Patent Publication Number: US-10313150-B2

Title: Data transmission method and device for robot using buffer

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to Chinese Patent Application No. 201611253294.4, filed Dec. 30, 2016, which is hereby incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to communication field, and particularly to a data transmission method for robot using buffer and a data transmission device for robot using buffer. 
     2. Description of Related Art 
     Controller Area Network (CAN) bus is a serial communication protocol for real-time applications, and is a point-to-multipoint mechanism. The CAN has been adopted in a variety of industries, such as, textile machinery, agricultural machinery, robots, CNC machine tools, medical equipment and sensors. 
     The demanding of the reliability with respect to the data-processing and the communication system has become higher, as the complexity of the device, the harshness of application environment, and the complexity of the system, tasks have been increased. Therefore, it is necessary to improve the communication process of the CAN bus protocol. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a flowchart illustrating a frame transmission method for robot in accordance with one embodiment of the present disclosure. 
         FIG. 2  is a flowchart illustrating a frame transmission method for robot in accordance with one embodiment of the present disclosure. 
         FIG. 3  is a flowchart illustrating a frame transmission method for robot in accordance with one embodiment of the present disclosure. 
         FIG. 4  is a flowchart illustrating a frame transmission method for robot in accordance with one embodiment of the present disclosure. 
         FIG. 5  is a schematic view of a data transmission device for robot in accordance with one embodiment of the present disclosure. 
         FIG. 6  is a schematic view of a data transmission device for robot in accordance with one embodiment of the present disclosure. 
         FIG. 7  is a schematic view of a data transmission device for robot in accordance with one embodiment of the present disclosure. 
         FIG. 8  is a schematic view of a data transmission device for robot in accordance with one embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     To clarify the purpose, technical solutions, and the advantages of the disclosure, embodiments of the invention will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. The figure and the embodiment described according to figure are only for illustration, and the present disclosure is not limited to these embodiments. It should be noted that the relational terms herein, such as “first” and “second”, are used only for differentiating one entity or operation, from another entity or operation, which, however do not necessarily require or imply that there should be any real relationship or sequence. Moreover, the terms “comprise”, “include” or any other variations thereof are meant to cover non-exclusive including, so that the process, method, article or device comprising a series of elements do not only comprise those elements, but also comprise other elements that are not explicitly listed or also comprise the inherent elements of the process, method, article or device. In the case that there are no more restrictions, an element qualified by the statement “comprises a . . . ” does not exclude the presence of additional identical elements in the process, method, article or device that comprises the said element. 
     A data transmission method and a device for robot in the present disclosure are based on a controller area network (CAN) bus. A main controller in the device is configured to be a control center to control each node within the device. The main controller may transmit broadcast messages to each of the nodes via a broadcast channel and may respectively configure a channel for each of the nodes. As such, the main controller may communicate with the respective node via the channel, and the device may achieve a variety of functions under different application scenarios, wherein the nodes may correspond to different elements under the different application scenarios. For example, a robot, the node may include joint servo steering gear, drive wheel, sensor, and dot matrix display. 
     The present disclosure relates to a data frame including a standard data frame and an extended data frame, wherein the standard data frame and the extended data frame are configured to improve the conventional standard data frame and the conventional extended data frame within the CAN bus 2.0B. 
     In the CAN bus 2.0B, the data frame may include a plurality of fields, including a frame start, an arbitration field, a control field, a data field, a cyclic redundancy check (CRC) field, a response field, and a frame end. Wherein the arbitration field may include an identity (ID) sub-field and other flags. The ID sub-field carries the identity of the node, wherein the identity of the node is configured to indicate the different nodes. The main difference between the standard data frame and the extended data frame resides in that the number of bits of the ID sub-field of the arbitration field is different. The number of bits of the ID sub-field of the arbitration field in the standard data frame is 11, and the number of bit of the ID sub-field of the arbitration field in the extended data frame is 29. 
     The data frame of the present disclosure is configured to improve the ID sub-field and data field of the arbitration field. However, only the enhancement will be described below. 
     1. The Standard Data Frame in the Present Disclosure. 
     1.1 The ID Sub-Field of the Arbitration Field. 
     The difference between the conventional CAN bus 2.0B and the standard data frame in present disclosure is illustrated in Table 1. 
     In one embodiment, the standard data, frame includes a frame-mode indication sub-field and a channel identification field. 
     The frame-mode indication sub-field includes 2 bits, including M 1  and M 0 , wherein the frame-mode indication sub-field is configured to indicate an analytical method of the frame. 
     The channel identification field includes 9 bits, including by CH 8  to CH 0 , wherein the channel identification field is configured to indicate the identity of the channel between the main controller and the node. The value of the channel in the standard data frame is in a range from 0 to 511. When the value of the channel identification field is zero, it is determined that the channel is a broadcast channel, wherein each of the nodes may receive messages transmitted from the main controller via the broadcast channel. 
     
