737-300 400 500 AMM 飞机维护手册 导航 NAVIGATION 1(121)

曝光台 注意防骗 网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者

 3)  Convert blocks of digital map data, received in terms of latitude and longitude, into usable display data and instructions (display directives).
 4)  Store current input data and instructions (display directives) in the memory (RAM), for construction of display tables. The display tables are then used for display generation.
 5)  Determine and store motion parameters (rotate/translate logic) used to update the weather radar display.
 6)  Perform alert checks for altitude, decision height, and decision height plus delta height. The results are stored in the symbol generator memory (RAM) for transmission to the EADI.
 7)  Test itself (processor circuits), and monitor system integrity also annunciate the response to a failure, and store failure information in BITE nonvolatile memory.
 (b)  
The controller circuits within the symbol generator retrieve the display tables generated by the processor circuits via the symbol generator transfer bus. The controller circuits then convert the display tables into display tables usable by the graphics section. The resulting display tables are subsequently stored in the memory (RAM) of the input/output processor circuitry, via the controller input/output bus.

 (c)  
The Input/Output processor circuits contain a microprocessor. The circuits perform the following functions: 1) Provide and control six independent direct memory access

 (DMA) channels, used for communicating with various sections of the symbol generator. 2) Determine which inputs on the analog input/output circuits will be processed.
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. AIRPLANES WITH EFIS ú

 34-22-00

 ú ú 14A Page 44 ú Jul 15/93
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
737-300/400/500MAINTENANCE MANUAL
 3)  Receive input data from analog input/output circuits, process the input data, and store the data in the memory (RAM).
 4)  Store in memory (RAM), interpreted display tables used by the graphics section.
 (4)  Display Generation
 (a)  
At the completion of processing, the display tables provide all the data required for video generation on the EADIs and the EHSIs. The displays on the EADIs and EHSIs are drawn as vectors, arcs, characters and special symbols in seven colors of two intensities. The presentation contains dynamic displays overlaying a background of fixed displays. For example, a glide slope pointer moving up and down a fixed scale.

 (b)  
Two different techniques are used to display the data on the EADIs and EHSIs. These techniques are stroke and raster. The special symbols, characters, letters, vectors and arcs are displayed using the stroke method. The EADI sky/ground ball or EHSI weather radar data are displayed using the raster method. The symbol generator has two raster channels, one for the EHSI and one for the EADI. The symbol generator has only one stroke channel, which is time-shared between the EADI and EHSI. When the raster data is being written on the EHSI, the stroke channel services the EADI, and vice versa. The raster and stroke control is sent from the symbol generator to the display units.

 (c)  
The display tables stored in the memory of the input/output processor circuits are read out by the graphics section. The display tables contain stroke directives (stroke data and instructions), and raster directives (raster data and instructions).

 (d)  
The circuits that make up the symbol generator graphics section are display driver circuits, stroke generation circuits, EADI raster generation circuits, and EHSI raster generation circuits. The graphics section uses the display table instuctions, stored in the memory of the Input/Output processor circuitry, and translates the data into analog deflection and video signals. The graphics section sends the deflection and video signals to the display units, while maintaining a refresh rate high enough to avoid observable flicker.

 (e)  
During the stroke mode, the stroke directives are sent to the stroke generation circuitry. The stroke generation circuitry provides the following major functions: 1) Beam Positioning 2) Generation of straight and curved vectors 3) Generation of predetermined symbols and characters 4) Selection of video and color

 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. AIRPLANES WITH EFIS ú
　
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：737-300 400 500 AMM 飞机维护手册 导航 NAVIGATION 1(121)