Relay equipment and network systems

Abstract

To provide a relay device and a network system that enable proper communication without using a relay node as a master when connecting a master-slave type network through a different network.SOLUTION: A relay node 10c comprises a first communication part 11 which communicates with a CAN network 51, a second communication part 12 which communicates with a LIN network 43, and a relay part 13 which relays the CAN network 51 and LIN network 43. When the first communication part 11 receives a header from the CAN network 51, the relay part 13 waits until the first communication part 11 receives a response corresponding to the header, and then lets the second communication part 12 transmit the header and response to the LIN network 43 if the header is not addressed to a LIN node 20c connected to the LIN network 43.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a relay device that relays two networks and a network system having the relay device.

Background Art

[0002] For example, in a network system where ECUs (Electronic Control Units) communicate with each other inside a vehicle, different networks with different communication protocols may be adopted for power train control, etc. that requires high communication speed and reliability, and communication of sensors and actuators, etc. that do not require such high communication speed and reliability.

[0003] In this case, a relay node (relay device) that performs protocol conversion, etc. when performing communication across networks is installed. As an invention related to relaying between different networks, for example, Patent Document 1 can be cited.

[0004] Patent Document 1 describes that when the upper network is a CAN (Controller Area Network) using an asynchronous communication protocol, the release of the upper network is defined using the ID of the data frame of CAN. And it is described that the release and end of the upper network are notified to each node of the lower network using the ID of the header of LIN (Local Interconnect Network) of the lower network using a synchronous communication protocol.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the invention described in Patent Document 1, the relay node (CAN, LIN node) needs to become the master of the LIN network. However, when attempting to connect to a LIN network where a master has already been configured, the master must be changed from the LIN node to the relay node.

[0007] Furthermore, when a LIN node other than a relay node is the master, and it sends a header to a LIN node beyond the CAN network, the response may not be able to send a response corresponding to that header, resulting in a mismatch between the header and the response. In such cases, other LIN nodes may not be able to understand the response as corresponding to the header.

[0008] Therefore, in view of the above-mentioned problems, the present invention aims to provide a relay device and network system that can properly communicate when connecting master-slave networks via different networks, even without designating the relay node as the master. [Means for solving the problem]

[0009] The invention made to solve the above problems comprises a first communication unit that communicates with a first network, a second communication unit that communicates with a master-slave second network, and a relay unit that relays between the first network and the second network, wherein when the first communication unit receives a data transmission command from the first network, if the destination of the data transmission command is not a node connected to the second network, the relay unit waits until the first communication unit receives the data corresponding to the data transmission command, and then transmits the data transmission command and the data from the second communication unit to the second network. [Effects of the Invention]

[0010] According to the present invention, since data is waited for before being transmitted upon receiving a data transmission command, master-slave communication can be properly performed even without designating a relay node as the master. [Brief explanation of the drawing]

[0011] [Figure 1] This is a diagram showing the configuration of a network system according to the first embodiment of the present invention. [Figure 2] Figure 1 is a functional configuration diagram of the relay node. [Figure 3] Figure 1 is an explanatory diagram of the operation of the network system shown. [Figure 4] Figure 1 is a sequence diagram of the operation of the network system shown. [Figure 5] This is a diagram showing the configuration of a network system according to a second embodiment of the present invention. [Figure 6] Figure 5 is an explanatory diagram of the operation of the network system shown. [Figure 7] Figure 5 is a sequence diagram of the operation of the network system shown. [Modes for carrying out the invention]

[0012] (First Embodiment) Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. Figure 1 is a configuration diagram of a network system according to the first embodiment of the present invention.

[0013] Network system 1 includes relay nodes 10a, 10b, and 10c, LIN nodes 20a, 20b, and 20c, and a CAN node 30.

[0014] The relay node 10a and the LIN node 20a are connected by a LIN network 41. The relay node 10b and the LIN node 20b are connected by a LIN network 42. The relay node 10c and the LIN node 20c are connected by a LIN network 43. Also, the relay node 10a, the relay node 10b, the relay node 10c, and the CAN node 30 are connected by a CAN network 51.

[0015] As is well known, the LIN networks 41, 42, and 43 are communication networks of the master-slave system. In the present embodiment, the following description will be given with the LIN node 20b as the master and the LIN nodes 20a and 20c as the slaves. That is, in the present embodiment, no slaves are connected to the LIN network to which the master is connected. Also, the LIN nodes 20a, 20b, and 20c in FIG. 1 constitute the same network system, such as devices provided on the same door.

[0016] As is well known, the CAN network 51 is an asynchronous communication network. The CAN node 30 is a node connected to the CAN network 51. In the present embodiment, the CAN network 51 corresponds to the first network, and the LIN networks 41, 42, and 43 correspond to the second network.

