WO2016131404A1

WO2016131404A1 - New type can frame based communication method, device and system

Info

Publication number: WO2016131404A1
Application number: PCT/CN2016/073765
Authority: WO
Inventors: 王海峰; 方庆银; 王伶俐; 邝育军
Original assignee: 华为技术有限公司; 复旦大学
Priority date: 2015-02-17
Filing date: 2016-02-14
Publication date: 2016-08-25
Also published as: CN104836636B; CN104836636A

Abstract

Provided in embodiments of the present invention are a new type CAN frame based communication method, device and system. The method comprises: expanding a data field of an original CAN 2.0 frame in size to enable more data to be transmitted by the expanded data field. Further, fixed values are added to fixed positions of the data field and a check field of the new type of frame for a CAN 2.0 device to sample the fixed values and complete an error correction check, thereby avoiding errors, and providing compatibility with the existing CAN 2.0 devices.

Description

Method, device and system for communicating based on novel CAN frame

The present application claims priority to Chinese Patent Application No. 201510086524.1, entitled "Method, Apparatus and System for Communication Based on New CAN Frames", filed on February 17, 2015, the entire contents of which are incorporated by reference. Combined in this application.

Technical field

Embodiments of the present invention relate to communication technologies, and in particular, to a data communication method, apparatus, and system in a bus.

Background technique

Controller Area Network (CAN) is a standardized serial communication bus protocol with a maximum physical layer (PHY) rate of 1 Mbps/s. CAN with Flexible Data Rate (CAN-FD) achieves a bus communication rate of 1 Mbps/s or more by increasing the rate of the PHY of the CAN.

However, when the CAN-FD node works with the existing CAN 2.0 node, the CAN 2.0 node will have a data padding error and a Cyclic Redundancy Check (CRC) when processing the data of the CAN-FD node. The error is detected, causing the CAN 2.0 node to interrupt the current CAN communication. Therefore, CAN-FD cannot be compatible with the existing CAN bus mode.

Summary of the invention

The embodiment of the invention provides a data communication method, device and system in a bus, so as to realize that the node of the first bus mode is compatible with the existing bus mode while improving the rate of the PHY, and the data occurs when the two bus modes coexist. A fill error, CRC check error, causing the CAN 2.0 node to interrupt the current CAN communication problem.

In a first aspect, an embodiment of the present invention provides a data communication method in a bus, where the method is applicable to a controller area network CAN including at least one node of a first bus mode and at least one node of a second bus mode, Methods include:

Determining, by the node, a bus mode of the data communication according to the preset bus frame, where the frame format of the preset bus frame includes a first frame format and a second frame format, where the first frame format corresponds to the first bus mode, The second frame format corresponds to the second bus mode, the preset bus frame includes an identity identifier, and the identifier has a preset number of bits for identifying the frame format;

The node communicates with a frame format corresponding to the determined bus mode of the data communication.

With reference to the first aspect, in a first possible implementation manner of the first aspect, the node is a master node;

The node determines a bus manner of data communication according to a preset bus frame, including:

Determining, by the node, a bus manner of the data communication according to the preset bus frame at a time when a preset polling time arrives;

The node communicates with a frame format corresponding to the bus mode of the data communication, including:

The node communicates with a frame format corresponding to the bus mode of the data communication at a time when the preset polling time has not arrived.

With reference to the first possible implementation manner of the first aspect, in a second possible implementation manner of the first aspect, the node is a node in the first bus mode;

Determining, by the node, the bus mode of the data communication according to the preset bus frame, when the preset polling time arrives, including:

The node polls all other nodes by using the preset bus frame in the first frame format at a time when the preset polling time arrives;

Receiving, by the node, a first information response, where the first information response is in the first frame format;

Determining, by the node, the identity identifier of the node that sends the first information response according to the first information, and determining, by the node that sends the first information response, the node in the first bus mode, Determining to communicate with the node of the first bus mode by using the first bus mode;

The node polls other nodes except the node determined to be the first bus mode by using the preset bus frame in the second frame format at a time when the preset polling time arrives. ;

Receiving, by the node, a second information response, where the second information response is in the second frame format;

Determining, by the node, the identity identifier of the node that sends the second information response according to the second information, and determining, by the node that sends the second information response, the node in the second bus mode, Determining to communicate with the node of the second bus mode by using the second bus mode.

In conjunction with the second possible implementation of the first aspect, in a third possible implementation manner of the first aspect, the node is configured to communicate with the data at a time when the preset polling time is not reached. Communication in the frame format corresponding to the bus mode, including:

And the node communicates with the node of the first bus mode by using the first frame format by the first frame format at a time when the preset polling time has not arrived; and/or,

The node communicates with the node of the second bus mode in the second bus mode by using the second frame format at a time when the preset polling time has not arrived.

In conjunction with the first possible implementation of the first aspect, in a fourth possible implementation manner of the first aspect, the node is a node of the second bus mode;

The node polls all other nodes by using the preset bus frame in the second frame format at a time when the preset polling time arrives;

Receiving, by the node, a third information response, where the third information response is in the second frame format;

Determining, by the node, the identity identifier of the node that sends the third information response according to the third information response, and determining, by the node that sends the third information response, the node in the second bus mode, Determining to communicate with the node of the second bus mode by using the second bus mode.

In conjunction with the fourth possible implementation of the first aspect, in a fifth possible implementation manner of the first aspect, the node is configured to communicate with the data at a time when the preset polling time is not reached. Communication in the frame format corresponding to the bus mode, including:

With reference to the possible implementation manners of any one of the first to fifth aspects of the first aspect, in a sixth possible implementation manner of the first aspect, the determining, by the node, the bus mode of the data communication according to the preset bus frame ,Also includes:

The node starts a polling task and periodically determines whether the preset polling time has arrived.

With reference to the first aspect, in a seventh possible implementation manner of the first aspect, the node is a slave node;

The node actively initiates a handshake communication to the primary node, and determines a bus manner of the data communication according to the preset bus frame.

In conjunction with the seventh possible implementation of the first aspect, in an eighth possible implementation manner of the first aspect, the node is a node of the first bus mode;

The node actively initiates a handshake communication to the master node, and determines a bus manner of the data communication according to the preset bus frame, including:

Sending, by the node, the preset bus frame in the first frame format to the primary node;

Receiving, by the node, a fourth information response sent by the primary node, and the fourth information response is in the first frame format;

The node determines that the master node is a node of the first bus mode, and communicates with the master node by using the first bus mode.

With reference to the seventh possible implementation of the first aspect, in a ninth possible implementation manner of the first aspect, the node is a node of the first bus mode;

After the preset timeout has not received the fourth information response sent by the primary node, the node determines that the primary node is a node in the second bus mode, and sends the node to the primary node. Transmitting the preset bus frame of the second frame format;

Receiving, by the node, a fifth information response sent by the primary node, and the fifth information response is in the second frame format;

The node determines to communicate with the master node by using the second bus mode.

