JP6200268B2 - Relay terminal for communication network system and communication network system - Google Patents

Description

  The present invention relates to a communication network system having an upper network in which upper terminals communicate with each other and a lower network in which lower terminals communicate with each other.

  Conventionally, a network for performing data communication between terminals is divided into a plurality of hierarchies as needed. For example, even in a network in which ECUs (Electronic Control Units) communicate with each other inside a vehicle, power train control that requires high communication speed and reliability, and sensors and actuators that do not require such high communication speed and reliability In some cases, networks having different communication protocols are employed for communication such as the above.

  In this case, protocol conversion is performed when communication across networks is performed. When this protocol conversion is performed, for example, identification information such as a destination defined on the frame of one communication protocol may not be reflected in the frame after the protocol conversion. Such protocol conversion cannot fully take advantage of the communication protocol of each network.

  Therefore, it has been conventionally proposed to reflect not only data but also identification information in a frame after protocol conversion. In this proposal, FlexRay (registered trademark) is used for the upper network, and CAN (Controller Area Network) or the like is used for the lower network.

  Then, a relay terminal connected to both networks transmits a CAN data frame (start request frame) to a lower network terminal during a FlexRay static segment transmission period, and then transmits a dynamic segment in the same cycle. During the period (pass-through period), a CAN data frame (communication frame) is transmitted.

  Note that the CAN data frame (start request frame or communication frame) is transmitted during the payload portion after the header portion is transmitted in the FlexRay dynamic segment.

  Therefore, in this proposal, data such as the priority order defined in the arbitration field of the CAN data frame can be transmitted together with the data of the data field using the FlexRay communication protocol. As a result, the CAN communication protocol-specific effect of avoiding collision at the time of simultaneous transmission can be utilized as it is even during communication across FlexRay (for example, Patent Document 1).

JP 2011-193227 A

  In the above-described proposal, the FlexRay of the synchronous time division communication method is used as the upper network. For this reason, each relay terminal and each lower-level terminal must share in advance a FlexRay (dynamic segment payload period) that is open to communication (data frame transmission) between CAN terminals. Therefore, in the above-described conventional proposal, each relay terminal outputs a trigger signal to each lower terminal in advance, and causes each lower terminal to calculate the start and end of the open period.

  Such an operation of allocating and sharing the open period of the upper network in advance to each terminal is necessary and feasible because the upper network is a synchronous time division communication method. On the other hand, when the upper network is an asynchronous time division communication system such as CAN, for example, the timing at which the CAN is released to communication between terminals of the lower network is not specified. For this reason, it is impossible to allocate a CAN release period in advance, or to share the assigned CAN release period in advance with each relay terminal or each lower terminal (not necessary).

  That is, when the upper network is an asynchronous time division communication method such as CAN, the conventional proposed method described above transmits a frame based on the communication protocol of the lower network as it is using a frame based on the communication protocol of the upper network. I can't.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to transmit a frame based on a lower-layer network communication protocol in which lower-level network terminals communicate with each other by using a frame based on an asynchronous communication protocol for an upper-level network. Another object of the present invention is to provide a communication network system that can be used, and a relay terminal suitable for use in the system.

In order to achieve the above object, a relay terminal for a communication network system according to the present invention described in claim 1 comprises:
In a communication network system having an upper network in which upper terminals communicate with each other using an asynchronous communication protocol and a plurality of lower networks in which lower terminals communicate with each other using an asynchronous communication protocol or a synchronous communication protocol, the upper network and a plurality of A relay terminal connected to both the lower network and serving as both the upper terminal and the lower terminal;
Data defined in an area following the release identifier in the frame received from the upper network 3 when a frame received from the upper network includes an release identifier that opens the upper network in communication between the lower terminals A connection means for connecting the lower network to the upper network for a predetermined period in which a data area having a length is transmitted;
When the connection means connects the lower network to the upper network, an open notification for transmitting a request or response including an open notification identifier for notifying the release of the upper network for communication between the lower terminals to the lower network Means,
After the connection means connects the lower network to the upper network, an end notification identifier for notifying each lower terminal of the end of opening of the upper network for communication between the lower terminals before the predetermined period elapses. An end notification means for transmitting a request or response including the request to the lower network;
While connecting to the upper network of the lower network, the request and response received from the lower network are passed through, and transmitted to the upper network as transmission data in the data area in the frame and received from the upper network. Pass-through means for passing through transmission data in a data area in a frame and transmitting the request or response to the lower network; and
It is characterized by providing.

In order to achieve the above object, a communication network system according to the present invention described in claim 5 includes:
In a communication network system having an upper network in which upper terminals communicate with each other using an asynchronous communication protocol and a plurality of lower networks in which lower terminals communicate with each other using an asynchronous communication protocol or a synchronous communication protocol,
A plurality of relay terminals connected to both the upper network and one of the plurality of lower networks and serving as both the upper terminal and the lower terminal;
The relay terminal according to claim 1, 2, 3, or 4 is used as each relay terminal.
It is characterized by that.

  According to the relay terminal for the communication network system of the present invention described in claim 1 and the communication network system of the present invention described in claim 5, if the frame received from the upper network includes an open identifier, Connect the network to the upper network. Then, a response including the release notification identifier is transmitted to the lower network to notify the lower terminal of the start of connection.

  Here, the relay terminal that has received the frame including the release identifier from the upper network can transmit the request or response including the release notification identifier in the lower network. When sending a request including the release notification identifier, it can be sent as it is, but when sending a response containing the release notification identifier, the request that triggers the response is sent with a frame containing the release identifier. The relay terminal received from the upper network needs to receive it on the lower network.