[0017] FIG. 2 shows a functional configuration diagram of the relay node 10a. Note that the relay nodes 10b and 10c have the same configuration. The relay node 10a includes a first communication unit 11, a second communication unit 12, and a relay unit 13. That is, the relay nodes 10a, 10b, and 10c are relay devices according to the first embodiment of the present invention.

[0018] The first communication unit 11 communicates with the CAN network 51. That is, it communicates with other nodes in accordance with the CAN protocol.

[0019] The second communication unit 12 communicates with the LIN network 41 (LIN network 42 in the case of the relay node 10b, LIN network 43 in the case of the relay node 10c). That is, it communicates with other nodes in accordance with the LIN protocol.

[0020] The relay unit 13 relays the transmission and reception of data and the like between the LIN network 41 and the CAN network 51. Note that the relay unit 13 has previously acquired and stored the ID and the like of the nodes (subordinate nodes) connected to the LIN network. Details of the operation of the relay unit 13 will be described later.

[0021] Next, the operation of the network system 1 having the above-described configuration will be described with reference to FIGS. 3 and 4. The following operation is the case where the LIN node 20b, which is the master, transmits a header of a transmission instruction to the LIN node 20a, which is the slave. Note that FIG. 3 is a diagram in which the transmission direction of data and the like corresponding to the sequence diagram of FIG. 4 and its order are added to FIG. 1. In the present embodiment, the transmission instruction header corresponds to a data transmission command, and the response corresponds to data.

[0022] First, a LIN frame of a transmission instruction header (hereinafter referred to as a transmission instruction header, which is abbreviated as a header in FIG. 4) is transmitted from the LIN node 20b, which is the master, to the relay node 10b. The relay node 10b converts the transmission instruction header into a CAN frame and transmits it to the relay node 10a and the relay node 10c ((1) in FIGS. 3 and 4).

[0023] In the relay node 10b in (1) of FIGS. 3 and FIG. 4 described above, since the destination of the transmission instruction header received by the second communication unit 12 via the LIN network 42 is not addressed to a node connected to the LIN network 42, the transmission instruction header is output from the relay unit 13 to the first communication unit 11. The first communication unit 11 converts the transmission instruction header into a CAN frame and outputs it to the CAN network 51.

[0024] Next, the relay node 10a transmits the transmission instruction header received from the relay node 10b to the subordinate LIN node 20a ((2) in FIGS. 3 and 4).

[0025] In the relay node 10a shown in Figures 3 and 4 (2) above, the destination of the CAN frame (transmit instruction header) received by the first communication unit 11 via the CAN network 51 is a LIN node connected to the LIN network 41. Therefore, the relay unit 13 immediately outputs the received transmit instruction header to the second communication unit 12. The second communication unit 12 then outputs the transmit instruction header to the LIN network 41. Here, "immediately" means without waiting for a response to be received.

[0026] Next, LIN node 20a, having received the transmit instruction header, sends a response to the transmit instruction header to relay node 10a. Relay node 10a converts the received response into a CAN frame and sends it to relay nodes 10b and 10c, respectively (Figures 3 and 4 (3)).

[0027] In the relay node 10a described above in Figures 3 and 4 (3), the relay unit 13 outputs the response received by the second communication unit 12 via the LIN network 41 as a response to the transmission instruction header to the first communication unit 11. The first communication unit 11 converts the response into a CAN frame and outputs it to the CAN network 51.

[0028] On the other hand, relay node 10c, which has received the transmit instruction header, does not have a LIN node 20a connected to it, so it waits to receive a response from LIN node 20a before sending the transmit instruction header + response to the LIN node 20c (Figures 3 and 4 (4) and (5)).

[0029] In the case of relay node 10c in (4) and (5) of Figures 3 and 4 described above, the transmission instruction header that the first communication unit 11 received first via the CAN network 51 is not destined for a subordinate LIN node, so the relay unit 13 holds onto the transmission instruction header and waits.

[0030] Then, when the first communication unit 11 receives a response via the CAN network 51, the relay unit 13 outputs the response and the transmission instruction header together to the second communication unit, which then outputs it to the LIN network 43.

[0031] According to this embodiment, for example, the relay node 10c includes a first communication unit 11 that communicates with the CAN network 51, a second communication unit 12 that communicates with the master-slave LIN network 43, and a relay unit 13 that relays between the CAN network 51 and the LIN network 43. When the first communication unit 11 receives a transmit instruction header from the CAN network 51, if the destination of the transmit instruction header is not to a LIN node 20c connected to the LIN network 43, the relay unit 13 waits until the first communication unit 11 receives a response corresponding to the transmit instruction header, and then has the second communication unit 12 send the transmit instruction header and the response to the LIN network 43.