With reference to the seventh possible implementation of the first aspect, in a tenth possible implementation manner of the first aspect, the node is a node of the second bus mode;

Sending, by the node, the preset bus frame in the second frame format to the primary node;

Receiving, by the node, a sixth information response sent by the primary node, and the sixth information response is in the second frame format, where the primary node includes the first bus mode node and the second bus mode Node

In a second aspect, an embodiment of the present invention provides a controller area network (CAN) CAN node, that is, a CAN device that performs communication based on a new CAN frame, where the CAN includes at least one node of the first bus mode and at least one node of the second bus mode. The node includes:

a determining module, configured to determine a bus manner of data communication according to a preset bus frame, where a frame format of the preset bus frame includes a first frame format and a second frame format, and the first frame format and the first bus mode Correspondingly, the second frame format is corresponding to the second bus mode, and the preset bus frame includes an identity identifier, where the preset identifier has a plurality of bits for identifying the frame format;

And a communication module, configured to communicate by using a frame format corresponding to the determined bus mode of the data communication.

With reference to the second aspect, in a first possible implementation manner of the second aspect, the node is a master node;

The determining module is specifically configured to determine, according to the preset bus frame, a bus manner of the data communication, when a preset polling time arrives;

The communication module is specifically configured to perform communication by using a frame format corresponding to the bus mode of the data communication when the preset polling time has not arrived.

With reference to the first possible implementation of the second aspect, in a second possible implementation manner of the second aspect, the node is a node of the first bus mode;

The determining module is configured to: when the preset polling time arrives, use the preset bus frame in the first frame format to poll all other nodes; receive the first information response, The first information response is the first frame format; the identity identifier of the node that sends the first information response is obtained according to the first information response, and the node that sends the first information response is determined as The node of the first bus mode determines that the first bus mode is used to communicate with the node of the first bus mode; when the preset polling time arrives, the second frame format is adopted. The preset bus frame polls other nodes except the node determined to be the first bus mode; receiving a second information response, the second information response being the second frame format; The second information response acquires the identity identifier of the node that sends the second information response, and determines the node that sends the second information response as the node of the second bus mode, and determines to adopt the And second bus node of the second embodiment mode communication bus.

With reference to the second possible implementation of the second aspect, in a third possible implementation manner of the second aspect, the communication module is specifically configured to: when the preset polling time is not reached, pass the The first frame format communicates with the node of the first bus mode in the first bus manner; and/or, at a time when the preset polling time has not arrived, by the second frame format The second bus mode communicates with the nodes of the second bus mode.

With reference to the first possible implementation of the second aspect, in a fourth possible implementation manner of the second aspect, the node is a node of the second bus mode;

The determining module is configured to: when the preset polling time arrives, use the preset bus frame in the second frame format to poll all other nodes; receive a third information response, The third information response is the second frame format; the identity identifier of the node that sends the third information response is obtained according to the third information response, and the node that sends the third information response is determined as The node of the second bus mode determines to communicate with the node of the second bus mode by using the second bus mode.

With reference to the fourth possible implementation of the second aspect, in a fifth possible implementation manner of the second aspect, the communication module is specifically configured to: when the preset polling time is not reached, The second frame format communicates with the nodes of the second bus mode in the second bus mode.

With reference to the possible implementation of any one of the first to the fifth aspects of the second aspect, in a sixth possible implementation manner of the second aspect, the method further includes:

The determining module is configured to start a polling task, and periodically determine whether the preset polling time arrives.

With reference to the second aspect, in a seventh possible implementation manner of the second aspect, the node is a slave node;

The determining module is specifically configured to initiate a handshake communication to the primary node, and determine a bus manner of the data communication according to the preset bus frame.

With reference to the seventh possible implementation of the second aspect, in an eighth possible implementation manner of the second aspect, the node is a node of the first bus mode;

The determining module is configured to send the preset bus frame in the first frame format to the primary node, receive a fourth information response sent by the primary node, and the fourth information response is the a first frame format; determining that the master node is a node of the first bus mode, and communicating with the master node by using the first bus mode.

With reference to the seventh possible implementation of the second aspect, in a ninth possible implementation manner of the second aspect, the node is a node of the first bus mode;

The determining module is specifically configured to send the preset bus frame in the first frame format to the primary node; after receiving the preset timeout, the fourth information response sent by the primary node is not received yet, And the node determines that the primary node is the node of the second bus mode, and sends the preset bus frame in the second frame format to the primary node; and receives the fifth information sent by the primary node. Responding, and the fifth information response is in the second frame format; determining to communicate with the master node by using the second bus mode.

With reference to the seventh possible implementation of the second aspect, in a tenth possible implementation manner of the second aspect, the node is a node of the second bus mode;

The determining module is specifically configured to send the preset bus frame in the second frame format to the primary node, receive a sixth information response sent by the primary node, and the sixth information response is the In the second frame format, the master node includes the node of the first bus mode and the node of the second bus mode; determining to communicate with the master node by using the second bus mode.

In a third aspect, an embodiment of the present invention provides a controller area network (CAN) system, including: at least one node of a first bus mode and at least one node of a second bus mode, wherein the first bus mode The node adopts the second aspect, the first to third of the second aspect, and the sixth to the ninth possible The node described in the implementation manner, wherein the node in the second bus mode adopts the second aspect, the first aspect of the second aspect, the fourth to the seventh, and the possible implementation manner of any one of the tenth node.

The data communication method, device and system in the bus of the embodiment of the invention enable the node in the CAN to determine the bus mode for communication by presetting the bus frame, so that the node of the first bus mode is compatible with the existing bus while increasing the transmission rate. In the way, when the two bus modes coexist, data filling error and CRC check error will occur, which causes the CAN2.0 node to interrupt the current CAN communication problem.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, a brief description of the drawings used in the embodiments or the prior art description will be briefly described below. Obviously, the drawings in the following description It is a certain embodiment of the present invention, and other drawings can be obtained from those skilled in the art without any inventive labor.

1 is a schematic structural view of an embodiment of a CAN system according to the present invention;

1A is a schematic diagram of a bus frame format in an embodiment of the present invention;

2 is a flow chart of an embodiment of a data communication method in a bus according to the present invention;

3 is a flow chart of another embodiment of a data communication method in a bus of the present invention;

4 is a flow chart of still another embodiment of a data communication method in a bus according to the present invention;

5 is a flow chart of a fourth embodiment of a data communication method in a bus according to the present invention;

6 is a flowchart of a fifth embodiment of a data communication method in a bus according to the present invention;

7 is a flow chart of a sixth embodiment of a data communication method in a bus according to the present invention;

8 is a schematic structural diagram of an embodiment of a CAN node according to the present invention;

9 is a schematic structural diagram of another embodiment of a CAN node according to the present invention;

10 is a schematic structural view of another embodiment of a CAN system according to the present invention;

11 is a schematic structural diagram of an embodiment of a node in a first bus mode according to the present invention;

FIG. 12 is a schematic structural diagram of another embodiment of a node in a first bus mode according to the present invention.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. It is a partial embodiment of the invention, and not all of the embodiments. General techniques in the art based on embodiments in the present invention All other embodiments obtained by the skilled person without creative efforts are within the scope of the present invention.

