CN101409727B - Document transmission method and apparatus - Google Patents

Abstract

The invention discloses a file transmission method for a train communication network, comprising: sending operation request information to an opposite device according to a predetermined format, the operation request information including operation code, transmission mode and path information; After the confirmation information returned by the peer device, the data packet operation is performed according to the operation request information. The invention also provides a file transmission device used in the train communication network. According to the present invention, the five functions of file upload, file download, file or directory query, file deletion, and disk space usage check can be realized. On the train communication network, system files, configuration files, and application files can be transmitted through a smart device. To other smart devices, it is beneficial to the maintenance of the file system on the train device.

Description

A file transfer method and device

technical field

The present invention relates to the field of network and communication technologies, in particular to a file transmission method and device.

Background technique

Train Communication Network (TCN, Train Communication Network) is used for data file exchange between various operation management devices on the train, and usually adopts a distributed modular structure. Because it is a dedicated network, its transmission speed, transmission capacity, and real-time performance must meet the requirements of train operation, realizing a technological leap from centralized control to distributed network control. For TCN-based file transfer, methods that can be used for reference include the widely used TCP/IP-based TFTP and FTP (File Transfer Protocol).

The Trivial File Transfer Protocol (TFTP, Trivial File Transfer Protocol) in the prior art is an application based on the User Datagram Protocol (UDP, User Datagram Protocol). At the beginning of the work, the client of TFTP exchanges information with the server, and the client sends a read request or write request to the server. For a read request, if the file can be read by the client, the TFTP server returns a data packet with a block number of 1. The TFTP client sends an acknowledgment (ACK, Acknowledge) containing block number 1. Then the TFTP server continues to send the data packet whose block number is 2, and TFTP returns an ACK whose block number is 2. Repeat this process until the file is transferred. In the case of a write request, the TFTP server returns an ACK with block number 0 if the file can be written by the client. The client sends the first 512 bytes of the file with block number 1. The server returns an ACK with block number 1. The advantage of TFTP lies in its simplicity of implementation.

For the train network management of TCN, no specific implementation method of file transfer has been proposed yet, but file transfer is very necessary. Various system files and configuration files need to be transferred between devices on the train. If the TFTP or FTP protocol is copied completely, it is not feasible for the train network. This is because the train communication network uses a multifunctional vehicle bus (MVB, Multifunction Vehicle Bus) and a twisted train bus (WTB, Wire TrainBus) bus, and uses a real-time protocol (RTP, Real Time Protocol), while the TFTP protocol, The FTP protocol is the application of UDP and TCP based on the TCP/IP protocol family respectively. Therefore, the TFTP protocol and the FTP protocol are not suitable for the train network.

In addition, although TFTP is simple to implement, its functions are too simple, and it can only upload and download files, which cannot meet the needs of train network management. For example on a train network, it is necessary to view a list of files on a remote device in order to select a file to download. And FTP has rich functions, but the implementation is too complicated.

Contents of the invention

In view of this, the present invention provides a file transmission method and device, which can realize file transmission between two devices in a train communication network and meet the requirements of train network management.

A file transfer method provided by an embodiment of the present invention is used in a train communication network, including:

Sending operation request information to the peer device according to a predetermined format, the operation request information including operation code, transmission mode and path information;

After receiving the confirmation information returned by the peer device, the data packet operation is performed according to the operation request information.

The embodiment of the present invention also provides a file transmission device for a train communication network, including:

The operation request sending unit sends operation request information to the peer device according to a predetermined format, and the operation request information includes operation code, transmission mode and path information;

The response message receiving unit receives the response message returned by the peer device;

The data operation unit, after receiving the confirmation information returned by the peer device, performs data message operations according to the operation request information.

To sum up, among the technical solutions provided by the embodiments of the present invention, a file transfer method and device based on a train communication network is provided, which can provide file transfer between devices in a vehicle or between vehicles. The present invention is based on RTP The application on the protocol is based on the RTP (Real Time Protocol) used in the train communication network. One smart device sends a function request to another device. After the device responds to the request, the file transfer starts. By defining and implementing five functions of file upload, file download, query file or directory, delete file, and check disk usage space, the file transfer between two devices in the train communication network is realized.

The method of the present invention makes full use of the idea of Trivial File Transfer Protocol (TFTP) to realize the function of file upload/download, and provides abundant file transfer commands, which is simple and easy to operate, and has high reading and writing efficiency. Realized that on the train communication network, system files, configuration files, and application files can be transmitted to other smart devices through one smart device, which is beneficial to the maintenance of the file system on the train device.

