 and outputs a message transmission instruction or waits until the message transmission is successful. Continue to do.

  When the transmission success is notified (S37: YES), the control unit 70 deletes the transmitted message from the transmission message area of the storage unit 74 (step S38). When it is determined that the message to be transmitted is not stored (S31: NO) or after executing step S38, the control unit 70 ends the transmission control process. The control unit 70 resumes the transmission control process when the next cycle arrives.

When it is determined that the messages should be transmitted simultaneously (S33: YES), the control unit 70 is connected to each of the communication lines determined in step S32 with a prohibited transmission instruction for instructing transmission of a message indicating that transmission is prohibited. (Step S39). For example, when the control unit 70 determines two communication lines 4 and 5 as communication lines used for message transmission in step S <b> 32, the control unit 70 outputs a prohibited transmission instruction to the communication units 72 and 73.
When the messages are to be transmitted at the same time, as a matter of course, the number of communication lines determined in step S32 is K (K: an integer from 2 to N). Accordingly, in step S39, the control unit 70 outputs a prohibited transmission instruction to the K communication units connected to the K communication lines determined in step S32.

  Each of the communication units 71, 72, and 73 executes transmission processing even when a prohibited transmission instruction is input from the control unit 70. Each of the communication units 71, 72, and 73 notifies the control unit 70 of success and failure of transmission of a message indicating that transmission is prohibited in the transmission process.

  The control unit 70 determines whether or not a transmission failure has been notified from at least one of the K communication units that are executing transmission processing of a message indicating transmission prohibition in the communication units 71, 72, and 73. (Step S40). When it is determined that the transmission failure is notified from at least one of the K communication units (S40: YES), the control unit 70 notifies the transmission failure in the communication units 71, 72, and 73. It outputs to a communication part (step S41). Thereafter, the control unit 70 executes Step S40 again.

  When the transmission failure is not notified from any of the K communication units executing the transmission process of the message indicating the transmission prohibition in the communication units 71, 72, and 73 (S40: NO) In the communication units 71, 72, and 73, it is determined whether or not transmission success has been notified from all of the K communication units that are executing transmission processing of a message indicating transmission prohibition (step S42). When it is determined that the transmission success has not been notified from all of the K communication units that are executing the transmission process of the message indicating that transmission is prohibited (S42: NO), the control unit 70 executes step S40 and transmits the message. Until transmission of all messages indicating prohibition is successful, output of the prohibition transmission instruction or standby is continued.

  If the control unit 70 determines that transmission success has been notified from all of the K communication units that are executing transmission processing of a message indicating transmission prohibition (S42: YES), the storage unit 74 is the same as step S34. A message transmission instruction for instructing transmission of the message stored in the transmission message area is output to the K communication units connected to the K communication lines determined in step S32 (step S43).

  The K communication units that output the message transmission instruction in step S43 are the K communication units that output the prohibited transmission instruction in step S39. For this reason, no message is transmitted via the K communication lines connected to the K communication units that output the message transmission instructions in step S43. Therefore, each of the K communication units to which the message transmission instruction is output in step S43 does not notify the control unit 70 of the message transmission failure.

  After executing step S43, the control unit 70, among the communication units 71, 72, 73, of the K communication units that are executing the transmission process of the message stored in the transmission message area of the storage unit 74. It is determined whether or not transmission success has been notified from all (step S44). When determining that the transmission success has not been notified from all of the K communication units that are executing the message transmission process (S44: NO), the control unit 70 executes step S44 again and performs the message transmission process. The process waits until all the K communication units executing the notification of successful transmission.

  When it is determined that the transmission success has been notified from all of the K communication units executing the message transmission process (S44: YES), the control unit 70 transmits the transmitted message from the transmission message area of the storage unit 74. Delete (step S45), and the transmission control process ends. Thereafter, the control unit 70 resumes the transmission control process when the next cycle arrives.