[0032] With the relay node 10c configured as described above, it waits for a response upon receiving the transmission instruction header before transmitting, allowing for proper master-slave communication even without the relay node 10c being the master.

[0033] Furthermore, when the second communication unit 12 receives a transmission instruction header from the LIN network 42, the relay unit 13, if the destination of the transmission instruction header is not a node connected to the LIN network 42, causes the relay unit 13 to send the header from the first communication unit 11 to the CAN network 51. In this way, transmission instruction headers destined for networks other than the LIN network to which it is connected can be relayed and transmitted externally.

[0034] Furthermore, when the first communication unit 11 receives a transmission instruction header from the CAN network 51, the relay unit 13 immediately sends the transmission instruction header from the second communication unit 12 to the LIN network 41 if the destination of the transmission instruction header is a LIN node 20a connected to the LIN network 41. In this way, it is possible to relay and transmit transmission instruction headers from the CAN network 51 to the LIN network 41 connected to itself.

[0035] Furthermore, when the relay unit 13 receives a response from the LIN network 41 as a response to the transmission instruction header received by the first communication unit 11 from the CAN network 51, the relay unit 13 immediately causes the first communication unit 11 to send the response to the CAN network 51. In this way, responses to transmission instruction headers addressed to the LIN network 41 to which it is connected can be relayed and transmitted without delay.

[0036] (Second Embodiment) Next, a second embodiment of the present invention will be described with reference to the drawings. Parts identical to those in the first embodiment described above are denoted by the same reference numerals and their descriptions are omitted.

[0037] As shown in Figure 5, the network system 1A according to this embodiment includes relay nodes 10d and 10e, LIN nodes 20a, 20b, and 20c, and a CAN node 30. The LIN nodes 20a, 20b, and 20c and the CAN node 30 are the same as in the first embodiment. In this embodiment as well, the following description will assume that LIN node 20b is the master and LIN nodes 20a and 20c are slaves.

[0038] In this embodiment, relay node 10d is connected to LIN nodes 20a and 20b via LIN network 44. That is, the master and at least one of the slaves are connected to the same LIN network. Relay node 10e is connected to LIN node 20c via LIN network 45. The functional configuration of relay nodes 10d and 10e is the same as in Figure 2. That is, relay nodes 10d and 10e are relay devices according to the second embodiment of the present invention. In this embodiment as well, LIN nodes 20a, 20b, and 20c in Figure 5 constitute the same network system, for example, devices installed in the same door.

[0039] Next, the operation of the network system 1A in this embodiment will be described with reference to Figures 6 and 7. The following operation is when the master LIN node 20b sends a transmission instruction header to the slave LIN node 20a. Figure 6 is a diagram that adds the transmission direction and order of data, etc., corresponding to the sequence diagram in Figure 7, to Figure 5.

[0040] First, a LIN frame containing a transmit instruction header is sent from LIN node 20b to LIN node 20a. In this embodiment, since LIN node 20a and LIN node 20b are connected to the same LIN network 44, LIN node 20a receives the transmit instruction header as is. At the same time, relay node 10d also receives the transmit instruction header.

[0041] Upon receiving the transmission instruction header, LIN node 20a sends a response corresponding to that header. The response is received by LIN node 20b and relay node 10d.

[0042] When relay node 10d receives a transmit instruction header, it waits for a response to that header because LIN node 20a and the master (LIN node 20b) are connected to it (Figures 6 and 7 (6)). Upon receiving the response, it sends the transmit instruction header + response CAN frame to relay node 10e via the CAN network 51 (Figures 6 and 7 (7)).

[0043] In the case of relay node 10d in (6) and (7) of Figures 6 and 7 described above, the destination of the transmission instruction header that the second communication unit 12 received first via the LIN network 44 was a node connected to the LIN network 44, so the relay unit 13 waits while holding the transmission instruction header. After the second communication unit 12 receives the response transmitted by the LIN node 20a, the relay unit 13 outputs a CAN frame containing the transmission instruction header and the response from the first communication unit 11.

[0044] Then, relay node 10e, having received the CAN frame output by relay node 10d, sends the transmission instruction header + response to its subordinate LIN node 20c (Figure 6, Figure 7 (8)).

[0045] In the relay node 10e described in Figures 6 and 7(8) above, the first communication unit 11 simultaneously receives the transmit command header and response from the CAN network 51. Therefore, it immediately converts the transmit command header and response into a LIN frame and outputs it to the LIN network 45 from the second communication unit 12. Here, "simultaneously" does not mean at the same time, but rather the same CAN frame (a single block of data).