Description of drawings

Fig. 1 is the flow chart of uploading data file provided in the embodiment of the present invention;

Fig. 2 is the flow chart of downloading data file provided in the embodiment of the present invention;

FIG. 3 is a schematic diagram of a finite state machine for processing an agent uploading a file according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a finite state machine for file upload processing by an operator according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a file transmission device provided by an embodiment of the present invention.

Detailed ways

In view of the characteristics and environment of the train communication network, the present invention proposes a file transfer method based on the train communication network for the train communication network, which not only makes full use of the idea of TFTP, but also provides rich file transfer functions.

The data transfer operations provided by this file transfer method include data upload, data download, list display of files or directories, file deletion, and viewing of available disk space. It is implemented as follows:

In order to be integrated into the train network management TNM, the function number of the file transfer service is defined as follows:

The file upload function number is 100;

The file download function number is 101;

The list shows that the function number of the file or directory is 102;

Delete file function number is 103;

The function number for viewing the available disk space is 105.

First, the message format is defined. In the embodiment of the present invention, the file transfer protocol uses 5 types of messages:

Read request (RRQ): Read request for downloading data files.

Write request (WRQ): write request for uploading data files.

Data (DATA): data message, used to transmit file content.

Acknowledgment (ACK): Acknowledgment message, used to indicate the transmission status.

Error(ERROR): Error return message, used to indicate transmission error.

The format and description of the message are as follows:

(1) RRQ/WRQ message format

The formats of RRQ and WRQ messages (opcodes are 1 and 2 respectively) are as above. Filenames are ASCII characters, ending with 0. Mode indicates the transfer mode of the file, there are character mode (0) or binary mode (3).

DATA message format

Data is transmitted in datagrams, the format of which is shown in the figure above. The opcode of the data packet is 3, and it also includes a data block number and data. The data block number starts from 1 and increases by 1 for each data block, so that the receiver can determine whether the packet is new data or already received data. The data field is from 0 bytes to 512 bytes. If the data field is 512 bytes, it is not the last packet, and if it is less than 512 bytes, it means that this packet is the last packet.

ACK message format

The opcode of the ACK packet is 4. The packet number is the packet number of the data packet to be confirmed.

ERROR message format

The operation code opcode of the ERROR message is 5, and its format is shown above, and this packet can be confirmed by any other type of packet. The error code specifies the type of error. The value of the error code is:

0 undefined

1 file open error

2 Timer setting error

3 file not opened

4 Unexpected message

5 Wrong block number sent

disk full or exceeds allocated quota file

already exists

no similar users

8 Illegal file transfer operations

A data transmission method provided by an embodiment of the present invention is used in a train communication network, including:

Sending operation request information to the peer device according to a predetermined format, the operation request information including operation code, transmission mode and path information;

After receiving the confirmation information returned by the peer device, the data packet operation is performed according to the operation request information. For example, data packets are uploaded or downloaded.

Embodiment one

In this embodiment, based on the process of uploading files, the transmission process of the message is described, with reference to Figure 1, as follows:

In step S101, the operator sends a write request WRQ message to the agent.

The operator plays the function similar to the file transfer client, and the agent plays the function similar to the file transfer server.

Step S102, the agent judges whether the file name and path are correct, and whether the system can accept it. If correct, answer the ACK message. If it is wrong, reply with an ERROR message.

Step S103, after receiving the ACK message, the operator starts to send the DATA message to the agent.

Step S104, the agent receives the DATA message, writes it into the data file, and replies with an ACK message, and if an error occurs, replies with an ERROR message.

The operator repeats step S103, and the agent repeats step S104. until the data is sent. If the operator receives an ERROR message during the previous process, the transmission process ends.

State machine on operator and agent side

The working status of the agent's upload file processing module can be divided into three: Idle, Start, Run status. The Idle state indicates that upload file processing has not started yet. The Start state means entering the state of file upload, but the data transmission has not yet started. The Run state indicates that the file is being uploaded and the agent is receiving data.

The working state of the operator's uploaded file processing module can be divided into three: Idle, Start, and Run states. The Idle state indicates that upload file processing has not started yet. The Start state means entering the state of file upload, but the data transmission has not yet started. The Run state indicates that the file is being uploaded and the agent is receiving data.

In this example. The timeout value is set to: 2 seconds.

Embodiment two

In this embodiment, the file transfer protocol uses 5 types of messages as mentioned above: read request Readrequest (RRQ), write request Write request (WRQ), data message Data (DATA), confirmation message Acknowledgment (ACK) and Error returns message Error(ERROR).