  Therefore, when transmitting a response including a release notification identifier, the relay terminal that has received a frame including the release identifier from the upper network behaves as a lower terminal and sends a request for requesting the release notification identifier to the lower network itself. Send. This request includes an identifier that designates a lower terminal that is also used by the request. Therefore, the same relay terminal that has received this request can act as a lower terminal and transmit a response including the release notification identifier to the lower network.

  A relay terminal that has received a frame including an open identifier from an upper network transmits a request or response including an open notification identifier to a lower network, and then further includes a request including an identifier for designating each lower terminal or data to be transmitted A request including an identifier for designating a lower-level terminal having an ID is sequentially transmitted to the lower-level network.

  Also, the relay terminal that has received the frame including the open identifier from the upper network transmits the request or response including the end notification identifier in the lower network before the predetermined period has elapsed since the connection to the upper network of the lower network. be able to. When transmitting a request including an end notification identifier, the request may be transmitted as it is, as in the case of transmitting a request including an open identifier.

  On the other hand, when transmitting a response including an end notification identifier, as in the case of transmitting a response including an open identifier, a relay terminal that has received a frame including the open identifier from the upper network requests an end notification identifier. Request itself to the lower network. This request includes an identifier that designates a lower terminal that is also used by the request. Accordingly, the same relay terminal that has received this request can act as a lower terminal and transmit a response including the end notification identifier to the lower network.

  Each lower terminal recognizes that the lower network is connected to the upper network by receiving a request or response including the release notification identifier in the lower network. Each lower terminal recognizes that the lower network is disconnected from the upper network by receiving a request or response including the end notification identifier in the lower network.

  Then, in the lower level network, the lower level terminal having the data to transmit from the reception of the request or response including the release notification identifier to the reception of the request or response including the end notification identifier specifies its own lower level terminal. In response to the request from the relay terminal including the identifier to be transmitted, the data to be transmitted is transmitted as a response to the lower network. When the relay terminal that also serves as the lower terminal has data to be transmitted to the lower terminal by itself, the relay terminal may transmit the response to the lower network by itself.

  The response transmitted from the lower terminal to the lower network is received by another lower terminal of the same lower network. In addition, this response is passed through by a relay terminal in the same lower network as the lower terminal that transmitted the response to be transmitted to the lower terminal in another lower network connected via the upper network, and the relay terminal is connected. It is transmitted to the higher level network as transmission data in the data area in the frame.

  Then, the response that the relay terminal has passed through to the upper network as transmission data in the data area in the frame is passed through by another relay terminal of the upper network and transmitted as a response to the lower network connected to the other relay terminal. And received by each lower terminal of the lower network. Therefore, each lower terminal receives the response across the upper network with the content of the response transmitted by the original lower terminal.

  During the connection to the higher level network of the lower level network, every time the lower level terminal sends a request or response to the lower level network, the request or response is passed through by the relay terminal of the same lower level network. Is transmitted as transmission data in the data area in the frame to the higher level network to which is connected.

  Then, the response that the relay terminal has passed through to the upper network as transmission data in the data area in the frame is passed through by another relay terminal of the upper network and is sent as a request or response to the lower network connected to the other relay terminal. Sent and received by each lower terminal in the lower network. Accordingly, each lower terminal receives the request and response across the upper network with the contents of the request and response transmitted by the original lower terminal.

  A lower terminal that has received a request from a lower network via a relay terminal across the upper network transmits a response corresponding to the request to the lower network when the request is a request directed to itself.

  Note that the request and response of the lower network that the relay terminal receives from the lower network and passes through to the upper network while connected to the upper network of the lower network remains unchanged on the upper network. . Therefore, the information included in the request and response of the lower network can be utilized in the received lower terminal even after being received by the lower terminal of the lower network via the upper network and the relay terminal.

  For this reason, it is possible to transmit a frame based on the communication protocol of the lower network in which the terminals of the lower network communicate with each other using the frame transmission period based on the asynchronous communication protocol of the upper network as it is.

  Furthermore, the relay terminal for a communication network system of the present invention described in claim 2 is the relay terminal for the communication network system of the present invention described in claim 1, wherein the upper network is opened for communication between the lower terminals. And further comprising a release request means for transmitting a frame including the release identifier to the upper network.

  According to the communication network system relay terminal of the present invention described in claim 2, in the communication network system relay terminal of the present invention described in claim 1, when the frame including the open identifier is transmitted to the upper network, The frame is received by a host terminal (including a relay terminal that also serves as a host terminal) of the host network.

  The open identifier included in the received frame is recognized by the relay terminal (including the relay terminal itself that transmitted the frame including the open identifier). That is, the release of the upper network for communication between lower terminals is performed by connection of the lower network to the upper network, and the relay terminal performs this. Therefore, the open identifier is recognized by the relay terminal and is not recognized by other upper terminals.

  In the relay terminal that recognizes the open identifier, the lower network is connected to the upper network for a predetermined period, and the lower terminals across the upper network can communicate with each other.

  For this reason, when it is necessary to open the upper network for communication between lower terminals, the lower network is connected to the upper network so that the lower terminals can communicate across the upper network by transmitting a frame including an open identifier to the upper network. Can be connected to.