In order to more easily understand the following embodiments, here is a brief introduction to the CAN protocol. After years of development, the existing CAN protocol and the CAN protocol referred to in the present invention refer to the CAN 2.0 protocol (hereinafter referred to as "CAN 2.0"). CAN 2.0 includes two technical specifications, namely CAN 2.0A and CAN 2.0B, in which CAN 2.0A provides a standard format using an 11-bit ID; CAN 2.0B is extended on a standard format using a 29-bit ID. Since the two have some small differences in the format definition, the rest of the processing is basically the same. Therefore, for convenience of description, the following embodiments of the present invention do not strictly distinguish between CAN 2.0A and CAN 2.0B, and uniformly use CAN 2.0. Be explained. For some specific examples, the default is to use CAN 2.0B as an example, and those skilled in the art can implement CAN 2.0A without any creative work.

The solution of the present invention will be specifically described below by way of various embodiments.

Embodiment 1

Embodiments of the present invention disclose a method for communication based on a novel CAN frame, which is applied to a CAN network as shown in FIG. 1, the CAN network including one or more conventional CAN 2.0 nodes (eg, node 3, node 4) And one or more new CAN (CAN-HW) nodes provided by this embodiment, such as node 1, node 2). Each node is connected by a printed circuit board PCB trace or cable to implement bus communication. The CAN differential line matching resistors shown in the figure are set in the same manner as in the prior art, and are not described here.

The communication in the CAN network is performed based on the CAN frame. In the embodiment of the present invention, the new CAN-HW node can use the new CAN frame to communicate with other CAN-HW nodes faster than the existing CAN 2.0 rate, and at the same time, It can avoid the various errors produced by CAN-FD mentioned in the background technology when working with CAN 2.0 nodes, and achieve compatibility with existing CAN2.0 implementation.

Specifically, a method for performing communication based on a novel CAN frame according to an embodiment of the present invention includes the following steps:

S11. Generate a new CAN frame.

Among them, the new CAN frame is generated based on the frame format of the CAN 2.0 frame. Herein, "based on" refers to the content of the modification (such as the definition of some fields) described in the following embodiments, and the rest can be performed by referring to the frame format defined by the existing CAN 2.0 protocol.

Referring to FIG. 1A, a schematic diagram of a format of a CAN 2.0 frame and a novel CAN frame (CAN-HW) frame according to the present embodiment. Among them, the new CAN frame includes a new data domain and a new check domain (ie, the CRC field in the figure), and the new data domain and the new check domain are respectively modified by modifying the data domain and the check domain based on the CAN 2.0 frame. get.

Specifically, the new data domain includes a user data subdomain and a fixed data subdomain, where:

The user data subdomain functions as the data field in the existing CAN 2.0, and is used to transmit real user data, but in this embodiment, the number of bits of the user data subfield is larger than the data field in the CAN 2.0 frame. The number of bits; in another embodiment, the number of bits of the user data subfield may be approximately equal to an integer multiple of the number of existing CAN 2.0 maximum data bits. For example, suppose the existing CAN 2.0 frame supports a maximum of 8 bytes of 64-bit data, then the user data sub-field can be 128 bits (16 bytes), or 512 bits (64 bytes), or 1024 bits (128). Bytes) and so on. Here, "about equal" means that the actual is not required to be strictly equal, and may be slightly less than the integer multiple, and a small portion is used for the fixed data subdomain or other subdomains that need to be expanded.

The fixed data subfield includes a plurality of first fixed bit groups, each of the first fixed bit groups includes one or more consecutive first fixed bits (0 or 1) having the same value, and the plurality of first fixed bit groups are one by one Set the sampled position when multiple CAN 2.0 data fields can be sampled by a CAN 2.0 device based on the CAN 2.0 protocol (such as node 3, node 4 in Figure 1); preferably, the number of first fixed bit groups is the same as CAN The number of bits of the data bit data to be sampled by the 2.0 device is the same. For example, assuming that the data field in the CAN 2.0 frame has 64 bits of data, then in the new CAN frame, 64 sets of the first fixed bit group are set accordingly. It should be noted that the prefix “first” in the “first fixed bit group” in this embodiment is only used to distinguish the fixed bit groups mentioned in the following for other places (such as the check field), and Other special meanings, similarly, the prefixes such as "second" and "third" mentioned later also have similar meanings.

In this embodiment, the "CAN 2.0 device based on the CAN 2.0 protocol" refers to various devices capable of processing the CAN 2.0 protocol, such as node 3 and node 4 in FIG. 1, and these CAN 2.0 devices do not recognize the new CAN. The frame format of the frame, corresponding to these devices, whether it is actually receiving a new CAN frame sent by a new CAN device (such as Node 1) or a CAN 2.0 frame sent by a CAN 2.0 device, is processed according to the CAN 2.0 protocol frame. The way to handle it. In this embodiment, since each first fixed bit group is set one by one at a position where a plurality of CAN 2.0 devices sample the CAN 2.0 data field, that is, each first fixed bit group corresponds to a sampling time of one CAN 2.0 device, when After the CAN 2.0 device receives the new CAN frame, if it is sampled according to the way defined by the CAN 2.0 device, then the sampled is the value of each first fixed bit group (defined as the value of any bit in the group, due to the first The fixed bit group includes the same value of one or more first fixed bits, and therefore, the value of this first fixed bit group can be represented by "a value of any one bit".

The following describes how to set the position of the first fixed bit group and the number of fixed bits included so that the first fixed bit group can be sampled by the CAN 2.0 device. Specifically, existing CAN 2.0 devices can be configured to be sampled at a specific frequency during sampling, and at which relative time to sample. For example, referring to FIG. 1A, a CAN 2.0 device can be configured to transmit and sample at a frequency of 1 MHz, and the sampling time is at 2/3 of the signal waveform corresponding to this data bit, in which case, in the network, The data field in the CAN 2.0 frame is 64 bits, and the number of bits in the new data field is expanded by 8 times, which is equivalent to each number in the original CAN 2.0 frame. The data is split into 8 copies in the same time. In this way, 1us transmits a data in the CAN 2.0 device. After the split, the new CAN device needs to transmit 8 data for 1us. Since it is sampled at 2/3, after calculation, 2/3 of 1us is equal to 0.667us, which corresponds to the 6th bit, then a fixed bit can be set in the 6th bit (set to a fixed value of 0 as shown in Figure 1A). . If the new CAN 2.0 frame expands the number of bits in the original data field more, at this time, each data bit in the original CAN 2.0 frame is split more in the same time (for example, split into 32 In this case, in order to prevent the CAN 2.0 device clock from being inaccurate enough to accurately sample at 2/3, you can add some more bits around 2/3, so that even if CAN 2.0 samples early, or late The value of the fixed bit can be sampled at a time.

Similar to the above modification of the data field in the CAN 2.0 frame, this embodiment also performs similar modifications to the check field (or also referred to as the CRC field) in the CAN 2.0 frame. The new check field number in the modified CAN frame is larger than the number of check fields in the CAN 2.0 frame. The new check field includes a user data check subfield and a fixed data check subfield, wherein the user data is corrected. The value of the test field is the first check value after verifying the user data sub-domain; the fixed data check sub-domain is the second check value obtained by verifying the value of each first fixed bit group, fixed The data check subfield includes a plurality of second fixed bit groups, each second fixed bit group includes one or more consecutive second fixed bits of the same value, and the value of each second fixed bit group (ie, any one of the groups) The fixed bit value constitutes the second check value; the plurality of second fixed bit groups are one-to-one set at a position that can be sampled by the CAN 2.0 device when the CAN 2.0 check field is sampled, and the specific setting method and the new data field are set. The setting method of the first fixed bit group is similar, and will not be described here.