The following is based on the process of downloading files to illustrate the transmission process of the message, as follows:

Step S201. The operator sends a read request RRQ message to the agent;

Step S202. The agent judges whether the file name and path are correct, and whether the file can be opened. If correct, start transmitting the DATA message. If wrong, answer ERROR message;

Step S203. After receiving the DATA message, the operator determines if it is not the last message, and sends an ACK message to the agent to request the next piece of data;

Step S204. The agent receives the ACK message, if the file has not been transmitted, continue to answer the DATA message, if an error occurs, answer the ERROR message;

The operator repeats step S203, and the agent repeats step S204; until the data is sent. If the operator receives an ERROR message during the previous process, the transmission process ends.

Referring to Fig. 3 and Fig. 4, the state machines of the operators and agents are shown respectively.

In the file download process, the agent performs a function similar to that of the file transfer server.

The working state of the agent's upload file processing module can be divided into two: Idle and Run states. The Idle state indicates that the download file processing has not started yet. The Run state indicates that the file is being downloaded and the agent is sending data.

In file download processing, the operator functions similarly to a file transfer client.

The working state of the operator's download file processing module can be divided into three states: Idle, Start, and Run states. The Idle state indicates that the download file processing has not started yet. The Start state means entering the state of file download, but the data transmission has not yet started. The Run state indicates that the file is being downloaded and the agent is receiving data.

Embodiment Three

Compared with the foregoing embodiments, the data transmission method provided by the embodiment of the present invention further includes:

The functions of querying files or directories, deleting files, and viewing the available disk space are implemented by calling the library functions of the operating system on the smart device. Different operating systems have different specific implementation methods.

(a) query file or directory operation

View the file list of the specified directory of the smart device on the train network, the attribute of the file (regular file or directory) and file size. Or view the list of devices on that device. The device list includes physical serial ports, Flash storage devices, remote host directories, and other devices and drivers.

The call message structure is defined as follows:

Call_Get_Dir::RECORD

{

dir_name_len UNSIGNED16;--used to store "/" (referring to the device list) or the length of the directory name

dir_name[256]UNSIGNED8;--used to send "/" (refers to read device list) or directory name

}

The structure of the response message is as follows:

Reply_Get_Dir::RECORD

{

flag UNSIGNED8;--Used to identify whether the reply is a device list or a file list

    nr_files_or_drvs UNSIGNED16;--used to store the number of devices or the number of files

body union

{

    file_list ARRAY[NM_MAX_FILE_NUM]of

{

         file_state UNSIGNED8;--The type used to store the file

        file_size UNSIGNED32; -- used to store the size of the file

        file_name[32] UNSIGNED8; -- used to store the file name

            }

dev_list ARRAY[NM_MAX_FILE_NUM]of

{

        dev_num UNSIGNED16;--used to store the device number;

        dev_name[32] UNSIGNED8;--used to store the device name

            }

}

}

Among them flag:

0 means that the file_Or_Dev_Object array stores the device name and the driver letter of the device.

1 means that the file name and its type value are stored in the File_Or_Dev_Object array.

2 indicates that the name of the directory to be opened is incorrect.

When flag is 1,

file_state is:

0 means the file name is a directory

1 indicates that the file name is a regular file

2 indicates that the type of the file is other

3 indicates that the type of the file failed to be obtained

(b) delete file operation

Deleted files can be system files, configuration files, and application files. The security of the file system is implemented by the software on the PC side. When sending the delete command, you need to specify the absolute path of the file to be deleted.

The call message structure is as follows:

Call_Remove_File::Record

{

file_name_len UNSIGNED16; -- used to store the length of the file name

file_name[256]UNSIGNED8;--used to store the file name

}

The response message is as follows:

Reply_Remove_File::Record

{

};

(c) View storage space operations

View the available space of the specified disk. It should be noted that the available space of the disk is not necessarily equal to the free space.

The structure of the request message is as follows:

Call_Get_Disk_Free_Space::Record

{

Disk_name[32]UNSIGNED8;--used to store the disk name

};

The structure of the response message is as follows:

Reply_Get_Disk_Free_Space::Record

{

free_space UNSIGNED32;-- used to store the disk space size, if the disk space size fails to be obtained, -1 will be returned.

};

Embodiment four

A data transmission device 400 provided in this embodiment is used in a train communication network. As shown in FIG. 5, the data transmission device 400 includes:

The operation request sending unit 401 sends operation request information to the peer device according to a predetermined format, the operation request information including operation code, transmission mode and path information;

The response message receiving unit 402 receives the response message returned by the peer device;

The data operation unit 403, after receiving the confirmation information returned by the peer device, performs data packet operations according to the operation request information.