Further, the communication network system relay terminal of the present invention described in claim 3 is the communication network system relay terminal of the present invention described in claim 1 or 2,
The upper network is a CAN (Controller Area Network),
The frame including the release identifier is transmitted to the upper network in the ID field of the data frame of the CAN,
The predetermined period is a period for securing transmission of a data field after the ID field in the data frame of the CAN,
The pass-through means transmits a request or response received from the lower network and passed through to the upper network in the data field of the data frame, and receives data received from the upper network in the data field of the data frame. Send it as a request or response to the lower network,
It is characterized by that.

  According to the relay terminal for the communication network system of the present invention described in claim 3, in the relay terminal for the communication network system of the present invention described in claim 1 or 2, when the upper network is configured by CAN, Using the data field of the data frame, requests and responses based on the communication protocol of the lower network are transmitted / received on the CAN.

  Here, each relay terminal connects the CAN to the lower network in advance by receiving the release identifier in the ID field preceding the data field in time series in the CAN data frame. Each relay terminal notifies the lower terminal through the lower network that the CAN has been released for communication between the lower terminals as a request including the release notification identifier.

  Therefore, the lower-level terminal transmits a request and a response to the lower-level network in a state where the lower-level network recognizes in advance that the lower-level network is connected to the CAN. Then, the relay terminal that has received the request or response from the lower-level terminal uses the data field after the ID field in the CAN data frame, and the request from the lower-level terminal with the content corresponding to the communication protocol of the lower-level network. And response to CAN.

  For this reason, when the upper network is configured by CAN, requests and responses based on the communication protocol of the lower network can be transmitted and received in the CAN data frame with the same contents between the lower terminals of the lower network straddling the CAN. it can.

Furthermore, the relay terminal for the communication network system of the present invention described in claim 4 is the relay terminal for the communication network system of the present invention described in claim 3,
The lower network is a LIN (Local Interconnect Network),
The release notification means and the end notification means respectively notify the release and release end of the upper network by an identifier of a header of a LIN frame transmitted to the lower network,
The pass-through means passes through the header or response of the LIN frame received from the lower network and transmits it to the upper network in the data field of the data frame and receives from the upper network in the data field of the data frame. Sending the passed-through data to the lower network as a header or response of the LIN frame;
It is characterized by that.

  According to the communication network system relay terminal of the present invention described in claim 4, in the communication network system relay terminal of the present invention described in claim 3, the upper network is configured by CAN and the lower network is configured by LIN. In this case, a header and response according to the LIN communication protocol are transmitted / received on the CAN using the data field of the CAN data frame.

  Here, the relay terminal functions as a master node in the LIN, and the other LIN terminals function as slave nodes. As a result, the relay terminal can transmit a header (request) to the LIN terminal, and can receive a response from each LIN terminal (including the relay terminal).

  For this reason, the LIN terminal transmits a header and a response to the LIN in a state in which it is recognized in advance that the LIN is connected to the CAN. Then, the relay terminal that has received the header or response from the LIN transmits the header or response from the LIN terminal to the CAN using the CAN data frame with the content corresponding to the LIN communication protocol.

  For this reason, when the upper network is configured with CAN and the lower network is configured with LIN, the frame according to the LIN communication protocol is directly used between the LIN terminals, and the CAN is determined according to the data field of the CAN data frame. It is possible to send and receive across straddles.

  According to the present invention, it is possible to transmit a frame based on a lower-layer network communication protocol in which lower-level network terminals communicate with each other as it is, using a frame based on an upper-layer network asynchronous communication protocol.

It is explanatory drawing which shows the basic composition of the communication network system of this invention. It is explanatory drawing which shows the frame structure of the data frame of the CAN communication protocol used with the high-order network of FIG. It is explanatory drawing of the communication schedule by the master-slave system by the communication protocol of LIN used with the low-order network of FIG. It is a flowchart which shows the process sequence of the connection of the high-order network and low-order network which the CAN and LIN node of FIG. FIG. 2 is a flowchart showing a processing procedure for connection and termination of an upper network and a lower network performed by the CAN and LIN nodes of FIG. 1 that behave as a slave node during connection between the upper network and the lower network. It is explanatory drawing which shows notionally the communication performed in the communication network system of FIG.

  The present invention will be described below with reference to the drawings. First, the basic configuration of the communication network system of the present invention will be described with reference to the explanatory diagrams of FIGS.

  The communication network system of this embodiment constitutes, for example, a control system network system for a vehicle (not shown). As shown in FIG. 1, the communication network system 1 includes an upper network 3 and two lower networks. Network 5a, 5b.

  The host network 3 is used for a main network of a vehicle that requires relatively high communication speed and reliability, and the host network 3 performs communication using a CAN communication protocol. Each of the lower networks 5a and 5b is used for a sufficient vehicle sub-network even at a relatively low communication speed, and the lower networks 5a and 5b perform communication using the LIN communication protocol.

  The host network 3 is configured by connecting five nodes 31 to 33, 41, and 42 (corresponding to host terminals in claims) by a bus 34. Of these, the three nodes 31 to 33 are CAN dedicated nodes (CAN nodes) that only support communication using the CAN communication protocol, and the two nodes 41 and 42 correspond to CAN that supports communication using the CAN and LIN communication protocols. , LIN combined node (CAN, LIN node, corresponding to the relay terminal in the claims).

  The CAN communication protocol used in the upper network 3 is an asynchronous communication protocol. As shown in FIG. 2, data is obtained by communication using a data frame that starts with SOF (Start Of Frame) and ends with EOF (End Of Frame). Execute sending.