       
         
           
               
               
             
               
                   
                 TABLE 1 
               
             
            
               
                   
                   
               
               
                   
                 ID sub-field (11 bits) 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
               
            
               
                 CAN bus 2.0B 
                 ID10 
                 ID9 
                 ID8 
                 ID7 
                 ID6 
                 ID5 
                 ID4 
                 ID3 
                 ID2 
                 ID1 
                 ID0 
               
               
                   
               
               
                 Examples 
                 M1 
                 M2 
                 CH8 
                 CH7 
                 CH6 
                 CH5 
                 CH4 
                 CH3 
                 CH2 
                 CH1 
                 CH0 
               
               
                   
               
            
           
         
       
     
     The difference between the conventional CAN bus 2.0B and the extended data frame in present disclosure is illustrated in Table 2. 
     The extended data frame in the present disclosure includes the frame-mode indication sub-field, the channel identification field, and a flag field. 
     The frame-mode indication sub-field includes 3 bits, including M 1 , M 0 , and EM 0 , wherein the frame-mode indication sub-field is configured to indicate the analytical method of the frame. 
     The flag field includes 10 bits. N indicates a reserved bit, END is configured to indicate the last frame. For example, if the value of the END equals to zero, it is determined that the frame is not the last frame. If the value of the END equals to 1, the frame is configured to be the last frame. “I” is a self-increasing cycle code configured to indicate a sending serial number of the frame. 
     The channel identification field includes 16 bits illustrating by CH 15  to CH 0 , wherein the channel identification field is configured to indicate the channel between the main controller and the node. The value of the channel identification field in the extended data frame is in a range from 0 to 65535. The zero value indicates the broadcast channel, wherein each of the nodes may receive messages transmitted from the main controller via the broadcast channel. 
     
       
         
           
               
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 CAN 
                   
               
               
                 bus 
                 ID sub-field (29 bits) 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
               
               
               
            
               
                 2.0B 
                 ID10 
                 ID9 
                 ID8 
                 ID7 
                 ID6 
                 ID5 
                 . . . 
                 ID0 
                 EID17 
                 EID16 
                 EID15 
                 . . . 
                 EID0 
               
               
                   
               
               
                 Example 
                 M1 
                 M2 
                 EM0 
                 N 
                 END 
                 17 
                 . . . 
                 12 
                 11 
                 10 
                 CH15 
                 . . . 
                 CH0 
               
               
                   
               
            
           
         
       
     
     An example of the frame-mode indication sub-field of the present disclosure is shown in Table 3. It is note that the different values of the frame-mode indication sub-field may indicate different analytical methods of the frame, wherein the different analytical method are configured to different application scenarios. 
     
       
         
           
               
               
               
               
               
             
               
                   
               
               
                 M1 
                 M0 
                 EM0 
                 Description 
                 Remarks 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                 0 
                 0 
                 0 
                 Node controlling 
                 Adopting the standard 
               
               
                   
                   
                   
                 instruction frame 
                 data frame if the 
               
               
                 0 
                 1 
                 0 
                 Node return 
                 identity of the channel 
               
               
                   
                   
                   
                 instruction frame 
                 corresponding to the 
               
               
                   
                   
                   
                   
                 node is less than 512, 
               
               
                   
                   
                   
                   
                 so as to improve the 
               
               
                   
                   
                   
                   
                 efficiency of the bus 
               
               
                 0 
                 0 
                 1 
                 Upload node string 
                 Adopting the extended 
               