S12. Send the new CAN frame, wherein the new data domain and the new check domain are sent at a highest transmission rate than defined by the CAN 2.0 protocol.

Since the data field and the check field in the CAN 2.0 frame are expanded in this embodiment, the number of bits is increased, and in order to realize high-speed transmission, the extended fields are transmitted at a higher frequency. For example, if you expand to 8 times, you can also increase the frequency to 8 times. If you expand to 16 times, the frequency can be increased to 16 times. Of course, in practice, it is not necessary to accurately increase to 8 or 16 times, as long as the extended data bits can be transmitted, other transmission frequencies are also possible.

For other data fields, if there is no extension, it will still be sent at the transmission rate specified by the CAN 2.0 protocol. In terms of implementation, the new CAN 2.0 device is equivalent to two registers to control the transmission rate, one register for controlling the number of bits to be expanded, the frequency of transmission and reception of the domain to be transmitted and received, and the other register to the existing CAN 2.0. Like the rate control register, it is used to control the transceiving rate of the unmodified domain.

After the new CAN frame is sent to the CAN network, other new CAN devices can correctly receive the frame because they can recognize the frame, and since the number of bits of the data field of the CAN 2.0 frame has been expanded at the time of transmission, and The frequency is transmitted, thus increasing the transmission rate. At the same time, the existing CAN 2.0 device can receive the frame. The sample is still sampled in the original sampling mode. Since this embodiment has fixed values in the CAN 2.0 sample data field and the check field position, the CAN 2.0 samples the value of the fixed data subfield and performs check calculation. After that, its value must be consistent with the second check value indicated by the sampled fixed data check subfield, so that no check error will occur, thus achieving compatibility with CAN 2.0 devices.

Embodiment 2

Based on the first embodiment, the present embodiment further describes the solution.

Since there are two CAN frames (CAN devices) in the networking shown in FIG. 1, in order to distinguish the two frames, in this embodiment, the new CAN frame may further include: a type indicating subfield for indicating a CAN frame type. Used to indicate that it is a CAN 2.0 frame, or a new frame.

The type indicator subdomain can be implemented by reserved bits in the arbitration domain, for example, using reserved two bits, 00 for CAN 2.0 frames, and 11 for new frames, of course, in this case, CAN 2.0 software also needs these The reserved bits are judged to determine which frame format is received.

The type indicator subfield may also be implemented by at least one of two bits R1, R0 in the control domain in the CAN 2.0 frame, with at least one of the two bits being the subtype of the type indication.

Since the number of bits in these fields is not extended at this time, these fields are still sent at the rate defined by CAN 2.0.

In this embodiment, the new CAN frame may further include: a bit indication information subfield for indicating the number of bits of the user data subfield in the new data domain.

The number of bits indicates that the information sub-domain can be implemented by extending the data bits in the control domain in CAN2.0. The principle is similar to that of extending the data field. Since it is extended, it is necessary to upgrade this part later. Transceiver rate. In addition, if it is identified by a reserved bit table in other domains, there is no need to increase the transmission and reception rate of the domain.

In the embodiment of the present invention, hard resynchronization is also set, and specifically, the new data field in the new CAN frame corresponds to the edge change between the two bits in the data field of the CAN 2.0 device. For example, the new CAN frame extends the data field of the CAN 2.0 frame by a factor of eight, assuming that the first 8 bits of the CAN 2.0 frame data field are extended to A1-A8, and the second bit of the CAN 2.0 frame data field is expanded by 8 Bits B1-B8, you can set the transition edge between the two bits A8 and B1, then the corresponding two, also need to be set to a fixed value.

Setting the hard resynchronization can check the frequency to prevent sampling errors caused by the frequency deviation being accumulated.

Embodiment 3

Based on the foregoing embodiments, the specific application scenarios are introduced in the embodiment of the present invention. Referring to FIG. 1, as shown in the foregoing two embodiments, the first bus mode is a newly designed bus mode, which may be referred to as CAN-HW, and the second bus mode is an existing bus mode, that is, CAN 2.0, first. The frame format of the bus mode is compatible with the frame format of the second bus mode, that is, the frame format of the former is the same as the frame format of the latter, and the difference is that the content filled in the frame format is different, so the node of the second bus mode can receive The two bus mode frames are parsed and the frame is identified by the bit type of the bus type identifying the node, and the node of the first bus mode can also receive the frames of the two bus modes, and the communication is determined according to the bus type corresponding to the frame. The way of the bus. The first bus mode node can adopt two bus modes at the same time, and is compatible with the existing bus protocol while improving the transmission rate, thereby realizing data communication of the two bus mode hybrid networks.

2 is a flowchart of an embodiment of a data communication method in a bus of the present invention. As shown in FIG. 2, the method in this embodiment is applicable to the application scenario shown in FIG. 1, and the method may include:

Step 101: The node determines a bus manner of data communication according to the preset bus frame.

In this embodiment, the frame format of the preset bus frame includes a first frame format and a second frame format, where the first frame format corresponds to the first bus mode, and the second frame format and the first frame format Corresponding to the two-bus mode, the preset bus frame includes an identity identifier, and the identifier has a preset number of bits for identifying the frame format. The execution subject node may be any one of the nodes in FIG. The first frame format of the present invention is designed: the arbitration field, the Acknowledgement (ACK) field and the frame end bit in the first frame format are compatible with the corresponding fields of the second frame format (CAN 2.0 format); The reserved bits of the control domain and the arbitration domain in the format enable the nodes of the first bus mode to automatically recognize the bus type function and perform frame format switching; design the data domain and the CRC domain in the first frame format, and the PHY can be The rate is increased by N times (N can be 1, 2, 3...); when designing the data field and the CRC field, the second frame format is fixed bit-filled to ensure that the second bus mode is not caused. The node incorrectly generates a bit error and a CRC check error, thereby causing a communication interruption. The preset bus frame has two formats, which respectively correspond to the above two bus modes, and the corresponding bus mode can be determined by presetting the bus frame node.

Step 102: The node performs communication by using a frame format corresponding to the determined bus mode of the data communication.

After the node determines the bus mode, the bus mode can be adopted, and the frame format corresponding to the bus mode is used to communicate with other nodes, that is, if the node is a node of the first bus mode, the node can adopt the first bus mode. Sending a preset bus frame of the first frame format to the nodes of the other first bus mode, and sending the preset bus frame of the second frame format to the nodes of the other second bus mode by using the second bus mode; if the node is the first Two-bus mode Node, the node can only send the preset bus frame of the second frame format to other nodes by using the second bus mode. Since the nodes of the first bus mode can communicate in two bus modes, other nodes here may include the A bus mode node and a second bus mode node.