  Each of the CAN nodes 31 to 33 and the CAN and LIN nodes 41 and 42 transmits a data frame to the bus 34 at an arbitrary timing when data to be transmitted is generated. The data frame includes data contents to be transmitted, an ID (identifier) indicating a transmission destination node, and information (RTR: Remote Transmission Request) indicating the data frame. The data frame transmitted to the bus 34 is received by each of the nodes 31 to 33, 41 and 42.

  Each of the nodes 31 to 33, 41, and 42 that have received the data frame confirms the ID, and acquires data in the data field as necessary.

  Here, when a plurality of nodes 31 to 33, 41, and 42 transmit data frames to the bus 34 at the same time, the one with the lower ID number has priority. After confirming that the data frame that was not prioritized and was not transmitted to the bus 34 was in the bus idle state after the ITM (Inteemission, 3 bit recessive fixed) following the data frame (EOF), It is transmitted to the bus 34 again.

  Note that each of the nodes 31 to 33, 41, and 42 includes, for example, control objects for power train control such as an engine (not shown) and chassis control such as steering (not shown), and an ECU that controls them. .

  On the other hand, the lower network 5 a is configured by connecting three nodes 41, 51, 52 via a bus 53. The lower network 5 b is configured by connecting three nodes 42, 54, and 55 via a bus 56. Note that all the nodes 51, 52, 54, and 55 except the CAN and LIN nodes 41 and 42 are LIN dedicated nodes (LIN nodes) that only support communication using the LIN communication protocol.

  Each of the nodes 41, 42, 51, 52, 54, 55 (corresponding to the lower terminal in the claims) of the lower networks 5a, 5b includes a LIN transceiver (not shown) connected to the buses 53, 56, and a LIN transceiver. And a microcomputer (not shown) connected to the. Each node 41, 42, 51, 52, 54, 55 communicates in a master-slave manner using a serial communication device (UART: Universal Asynchronous Receiver / Transmitter) built in the microcomputer.

  In the lower network 5a, the CAN and LIN nodes 41 are master nodes, and the LIN nodes 51 and 52 are slave nodes. In the lower network 5b, the CAN and LIN nodes 42 are master nodes, and the LIN nodes 54 and 55 are slave nodes.

  In the lower networks 5a and 5b, master-slave communication using the LIN communication protocol is performed according to the LIN schedule as shown in FIG. The LIN schedule of the lower networks 5a and 5b is composed of repeated LIN frames.

  When the CAN and LIN nodes 41 and 42 as master nodes request a response, the LIN frame assigned to the communication with the request destination nodes 41, 42, 51, 52, 54, and 55 (for example, FIG. 3, a header (token) as a request is transmitted to the buses 53 and 56 at the beginning of the LIN frame (1) in FIG. The header includes an ID (identifier) of the LIN frame and data length information that can be transmitted as a response, and is received by each of the nodes 41, 42, 51, 52, 54, and 55.

  Each node 41, 42, 51, 52, 54, 55 that has received the header checks whether the header ID corresponds to the ID of the LIN frame assigned for transmission to its own node. Transmits transmission waiting data (data 1 to n) to the buses 53 and 56 using the frame portion of the response following the header of the LIN frame.

  The LIN nodes 51, 52, 54, and 55, which are slave nodes of the lower networks 5a and 5b, include control objects provided in each part of the vehicle and an ECU that controls them. Vehicle control targets include, for example, sensors for detecting opening / closing of doors, opening / closing of door mirrors, seat positions, power window opening / closing positions, etc., body control of electric seat motors, power window motor engines (not shown), etc. There are objects, objects for powertrain control such as engines, and objects for chassis control such as steering (not shown).

  By the way, when the CAN / LIN node 41 receives a data frame in which “open identifier” is defined as an ID from the upper network 3, the CAN / LIN node 41 is in the period of the data transmission field (data field) of the data frame that comes after the ID. (Corresponding to a predetermined period in the claims), the upper network 3 and the lower network 5a are connected for a predetermined period. Similarly, when the CAN and LIN node 42 receives a data frame in which “open identifier” is defined as an ID from the upper network 3, the upper network 3 and the lower network 5b are connected during the data field of the data frame. Connecting.

  The data transmission field (data field) of the data frame corresponds to the data area in the claims.

  Here, the “open identifier” is an identifier indicating that the upper network 3 is opened for communication between the LIN nodes 51 and 52 of the lower network 5a and the LIN nodes 54 and 55 of the lower network 5b. In this embodiment, the CAN node 31 transmits a data frame in which “open identifier” is defined as an ID to the upper network 3.

  The transmission of the data frame in which the “open identifier” is defined as the ID by the CAN node 31 may be performed at regular intervals or irregularly as necessary. Further, the transmission of the data frame to the upper network 3 may be performed by the other CAN nodes 32 and 33, or may be performed by one of the CAN and LIN nodes 41 and 42.

  When the CAN and LIN nodes 41 and 42 perform notification that the data to be transmitted has been generated from the lower terminals 51, 52, 54, and 55 of the lower networks 5a and 5b connected thereto, A data frame in which “open identifier” is defined as an ID may be transmitted to the upper network 3.

  The “open identifier” described above relates only to the CAN and LIN nodes 41 and 42 involved in the connection and termination of the lower networks 5a and 5b and the upper network 3, and does not relate to the other CAN nodes 31 to 33. Therefore, even if the CAN nodes 31 to 33 recognize that the “open identifier” is defined in the ID of the data frame being received, the corresponding processing (operation) is not performed.