               
                   
                   
                   
                 code 
                 data frame to transmit 
               
               
                 0 
                 1 
                 1 
                 Frame for configuring 
                 data 
               
               
                   
                   
                   
                 the channel of the node 
               
               
                 1 
                 0 
                 0 
                 Block control 
                 Adopting the extended 
               
               
                   
                   
                   
                 instruction frame 
                 data frame to transmit 
               
               
                 1 
                 1 
                 0 
                 Block return 
                 data 
               
               
                   
                   
                   
                 instruction frame 
               
               
                 1 
                 0 
                 1 
                 Block data outputting 
               
               
                   
                   
                   
                 frame 
               
               
                 1 
                 1 
                 1 
                 Block data inputting 
               
               
                   
                   
                   
                 frame 
               
               
                   
               
            
           
         
       
     
     1.2 Data Field. 
     The difference between the conventional CAN bus 2.0B and the data field of the data frame in present disclosure is illustrated in Table 4. 
     The data field of the data frame in present disclosure may include a CMD field of 1 bit, indicating the different analytical methods of the frame. The CMD field is configured to indicate a secondary instruction, and the different values of the CMD field may represent the different secondary instructions. After the CMD field, the data field further includes 7 bits, from D 0  to D 6 , indicating the data carried by the secondary instruction. The data fields of the block data outputting frame and the block data inputting frame respectively include eight bits which are configured to carry the data, so as to improve the transmission efficiency of the block data. 
     
       
         
           
               
               
             
               
                   
                 TABLE 4 
               
               
                   
                   
               
               
                   
                 Data field (8 bits) 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 CAN bus 2.0B 
                 D0 
                 D1 
                 D2 
                 D3 
                 D4 
                 D5 
                 D6 
                 D7 
               
               
                 Node controlling 
                 CMD 
                 D0 
                 D1 
                 D2 
                 D3 
                 D4 
                 D5 
                 D6 
               
               
                 instruction frame 
               
               
                 Node return 
                 CMD 
                 D0 
                 D1 
                 D2 
                 D3 
                 D4 
                 D5 
                 D6 
               
               
                 instruction frame 
               
               
                 Upload node 
                 D0 
                 D1 
                 D2 
                 D3 
                 D4 
                 D5 
                 D6 
                 D7 
               
               
                 string code 
               
               
                 Frame for 
                 D0 
                 D1 
                 D2 
                 D3 
                 D4 
                 D5 
                 D6 
                 D7 
               
               
                 configuring the 
               
               
                 channel of the 
               
               
                 node 
               
               
                 Block control 
                 CMD 
                 D0 
                 D1 
                 D2 
                 D3 
                 D4 
                 D5 
                 D6 
               
               
                 instruction frame 
               
               
                 Block return 
                 CMD 
                 D0 
                 D1 
                 D2 
                 D3 
                 D4 
                 D5 
                 D6 
               
               
                 instruction frame 
               
               
                 Block data 
                 D0 
                 D1 
                 D2 
                 D3 
                 D4 
                 D5 
                 D6 
                 D7 
               
               
                 outputting frame 
               
               
                 Block data 
                 D0 
                 D1 
                 D2 
                 D3 
                 D4 
                 D5 
                 D6 
                 D7 
               
               
                 inputting frame 
               
               
                   
               
            
           
         
       
     