FIG. 11 is a flowchart illustrating a procedure of transmission processing executed by the communication unit 71 of the relay apparatus 2. As described above, the communication unit 71 performs a transmission process when a message transmission instruction or a prohibited transmission instruction is input from the control unit 70.
The communication units 72 and 73 execute the same transmission process as the communication unit 71. In the description of the transmission process performed by the communication unit 71, the transmission process performed by the communication unit 72 by replacing the communication line 3, the communication device 30, and the communication unit 71 with the communication line 4, the communication device 40, and the communication unit 72, respectively. can do. In the description of the transmission process executed by the communication unit 71, the transmission process executed by the communication unit 73 by replacing the communication line 3, the communication device 30, and the communication unit 71 with the communication line 5, the communication device 50, and the communication unit 73, respectively. can do.

  The communication unit 71 determines whether or not a message can be transmitted via the communication line 3 as in step S11 of the transmission process executed by the communication unit 61 of the communication device 30 (step S51). When it is determined that the message can be transmitted (S51: YES), the communication unit 71 transmits 1-bit data of the message (step S52). In step S52 of the transmission process executed by the communication unit 71 to which the message transmission instruction has been input, the communication unit 71 transmits 1-bit data of the message stored in the transmission message area of the storage unit 74. In step S52 of the transmission process executed by the communication unit 71 to which the prohibited transmission instruction has been input, the communication unit 71 transmits 1-bit data of a message indicating that transmission is prohibited.

  Next, the communication unit 71 determines whether or not the transmission of the message should be stopped, similarly to step S14 of the transmission process executed by the communication unit 61 of the communication device 30 (step S53). When the communication unit 61 determines that the message cannot be transmitted (S51: NO) or determines that the message transmission should be stopped (S53: YES), the communication unit 61 controls the message transmission failure. The unit 70 is notified (step S54), and the transmission process is terminated.

  When the communication unit 71 determines that the message transmission should not be stopped (S53: NO), the communication unit 71 has acquired the message transmission right in the same manner as in step S16 of the transmission process executed by the communication unit 61 of the communication device 30. It is determined whether or not (step S55). When it is determined that the message transmission right has not been acquired (S55: NO), the communication unit 71 executes step S52 and determines that the message transmission should be stopped or acquires the message transmission right. The message data is transmitted bit by bit until it is determined that it has been completed.

  If it is determined that the message transmission right has been acquired (S55: YES), the communication unit 71 transmits 1-bit data of the message (step S56) as in step S52. The communication unit 71 repeatedly executes step S56 as in step S52. The data transmitted by the communication unit 71 in step S56 is message data included after the arbitration field.

  After executing step S56, the communication unit 71 determines whether or not the transmission of the message is completed (step S57). When the communication unit 71 determines that the message transmission is not completed (S57: NO), the communication unit 71 executes step S56 and transmits the message data bit by bit until the message transmission is completed. If the communication unit 71 determines that the message transmission is completed (S57: YES), the communication unit 71 notifies the control unit 70 of the successful message transmission (step S58), and ends the transmission process.

FIG. 12 is a flowchart illustrating a procedure of reception processing executed by the communication unit 71 of the relay device 2. The communication unit 71 executes the reception process when detecting the SOF of the message or when determining that the transmission should be stopped by the transmission process.
The communication units 72 and 73 execute the same reception process as that of the communication unit 71. In the description of the reception process executed by the communication unit 71, the reception process executed by the communication unit 72 can be described by replacing the communication unit 71 with the communication unit 72. In the description of the reception process performed by the communication unit 71, the reception process performed by the communication unit 73 can be described by replacing the communication unit 71 with the communication unit 73.

  The communication unit 71 receives 1-bit data of the message (step S61), and determines whether or not reception of the message is completed (step S62). If the communication unit 61 determines that the message reception is not completed (S62: NO), the communication unit 61 executes the process in step S61 and sequentially receives 1-bit data until the message reception is completed.