  Further, while the lower networks 5 a and 5 b are connected to the upper network 3, the lower networks 5 a and 5 b constitute a single network via the upper network 3. Therefore, while the lower networks 5a and 5b are connected to the upper network 3, the CAN, LIN nodes 41 and 42 and the LIN nodes 51, 52, 54 and 55 on the lower networks 5a and 5b Master-slave communication over the network 3 is performed.

  At this time, a node that acts as a master node in the lower networks 5a and 5b constituting one network via the upper network 3 is determined as one of the CAN and LIN nodes 41 and 42, for example. In the present embodiment, the master node connected to the upper network 3 of the lower networks 5a and 5b is a CAN and LIN node 41, and the slave nodes are a CAN and LIN node 42 and LIN nodes 51, 52, 54, and 55.

  Then, after each CAN, LIN node 41, 42 connects the lower networks 5a, 5b to the upper network 3, the CAN, LIN node 41, which is the master node, uses the identifier as the LIN node that it serves as the ID of the LIN frame. The included header is transmitted to the lower network 5a and the upper network 3 (via the lower network 5b).

  Further, the CAN and LIN node 41 that has received this header sends a response including the “release notification identifier” in the ID of the LIN frame to the CAN and LIN nodes 42 and LIN nodes 51 and 52 that are slave nodes, and CAN and LIN. The data is transmitted to the LIN nodes 54 and 55 via the node 42, respectively. The CAN / LIN node 42 and the LIN nodes 51, 52, 54, and 55 that have received this response recognize that the upper network 3 is connected to the lower network 5a and the lower network 5b.

  Further, the CAN / LIN node 41, which is the master node, sets an identifier as a LIN node that it serves as a LIN node immediately before the transmission period (predetermined period) of the data field ends and the lower networks 5a and 5b are disconnected from the upper network 3. The header included in the frame ID is transmitted to the lower network 5a and the upper network 3 (via the lower network 5b).

  Further, the CAN and LIN node 41 that has received this header sends a response including the “end notification identifier” in the ID of the LIN frame to the CAN and LIN nodes 42 and LIN nodes 51 and 52 that are slave nodes, and CAN and LIN. The data is transmitted to the LIN nodes 54 and 55 via the node 42, respectively. The CAN / LIN node 42 and the LIN nodes 51, 52, 54, and 55 that have received this response recognize that the upper network 3 has been disconnected from the lower network 5a and the lower network 5b.

  The period during which the lower networks 5a and 5b are connected to the upper network 3, that is, the data length of the data field of the data frame transmitted in the upper network 3, is determined in the control field of the data frame in which the “open identifier” is defined as the ID. Defined. The control field is assigned after the ID of the data frame followed by the identifier (RTR). A data field having a data length defined in the control field is assigned to the data frame following the control field.

  Therefore, during the period of the data length defined in the control field following the control field (during the period of the data field), the nodes 41, 51, 52 of the lower network 5a and the nodes 42, 54, 55 of the lower network 5b The upper network 3 is opened for communication between them.

  Specifically, while the upper network 3 and the lower networks 5a and 5b are connected, the CAN and LIN nodes 41 and 42 communicate with the LIN received by the CAN and LIN nodes 41 and 42 from the lower networks 5a and 5b. The header and response based on the protocol are passed through to the upper network 3 as they are.

  While the upper network 3 and the lower networks 5a and 5b are connected, the CAN and LIN nodes 41 and 42 pass-through transmit the data received from the upper network 3 to the lower networks 5a and 5b as it is. . Therefore, when the data received from the upper network 3 is originally a header or response according to the LIN communication protocol received by the CAN and LIN nodes 41 and 42 from the lower networks 5a and 5b and transmitted to the upper network 3, The header and response are transmitted through the lower networks 5a and 5b by the CAN and LIN nodes 41 and 42 with the LIN communication protocol maintained.

  When performing the above-described pass-through transmission, the CAN and LIN nodes 41 and 42 appropriately set the potential difference in the physical layer between the communication protocols between the bus 34 of the upper network 3 and the buses 53 and 56 of the lower networks 5a and 5b. Convert. In addition, the insertion of stuff bits according to the bit stuffing rule in the CAN communication protocol is performed in the same manner for the header and response data according to the LIN communication protocol transmitted through the lower network 5a, 5b to the upper network 3.

  The flowchart of FIG. 4 shows a processing procedure performed by the CAN / LIN node 41 acting as a master node during the connection between the upper network 3 and the lower networks 5a and 5b described above. This processing procedure is executed by the CPU according to a program stored in a ROM of a microcomputer (not shown) included in the CAN / LIN node 41.

  Note that some or all of the following processing procedures can be executed by hardware such as a DSP or an ASIC. However, in the present embodiment, a case where the CPU executes in accordance with the ROM program will be described.

  As shown in FIG. 4, the CAN / LIN node 41 receives a data frame based on the CAN communication protocol from the upper network 3 (step S1), and whether or not an “open identifier” is defined in the ID of the received data frame. (Step S3). If the “open identifier” is not defined (NO in step S3), the process returns to step S1, and if the “open identifier” is defined (YES in step S3), the CAN / LIN node 41 receives the data. The data length of the data field is acquired from the control field of the data frame (step S5).

  Then, the CAN / LIN node 41 calculates the time required for transmission of the data field (transmission equivalent time) from the acquired data length as a predetermined period for connecting the upper network 3 and the lower network 5a (step S7). If calculated, the CAN and LIN node 41 waits for the end of the control field (start of the data field) (step S9), and starts counting time for a predetermined period from the start of the data field (step S11). The network 3 and the lower network 5a are connected (step S13).

