SPECIFICATION OF THE INVENTION

1. Title of the invention

A Unified System for Transfer of Mission Critical Data to Line Replaceable Units over a Digital Avionics Bus

2. Field of Invention

This invention relates to data transmission between Line Replaceable Units (LRU) in an avionics system. It defines the system and methodology that facilitate uploading of data from a storage medium to various LRUs, and also downloading of data from different LRUs to the storage medium over a digital avionics bus.

3. Prior art and Draw backs of prior art

In conventional systems, the mission related data is uploaded (/downloaded) to (/from) the various LRUs using dedicated ground servicing equipment. To connect the ground servicing equipment to separate sub-systems for uploading and downloading is a time consuming process. It also requires maintenance of separate ground equipment for the different subsystems available in the aircraft at the site of operation.

4. Aim of the Invention

The main objective of the invention is to provide a method that unifies the data uploading and downloading functionalities for different systems in an avionics suite into a single system.

5. Summary of the present invention

This invention presents a system for transfer of data to multiple sub-systems from a single source over an avionics bus like MIL-1553-B. Instead of using separate systems for loading data to different LRUs, the uploading and downloading functions are collated into a single system provided with a dedicated MMI for user inputs. As shown in Figure 1, the system consists of the Data Transfer Controller (DTC), 103, which functions as the central unit for handling the data transmission operation. The DTC reads data from a Data Loader Unit (DLL)), 101, which stores the data in a Removable Storage Media, 102. It processes the data for detecting errors, packages it in a form suitable for the target LRU to receive and transmits it over the data bus to the designated LRU. Similarly, it also downloads data from various LRUs and sends them to the DLU for storage in the Removable Storage Medium to be used for post-flight analysis.

6. Brief Description of the Drawings and Tables

Figure 1 is a block diagram of the Data Transfer System for uploading and downloading data to different LRUs.

Figure 2 depicts the command and response sequence followed for transfer of data from Data Loader Unit (DLU) to Data Transfer Controller (DTC).

Figure 3 depicts the command and response sequence followed for transfer of data from Data Transfer Controller (DTC) to LRUs.

Figure 4 depicts the Flowchart for Downloading data from an LRU to Data Transfer Controller.

Figure 5 depicts the Flowchart for Downloading data from Data Transfer Controller (DTC) to Data Loader Unit (DLU)

7. Detailed Description of the Invention

Uploading and Downloading of data from LRUs is a critical operation in context of Mission Requirements. Normally configuration and mission related data have to be uploaded on ground prior to sortie using a dedicated ground servicing equipment. Similarly, for post-flight analysis of a sortie, data has to be downloaded from different LRUs using a dedicated ground servicing equipment. Maintaining separate ground servicing equipment for each LRU is not a user friendly approach. Also, updating the data of individualLRUs using separate ground servicing equipment increasesthe time required to prepare the aircraft for any mission. This invention presents a Data Transfer System (Figure 1) for uploading and downloading of data to Mission Critical LRUs in a single unified system for easy operation. The system comprises of a Data Loader Unit (DLU), 101, with a Removable Storage Medium, 102, for storing the uploaded and downloaded data, a Data Transfer Controller (DTC), 103, which controls the command and response sequence and routes the data between LRUs, the Man Machine Interface (MMI), 104 for selecting the desired operation, and the target LRUs (105,106,107 etc.) with one or more data buses of same or different kind.

Data Uploading: For uploading of data to an LRU, the sequence of operations followed is shown in Figures 2 and 3. The operation is initiated by the user on the MMI, 104 by selecting the desired LRU. The DTC, 103 sends a command to the DLU, 101 (Step 201) with the following data:

• Upload Operation is selected

• Type of Data to be uploaded (LRU specific)

• Size of Data to be uploaded

The DTC waits for acknowledgement from the DLU and analyses the received message to determine whether the DLU is ready for Data Transfer (Step 204). If no reply is received or reply is invalid, it abandons the operation. Simultaneously, the DTC sends a message to the selected LRU with the following information (Step 301 of Figure 3), and requests for an acknowledgement:

• Command to initiate uploading operation

The DTC waits for a designated period of time for acknowledgement from the LRU and when received, the reply is analyzed to determine whether the LRU is ready to receive the data (Step 303). This is repeated till valid reply is received or till the number of retries allowed is exhausted {Step 304, 305). If no reply is received or reply is invalid, it abandons the operation with a failure indication on the MMI. If the replies from DLU and the LRU are received correctly, the DTC requests the first block of data from the DLU. It checks the validity of the data using the checksum embedded in the message. The received data is then transferred to the LRU, and a request is sent to acknowledge the receipt of the data (Step 211,307,308). The DTC waits for the acknowledgement from the LRU (Step 309); if it is not received the process is repeated for the data block a designated number of times (Step 310, 311). After all the blocks of data have been transferred, the DTC sends End of Data Transfer command to the DLU (Step 213). Simultaneously, it displays data transfer success indication on the MMI (Step 214).

Data Downloading: For downloading data from various LRUs to DLU for post-flight analysis, the process detailed in Figures 4 and 5 is followed. The data download process is initiated by the user by selecting the respective LRU for data download form the options available on the MMI.
When download is initiated, the DTC sends Download Initiation Command to DLU with the following information (Step 401):

• Download Operation is selected

• Type of Data to be downloaded (LRU specific)

• Size of Data to be downloaded

It then requests for the status message from DLU to confirm its status. Simultaneously, the DTC commands the selected LRU to start the download process (Step 401) and sends a request to confirm that the command has been received by the LRU (Steps 402, 403, 404). When the LRU is ready, DTC sends command for transfer of one block of data (Step 406). The data received from the LRU is then checked for errors using an embedded checksum (Step 407, 408) and if any error is detected, the process is repeated a designated number of times (Steps 409, 410).
After a block of data is successfully received, it is transferred by the DTC to the DLU (Block 416, and Steps 505 to 511). The DTC then commands the LRU for the next block of data and the process is repeated (Steps 417, 512) till all the data blocks have been transferred. After all the data blocks have been transferred successfully, the DTC sends End of Data Transfer command to the DLU and displays data transfer success indication on the MMI.

CLAIMS

We claim

1. A system and methodology for unification of uploading and downloading functionalities of mission critical data for various Line Replaceable Units over an avionics digital bus. The system is comprised of Data Loader Unit (101), Data Transfer Controller (103), the Man Machine Interface (104) and the Line Replaceable Units (105, 106, 107 etc.) provided with one or more digital avionics buses for communication between them.

2. The method and system of Claim 1, where the Data Transfer Controller (103) receives the data from Data Loader Unit (101) based upon selection on the Man Machine Interface (104), checks the received data for errors in communication and repacks the data words in a format readable to the target LRU, and transmits the data to the respective LRU.

3. The method and system of Claim 1, where the Data Transfer Controller (103) receives the data from different LRUs based upon selection on the Man Machine Interface (104), checks the received data for errors in communication, extracts the relevant data from the message and sends it to the Data Loader Unit (101) for storage and post-flight analysis.

4. The method and system of claim 1, where the Data Transfer Controller (103) acts as a bridge for transmission of data to LRUs using data buses of different types.