If the communication unit 71 determines that the message has been received (S62: YES), the communication unit 71 ends the reception process.
Note that the communication unit 71 determines whether each message received in the reception process is a message transmitted to the relay device 2 based on the message ID. If the communication unit 71 determines that the message is not a message transmitted to the relay device 2, the communication unit 71 discards this message. When determining that the message is a message transmitted to the relay device 2, the communication unit 71 stores this message in the transmission message area of the storage unit 74.

As described above, at least two of the communication units 71, 72, and 73 of the relay device 2 can simultaneously transmit messages via K communication lines of N (= 3) communication lines 3, 4, and 5. When transmission is performed, a message indicating transmission prohibition is transmitted to the communication unit 61 of the communication apparatus connected to the K communication lines, and transmission of messages performed by these communication apparatuses is prohibited. For example, when the communication units 72 and 73 perform simultaneous transmission of messages via the two communication lines 4 and 5, a message indicating transmission prohibition is transmitted to the communication units 61 of the communication devices 40, 41, 50, and 51. Then, the transmission of the message performed by the communication unit 61 of the communication devices 40, 41, 50, 51 is prohibited.
Each of the communication units 71, 72, and 73 functions as a prohibited transmission unit.

  Therefore, for example, when it is necessary for the communication units 72 and 73 of the relay device 2 to simultaneously transmit a message having the message ID “A2” to the communication devices 40 and 50, the communication units 72 and 73 are connected to the two communication lines 3 and 4 in advance. A message indicating transmission prohibition is transmitted to the communication units 61 of the four communication devices 40, 41, 50, 51. Accordingly, transmission of each of the four communication devices 40, 41, 50, 51 connected to the two communication lines 3, 4 is prohibited, so that the communication units 72, 73 connect the two communication lines 4, 5 to each other. Thus, simultaneous transmission of messages can be reliably performed. In this example, the number K of communication lines for which data transmission / reception is prohibited is two.

At least two of the communication units 71, 72, and 73 of the relay device 2 connect each of the K communication lines while the transmission of the message of the communication device connected to each of the K communication lines is prohibited. Send a common message via For example, when the message ID is “A2”, the communication units 72 and 73 of the relay device 2 transmit the messages of the communication devices 40, 41, 50, and 51 connected to the two communication lines 4 and 5, respectively. While being prohibited, a common message with the message ID “A2” is transmitted via the two communication lines 4 and 5 respectively. Thereby, for example, in the communication devices 40 and 50, simultaneous reception of a common message via the two communication lines 4 and 5 is realized. Also in this example, the number K of communication lines for which data transmission / reception is prohibited is two.
Each of the communication units 71, 72, 73 also functions as a data transmission unit.

As described above, the communication units 61 of the communication devices 30, 31, 40, 41, 50, and 51 resume message transmission after a standby time has elapsed after receiving a message indicating that transmission is prohibited.
Thereby, in each of the communication devices 30, 31, 40, 41, 50, and 51, transmission of a message can be permitted with a simple configuration.

  Each of the communication units 71, 72, 73 of the relay apparatus 2 requires a specific message, specifically, simultaneous transmission via one of N (= 3) communication lines 3, 4, 5. Receive messages. When one of the communication units 71, 72, and 73 receives a specific message, at least two of the communication units 71, 72, and 73 transmit a message indicating that transmission is prohibited, and prohibit transmission of the message. . For example, when the message having the message ID “A2” is received by the communication unit 71, the communication units 72 and 73 transmit a message indicating transmission prohibition via the communication lines 4 and 5, and the communication device 40. , 41, 50, 51 are prohibited from being transmitted. Thereafter, the message with the message ID “A2” is simultaneously transmitted. Each of the communication units 71, 72, 73 also functions as a data receiving unit.