     The present disclosure relates to a data transmission method for robot, as shown in  FIG. 1 . The data transmission method may be adopted by a main controller, including the following steps. 
     In step  101 : transmitting an attribute reporting request to the node, wherein the attribute reporting request carries a length of a buffer configured to store attribute data. 
     In step  102 : receiving the attribute data reported from the node, wherein a length of the attribute to be reported is less than or equals to the length of the buffer. 
     In step  103 : receiving an attribute reporting response transmitted from the node. 
     The present disclosure relates to a data transmission method for robot, wherein the main controller may receive the attribute data reported from the node. The main controller may inform the length of the buffer for storing the attribute data, while requesting the node to report the attribute data. As such, the node is aware of the length of the buffer, so as to enhance the reliability. 
     The present disclosure relates to the data transmission method for robot, as shown in  FIG. 2 . The data transmission method may be adopted by the main controller, including the following steps. 
     In step  201 : transmitting the attribute reporting request to the node, wherein the attribute reporting request carries the length of the buffer configured to store the attribute data. 
     The attribute reporting request may be transmitted via an attribute request frame which is block instructions, wherein the attribute request frame adopts an extended data frame format. A value of the frame-mode indication, sub-field of the ID sub-field in the arbitration field is configured to be M 1 M 0 EM 0 =100. A format of the data field in the attribute request frame is illustrated in Table 5. The 0 th  bit of the data field is configured to be the CMD instruction code. The value FE indicates the frame is an attribute request frame. The main controller transmits the attribute request frame to the node which indicates that the main controller requires the node to report the attribute data. The first bit to the fourth bit of the data field indicates the length of the buffer in the main controller, wherein the length of the buffer is configured to receive the attribute data reported from the node. The length of the attribute may not be greater than the length of the buffer. The attribute request frame is transmitted via a channel between the main controller and the node, wherein the channel is assigned by the main controller. If the node receives the block instruction attribute request via the broadcast channel, the block instruction attribute request is configured to be an invalid frame, and the node may ignore the block instruction attribute request. 
     
       
         
           
               
               
               
               
               
             
               
                 TABLE 5 
               
               
                   
               
               
                   
                   
                 Range of 
                   
                   
               
               
                 Bit 
                 Description 
                 value 
                 Usage 
                 Remarks 
               
               
                   
               
             
            
               
                 0 
                 Instruction 
                 0XFE 
                 Receiving the attribute 
                 Invalid 
               
               
                   
                 code 
                   
                 data reported from the 
                 broadcast 
               
               
                   
                   
                   
                 node, wherein a length 
               
               
                   
                   
                   
                 of the attribute to be 
               
               
                   
                   
                   
                 reported is less than or 
               
               
                   
                   
                   
                 equals to the length of 
               
               
                   
                   
                   
                 the buffer 
               
               
                 1~4 
                 Length of 
                 0~4G 
                 Receiving the length of 
                 No 
               
               
                   
                 buffer 
                   
                 the attribute data of the 
                 symbols 
               
               
                   
                   
                   
                 node 
               
               
                   
               
            
           
         
       
     
     In one example, the node may receive the attribute reporting request transmitted from the main controller, obtain the length of the buffer within the main controller configured to receive the attribute data of the node, and determine whether the length of the attribute data to be reported is greater than the length of the buffer. The node may inform the main controller to update the buffer in order to receive the attribute data before reporting the attribute data upon determining the length of the attribute data to be reported is greater than the length of the buffer. This embodiment is an example illustrating the length of the attribute data to be reported is greater than the length of the buffer. 
     In step  202 : receiving the attribute reporting response transmitted from the node before receiving attribute data reported from the node, wherein the attribute reporting response carries the length of the attribute data. 
     The attribute reporting response may be received via the block instruction attribute request response frame, wherein the block instruction attribute request response frame adopts the extended data frame format. The value of the frame-mode indication sub-field of the ID sub-field in the arbitration field is configured to be M 1 M 0 EM 0 =110. A format of the data field in the block instruction attribute request response frame is illustrated in Table 6. The 0 th  bit of the data field is configured to be the CMD instruction code. The value FD indicates the frame indicates the block instruction attribute request response frame. The node may transmit the block instruction attribute request response frame to the main controller under two circumstances. The first circumstance is that the node may transmit the block instruction attribute request response frame to the main controller after reporting the attribute data to the main controller, wherein the block instruction attribute request response frame is configured to indicate the process of transmitting the attribute data is completed. The second circumstance is the node may transmit the block instruction attribute request response frame to the main controller before reporting the attribute data to the main controller upon determining the length of the attribute data to be reported is greater than the length of the buffer of the main controller, wherein the block instruction attribute request response frame is configured to inform the main controller to update the buffer. The first bit to the fourth bit of the data field is configured to be the length of the attribute data. The block instruction attribute request response frame is transmitted via the channel between the main controller and the node, wherein the channel is assigned by the main controller. If the main controller receives the block instruction attribute request response frame via the broadcast channel, the block instruction attribute request response frame is configured to be an invalid frame, and the main controller may ignore the block instruction attribute request response frame. 
     