In this embodiment, by presetting the bus frame, the node in the CAN determines the bus mode for communication, and the node of the first bus mode is compatible with the existing bus mode while improving the rate of the PHY, and solves the problem that the two bus modes coexist. A data fill error and a CRC check error occurred, causing the CAN 2.0 node to interrupt the current CAN communication problem.

Further, the node in the foregoing embodiment is a master node, and the specific implementation method of step 101 may be: the node determines the bus of the data communication according to the preset bus frame at a time when the preset polling time arrives. The specific implementation method of step 102 may be: the node communicates with a frame format corresponding to the bus mode of the data communication when the preset polling time has not arrived.

Specifically, the above process may have two implementation processes depending on the node. The details are explained below.

One is that the node is a node of the first bus mode, and the node adopts the preset bus frame pair of the first frame format at a time when the preset polling time arrives. All other nodes perform polling; the node receives a first information response, the first information response is in the first frame format; and the node acquires a node that sends the first information response according to the first information response Determining, by the node that sends the first information response, the node in the first bus mode, and determining to communicate with the node in the first bus mode by using the first bus mode; The node polls other nodes except the node determined to be the first bus mode by using the preset bus frame in the second frame format at a time when the preset polling time arrives. The node receives the second information response, the second information response is the second frame format, and the node obtains the identity identifier of the node that sends the second information response according to the second information response. The second node transmitting the response information is determined as a node of the second embodiment of the bus, the second bus mode is determined using the second bus node communication mode. And the node communicates with the node of the first bus mode by using the first frame format by the first frame format at a time when the preset polling time does not arrive; and/or, the node is When the preset polling time has not arrived, the second bus format communicates with the node of the second bus mode by using the second bus mode.

FIG. 3 is a flowchart of another embodiment of the data communication method in the bus of the present invention. As shown in FIG. 3, the method in this embodiment is applicable to the application scenario shown in FIG. 1, and the node 1 in the first bus mode is used as the main Node, the method can include:

S201, node 1 starts a polling task, and periodically determines whether the preset polling time arrives;

When the node of the first bus mode acts as the master node, the token is used to communicate with other nodes in the CAN. Node 1 initiates the timed polling addressing function through the application layer software. The startup mode can be power-on startup or timer timing. Node 1 polls all addresses in the CAN at the time when the polling time arrives. All addresses correspond to All nodes in CAN.

S202: Node 1 polls node 2 (3, 4) by using a preset bus frame in a first frame format at a time when the preset polling time arrives;

The node 1 first polls all the nodes in the first frame format. In this embodiment, the preset bus frame in the first frame format is sent to the node 2 (3, 4).

S203. Node 2 sends a first information response to node 1 in a first frame format.

The node 2 can simultaneously receive and parse the first frame format and the second frame format, and determine the received first frame format according to the bus type bit in the preset bus frame, so the node 2 automatically sets the first frame format to the node. 1 Send the first message response.

S204, node 3 (4) does not respond to the preset bus frame of the first frame format sent by the node 1;

After receiving the preset bus frame of the first frame structure, the node 3 (4) passes the ID filtering function, and does not process the preset bus frame of the first frame structure from the node 1, and may directly discard the frame, and the preset is not The bus frame is answered.

S205, the node 1 obtains the ID of the node 2 that sends the first information response according to the first information response, and determines the node 2 as the node of the first bus mode, and determines to communicate with the node 2 by using the first bus mode;

The application software on the node 1 extracts the first information response in the CAN, and obtains the ID of the node 2 that sends the first information response. The node 1 can classify all the nodes that send the first information response into the first bus mode by means of table construction. Node, table A, in this embodiment is node 2, node 1 refreshes the newly inserted or deleted node in CAN by the change of table A.

S206: Node 1 polls node 3 (4) by using a preset bus frame in a second frame format at a time when the preset polling time arrives;

The node 1 then uses the second frame format to poll the node except the node in the table A. In this embodiment, the preset bus frame in the second frame format is sent to the node 3 (4).

S207, node 3 (4) sends a second information response to node 1 in a second frame format;

Node 3 (4) can parse the preset bus frame of the second frame format, so node 3 (4) sends a second information response to node 1 in the second frame format.

S208. The node 1 obtains the ID of the node 3(4) that sends the second information response according to the second information response, and determines the node 3(4) as the node of the second bus mode, and determines to adopt the second bus mode and the node 3 ( 4) conducting communication;

The application software on the node 1 extracts the second information response in the CAN, and obtains the ID of the node 3 (4) that sends the second information response. The node 1 can also classify all the nodes that send the second information response by the method of establishing the table. The node of the two bus mode, the table B is constructed, in this embodiment, the node 3 (4), and the node 1 refreshes the newly inserted or deleted node in the CAN by the change of the table B.

S209, node 1 communicates with node 2 in a first bus manner by using a first frame format at a time when the preset polling time has not arrived;

The application layer software on the node 1 determines that the polling is not started. If the node 1 communicates with the node (node 2) in the table A, the first frame format can be used to communicate with the node 2 by the software actively setting the frame format.

S210: Node 1 communicates with node 3 (4) in a second bus mode by using a second frame format at a time when the preset polling time has not arrived.

The application layer software on node 1 determines that polling is not started. If node 1 is in communication with the node in node B (node 3 (4)), the second frame format and node 3 (4) can be adopted by the software to actively set the frame format. Communicate.

The other is that the node is a node of the second bus mode, and the node adopts the preset bus frame of the second frame format at a time when the preset polling time arrives. Polling all other nodes; the node receives a third information response, the third information response is in the second frame format; and the node acquires the third information response according to the third information response Determining the identity of the node, and determining, by the node that sends the third information response, a node of the second bus mode, and determining to communicate with the node of the second bus mode by using the second bus mode . The node communicates with the node of the second bus mode in the second bus mode by using the second frame format at a time when the preset polling time has not arrived.

4 is a flowchart of still another embodiment of the data communication method in the bus of the present invention. As shown in FIG. 4, the method in this embodiment is applicable to the application scenario shown in FIG. 1, and the node 3 in the second bus mode is used as the main Node, the method can include:

S301, node 3 starts a polling task, and periodically determines whether the preset polling time arrives;

When the node of the second bus mode acts as the master node, the token is used to communicate with other nodes in the CAN. Node 3 initiates a timed polling addressing function through the application layer software. The startup mode may be a power-on startup or a timer timing. Node 3 polls all addresses in the CAN at the time when the polling time arrives, and all addresses correspond to All nodes in CAN.

S302: The node 3 polls the node 1 (2, 4) by using a preset bus frame in the second frame format at a time when the preset polling time arrives;

The node 3 is a node of the second bus mode and only supports the second frame format. Therefore, the node 3 polls all the nodes in the second frame format. In this embodiment, the second frame format is sent to the node 1 (2, 4). Preset bus frame.

S303, node 1 (2) sends a third information response to node 3 in a second frame format;

Node 1 (2) can simultaneously receive and parse the first frame format and the second frame format, and determine the received second frame format according to the bus type bits in the preset bus frame, so node 1 (2) is automatically set to The second frame format sends a third information response to node 3.