(Embodiment 2)
In the first embodiment, each communication unit 61 of communication devices 30, 31, 40, 41, 50, 51 resumes message transmission after a standby time has elapsed after receiving a message indicating that transmission is prohibited. . However, the timing at which the communication unit 61 resumes message transmission is not limited to the case where the standby time has elapsed after receiving a message indicating transmission prohibition. When the communication unit 61 receives a message indicating transmission permission from one of the communication units 71, 72, and 73 of the relay device 2, the communication unit 61 may resume message transmission.

  In the following, the differences between the second embodiment and the first embodiment will be described. Since the other configuration except the configuration to be described later is the same as that of the first embodiment, the same reference numerals are given and detailed description thereof is omitted. A message indicating transmission permission corresponds to permission information.

  The communication system 1 in the second embodiment is configured similarly to the communication system 1 in the first embodiment. Regarding the communication system 1 according to the second embodiment, the transmission control process executed by the control unit 60 of each of the communication devices 30, 31, 40, 41, 50, 51 and the communication devices 30, 31, 40, 41, 50, 51, respectively. The reception process executed by the communication unit 61 and the transmission control process executed by the control unit 70 of the relay apparatus 2 are different from those in the first embodiment. The communication units 61 of the communication devices 30, 31, 40, 41, 50, 51 notify the control unit 60 of message transmission permission when the received message indicates message transmission permission in the reception process. .

  FIG. 13 is a flowchart illustrating a procedure of transmission control processing executed by the control unit 60 of the communication device 30 according to the second embodiment. Similar to the first embodiment, the control unit 60 periodically performs transmission control processing. Steps S71, S73 to S77 of the transmission control process executed by the control unit 60 in the second embodiment are the same as steps S1, S5 to S9 of the transmission control process executed by the control unit 60 in the first embodiment. For this reason, detailed description of steps S71 and S73 to S77 is omitted.

  When it is determined that the message transmission prohibition has been notified from the communication unit 61 (S71: YES), the control unit 60 determines whether the communication unit 61 has notified the message transmission permission (step S72). When it is determined that the transmission permission is not notified (S72: NO), the control unit 60 executes step S72 and waits until the communication unit 61 notifies the message transmission permission. When it is determined that the message transmission prohibition is not notified (S71: NO), or when it is determined that the message transmission permission is notified (S72: YES), the control unit 60 executes Step S73.

  FIG. 14 is a flowchart illustrating a procedure of reception processing executed by the communication unit 61 of the communication device 30. Similarly to the first embodiment, the communication unit 61 according to the second embodiment also executes the reception process when detecting the SOF of the message or when determining that the transmission should be stopped by the transmission process. Steps S81 to S84 of the reception process executed by the communication unit 61 in the second embodiment are the same as steps S21 to S24 of the reception process executed by the communication unit 61 in the first embodiment. For this reason, detailed description of steps S81 to S84 is omitted.

  If the communication unit 61 determines that the received message does not indicate message transmission prohibition (S83: NO), the communication unit 61 determines whether the received message indicates message transmission permission (step S85). . If the communication unit 61 determines that the received message indicates message transmission permission (S85: YES), the communication unit 61 notifies the control unit 60 of message transmission permission (step S86).

  The communication part 61 complete | finishes a reception process, after determining whether the received message has performed any one of step S84, S86, or has not shown transmission permission of a message (S85: NO).

  In the second embodiment as well, the communication unit 61 transmits each received message to the communication device 30 based on the message ID when the message received in the reception process does not indicate transmission prohibition or transmission permission. It is determined whether it is a message. If the communication unit 61 determines that the message is not a message transmitted to the communication device 30, the communication unit 61 discards this message. When the communication unit 61 determines that the message is a message transmitted to the communication device 30, the communication unit 61 notifies the control unit 70 of data included in the message, and the control unit 70 is based on the data received by the communication unit 61. The control signal is output to the output unit 63 to control the operation of the electric device connected to the output unit 63.