       
         
           
               
               
               
               
               
             
               
                 TABLE 6 
               
               
                   
               
               
                   
                   
                 Range of 
                   
                   
               
               
                 Bit 
                 Description 
                 value 
                 Usage 
                 Remarks 
               
               
                   
               
             
            
               
                 0 
                 Instruction 
                 0XFD 
                 Transmitting the 
                 Invalid 
               
               
                   
                 code 
                   
                 attribute data to the 
                 broadcast 
               
               
                   
                   
                   
                 main controller 
               
               
                   
                   
                   
                 before responding 
               
               
                   
                   
                   
                 block attribute 
               
               
                   
                   
                   
                 instruction request 
               
               
                   
                   
                   
                 frame; 
               
               
                   
                   
                   
                 returning the frame 
               
               
                   
                   
                   
                 and inform the main 
               
               
                   
                   
                   
                 controller to update 
               
               
                   
                   
                   
                 the buffer, and to 
               
               
                   
                   
                   
                 re-transmit, the block 
               
               
                   
                   
                   
                 attribute instruction 
               
               
                   
                   
                   
                 request frame upon 
               
               
                   
                   
                   
                 determining the 
               
               
                   
                   
                   
                 length of the attribute 
               
               
                   
                   
                   
                 to be reported is 
               
               
                   
                   
                   
                 greater than the 
               
               
                   
                   
                   
                 length of the buffer 
               
               
                   
                   
                   
                 of the main controller 
               
               
                 1~4 
                 Length of 
                 0~4G 
                 Length of attribute 
                 No 
               
               
                   
                 attribute 
                   
                   
                 symbols 
               
               
                   
               
            
           
         
       
     