  When the connection between the upper network 3 and the lower network 5a is physically performed by switching, the CAN / LIN node 41 physically connects the bus 34 of the upper network 3 and the bus 53 of the lower network 5a.

  Subsequently, the CAN and LIN nodes 41 respectively transmit a header (release notification frame) including the “release notification identifier” in the ID of the LIN frame to the upper network 3 (via the lower network 5b) and the lower network 5a (step S1). S15). Then, it is confirmed whether or not the predetermined period has approached (immediately before the predetermined period elapses) (step S17). If the predetermined period has approached (or has already elapsed) (YES in step S17), the process proceeds to step S27 described later. If the predetermined period has not yet elapsed (NO in step S17), CAN, LIN The node 41 sends a header (token) as a request to the slave nodes CAN, LIN node 42, and LIN nodes 51, 52, 54, and 55 in a predetermined order, for example, in ascending order of ID (identifier). Is transmitted (step S19).

  Next, the CAN / LIN node 41 passes through the header and response according to the LIN communication protocol received from the lower network 5a to the upper network 3 (via the lower network 5b). At the same time, the header and response according to the LIN communication protocol received from the upper network 3 (via the lower network 5b) are transmitted through to the lower network 5a (step S21).

  When the upper network 3 and the lower network 5a are physically connected and connected, the CAN / LIN node 41 does not perform specific processing for pass-through transmission.

  Then, the CAN / LIN node 41 confirms whether the CAN / LIN node 42 and the LIN nodes 51, 52, 54, and 55 have transmission-waiting data to be transmitted as responses according to the LIN communication protocol (step S23). ). If there is data (YES in step S23), the process returns to step S17. If there is no data (NO in step S23), the time count of the data field started in step S11 (between the upper network 3 and the lower network 5a) The process waits until immediately before the connection time reaches the predetermined period (step S25), and the process proceeds to step S27.

  In step S27, the CAN / LIN node 41 transmits a header (end notification frame) including the “end notification identifier” in the ID of the LIN frame to the upper network 3 (via the lower network 5b) and the lower network 5a, respectively. The connection between the lower network 5a and the upper network 3 is terminated and disconnected (step S29). The transmission of the end notification frame is completed before the time count of the data field started in step S11 (connection time between the upper network 3 and the lower network 5a) reaches a predetermined period. Then, a series of procedures is completed.

  When the connection between the upper network 3 and the lower network 5a is physically performed by switching, the CAN / LIN node 41 physically separates the bus 34 of the upper network 3 and the bus 53 of the lower network 5a.

  Next, the flowchart of FIG. 5 shows a processing procedure performed by the CAN / LIN node 42 acting as a slave node during the connection between the upper network 3 and the lower networks 5a and 5b described above. This processing procedure is executed by the CPU according to a program stored in a ROM of a microcomputer (not shown) included in the CAN / LIN node 42.

  As shown in FIG. 5, the CAN / LIN node 42 receives a data frame based on the CAN communication protocol from the upper network 3 (step S31), and whether or not an “open identifier” is defined in the ID of the received data frame. (Step S33). If “open identifier” is not defined (NO in step S33), the process returns to step S31. If “open identifier” is defined (YES in step S33), the CAN and LIN nodes 42 are subordinate. The function of transmitting the header according to the LIN communication protocol to the LIN nodes 54 and 55 on the lower network 5b as the master node of the network 5b is stopped (step S35).

  Then, the CAN / LIN node 42 connects the upper network 3 and the lower network 5b (step S37). When the connection between the upper network 3 and the lower network 5b is physically performed by switching, the CAN / LIN node 42 physically connects the bus 34 of the upper network 3 and the bus 56 of the lower network 5b.

  Next, the CAN / LIN node 42 checks whether or not the predetermined period has approached (immediately before the predetermined period elapses) (step S39). Here, the data acquired from the data frame in which “open identifier” is defined in the ID of the data frame is the same as that performed by the CAN and LIN node 41 according to the procedure of steps S5 to S7 in FIG. The CAN / LIN node 42 calculates from the data length of the field.

If the predetermined period has approached (or has already elapsed) (YES in step S39), the process proceeds to step S47 described later, and if the predetermined period has not yet elapsed (NO in step S39), CAN , The LIN node 41 passes through the header and response of the LIN communication protocol received from the lower network 5b to the upper network 3 (via the lower network 5a). At the same time, the header and response based on the LIN communication protocol received from the upper network 3 (via the lower network 5a) are passed through to the lower network 5b (step S41).
When the upper network 3 and the lower network 5a are physically connected and connected, the CAN / LIN node 41 does not perform specific processing for pass-through transmission.

  Then, the CAN / LIN node 42 confirms whether the header received by the higher level network 3 (via the lower level network 5a) or the lower level network 5b is the header to be returned. (Step S43). Whether or not it is a header to be returned can be confirmed by whether or not the received header is a header corresponding to the ID of the LIN frame assigned to transmission to the own node.

  If it is not a header to be replied (NO in step S43), the process returns to step S39. If it is a header to be replied (YES in step S43), the corresponding data is used as a response, and the upper network 3 ( Then, the data is transmitted to the lower network 5a) and the lower network 5b (step S45). Then, the process returns to step S39.