  Also in the second embodiment, each of the communication devices 31, 40, 41, 50, 51 is configured similarly to the communication device 30. In the description of the configuration of the communication device 30, the configuration of the communication device 31 can be described by replacing the communication device 30 with the communication device 31. In the description of the configuration of the communication device 30, the configuration of the communication device 40 or the communication device 41 is described by replacing the communication line 3 with the communication line 4 and replacing the communication device 30 with the communication device 40 or the communication device 41. Can do. In the description of the configuration of the communication device 30, the configuration of the communication device 50 or the communication device 51 will be described by replacing the communication line 3 with the communication line 5 and replacing the communication device 30 with the communication device 50 or the communication device 51. Can do.

  As described above, each of the communication units 61 of the communication devices 30, 31, 40, 41, 50, 51 receives a message indicating transmission permission from the relay device 2. When the communication unit 61 receives a message indicating transmission prohibition in the reception process, the control unit 60 instructs the communication unit 61 to transmit data until the communication unit 61 receives a message indicating transmission permission in the transmission control process. Is not output. For this reason, the communication unit 61 stops the message transmission until the message indicating the transmission permission is received after the message indicating the transmission prohibition is received. When the communication unit 61 receives a message indicating transmission permission and the data to be transmitted is stored in the transmission data area of the storage unit 64, the control unit 60 outputs a data transmission instruction to the communication unit 61. The communication unit 61 resumes message transmission. The communication unit 61 also functions as a permission receiving unit.

  FIG. 15 and FIG. 16 are flowcharts showing the procedure of the transmission control process executed by the control unit 70 of the relay apparatus 2. The control unit 70 executes transmission control processing periodically as in the second embodiment. Steps S91 to S105 of the transmission control process executed by the control unit 70 in the second embodiment are the same as steps S31 to S45 of the transmission control process executed by the control unit 70 in the first embodiment. For this reason, detailed description of steps S91 to S105 is omitted.

  After executing step S105, the control unit 70 outputs a permission transmission instruction for instructing transmission of a message indicating transmission permission to the K communication units connected to the K communication lines determined in step S92. (Step S106). For example, when the control unit 70 determines that the communication lines 4 and 5 are K communication lines used for message transmission in step S92, the control unit 70 outputs a permission transmission instruction to the communication units 72 and 73.

  Each of the communication units 71, 72, and 73 executes transmission processing even when a permission transmission instruction is input from the control unit 70. Each of the communication units 71, 72, and 73 notifies the control unit 70 of success and failure of transmission of a message indicating transmission permission in the transmission process.

  The control unit 70 determines whether or not a transmission failure has been notified from at least one of the K communication units that are executing transmission processing of a message indicating transmission permission among the communication units 71, 72, and 73 ( Step S107). When it is determined that the transmission failure has been notified from at least one of the plurality of communication units (S107: YES), the control unit 70 sends a permission transmission instruction to the communication unit 71, 72, 73 that has notified the transmission failure. (Step S108). Thereafter, the control unit 70 executes Step S107 again.

  In the communication units 71, 72, 73, the control unit 70 is notified of no transmission failure from any of the K communication units that are executing transmission processing of a message indicating transmission permission (S 107: NO). In the communication units 71, 72, 73, it is determined whether or not transmission success has been notified from all of the K communication units that are executing transmission processing of a message indicating transmission permission (step S109). When the control unit 70 determines that the transmission success has not been notified from all of the K communication units that are executing transmission processing of a message indicating transmission permission (S109: NO), the control unit 70 executes step S107, and performs transmission. Until all the messages indicating permission are successfully transmitted, the permission transmission instruction is output or the standby is continued.

  When it is determined that the transmission success has been notified from all of the K communication units executing the transmission process of the message indicating the transmission permission (S109: YES), the control unit 70 ends the transmission control process. Thereafter, the control unit 70 resumes the transmission control process when the next cycle arrives.