     In step  203 : updating the buffer according to the length of the attribute data receiving from the node, and re-conducting the step  201 . 
     The main controller receives the attribute reporting response, and the main controller may update the buffer according to the length of the attribute to be reported, wherein the length of the attribute is carried by the attribute reporting response. 
     In step  204 : receiving the attribute data reported from the node. 
     The main controller may receive the attribute data reported from the node by receiving at least one block data transmitted from the node. The block data is transmitted via the block data inputting frame, wherein the block data inputting frame adopts the extended data frame format. The value of the frame-mode indication, sub-field of the ID sub-field in the arbitration field is configured to be M 1 M 0 EM 0 =111. The “I” of the ID sub-field of the arbitration field indicates a sending serial number of the frame, i.e., the “I” indicates the number of the data block that has been transmitted, and “I” may be refer to as a data block indicator. The END indicates a last frame. The data field of the block data inputting frame may not include the CMD field, and the 0 th  bit to the seventh bit may be configured to be the data bit. 
     In one example, the attribute data of the node adopt an “ini” configuration file format, including: a constant, portion and a variable portion. Elements within the constant portion may not be changed, wherein the elements within the constant portion may include: a production identity an upgrade indicator, and a secondary instruction to be used. Elements within the constant portion may be changed, such as a node identity (ID). The attribute of the node may be transform into a data format which may be carried by the block data inputting frame via coding. 
     In step  205 : receiving the attribute reporting response transmitted from the node, wherein the attribute reporting response carries the length of the attribute data. 
     The attribute reporting response may be transmitted via the block instruction attribute request response frame. The node may inform the main controller that the attribute data have been transmitted completely by transmitting the block instruction attribute request response frame after the node completes the transmission of the attribute data. 
     In one example, the main controller may receive the attribute reporting response. If the length of the received attribute is less than or is greater than the length carried by the attribute reporting response, the main controller may re-conduct the step  201  to request the node to report the attribute data. 
     In another aspect, as shown in the  FIG. 3 , the present disclosure relates to the data transmission method for robot, including the following steps. 
     In step  301 : receiving the attribute reporting request from the main controller, wherein the attribute reporting request carries the length of the buffer configured to store attribute data. 
     In step  302 : transmitting the attribute data to the main controller, wherein the length of the attribute to be reported is less than or equals to the length of the buffer. 
     In step  303 : transmitting the attribute reporting response to the main controller. 
     The present disclosure relates to the data transmission method for robot, wherein the node may report the attribute data to the main controller. The main controller may inform the length of the buffer, which is configured to store the attribute data, while transmitting the attribute reporting request to the node. As such, the length of the attribute to be reported may be configured to be less than the length of the buffer, so as to enhance the reliability. 
     In another aspect, as shown in the  FIG. 4 , the present disclosure relates to the data transmission method for robot, including the following steps. 
     In step  401 : receiving the attribute reporting request from the main controller, wherein the attribute reporting request carries the length of the buffer configured to store attribute data. 
     The attribute reporting request may be transmitted via the attribute request frame described in above. 
     In step  402 : determining whether the length of the attribute data to be reported is greater than the length of the buffer, if the length of the attribute data to be reported is greater than the length of the buffer, the process goes to step  403 , if the length of the attribute data to be reported is not greater than the length of the buffer, the process goes to step  404 . 
     In step  403 : transmitting the attribute reporting response to the main controller, wherein the attribute reporting response carries the length of the attribute data to be reported. 
     The attribute reporting response may be received via the block instruction attribute request response frame described in above. 
     The node may receive the attribute reporting request from the main controller, i.e., re-conducting the step  401 , after the step  403 . Wherein the length of the buffer carried by the attribute reporting request, which is transmitted by the main controller, has been updated according to the length of the attribute to be reported. 
     In step  404 : transmitting the attribute data to the main controller. 
     The main controller may receive the attribute data reported from the node by receiving the at least one block data transmitted from the node. The block data is transmitted via the block data inputting frame, wherein the block data inputting frame adopts the extended data frame format. The value of the frame-mode indication sub-field of the ID sub-field in the arbitration field is configured to be M 1 M 0 EM 0 =111. The “1” of the ID sub-field of the arbitration field indicates a sending serial number of the frame, i.e., the “1” indicates the number of the data block that has been transmitted, and “1” may be refer to as a data block indicator. The END indicates a last frame. The data field of the block data inputting frame may not include the CMD add, and the 0 th  bit to the seventh bit may be configured to be the data bit. 
     In one example, the attribute data of the node adopt the “ini” configuration file format, including: the constant portion and the variable portion. The elements within the constant portion may not be changed, wherein the elements may include: the production identity, the upgrade indicator, and the secondary instruction to be used. The elements within the constant portion may be changed, such as the node identity (ID). The attribute of the node may be transform into the data format which may be carried by the block data inputting frame via coding. 
     In step  405 : transmitting the attribute reporting response to the main controller, wherein the attribute reporting response carries the length of the attribute data to be reported. 
     The attribute reporting response may be transmitted via the block instruction attribute request response frame described in above. The node may inform the main controller that the attribute data have been transmitted completely by transmitting the block instruction attribute request response frame after the node completes the transmission of the attribute data. 