[0046] According to this embodiment, when the relay node 10d receives a transmission instruction header from the LIN network 44 via the second communication unit 12, if the destination of the transmission instruction header is a LIN node connected to the LIN network 44, the relay unit 13 of the relay node 10d waits until the second communication unit 12 receives a response corresponding to the transmission instruction header before sending the transmission instruction header and the response from the first communication unit 11 to the CAN network 51.

[0047] With the relay node 10d configured as described above, even in cases where the exchange of transmission command headers and responses is completed within the subordinate network, it is possible to send transmission command headers and responses to a slave via an external network. Therefore, master-slave communication can be properly performed even without relay node 10c being the master.

[0048] Furthermore, when the first communication unit 11 simultaneously receives a transmit command header and a response from the CAN network 51, the relay unit 13 immediately causes the second communication unit 12 to transmit the transmit command header and response to the LIN network 45. In this way, when a CAN frame consisting of a transmit command header and a response is received, it can be transmitted immediately without any waiting period.

[0049] In the configuration shown in Figure 5, if LIN node 20b (master) sends a transmit command header to LIN node 20c, the operation is the same as in the first embodiment. That is, relay node 10d sends a transmit command header to relay node 10e (same as (1) in Figure 3), and relay node 10e sends the received transmit command header to LIN node 20c (same as (2) in Figure 3). The response sent from LIN node 20c is received by relay node 10d via relay node 10e and output to the LIN network 44 (same as (3) in Figure 3). Then, LIN node 20b and LIN node 20a each receive the response.

[0050] In the configuration shown in Figure 5, since LIN node 20a is connected to the same LIN network 44 as the master LIN node 20b, relay node 10d does not perform standby operations like relay node 10c did.

[0051] Furthermore, although the embodiments described above used CAN as the first network and LIN as the second network, at least the second network can be a master-slave network. The first network is not limited to CAN; it may also be other networks such as FlexRay.

[0052] It should be noted that the present invention is not limited to the embodiments described above. That is, those skilled in the art can implement the invention in various ways, without departing from the core principles, in accordance with prior art knowledge. Such modifications, as long as they still possess the configuration of the relay device and network system of the present invention, are of course included within the scope of the present invention. [Explanation of Symbols]

[0053] 1. 1A Network System 10a Relay node (relay device) 10b Relay node (relay device) 10c relay node (relay device) 10d Relay node (relay device) 10e Relay node (relay device) 11. First Communications Department 12. Second Communications Department 13 Relay section 20a LIN node (a node connected to the second network) 20b LIN node (a node connected to the second network) 20c LIN node (node ​​connected to the second network) 30 CAN nodes 41 LIN Network (Second Network) 42 LIN Network (Second Network) 43 LIN Network (Second Network) 44 LIN Network (Second Network) 45 LIN Network (Second Network) 51 CAN Network (First Network)

Claims

1. A first communication unit that communicates with the first network, A second communication unit that communicates with a second network in a master-slave configuration, The system includes a relay unit that relays between the first network and the second network, When the first communication unit receives a data transmission command from the first network, if the destination of the data transmission command is not a node connected to the second network, the relay unit waits until the first communication unit receives the data corresponding to the data transmission command, and then transmits the data transmission command and the data from the second communication unit to the second network. A relay device characterized by the following features.

2. The relay device according to claim 1, characterized in that when the second communication unit receives the data transmission command from the second network, if the destination of the data transmission command is not a node connected to the second network, the relay unit causes the first communication unit to transmit the data transmission command to the first network.

3. The relay device according to claim 1, characterized in that when the first communication unit receives the data transmission command from the first network, if the destination of the data transmission command is a node connected to the second network, the relay unit immediately causes the second communication unit to transmit the data transmission command to the second network.

4. The relay device according to claim 1, characterized in that, when the second communication unit receives the data from the second network as a response to the data transmission command received by the first communication unit from the first network, the relay unit immediately causes the first communication unit to transmit the data to the first network.

5. A first communication unit that communicates with the first network, The second communication unit communicates with the second network. The system includes a relay unit that relays between the first network and the second network, When the second communication unit receives a data transmission command from the second network, if the destination of the data transmission command is a node connected to the second network, the relay unit waits until the second communication unit receives the data corresponding to the data transmission command, and then transmits the data transmission command and the data from the first communication unit to the first network. A relay device characterized by the following features.

6. The relay device according to claim 5, characterized in that when the relay unit receives the data transmission command and the data simultaneously from the first network, the relay unit immediately causes the second communication unit to transmit the data transmission command and the data to the second network.

7. A relay device according to any one of claims 1 to 6, The first network described above, The second network and, The node connected to the second network, A network system characterized by having the following features.

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