Schematically the principle of representation of information from the sensors on EIS is shown on fig. 149. Information from different sensors and other aircraft system is sent in digital form to the data storage devices, that is capable of receiving of information and chooseing the necessary information tobe showed.
The module of system control operates with regimes and subregimes of information indication, filters and chooses the necessary information to be indicated in the certain place and prepeares this information to be shown. The module of image construction places the information that has to be indicated and shown in certain place and generates it. The final digital image is transferred to image repesentation equipment.
Fig. 149 Principle of EFIS structure
Depending on the combination and association of major structural features in the EIS LRU distinguish different types of construction EIS [ 76 ]
" Dumb " type of system building electronic display (Dumb Display Architecture - DDA)
This principle of construction is most common in the AIRCRAFT of civil aviation. EIS of this type consist of two main types of blocks: building an image and display unit (Fig. 150). The unit build basic functions performed by image processing and data generated image. The resulting image is digitally transmitted through special transmission channels of digital image information (eg , ARINC 629 ) in the information display unit that displays only the already constructed image.
Fig. 150. " Dumb " display
Semi-Smart Display Architecture - SSDA
In this type of EIS LRU evaluator prepares the information to display (Fig. 151 ) and digitally via ultrafast digital channel information transfer (eg , ARINC 429 ) transmits information in a certain mode indication. Information display unit receives the data to be displayed , and builds a graphic representation of data placement in certain places depending on the operating mode and displays the resulting graphical display.
Fig. 151. «Semi-smart» display
Integrated Display Architecture – IDA
EIS systems of this type are made of only 1 LRU and control device (Fig. 152).
Fig. 152. Integrated construction principle
The pilot information in the EIS is shown witing special displays ( Fig. 153). Depending on the type of information displayed these types are distinguished:
- Pilot display showing the data necessary for piloting and control of the flight ;
- Navigation display that shows information about the position of the AIRCRAFT;
- Systematic Display system that provides data on the functioning of the AIRCRAFT.