  In step S47, the CAN / LIN node 42 receives the header (end notification frame) including the “end notification identifier” in the ID of the LIN frame from the upper network 3 (via the lower network 5a), and responds thereto. Then, the connection between the lower network 5b and the upper network 3 is terminated and disconnected (step S49). Then, a series of procedures is completed.

  When the connection between the upper network 3 and the lower network 5b is physically performed by switching, the CAN / LIN node 42 physically separates the bus 34 of the upper network 3 and the bus 56 of the lower network 5b.

  As is clear from the above description, in this embodiment, steps S1 to S13, step S17, and step S29 in the flowchart of FIG. 4 and steps S31, S33, S37, and step in the flowchart of FIG. S39 and step S49 are processing corresponding to the connection means in the claims. Moreover, in this embodiment, step S15 in FIG. 4 is a process corresponding to the release notification means in the claims.

  Furthermore, in this embodiment, step S21 in FIG. 4 and step S41 in FIG. 5 are processing corresponding to the pass-through means in the claims. In the present embodiment, step S27 in FIG. 4 is processing corresponding to the end notification means in the claims.

  Next, communication performed in the communication network system 1 of the present embodiment shown in FIG. 1 will be described with reference to the explanatory diagram of FIG.

  In the explanatory diagram of FIG. 6, data transmitted in the upper network 3 is schematically shown. First, in the upper network 3, communication between the CAN nodes 31 to 33 and the CAN and LIN nodes 41 and 42 is usually performed using a frame based on the CAN communication protocol.

  In this communication, as shown in the left frame in the figure, nodes 31 to 33, 41, and 42 having data waiting to be transmitted have data frames (header portion, data load portion (= data field, the same applies hereinafter), footer). Part) to the upper network 3 at an arbitrary timing. Then, the CAN contents 31 to 33 and the CAN and LIN nodes 41 and 42 corresponding to the data content defined in the ID field of the header part of the data frame and the transmission partner receive the transmission data of the data load part.

  On the other hand, when the upper network 3 is opened for communication between the nodes 41, 42, 51, 52, 54, and 55 of the lower networks 5a and 5b, the lower network straddling the upper network 3 using a frame based on the CAN communication protocol. Communication is performed between the nodes 41, 51, and 52 of the network 5a and the nodes 42, 54, and 55 of the lower network 5b.

  In this communication, a header or response frame according to the LIN communication protocol is communicated on the upper network 3 during a data frame transmission period according to the CAN communication protocol, as in the center frame in the figure.

  Therefore, in the state where the CAN node 31 (or the CAN nodes 32 and 33 and the CAN and LIN nodes 41 and 42) is not communicating in the upper network 3, the “open identifier” is defined in the header part as an ID. The transmitted data frame is transmitted to the upper network 3. In this case, the data load part of the data frame to be transmitted is set to recessive (bus idle state).

  Then, the CAN and LIN nodes 41 and 42 connect the lower networks 5a and 5b to the upper network 3, and the fact is indicated by the release notification identifier defined in the header ID transmitted to the lower networks 5a and 5b by the LIN communication protocol. The nodes 41, 42, 51, 52, 54, and 55 of the lower networks 5a and 5b are notified.

  Thereafter, the CAN and LIN nodes 41 that act as master nodes in the lower networks 5a and 5b that are connected via the upper network 3 to form a single network send headers based on the LIN communication protocol to the upper network 3 as well as the lower network 5a. To the lower network 5b. Thus, the header transmitted by the CAN / LIN node 41 of the master node is transmitted not only to the lower network 5a but also to the other lower networks 5b and 5a across the upper network 3.

  Further, the nodes 41, 42, 51, 52, 54, 55 corresponding to the header ID transmit responses following the header to the lower networks 5a, 5b using the LIN communication protocol, and receive each CAN, The LIN nodes 41 and 42 pass through the received response and transmit it to the upper network 3 as well. Further, data (response) received from the other lower networks 5a and 5b via the upper network 3 is transferred to the nodes 41 and 42 in the lower networks 5a and 5b to which the CAN and LIN nodes 41 and 42 are connected. 42, 51, 52, 54, and 55 are transmitted as responses. Thereby, the response transmitted in each lower network 5a, 5b is also transmitted to the other lower networks 5b, 5a across the upper network 3.

  Immediately before the end of the predetermined period, the CAN / LIN node 41 defines the end notification identifier defined in the ID of the header transmitted to the lower networks 5a and 5b as to the end of the connection to the upper network 3 of the lower networks 5a and 5b. To notify the nodes 42, 51, 52, 54, and 55 of the lower networks 5a and 5b.

  When the predetermined period ends, the lower networks 5a and 5b are disconnected from the upper network 3, and the CAN nodes 31 to 33 and the CAN and LIN nodes 41 and 42 communicate with each other again using a frame based on the CAN communication protocol. Specifically, as in the frame on the right side in FIG. 6, the nodes 31 to 33, 41, and 42 having data waiting to be transmitted can transmit data frames (header part, data load part, footer part) at an upper timing network at an arbitrary timing. 3 to send. Then, the CAN contents 31 to 33 and the CAN and LIN nodes 41 and 42 corresponding to the data content defined in the ID field of the header part of the data frame and the transmission partner receive the transmission data of the data load part.

  As described above, in the communication network system 1 of the present embodiment, even if the upper network 3 is a CAN using an asynchronous communication protocol, the opening of the upper network 3 is defined using the ID of the CAN data frame. Also, by using the ID of the LIN header to notify the opening and termination of the upper network 3, the upper network 3 is sent to each of the nodes 41, 42, 51, 52, 54, 55 of the lower networks 5a, 5b. The open period (predetermined period) can be recognized.

