Data communication method and device based on ARINC661 standard

Abstract

The invention provides a data communication method and device based on an ARINC661 standard, and the method comprises the steps: determining the data length according to a secondary packaging protocol; and unpacking the to-be-sent data packet based on the ARINC661 standard according to the data length, packaging each to-be-sent data stream according to the customized content and the secondary packaging protocol, and sending the packaged data stream to the cockpit display system. Under the condition of being compatible with the ARINC661 standard, the expansibility of the standard is increased, and system requirements can be accurately customized. And on the basis of ensuring high efficiency of the ARINC661 standard, the method can better adapt to different bus types and different data distribution modes, data can be normally communicated between channels with different bandwidths, the network utilization rate is improved, and the technology is applied to part of scientific research work and has a better effect.

Description

Technical Field

[0001] The present invention belongs to the technical fields of avionics systems, integrated display and control, and particularly relates to a data communication method and device based on the ARINC661 standard. Background Art

[0002] The ARINC661 specification, namely the "Interface between Cockpit Display System and User System" specification, is a set of interface specifications for cockpit display and user systems customized by ARINC. It defines graphic display and logic control methods and standardizes the interface between the cockpit display system (CDS) and the user system (UA). Its advantage is to separate the drawing code from the control logic such as the state and position of the graphic. The CDS provides its human-machine interaction interface, and the UA manages the operation logic of the graphic.

[0003] The ARINC 661 protocol only stipulates the data transmission format between the UA and the CDS, and does not stipulate which bus to use for communication at the physical layer. In theory, any bus can be used for communication between systems, but the bandwidth, rate, data transmission method and other attributes of different buses are different. Therefore, to output customized data, it is necessary to expand the communication method and establish a data communication method to meet different data requirements. Summary of the Invention

[0004] The present invention provides a data communication method and device based on the ARINC661 standard, which solves the problem that the existing ARINC 661 protocol only stipulates the data transmission format between the UA and the CDS.

[0005] The first aspect of the present invention provides a data communication method based on the ARINC661 standard, including:

[0006] The user system obtains customized content, which includes the states of each subsystem that need to be displayed in real time on the cockpit display system and the sending time;

[0007] The user system obtains a data packet to be sent based on the ARINC661 standard and a secondary encapsulation protocol;

[0008] The user system determines the data length according to the secondary encapsulation protocol;

[0009] The user system unpacks the data packet to be sent based on the ARINC661 standard according to the data length to obtain N data streams to be sent; N is a positive integer;

[0010] The user system encapsulates each data stream to be sent according to the customized content and the secondary encapsulation protocol to obtain N data packets to be sent based on the secondary encapsulation protocol, and sends them to the cockpit display system;

[0011] Among them, the data packet to be sent based on the secondary encapsulation protocol includes: application header, application type, customized content, data length, data stream to be sent, and application tail;

[0012] The application header is used to indicate the secondary encapsulation protocol; the application tail is used as the ending identifier of the data packet to be sent based on the secondary encapsulation protocol;

[0013] The application type is used to indicate the total number of packets and the packet sequence number.

[0014] Optionally, the user system determines the data length according to the secondary encapsulation protocol, including:

[0015] When the secondary encapsulation protocol is the 422 bus, the maximum data length is 2 kb;

[0016] When the secondary encapsulation protocol is Ethernet, the maximum data length is 64 kb;

[0017] When the secondary encapsulation protocol is the FC bus, the maximum data length is 2 mb.

[0018] Optionally, the value of N does not exceed 5.

[0019] Optionally, the application type also indicates the serial number of the user system.

[0020] Optionally, the length of the application header is the same as the length of the protocol header of the ARINC661 standard.

[0021] Optionally, sending N data packets to be sent based on the secondary encapsulation protocol to the cockpit display system includes:

[0022] Sending the N data packets to be sent based on the secondary encapsulation protocol to the cockpit display system in ascending order of the packet sequence number.

[0023] The second aspect of the present invention provides a data communication method based on the ARINC661 standard, including:

[0024] The cockpit display system receives the data packet, reads the packet header of the data packet, and determines the encapsulation protocol according to the packet header;

[0025] When the encapsulation protocol of the cockpit display system is the secondary encapsulation protocol, the total number of packets is determined according to the application type, and the packet sequence number is obtained;

[0026] When the total number of packets is greater than 1, the cockpit display system determines whether it has received the data packet corresponding to the previous packet sequence number of the current packet sequence number; if so, the data stream and the customized content are obtained according to the data length and sent to the display queue of the user system;

[0027] When the number of data streams in the display queue of the cockpit display system reaches the total packet count, the data streams are packetized to obtain data packets based on the ARINC661 standard, and are sent to the data stream based on the ARINC661 standard, clearing the queue.