The operation request includes a read request and a write request; the data operation unit 403 includes:

The data receiving unit 403a is configured to download data from the peer device after the response message receiving unit receives the confirmation information returned by the peer device when the operation request is a read request;

The data sending unit 403b, when the operation request is a write request, uploads data to the peer device after the response message receiving unit receives the confirmation information returned by the peer device.

The device 400 also includes:

The query unit 404 is configured to query directories and files in the peer device, including a file list, file attributes and file sizes; and view configuration information on the peer device.

The device also includes:

A deletion unit 405, configured to delete the file in the peer device; and/or

A storage space checking unit 406, configured to check the available storage space in the peer device.

To sum up, in the technical solution provided by the embodiment of the present invention, a data transmission method and device based on a train communication network is provided, which can provide communication between applications in a vehicle or between vehicles. The present invention is based on the RTP protocol In the application on the Internet, based on the RTP (Real Time Protocol) used in the train communication network, one smart device sends a function request to another device, and after the device responds to the request, the file transfer starts. By defining and implementing five functions of file upload, file download, query file or directory, delete file, and view disk space usage, the file transfer between two devices in the train network is realized.

The method of the present invention makes full use of the idea of TFTP (Trivial File Transfer Protocol, simple file transfer protocol) to realize the function of file upload/download, and provides rich file transfer commands, which is simple and easy to implement, and has high reading and writing efficiency. Realized that on the train communication network, system files, configuration files, and application files can be transmitted to other smart devices through one smart device, which is beneficial to the maintenance of the file system on the train device.

Obviously, those skilled in the art should understand that each unit or each step of the above-mentioned present invention can be realized by a general-purpose computing device, and they can be concentrated on a single computing device, or distributed in a network formed by multiple computing devices Optionally, they can be implemented with program codes executable by computing devices, thus, they can be stored in storage devices and executed by computing devices, or they can be made into individual integrated circuit modules, or they can be integrated into Multiple units or steps are fabricated into a single integrated circuit module to achieve. As such, the present invention is not limited to any specific combination of hardware and software.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present invention are included in the protection scope of the present invention.

Claims (9)

1. A file transfer method, used for train communication network, is characterized in that, comprising: Send operation request information to the peer device according to a predetermined format, the operation request information includes operation code, transmission mode and path information, and the transmission mode is character mode or binary mode; After receiving the confirmation information returned by the peer device, the data packet operation is performed according to the operation request information; the confirmation information is sent by the peer device in the following manner: the peer device receives the After receiving the operation request information, it is judged whether the path information is correct, and if it is correct, the operation is performed according to the operation request information, and the confirmation information is fed back. 2. The method of claim 1, further comprising: The message data capacity is determined according to the maximum transmission unit of the link layer of the train communication network. 3. The method according to claim 1, wherein the operation request comprises: A read request, for downloading the message data from the peer device; A write request, configured to upload the message data to the peer device. 4. The method according to claim 1, wherein the operation request further comprises: The query request is used to query directories and files in the peer device, including a file list, file attributes and file sizes. 5. The method according to claim 1, wherein the operation request further comprises: A delete operation request for deleting the file in the peer device; and/or The storage space check request is used to check the available storage space information in the peer device. 6. A file transmission device for a train communication network, characterized in that it comprises: The operation request sending unit sends operation request information to the peer device according to a predetermined format, the operation request information includes operation code, transmission mode and path information, and the transmission mode is character mode or binary mode; The response message receiving unit receives the response message returned by the peer device; The data operation unit, after receiving the confirmation information returned by the peer device, performs data packet operations according to the operation request information; the confirmation information is sent by the peer device in the following manner: the peer device After receiving the operation request information, it is judged whether the path information is correct, and if it is correct, the operation is performed according to the operation request information, and the confirmation information is fed back. 7. The device according to claim 6, wherein the operation request comprises a read request and a write request; the data operation unit comprises: The data receiving unit is configured to download data from the peer device after the response message receiving unit receives the confirmation information returned by the peer device when the operation request is a read request; The data sending unit, when the operation request is a write request, uploads data to the peer device after the response message receiving unit receives the confirmation information returned by the peer device. 8. The apparatus of claim 6, further comprising: The query unit is used to query the directories and files in the peer device, including the file list, file attributes and file sizes; and check the configuration information on the peer device. 9. The apparatus of claim 6, further comprising: a deletion unit, configured to delete files in the peer device; and/or A storage space checking unit, configured to check the available storage space in the peer device.

Images