  Each of the communication units 71, 72, and 73 executes a transmission process similar to that of the first embodiment when a message transmission instruction, a prohibited transmission instruction, or a permitted transmission instruction is input from the control unit 70. In the transmission process, each of the communication units 71, 72, and 73 transmits a message stored in the transmission message area of the storage unit 74 when a message transmission instruction is input, as in the second embodiment, and is prohibited. When a transmission instruction is input, a message indicating transmission prohibition is transmitted. In the second embodiment, each of the communication units 71, 72, 73 further transmits a message indicating transmission permission when a permission transmission instruction is input.

As described above, at least two of the communication units 71, 72, and 73 of the relay device 2 can simultaneously transmit messages via K communication lines of N (= 3) communication lines 3, 4, and 5. When transmitting, a message indicating transmission prohibition is transmitted to the communication unit 61 of the communication device connected to the K communication lines, and transmission of the message performed by the communication unit 61 of these communication devices is prohibited. Thereafter, a common message is transmitted via the K communication lines. At least two of the communication units 71, 72, 73 transmit a message indicating transmission permission to the communication unit 61 of the communication device connected to the K communication lines after transmitting a common message, The transmission of messages performed by these communication devices is permitted. For example, when the communication units 72 and 73 perform simultaneous transmission of messages via the two communication lines 4 and 5, the communication units 72 and 73 transmit to the communication units 61 of the communication devices 40, 41, 50, and 51. After transmitting a message indicating prohibition and prohibiting the transmission of the message performed by the communication unit 61 of the communication devices 40, 41, 50 and 51, a common message is transmitted via the two communication lines 4 and 5. After transmitting the common message, the communication units 72 and 73 transmit a message indicating transmission permission to the communication units 61 of the communication devices 40, 41, 50, and 51 connected to the two communication lines 4 and 5, respectively. Then, the transmission of the message performed by the communication unit 61 of the communication devices 40, 41, 50, 51 is permitted.
Each of the communication units 71, 72, and 73 functions as a permission transmission unit.

  The communication unit 61 of the communication devices 30, 31, 40, 41, 50, 51 stops transmitting the message when receiving a message indicating transmission prohibition, and transmits the message when receiving a message indicating transmission permission. Resume. For example, when the communication unit 61 of the communication device 30 receives a message indicating transmission prohibition from the communication unit 71 of the relay device 2, the communication unit 61 stops transmission of the message, and when receiving a message indicating transmission permission, 3 restarts the message transmission.

  The communication unit 61 of each of the communication devices 30, 31, 40, 41, 50, 51 does not resume message transmission after receiving a message indicating transmission prohibition until receiving a message indicating transmission permission. . For this reason, for example, the communication units 72 and 73 of the relay apparatus 2 can simultaneously transmit messages in a state where transmission of data via the two communication lines 3 and 4 is reliably prohibited. In this example, the number K of communication lines for which data transmission / reception is prohibited is two.

  In the second embodiment, the configuration other than the configuration in which the communication units 61 of the communication devices 30, 31, 40, 41, 50, and 51 resume message transmission is the same as that of the first embodiment. For this reason, the communication system 1 according to the second embodiment restarts the transmission of the message after the standby time has elapsed after receiving the message indicating the transmission prohibition, among the effects exhibited by the communication system 1 according to the first embodiment. Other effects are obtained except for the effects obtained by the configuration.

  In the first and second embodiments, when a plurality of communication units in the communication units 71, 72, and 73 of the relay apparatus 2 perform simultaneous transmission of messages, the transmitted messages are the communication units 71, 72, One of 73 is not limited to the received message.

  In addition, a plurality of communication units in the communication units 71, 72, and 73 of the relay device 2 may transmit different messages when performing simultaneous transmission. For example, while the communication units 72 and 73 of the relay device 2 prohibit the transmission of messages performed by the communication devices 40, 41, 50, and 51, the communication units 72 and 73 communicate with each other via the two communication lines 4 and 5, respectively. Different messages may be sent. For example, the messages that the communication devices 40 and 50 need to receive at the same time are not necessarily the same.