S304, the node 4 sends a third information response to the node 3 by using the second frame format;

The node 4 can only process the second frame format, and determines the received second frame format according to the bus type bits in the preset bus frame, so the node 4 automatically sets the second frame format to send the third information response to the node 3.

S305, the node 3 obtains the ID of the node 1 (2, 4) that sends the third information response according to the third information response, and determines to communicate with the node 1 (2, 4) by using the second bus mode;

The application software on the node 3 extracts the third information response in the CAN, acquires the ID of the node 1 (2, 4) that sends the third information response, and the node 3 can classify all the nodes that send the third information response by means of table construction. The node of the second bus mode, the table C is constructed, in this embodiment, the node 1 (2, 4), and the node 3 refreshes the newly inserted or deleted node in the CAN by the change of the table C.

S306. The node 3 communicates with the node 1 (2, 4) in a second bus manner by using the second frame format at a time when the preset polling time has not arrived.

The application layer software on node 3 determines that polling is not started, and node 3 communicates with the node (1 (2, 4)) in table C, and the second frame format and node 1 can be adopted by the software to actively set the frame format (2, 4). ) to communicate.

Further, the node in the foregoing embodiment is a slave node, and the specific implementation method of step 101 may be: the node actively initiates a handshake communication to the master node, and determines a bus mode of the data communication according to the preset bus frame.

Specifically, the above process may have three implementation processes depending on the node. The details are explained below.

One is that the node is a slave node and is a node of the first bus mode, and the node sends the preset bus frame in the first frame format to the master node; the node receives the master The fourth information sent by the node is replied, and the fourth information response is in the first frame format; the node determines that the primary node is a node in the first bus mode, and adopts the first bus mode and The master node communicates.

In this case, the master node is the node of the first bus mode. When the slave node of the first bus mode actively initiates the handshake communication, it does not know what type of node the master node is, so the first frame format pre-transmission can be sent first. Setting a bus frame, if the slave node of the first bus mode receives the fourth information response of the first frame format sent by the master node, The master node can parse the preset bus frame sent by the slave node, and the node can only be implemented by the node of the first bus mode, so the slave node can communicate with the master node in the first bus mode.

FIG. 5 is a flowchart of a fourth embodiment of the data communication method in the bus of the present invention. As shown in FIG. 5, the method in this embodiment is applicable to the application scenario shown in FIG. The slave node, the node 2 of the first bus mode is used as the master node, and the method may include:

S401. Initiating a handshake communication from the node 1, and sending a preset bus frame in a first frame format to the master node 2;

S402. The master node 2 sends a fourth information response to the slave node 1 in a first frame format.

S403. Determine, from the node 1, that the master node 2 is a node in a first bus mode;

S404, the slave node 1 communicates with the master node 2 by using the first bus mode.

Preferably, the master node 2 can communicate with the slave node 1 according to the type of the preset bus frame of the slave node 1 received last time.

The other is that the node is a slave node and is a node of the first bus mode, and the node sends the preset bus frame in the first frame format to the master node; the node is preset After the timeout has not received the fourth information response sent by the primary node, the node determines that the primary node is a node of the second bus mode, and sends the second frame to the primary node. The preset bus frame of the format; the node receives a fifth information response sent by the primary node, and the fifth information response is in the second frame format; the node determines to adopt the second bus mode Communicate with the master node.

In this case, the master node is a node in the second bus mode. When the slave node in the first bus mode actively initiates the handshake communication, the preset bus frame in the first frame format is sent first, and the slave node still after the preset timeout. The master node does not receive a response, indicating that the master node does not respond to the preset bus frame of the first frame structure sent from the node. Preferably, the slave node can start at the same time as the preset bus frame in the first frame format. Timer. Generally, the second bus mode node cannot parse the second frame structure, so the slave node can consider the master node to be the second bus mode node, and send the preset bus frame of the second frame structure to the master. After receiving the preset bus frame, the node identifies the frame according to the bus type bit in the ID and sends a fifth information response of the second frame structure. After receiving the fifth information response from the node, the node may adopt the first The second bus mode communicates with the master node.

FIG. 6 is a flowchart of a fifth embodiment of a data communication method in a bus according to the present invention. As shown in FIG. 6, the method in this embodiment is applicable to the application scenario shown in FIG. The slave node, the node 3 of the second bus mode is used as the master node, and the method may include:

S501: Initiating a handshake communication from the node 1, and sending, to the master node 3, a preset bus frame in a first frame format;

S502: The master node 3 does not respond to the preset bus frame of the first frame format sent from the node 1;

S503. After the preset timeout, the slave node 1 sends the preset bus frame of the second frame format to the master node 3;

S504. The master node 3 sends a fifth information response to the slave node 1 by using a second frame format.

S505, determining, from the node 1, that the master node 3 is a node in a second bus mode;

S506, the slave node 1 communicates with the master node 3 by using the second bus mode.

Still another is that the node is a slave node and is a node of the second bus mode, the node sends the preset bus frame in the second frame format to the master node; the node receives the The sixth information sent by the primary node is responsive, and the sixth information response is in the second frame format, and the primary node includes the node in the first bus mode and the node in the second bus mode; Determining to communicate with the master node by using the second bus mode.

The master node in this case can be either the first bus mode node or the second bus mode node. When the slave node in the second bus mode actively initiates the handshake communication, only the second frame structure pre-transmission can be sent. Set the bus frame. If the master node is the node of the first bus mode, after receiving the preset bus frame of the second frame structure sent from the node, it may be correspondingly set to the second bus mode, and return to the second frame format. Six information response, if the master node is a node of the second bus mode, after receiving the preset bus frame of the second frame structure sent by the slave node, it can be identified and parsed, so the second frame format can also be returned. Six information responses. The slave node communicates with the master node using the second bus mode.

FIG. 7 is a flowchart of a sixth embodiment of a data communication method in a bus according to the present invention. As shown in FIG. 7, the method in this embodiment is applicable to the application scenario shown in FIG. 1, and the node 3 in the second bus mode is used as The slave node, the node 1 of the first bus mode is used as the master node, and the method may include:

S601, initiating handshake communication from node 3, and sending a preset bus frame in a second frame format to the master node 1;

S602. The master node 1 is configured to send a sixth information response to the slave node 3 in a second frame format.

S603, determining, from the node 3, that the master node 1 is a node of the second bus mode;

S604, the slave node 3 communicates with the master node 1 by using the second bus mode.

In addition, the case where the node of the second bus mode is both the master node and the slave node is a prior art, and details are not described herein again.

FIG. 8 is a schematic structural diagram of an embodiment of a CAN node according to the present invention. As shown in FIG. 8, the node in this embodiment is any node in the application scenario shown in FIG. 1. The node in this embodiment may include: determining a module. And a communication module 12, wherein the determining module 11 is configured to determine a bus manner of data communication according to the preset bus frame, where the frame format of the preset bus frame includes a first frame format and a second frame format, where the first a frame format corresponding to the first bus mode, the second frame format corresponding to the second bus mode, the preset bus frame including an identity identifier, the identity tag A predetermined number of bits are used to identify the frame format, and the communication module 12 is configured to communicate by using a frame format corresponding to the determined bus mode of the data communication.

