Digital Electronics Flashcards
6 cards from real AET practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Digital Electronics flashcards as text
What is the primary characteristic of the ARINC 429 data bus used in commercial aviation?
Answer: Unidirectional single transmitter to multiple receivers
ARINC 429 is a unidirectional bus with one transmitter and up to 20 receivers, widely used in commercial transport aircraft.
What word length does ARINC 429 use for each data transmission?
Answer: 32 bits
Each ARINC 429 word is 32 bits long, containing a label, source/destination identifier, data, sign/status matrix bits, and a parity bit.
What does a flip-flop circuit do in digital avionics systems?
Answer: Stores a single bit of data
A flip-flop is a bistable multivibrator that stores one bit of digital information, maintaining its output state until triggered to change.
In avionics software, what does DO-178C define?
Answer: Software development and assurance levels for airborne systems
RTCA DO-178C defines the software development and verification processes required for airborne software to meet FAA certification levels (DAL A–E).
What is the function of a data concentrator unit (DCU) in a modern avionics suite?
Answer: Collect, process, and route data from multiple avionics sensors to display systems
A DCU aggregates data from multiple avionics buses and sensors, formats it, and distributes it to cockpit display systems and other LRUs.
What does the term 'LRU' stand for in avionics maintenance?
Answer: Line Replaceable Unit
LRU (Line Replaceable Unit) is an avionics component designed to be quickly removed and replaced at the flight line without depot-level maintenance.