[0028] The third aspect of the present invention provides a data communication device based on the ARINC661 standard for performing the method described in any one of the first aspects.

[0029] The fourth aspect of the present invention provides a data communication device based on the ARINC661 standard for performing the method described in the third aspect.

[0030] The present invention provides a data communication method and device based on the ARINC661 standard. Through the present invention, the function of using different sizes and different types of communication channels for the same UA can be achieved, the adaptability of the ARINC661 specification to various buses and various data distribution methods can be optimized, and the network utilization rate can be improved; through the present invention, customized data transmission can be realized with fewer modifications to the UA and CDS ends, and at the same time, it can be compatible with the original ARINC661 specification. While being compatible with the ARINC661 specification, the present invention increases the extensibility of the specification and can accurately customize system requirements. And on the basis of ensuring the high efficiency of the ARINC661 specification, it can better adapt to different types of bus types and different data distribution methods, enable data to communicate normally between different bandwidth channels, and improve the network utilization rate. This technology has been applied in some scientific research work with good results. Description of the Drawings

[0031] Figure 1 is the communication principle between UA and CDS;

[0032] Figure 2 is the secondary encapsulation of the original protocol;

[0033] Figure 3 is the new function and data stream of UA;

[0034] Figure 4 is the new function and data stream of CDS. Detailed Embodiments

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0036] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without some of these specific details. The following description of the embodiments is only intended to provide a better understanding of the present invention by showing examples of the present invention. The present invention is in no way limited to any specific arrangement and method set forth below, but covers any improvements, substitutions, and modifications of structures, methods, and devices without departing from the spirit of the present invention. In the drawings and the following description, well-known structures and techniques are not shown to avoid unnecessarily obscuring the present invention.

[0037] It should be noted that, without conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other, and the various embodiments may refer to and cite each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0038] The present invention will be further described in detail below in combination with the embodiments and the drawings, but the embodiments of the present invention are not limited thereto.

[0039] As Figures 1-4 shown, the present invention provides a data communication method and apparatus based on the ARINC661 standard.

[0040] The ARINC661 specification can efficiently implement communication and drawing instruction implementation between CDS and UA, but the data format is fixed and the scalability is poor. Therefore, it is difficult to directly implement specific communication requirements on different buses through the ARINC661 specification; moreover, the transmission rates of different buses are different. When the CDS end displays data and receives ARINC661 data transmitted from the UA segment of different buses, it is impossible to effectively distinguish the bus types, which affects the CDS end's judgment of the priorities of different data sources. Therefore, the present invention extends the communication method of ARINC661 on the basis of the protocol, enabling the system to better implement customized operations such as large-scale streaming data communication, multi-bus data reception, and distributed UA communication through the present invention.

[0041] I. Basic communication method between UA and CDS

[0042] All the graphic logic processing of the cockpit display system is carried out in the UA, mainly including the update of CDS data and the response to events sent by the Layer and widgets (response to user operations). For the UA software, the Layer is the highest unit it manages. The UA can receive events from the Layer and process widget events according to the Layer Id. The CDS software needs to load specific definition files to obtain display data and perform real-time rendering. During operation, the display data is updated through the data of the UA. The working principle is shown in the appendix Figure 1 。

[0043] The ARINC661 specification defines the instructions from the UA to the CDS during operation into two categories: parameter setting (A661_CMD_SET_PARAMETER) and status request (A661_CMD_UA_REQUEST); the events from the CDS to the UA are defined into three categories: Widget event (A661_NOTIFY_WIDGET_EVENT), Layer event (A661_NOTIFY_LAYER_EVENT), and error notification (A661_NOTIFY_EXCEPTION). The communication data types and protocol parsing methods are fixed, and customers cannot add customized instruction sets.

[0044] II. Secondary encapsulation of customized data between the UA and the CDS

[0045] The instruction set recognized by the ARINC661 specification is very difficult to change. Therefore, to meet customized requirements, secondary encapsulation needs to be carried out at the basic protocol layer.

[0046] The encapsulated protocol is as shown in the appendix Figure 2 On the basis of the original protocol, an application header, application type, customized content, and data length are added at the front, and an application tail is added at the back. The application header and application tail are used as specific data segments to identify whether the communication data is a secondary encapsulation protocol.