The node of this embodiment may be used to implement the technical solution of the method embodiment shown in FIG. 2, and the implementation principle and the technical effect are similar, and details are not described herein again.

Further, the node is a slave node; the determining module 11 is specifically configured to initiate a handshake communication to the master node, and determine a bus mode of the data communication according to the preset bus frame.

Further, the node is a node of the first bus mode; the determining module 11 is specifically configured to send the preset bus frame in the first frame format to the primary node; and receive the primary node Transmitting the fourth information response, and the fourth information response is the first frame format; determining that the primary node is the node of the first bus mode, and adopting the first bus mode and the primary node Communicate.

The foregoing node may be used to implement the technical solution of the method embodiment shown in FIG. 5, and the implementation principle and the technical effect are similar, and details are not described herein again.

Further, the node is a node of the first bus mode; the determining module 11 is specifically configured to send the preset bus frame in the first frame format to the primary node; after a preset timeout Receiving the fourth information response sent by the primary node, the node determines that the primary node is a node in the second bus mode, and sends the second frame format to the primary node. The preset bus frame receives a fifth information response sent by the master node, and the fifth information response is in the second frame format; determining to communicate with the master node by using the second bus mode.

The foregoing node may be used to implement the technical solution of the method embodiment shown in FIG. 6, and the implementation principle and the technical effect are similar, and details are not described herein again.

Further, the node is a node of the second bus mode; the determining module 11 is specifically configured to send the preset bus frame in the second frame format to the primary node; and receive the primary node Sending the sixth information response, and the sixth information response is in the second frame format, the primary node includes the first bus mode node and the second bus mode node; determining to adopt the first The second bus mode communicates with the master node.

The foregoing node may be used to implement the technical solution of the method embodiment shown in FIG. 7. The implementation principle and the technical effect are similar, and details are not described herein again.

FIG. 9 is a schematic structural diagram of another embodiment of a CAN node according to the present invention. As shown in FIG. 9 , the node in this embodiment is any node in the application scenario shown in FIG. 1 , and the node in this embodiment is in FIG. 8 . Based on the structure of the node, the method further includes: a determining module 13 configured to start a polling task, and periodically determine whether the preset polling time arrives.

The node is a node of the first bus mode; the determining module 11 is specifically configured to use the preset bus frame pair of the first frame format at a time when the preset polling time arrives The other node performs the polling; the first information response is received, the first information response is the first frame format; and the identity identifier of the node that sends the first information response is obtained according to the first information response, and Determining, by the node that sends the first information response, as a node of the first bus mode, determining to use the first bus mode to communicate with a node of the first bus mode; in the preset polling At a time when the time arrives, the preset bus frame in the second frame format is used to poll other nodes except the node determined to be the first bus mode; and receive a second information response, the first The second information response is the second frame format; the identity identifier of the node that sends the second information response is obtained according to the second information response, and the node that sends the second information response is determined as Said node of the second embodiment of the bus, the second bus determined using means of communication with a node of the second embodiment of the bus. The communication module 12 is configured to communicate with the node of the first bus mode by using the first frame format by the first frame format at a time when the preset polling time is not reached; and Or, when the preset polling time has not arrived, communicating with the node of the second bus mode in the second bus mode by using the second frame format.

The foregoing node may be used to implement the technical solution of the method embodiment shown in FIG. 3, and the implementation principle and the technical effect are similar, and details are not described herein again.

The node is a node of the second bus mode; the determining module 11 is specifically configured to use the preset bus frame pair of the second frame format at a time when the preset polling time arrives The other node performs polling; receives a third information response, the third information response is in the second frame format; and acquiring, according to the third information response, the identity identifier of the node that sends the third information response, and Determining, by the node transmitting the third information response, a node of the second bus mode, and determining to communicate with the node of the second bus mode by using the second bus mode. The communication module 12 is configured to communicate with the node of the second bus mode in the second bus mode by using the second frame format at a time when the preset polling time is not reached.

The foregoing node may be used to implement the technical solution of the method embodiment shown in FIG. 4, and the implementation principle and the technical effect are similar, and details are not described herein again.

10 is a schematic structural diagram of an embodiment of a CAN system according to the present invention. As shown in FIG. 10, the system of this embodiment includes: at least one

node

1 and 12 of a first bus mode and at least one node 13 of a second bus mode. The structure of the device embodiment shown in FIG. 8 or FIG. 9 is used in the first bus mode, and the technical solution of any of the method embodiments in FIG. 2 to FIG. The implementation principle and the technical effect are similar, and are not described herein again; the

nodes

13 and 14 of the second bus mode adopt the structure of the device embodiment shown in FIG. 8 or FIG. The technical solution of the method embodiment in any of the embodiments of FIG. 2 is performed, and the implementation principle and technical effects are similar, and details are not described herein again.

FIG. 11 is a schematic structural diagram of an embodiment of a node in a first bus mode according to the present invention. As shown in FIG. 11, the node 10 of this embodiment may include: a controller 11 and a CAN driver 12, where the controller 11 may be micro A control unit (Micro Control Unit, MCU for short) or a Field Programmable Gate Array (FPGA) for performing the technical solution of any one of the method embodiments of FIG. 2 to FIG. As described above, the CAN driver 12 converts the output of the controller 11 into a signal of a CAN differential line, outputs it to the CAN bus, or converts the signal input on the CAN bus to the controller 11 to implement the node of the first bus mode and the CAN bus. Network data interaction.

12 is a schematic structural diagram of another embodiment of a node in a first bus mode according to the present invention. As shown in FIG. 12, a controller of a node of a first bus mode is hung on an Advanced High Performance Bus (abbreviation: AHB). On the bus, the AHB bus is connected to the control register, and the controller of the node of the first bus mode may include: a data sending module 11, a data receiving module 12, and a control module 13, wherein the data sending module 11 may further include: a sending buffer The module 111 is configured to receive and buffer the data to be sent from the AHB, and perform parallel-to-serial conversion on the transmission data. The protocol selection module 112 selects a frame format used by the transmission data according to the control register command, and according to the determined frame format. Transmitting the data for encoding; the sending module 113 sends the encoded transmission data to the CAN driver according to the control register command; the data receiving module 12 may further include: a data frame identification module 121, configured to receive the data sent by the CAN driver, and receive the data Data is arbitrated, data frame type is recognized, and the processing result is fed back to the control register. The control register determines whether the data transmitting module 11 continues to transmit; the protocol selection module 122 performs sampling and demodulation on the received data according to the control frame command by using a corresponding frame format; and the receiving buffer module 123 is configured to demodulate the protocol selection module. Receiving data for serial-to-parallel conversion and buffering, and providing AHB bus access function; control module 13 for implementing AHB access control, sending frame format transmission, transmission rate setting, and receiving data status query function.

One of ordinary skill in the art will appreciate that all or part of the steps to implement the various method embodiments described above may be accomplished by hardware associated with the program instructions. The aforementioned program can be stored in a computer readable storage medium. The program, when executed, performs the steps including the foregoing method embodiments; and the foregoing storage medium includes various media that can store program codes, such as a ROM, a RAM, a magnetic disk, or an optical disk.

