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What are aircraft discretes?
DISCRETE FREQUENCY. A separate radio frequency for use in direct pilot-controller communications in air traffic control which reduces frequency congestion by controlling the number of aircraft operating on a particular frequency at one time.
What does Arinc 429 stand for?
ARINC 429, “Mark33 Digital Information Transfer System (DITS),” is also known as the Aeronautical Radio INC. (ARINC) technical standard for the predominant avionics data bus used on most higher-end commercial and transport aircraft.
What is the parity bit for on an Arinc 429 bus?
1. Each ARINC 429 word is a 32-bit sequence that contains five fields: Bit 32 is the parity bit, and is used to verify that the word was not damaged or garbled during transmission. Every ARINC 429 channel typically uses “odd” parity – there must be an odd number of “1” bits in the word.
What is a discrete interface?
A discrete interface involves a single signal, typically binary in nature. This is probably the most common, and useful, type of interface encountered in digital electronics. It is also the simplest. It is either true or false, on or off. The microwave oven is powered on, or it isn’t.
What is an ARINC frequency?
ARINC supplied FBOs (or other airport businesses) with a frequency between 128.825 and 132.00 MHz as well as between 136.5 and 136.975 MHz. FBOs are charged a monthly “station” fee and the cost of the FCC license.
Are there discrete interfaces that are part of ARINC 429?
There are two types, open/ground and 28V/open and are defined for both input and output. So yes, there are discrete interfaces that are part of ARINC standards, just not part of ARINC 429. This is an old question, but as I’ve stumbled, others will too, and the comments seem to have deviated a bit.
What kind of connection is needed for ARINC?
A typical connection used to transmit/receive ARINC data might consist of a cable and a connector similar to the one shown below. Although ARINC transmit/receive channels aren’t the only thing this interface can be used for. I’ve noticed that several different varieties of LRU also use some of the pin connections for I/O discretes.
How many data words can be sent in ARINC?
Discrete data may be sent in ARINC 429 data words, but that’s just bits in a word not the physical discretes you’re asking about. ARINC also has documents that cover standards for other interfaces as well as ‘Characteristics’ that define specific LRUs such as ARINC 735A for TCAS II.