[0047] a) The application header is the subject of the protocol transmission, defined as four bytes (the same length as the application header of the ARINC661 original protocol). In the present invention, according to the form of the ARINC661 data transmission bus, the following application headers are divided:

[0048] 0x0A0B00FC represents that this data packet is transmitted through the FC channel

[0049] 0x0A0B0422 represents that this data packet is transmitted through the 422 channel

[0050] 0x0A0B0FEA represents that this data packet is transmitted through the Ethernet channel

[0051] b) The application type represents the attributes of this data packet, defined as four bytes, divided into UA serial number and sub-packet status, each occupying two bytes.

[0052] The meaning of the UA serial number is: which UA this data packet is at the CDS end, defined as a double byte, representing the display information of this data packet for UA (1 - 65535);

[0053] The first byte of the sub-packet status is the total number of sub-packets, representing how many packets this data packet is divided into in total, 1 means not sub-packeted; the second byte is which packet it is currently, starting from 1, and at most divided into 5 packets.

[0054] c) The customized content is defined as four bytes, which is the specific data segment sent by the UA to the CDS

[0055] According to the ARINC661 standard protocol, the UA cannot send customized data (such as the values of specific parameters, the online status of devices, etc., which are periodic data that users want to interact with) to the CDS along with the ARINC661 data cycle. Therefore, this invention designs this field to solve this problem.

[0056] d) The data length is the total length of the encapsulated protocol, ensuring data integrity.

[0057] e) The application tail is defined as four bytes, fixed as 0x0F0E0D0C

[0058] In this invention, the maximum single data of the 422 bus is 2kb, the maximum single data of the Ethernet is 64kb, and the maximum single data of the FC is 2mb

[0059] III. New Content of the UA in this Invention

[0060] Due to the changes in the communication protocol, the system architecture of the UA needs to be adjusted adaptively. See Appendix Figure 3 , and the following functional modules are added:

[0061] a) Protocol sending topic: Newly define and register the sending channel type to meet the communication requirements of the new protocol for large data volume and high real-time performance, etc., and at the same time be compatible with the requirements of different buses. According to the transmission forms of different buses used, initialize the network settings of 422, Ethernet, FC, etc. respectively. The specific topic numbers can be seen in Section 4.2 Application Header;

[0062] b) Customized data space: Newly add the sending channel type, establish a new customized data storage area to store the changed protocol data. In this invention, the defined size of the data storage space of the 422 bus is 2kb * 5 = 10kb, the storage space size of the Ethernet is 64kb * 5 = 320kb, and the storage space size of the FC is 2mb * 5 = 10mb;

[0063] c) Communication protocol secondary encapsulation module: This module is used to perform operations such as secondary encapsulation of communication data, data unpacking, and customized data filling, enabling the CDS side to successfully receive data of the corresponding protocol; the customized content of the present invention is as follows:

[0064] The first two bytes are the statuses of each subsystem cross-linked with UA, used for online and offline display at the CDS side;

[0065] The third byte is the sending time, used to record the situation of sending packet loss;

[0066] The fourth byte is empty and has no meaning for the time being;

[0067] If UA uses the new protocol to send data, the data stream is as follows:

[0068] a) Fill in the customized content: including selecting the new data types to be sent and various attribute values included in the corresponding data types;

[0069] b) Data splitting: If the original protocol data packet to be sent based on the ARINC661 standard is too long, it needs to be unpacked to obtain up to 5 data streams to be sent, and secondary data encapsulation is performed on each data stream respectively;

[0070] c) Secondary encapsulate the data: Call the communication protocol designed by the present invention to perform secondary encapsulation on the original protocol data stream after packet splitting, and send it to the CDS in ascending order of packet numbers.

[0071] IV. New content added to the CDS of the present invention

[0072] The system architecture of the CDS also needs to be adjusted adaptively, as shown in the appendix Figure 4 , and the following functional modules are added:

[0073] a) Bus topic setting: Newly define and register the receiving channel type to meet the communication requirements of the new protocol for large data volume and high real-time performance, etc., and at the same time be compatible with the requirements of different buses. According to the transmission forms of different buses used, initialize the network settings of 422, Ethernet, FC, etc. respectively. The specific topic numbers can be seen in the application header of Section 4.2;

[0074] b) Customized data space: Establish a new customized data storage area to store the changed protocol data. In the present invention, the defined size of the data storage space for the 422 bus is 2kb * 5 = 10kb, the size of the Ethernet storage space is 64kb * 5 = 320kb, and the size of the FC storage space is 2mb * 5 = 10mb;

[0075] c) Encapsulated communication protocol parsing module: This module is used to parse the secondary encapsulated communication data, complete the CDS's recognition of the new communication protocol, enable the CDS side to successfully read the customized data, and the main functions of the parsing module are as follows:

[0076] Read the application type of the re-encapsulated communication data. If the total number of packets is less than 1, directly discard the data packet; if it is equal to 1, directly unpack according to the re-encapsulation protocol, obtain the data stream and customized content and send them to the display queue of the user system; if the total number of packets is greater than 1, determine whether the data packet corresponding to the previous packet number of the current packet number is received (the UA numbers are the same). If so, obtain the data stream and customized content according to the data length and send them to the display queue of the user system corresponding to the UA number. If not, directly discard the data packet.