  Further, an external device such as a diagnostic tool may be detachably connected to the relay device 2. In this case, when the relay device 2 receives a specific message from the external device, the relay device 2 performs simultaneous transmission of the message via a plurality of communication lines among the N (= 3) communication lines 3, 4, and 5. Also good.

  Further, the number N of communication lines connected to the relay apparatus 2 is not limited to 3, and may be 2 or an integer of 4 or more. Further, the number K of communication lines on which messages are simultaneously transmitted is not limited to 2, but may be 2 or more and N or less. The number of communication devices provided in the communication system 1 is not limited to 6, and may be 2 or more, 5 or less, or 7 or more. Furthermore, the number of communication devices that can be connected to one communication line is not limited to two, and may be one or three or more.

  Further, in the communication system 1, a communication device that does not control the operation of the electric device may be used instead of the communication device that controls the operation of the electric device. The protocol used for communication via the communication line is not limited to the CAN protocol, and may be, for example, a CAN_FD (Controller Area Network with Flexible Data Rate) protocol. In this case, in the message structure, the transmission rate of the data field is faster than the transmission rate of the other part, for example, four times the transmission rate of the other part.

  The disclosed first and second embodiments are examples in all respects and should not be considered as restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Communication system 2 Relay apparatus 3, 4, 5 Communication line 30, 31, 40, 41, 50, 51 Communication apparatus 61 Communication part (Prohibition receiving part, permission receiving part)
71, 72, 73 Communication unit (prohibited transmission unit, permission transmission unit, data transmission unit, data reception unit)

Claims (6)

In a relay device that is connected to one of N (N: an integer of 2 or more) communication lines and transmits data to a plurality of communication devices that transmit and receive data via the communication line,
A prohibition transmission unit that transmits prohibition information indicating prohibition of transmission to all the communication devices connected to K (K: an integer of 2 to N) communication lines;
While the transmission of the prohibition information to all the communication devices by the prohibition transmission unit is successful and the transmission of all the communication devices is prohibited, the all communication is performed via each of the K communication lines. A data transmission unit that performs simultaneous transmission for transmitting common data to the device. A data receiving unit for receiving specific data via one of the N communication lines;
The relay apparatus according to claim 1, wherein the prohibition transmission unit transmits the prohibition information when the data reception unit receives the specific data. The relay device according to claim 1 or 2 ,
A plurality of the communication devices that receive data from the relay device;
Each of the plurality of communication devices includes a prohibition receiving unit that receives the prohibition information transmitted by the prohibition transmission unit, and stops transmission of data when the prohibition reception unit receives the prohibition information. Communication system. The communication system according to claim 3 , wherein the communication device resumes data transmission after a predetermined period has elapsed since the prohibition receiving unit received the prohibition information. The relay device includes a permission transmission unit that transmits permission information indicating transmission permission to the plurality of communication devices connected to the K communication lines,
Each of the plurality of communication devices has a permission receiving unit that receives permission information transmitted by the permission transmitting unit, and when the permission receiving unit receives the permission information , restarts data transmission. The communication system according to claim 3 . A relay device according to claim 1 ;
A plurality of the communication devices that receive data from the relay device;
The relay device includes a permission transmission unit that transmits permission information indicating transmission permission to the plurality of communication devices connected to the K communication lines after the data transmission unit transmits the common data. And
Each of the plurality of communication devices includes:
A prohibition receiving unit for receiving prohibition information transmitted by the prohibition transmission unit;
A permission receiver for receiving permission information transmitted by the permission transmitter; and
A communication system, wherein the prohibition receiving unit stops transmitting data when receiving the prohibition information, and resumes data transmission when the permission receiving unit receives the permission information.

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