     The following description is an example of the data transmission method applied to application scenario. 
     The channel between the main controller and the node is assumed to be 10 (channel=10), the length of the buffer configured to receive the attribute in the main controller is assumed to be 2 k, and the length of the attribute to be reported by the node is assumed to be 900. 
     1. The main controller transmits the attribute request frame to the node, and the value of each field is configured to be as: M 1 M 0 EM 0 =100, channel=10, CMD=0XFE, D 1 ˜D 4 =2K. 
     2. The node transmits the first block data inputting frame to the main controller, and the value of each field is configured to be as: M 1 M 0 EM 0 =111, channel=10, END=0, I=0, D 0 ˜D 7  is configured to be the first 8 bits of the attribute data of the node. 
     3. The node transmits the n-th block, data inputting frame to the main controller, and the value of each field is configured to be as: M 1 M 0 EM 0 =111, channel=10, END=0, 1=n−1, D 0 ˜D 7  is configured to be the nth 8 bite of the attribute data of the node. 
     4. The node transmits the (n+1)-th block data inputting frame to the main controller, and the value of each field is configured to be as: M 1 M 0 EM 0 =111, channel=10, END=1, 1=n, D 0 ˜D 7  is configured to be the last (n+1)-th packet 8 of the attribute data of the node. 
     5. The node transmits the block instruction attribute request response frame, and the value of each field is configured to be as: M 1 M 0 EM 0 =110, channel=10, CMD=0XFD, D 1 ˜D 4 =900. 
     In another aspect, the present disclosure further relates to a data transmission device. The frame structure of the embodiment is the same with the above, and may not be described again. 
     The data transmission device for robot, as shown in  FIG. 5 , may include a transmitter  501  and a receiver  502 . 
     The transmitter  501  is configured to transmit the attribute reporting request to the node, wherein the attribute reporting request carries the length of the buffer configured to store the attribute data. 
     The receiver  502  is configured to receive the attribute data reported from the node and to receive the attribute reporting response transmitted from the node. 
     Wherein the length of the attribute data is less than or equals to the length of the buffer. 
     The present disclosure relates to the data transmission device for robot, wherein the main controller may receive the attribute data transmitted from the node. The main controller may inform the length of the buffer for storing the attribute data, while requesting the node to report the attribute data. As such, the node is aware of the length of the buffer, so as to enhance the reliability. 
     The data transmission device for robot, as shown in  FIG. 6 , may include the transmitter  501 , the receiver  502  and a processor  503 . 
     The transmitter  501  and the receiver  502  shown in  FIG. 6  may have the same function in a portion with the transmitter  501  and the receiver  502  shown in  FIG. 5 . 
     In one example, the receiver  502  may be further configured to receive the attribute reporting response transmitted from the node before received attribute date reported from the node, wherein the attribute reporting response carries the length of the attribute data to be reported. The processor  503  is configured to update the buffer according to the length of the attribute data reported from the node and is configured to drive the transmitter to transmit the attribute reporting request to the node. 
     In one example, the receiver  502  may be further configured to receive the at least one block data transmitted from the node, wherein each of the block data carries the data block identification and the indicator bit indicating the end of the attribute reporting process by the node. 
     The main controller may receive the attribute reporting response. If the main controller determines the length of the received attribute is greater than or is less than the length carried by the attribute reporting response, the main controller may request the node to re-transmit the attribute. That is, the processor  503  is further configured to drive the transmitter  501  to transmit the attribute reporting request to the node upon determining the length of the received attribute data is greater than or less than the length earned by the attribute reporting response. 
     In one example, as shown in  FIG. 7 , the data transmission device may be adopted by the node, and may include the transmitter  701  and the receiver  702 . 
     The receiver  702  is configured to receive the attribute reporting request from the main controller, wherein the attribute reporting request, carries the length of the buffer configured to store the attribute data. 
     The transmitter  701  is configured to transmit the attribute data to the main controller and to transmit an attribute reporting response to the main controller. 
     Wherein the length of the attribute data is less than or equals to the length of the buffer. 
     The present disclosure relates to the data transmission device for robot, wherein the node may receive the attribute reporting request transmitted from the main controller. The main controller may inform the length of the buffer for storing the attribute data, while requesting the node to report the attribute data. As such, the node is aware of the length of the buffer, so as to enhance the reliability. 
     In one example, as shown in  FIG. 8 , the data transmission device may be adopted by the node, and may include the transmitter  701 , the receiver  702  and the processor  703 . 
     The transmitter  701  and the receiver  702  shown in  FIG. 8  may have the same function in a portion with the transmitter  701  and the receiver  702  shown in  FIG. 7 . 
     In one example, the processor  703  may be further configured to determine whether the length of the attribute data to be reported is greater than the length of the buffer, to drive the transmitter  701  to transmit the attribute reporting response to the node upon determining the length of the attribute data to be reported is greater than the length of the buffer, wherein the attribute reporting response carries the length of the attribute data to be reported, and the length of the attribute data to be reported drives the main controller to update the buffer. The processor  703  may be further configured to drive the transmitter  701  to transmit the attribute data to the main controller upon determining the length of the attribute data to be reported is less than or equals to the length of the buffer. 
     In one example, the transmitter  701  may be further configured to transmit the at least one block data to the main controller, wherein each of the block data carries the data block identification and the indicator bit indicating the end of the attribute reporting process by the node. 
     The above description is merely the embodiments in the present disclosure, the claim is not limited to the description thereby. The equivalent structure or changing of the process of the content of the description and the figures, or to implement to other technical field directly or indirectly should be included in the claim.