[0077] d) Customized content parsing module: Parse the customized content in the protocol. The present invention will read the online status of each subsystem sent in the UA segment of the first two bytes for display, and read the sending time of the third byte for detection. Once the time is discontinuous, the lost packet status variable is incremented by 1.

[0078] If CDS receives new protocol data, the data stream is as follows:

[0079] a) Data identification: Include identifying the received application header, data length, etc. If the received application header is identified as the one defined by the present invention, process the current data packet as follows. Otherwise, process it according to the original protocol.

[0080] b) Parse new protocol data: Call the encapsulated communication protocol parsing module to parse and assemble the received new communication protocol data packet.

[0081] c) Incorporate into the original data stream: The assembled original protocol data stream is incorporated into the original data stream of the ARINC661 corresponding UA number display channel.

[0082] d) Parse the original protocol data and send it for display after unified parsing.

[0083] As described above, these are only further embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the scope disclosed by the present invention, according to the technical solution and concept of the present invention, makes equivalent substitutions or changes, and all belong to the protection scope of the present invention.

Claims

1. A data communication method based on the ARINC661 standard, characterized in that, including: The user system obtains customized content, which includes the statuses of each subsystem that needs to be displayed in real time on the cockpit display system and the sending time; The user system obtains the data packet to be sent based on the ARINC661 standard and the secondary encapsulation protocol; The user system determines the data length according to the secondary encapsulation protocol; The user system unpacks the data packet to be sent based on the ARINC661 standard according to the data length to obtain N data streams to be sent; N is a positive integer; The user system encapsulates each data stream to be sent according to the customized content and the secondary encapsulation protocol to obtain N data packets to be sent based on the secondary encapsulation protocol, and sends them to the cockpit display system; Among them, the data packet to be sent based on the secondary encapsulation protocol includes: application header, application type, customized content, data length, data stream to be sent, and application tail; The application header is used to indicate the secondary encapsulation protocol; the application tail is used as the end identifier of the data packet to be sent based on the secondary encapsulation protocol; The application type is used to indicate the total number of packets and the packet sequence number.

2. The data communication method based on the ARINC661 standard according to claim 1, wherein The user system determines the data length according to the secondary encapsulation protocol, including: When the secondary encapsulation protocol is the 422 bus, the maximum data length is 2kb; When the secondary encapsulation protocol is Ethernet, the maximum data length is 64kb; When the secondary encapsulation protocol is the FC bus, the maximum data length is 2mb.

3. The data communication method based on the ARINC661 standard according to claim 1, characterized in that The value of N does not exceed 5.

4. The data communication method based on the ARINC661 standard according to claim 1, wherein The application type also indicates the serial number of the user system.

5. The data communication method based on the ARINC661 standard according to claim 1, characterized in that The length of the application header is the same as the length of the protocol header of the ARINC661 standard.

6. The data communication method based on the ARINC661 standard according to claim 1, wherein Sending the N data packets to be sent based on the secondary encapsulation protocol to the cockpit display system includes: Sending the N data packets to be sent based on the secondary encapsulation protocol to the cockpit display system in ascending order of the packet sequence number.

7. A data communication method based on the ARINC661 standard, characterized in that, including: The cockpit display system receives the data packet, reads the packet header of the data packet, and determines the encapsulation protocol according to the packet header; When the encapsulation protocol of the cockpit display system is the secondary encapsulation protocol, it determines the total number of packets and obtains the packet sequence number according to the application type; When the total number of packets is greater than 1, the cockpit display system determines whether it has received the data packet corresponding to the previous packet sequence number of the current packet sequence number; if so, it obtains the data stream and the customized content according to the data length and sends them to the display queue of the user system; When the number of data streams in the display queue reaches the total number of packets, the cockpit display system assembles the data streams to obtain a data packet based on the ARINC661 standard, and sends it to the data stream based on the ARINC661 standard, emptying the queue.

8. A data communication device based on the ARINC661 standard, characterized in that, for performing the method according to any one of claims 1-6.

9. A data communication device based on the ARINC661 standard, characterized in that, for performing the method according to claim 7.

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