Finally, it should be noted that the above embodiments are merely illustrative of the technical solutions of the present invention, and are not intended to be limiting; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that The technical solutions described in the foregoing embodiments may be modified, or some or all of the technical features may be equivalently replaced; and the modifications or substitutions do not deviate from the technical solutions of the embodiments of the present invention. range.

Claims

A method for communicating based on a novel CAN frame, comprising:

Generating a new CAN frame;

Wherein, the new CAN frame is generated based on a frame format of a CAN 2.0 frame, the new CAN frame includes a novel data domain and a new check domain, and the new data domain and the new check domain respectively pass through the CAN 2.0 frame. The data field and the verification field are modified;

The new data field includes a user data sub-domain and a fixed data sub-domain, the user data sub-domain has a number of bits greater than a number of data fields in the CAN 2.0 frame; the fixed data sub-domain includes a plurality of first a fixed bit group, each of the first fixed bit groups includes one or more consecutive first fixed bits having the same value, and the plurality of first fixed bit groups are one by one set in a plurality of CANs capable of being CAN 2.0 based The location where the 2.0 device samples the CAN 2.0 data field;

The new check field includes a user data check subfield and a fixed data check subfield, where the value of the user data check subfield is a first check value after verifying the user data subdomain; The fixed data check subfield is a second check value obtained by verifying values of the respective first fixed bit groups, wherein the fixed data check subfield includes a plurality of second fixed bit groups, each second The fixed bit group includes one or more consecutive second fixed bits having the same value, and the values of the respective second fixed bit groups constitute the second check value; the plurality of second fixed bit groups are one-to-one set in a plurality of The position sampled by the CAN 2.0 device when sampling the CAN 2.0 check field;

The novel CAN frame is transmitted, wherein the new data field and the new check field are transmitted at a higher transmission rate than defined by the CAN 2.0 protocol.
The method of claim 1 wherein said new CAN frame further comprises:

A type indicating subfield for indicating the type of CAN frame to be transmitted.
A method according to any of claims 1-2, characterized in that the type indicator subfield can be implemented by reserved bits in the arbitration domain; or by two bits of R1, R0 in the control domain in the CAN 2.0 frame. At least one to achieve.
The method of any of claims 1-3, wherein the new CAN frame further comprises: a bit number indicating information subfield for indicating the number of bits of the user data subfield in the new data field.
The method according to claim 4, wherein the number of bits indicating information subfield can be implemented by expanding data bits in the control domain in CAN2.0, and when the new frame is transmitted, The control domain is sent at an elevated rate.
A method according to any of claims 1-5, wherein:

The rate of transmission is determined by the value set by the register at the time of transmission, including two registers, one for configuring the rate of transmission after speeding up and the other for configuring the transmission rate based on CAN 2.0.
The method of any of claims 1-6, further comprising: setting hard resynchronization.
The method of claim 7 wherein setting the hard resynchronization comprises: setting a change between two bits in a data field of the CAN 2.0 device in a new data field in the new CAN frame.
A controller area network CAN node, characterized in that the CAN comprises at least one node of a first bus mode and at least one node of a second bus mode, the node comprising:

a determining module, configured to determine a bus manner of data communication according to a preset bus frame, where a frame format of the preset bus frame includes a first frame format and a second frame format, and the first frame format and the first bus mode Correspondingly, the second frame format is corresponding to the second bus mode, and the preset bus frame includes an identity identifier, where the preset identifier has a plurality of bits for identifying the frame format;

And a communication module, configured to communicate by using a frame format corresponding to the determined bus mode of the data communication.
The node according to claim 9, wherein the node is a master node;

The determining module is specifically configured to determine, according to the preset bus frame, a bus manner of the data communication, when a preset polling time arrives;

The communication module is specifically configured to perform communication by using a frame format corresponding to the bus mode of the data communication when the preset polling time has not arrived.
The node according to claim 10, wherein said node is a node of said first bus mode;

The determining module is configured to: when the preset polling time arrives, use the preset bus frame in the first frame format to poll all other nodes; receive the first information response, The first information response is the first frame format; the identity identifier of the node that sends the first information response is obtained according to the first information response, and the node that sends the first information response is determined as The node of the first bus mode determines that the first bus mode is used to communicate with the node of the first bus mode; when the preset polling time arrives, the second frame format is adopted. The preset bus frame polls other nodes except the node determined to be the first bus mode; receiving a second information response, the second information response being the second frame format; The second information response acquires the identity identifier of the node that sends the second information response, and determines the node that sends the second information response as the node of the second bus mode, and determines to adopt the And second bus node of the second embodiment mode communication bus.
The node according to claim 11, wherein the communication module is specifically configured to use the first frame format and the first bus mode at a time when the preset polling time has not arrived. a node of the first bus mode performs communication; and/or, at a time when the preset polling time has not arrived, the second bus mode and the second bus mode node by the second frame format Communicate.
The node according to claim 10, wherein said node is a node of said second bus mode;

The determining module is configured to: when the preset polling time arrives, use the preset bus frame in the second frame format to poll all other nodes; receive a third information response, The third information response is the second frame format; the identity identifier of the node that sends the third information response is obtained according to the third information response, and the node that sends the third information response is determined as The node of the second bus mode determines to communicate with the node of the second bus mode by using the second bus mode.
The node according to claim 12, wherein the communication module is specifically configured to use the second frame format to use the second bus mode at a time when the preset polling time has not arrived. The nodes of the second bus mode communicate.
The node according to any one of claims 10 to 14, further comprising:

The determining module is configured to start a polling task, and periodically determine whether the preset polling time arrives.
The node according to claim 9, wherein said node is a slave node;

The determining module is specifically configured to initiate a handshake communication to the primary node, and determine a bus manner of the data communication according to the preset bus frame.
The node according to claim 16, wherein said node is a node of said first bus mode;

The determining module is configured to send the preset bus frame in the first frame format to the primary node, receive a fourth information response sent by the primary node, and the fourth information response is the a first frame format; determining that the master node is a node of the first bus mode, and communicating with the master node by using the first bus mode.
The node according to claim 16, wherein said node is a node of said first bus mode;

The determining module is specifically configured to send the preset bus frame in the first frame format to the primary node; after receiving the preset timeout, the fourth information response sent by the primary node is not received yet, And the node determines that the primary node is a node of the second bus mode, and sends the preset total of the second frame format to the primary node. a line frame; receiving a fifth information response sent by the master node, and the fifth information response is in the second frame format; determining to communicate with the master node by using the second bus mode.
The node according to claim 16, wherein said node is a node of said second bus mode;

The determining module is specifically configured to send the preset bus frame in the second frame format to the primary node, receive a sixth information response sent by the primary node, and the sixth information response is the In the second frame format, the master node includes the node of the first bus mode and the node of the second bus mode; determining to communicate with the master node by using the second bus mode.
A controller area network CAN system, comprising: at least one node of a first bus mode and at least one node of a second bus mode, wherein the node of the first bus mode adopts claims 9 to 12, The node according to any one of 15 to 18, wherein the node of the second bus mode adopts the node according to any one of claims 9 to 10, 13 to 16, and 19.