  For this reason, in a predetermined period in which the CAN and LIN nodes 41 and 42 connect the lower networks 5a and 5b to the upper network 3, the header and response according to the LIN communication protocol are transmitted to the upper network 3 as they are. Communication between the nodes 41, 42, 51, 52, 54, and 55 of the lower networks 5a and 5b across the network 3 can be realized.

  In the present embodiment, the case where the upper network 3 is CAN and each of the lower networks 5a and 5b is LIN has been described as an example. However, the present invention can also be applied to a case where a network using an asynchronous communication protocol other than CAN is used for the upper network. In that case, the lower network may be a network using an asynchronous communication protocol or a network using a synchronous communication protocol.

  That is, for example, the present invention can also be applied to the case where separate CAN networks are used for the upper network 3 and the lower networks 5a and 5b. In this case, there is an advantage that the ID space used in each network can be distinguished and operated.

  In the present embodiment, the CAN / LIN node 41 transmits a header (release notification frame, end notification frame) including “release notification identifier” or “end notification identifier” in the ID of the LIN frame. However, the other CAN, LIN node 42 may transmit them instead of the CAN, LIN node 41, or each CAN, LIN node 41, 42 may transmit.

  Furthermore, in this embodiment, the case where each node 31-33, 41, 42 communicates using only a data frame in the high-order network 3 was demonstrated. However, any one of the nodes 31 to 33, 41, and 42 transmits the remote frame to the upper network 3 at an arbitrary timing, and the nodes 31 to 33, 41, and 42 corresponding to the ID of the remote frame (the node that transmitted the header is also included). However, the present invention can also be applied to the case where data waiting to be transmitted is transmitted to the upper network 3 by a data frame.

  Also in this case, the frame transmitted by the CAN node 31 to 33 or any of the CAN and LIN nodes 41 and 42 to the upper network 3 with the “open identifier” defined as an ID is the same as the above-described embodiment. Become. Further, the CAN and LIN node 41 and the CAN and LIN node 42 that receive this data frame from the upper network 3 connect the upper network 3 and the lower network 5b during the period in which the received data frame is received. During the data field.

  The present invention is used in a communication network system having an upper network in which upper terminals communicate with each other using an asynchronous communication protocol and a plurality of lower networks in which lower terminals communicate with each other using an asynchronous communication protocol or a synchronous communication protocol. Very useful.

DESCRIPTION OF SYMBOLS 1 Communication network system 3 Upper network 5a, 5b Lower network 31-33 CAN exclusive node 34 bus 41, 42 CAN, LIN combined node 51, 52, 54, 55 LIN exclusive node 53, 56 bus

Claims (5)

In a communication network system having an upper network in which upper terminals communicate with each other using an asynchronous communication protocol and a plurality of lower networks in which lower terminals communicate with each other using an asynchronous communication protocol or a synchronous communication protocol, the upper network and a plurality of A relay terminal connected to both the lower network and serving as both the upper terminal and the lower terminal;
The data length defined in the area following the release identifier in the frame received from the higher level network when the frame received from the higher level network includes the release identifier for releasing the higher level network in communication between the lower level terminals Connecting means for connecting the lower network to the upper network for a predetermined period in which a data area having
When the connection means connects the lower network to the upper network, an open notification for transmitting a request or response including an open notification identifier for notifying the release of the upper network for communication between the lower terminals to the lower network Means,
After the connection means connects the lower network to the upper network, an end notification identifier for notifying each lower terminal of the end of opening of the upper network for communication between the lower terminals before the predetermined period elapses. An end notification means for transmitting a request or response including the request to the lower network;
While connecting to the upper network of the lower network, the request and response received from the lower network are passed through, and transmitted to the upper network as transmission data in the data area in the frame and received from the upper network. Pass-through means for passing through the transmission data in the data area in the response, and sending it as a request or response to the lower network; and
A relay terminal for a communication network system, comprising:   2. The communication network system according to claim 1, further comprising a release request unit that transmits a frame including the release identifier to the higher network when the higher network is released for communication between the lower terminals. Relay terminal. The upper network is a CAN (Controller Area Network),
The response including the release identifier is transmitted to the upper network in the ID field of the data frame of the CAN,
The predetermined period is a period for securing transmission of a data field after the ID field in the data frame of the CAN,
The pass-through means transmits a request or response received from the lower network and passed through to the upper network in the data field of the data frame, and receives data received from the upper network in the data field of the data frame. Send it as a request or response to the lower network,
The relay terminal for a communication network system according to claim 1 or 2. The lower network is a LIN (Local Interconnect Network),
The release notification means and the end notification means respectively notify the release and release end of the upper network by a header or response identifier of a LIN frame transmitted to the lower network,
The pass-through means passes through the header or response of the LIN frame received from the lower network and transmits it to the upper network in the data field of the data frame and receives from the upper network in the data field of the data frame. Sending the passed-through data to the lower network as a header or response of the LIN frame;
The relay terminal for a communication network system according to claim 3. In a communication network system having an upper network in which upper terminals communicate with each other using an asynchronous communication protocol and a plurality of lower networks in which lower terminals communicate with each other using an asynchronous communication protocol or a synchronous communication protocol,
A plurality of relay terminals connected to both the upper network and one of the plurality of lower networks and serving as both the upper terminal and the lower terminal;
The relay terminal according to claim 1, 2, 3, or 4 is used as each relay terminal.
A communication network system characterized by the above.

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