This document discusses the limitations of the ARINC 429 data bus standard. It begins with learning objectives and a safety tip about documentation. The main points are: - ARINC 429 has a simplex architecture, meaning data can only travel in one direction at a time. This limits bi-directional communication on the same bus. - If multiple receivers need to transmit back to the source or each other, separate wiring is required since data cannot flow both ways on a single ARINC 429 bus. - ARINC 429 uses return-to-zero modulation and has a defined data word format including fields for parity bits, status bits, data bits, source/destination IDs, and labels.

1. IN THE NAME OF
ALLAH, THE MOST
BENIFICIENT,
THE MOST MERCIFUL
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2. 2
How data is transferred to different computer
devices?

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PLEASE SEE THE VIDEO

4. ARINC 429 4

5. ARINC 429 5
STATEMENT OF AIM
ARINC 429 Limitations
ARINC 429

6. ARINC 429
At the end of the lesson students will be
able to:-
 Define Limitations of ARINC 429
 Explain Architecture of ARINC 429
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DESIRED LEARNING OBJECTIVES

7. ARINC 429
SAFETY TIP
No work is complete without
documentation so must take documentation
up to date.
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8. ARINC 429
Modern day Aircraft is being operated with
most advance Avionics and Digital instrumentation
for such advance technique data transfer is carried
out with digital buses and one type of digital bus is
ARINC 429.
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RATIONALE

9. ARINC 429
 The major limitation of ARINC 429 is that it has
a simplex architecture
 Its mean that digital data can travel only in one
direction from the transmitter source to the receiver
sink at any one time
 Data can’t travel in the opposite direction on
the same bus
ARINC 429 LIMITATIONS
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10. ARINC 429
 It means that if there are multiple sinks for one
source and one of those sinks needs to transmit
back to the source and / or the other sinks
 It will need a separate twisted-pair wire to do
so since data transfer is not bi-directional
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ARINC 429 LIMITATIONS

11. ARINC 429
ARINC 429
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12. ARINC 429
 ARINC 429 uses a return-to-zero modulation
technique to form each bit meaning that logic state
"1" is achieved by voltage moving from high
(e.g., +10 volts) to null (zero volts) and logic state "0"
is obtained by going from null to low (e.g., -10 volts)
ARINC 429
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13. ARINC 429
ARINC 429 Data Word format
ARINC 429
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14. ARINC 429
 The first bit is the parity bit (used for error
detection), followed by three sign and status matrix
bits, 18 data bits, 2 bits for the source destination
identifier and an 8 bit data word label
 A message consists of a start-of-transmission
signal, up to 253 data words, and an end-of-
transmission signal
ARINC 429
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15. ARINC 429
ARINC 429 VIDEO
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16. ARINC 429
ARINC 429 Limitations
RECAP
ARINC 429
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17. M-3, Chap-no, Topic name 17

18. ARINC 429
Q.1 What is the bit architecture of ARINC 429?
A.1 One parity bit followed by three sign and
status matrix bits, 18 data bits, 2 bits for the source
destination identifier and an 8 bit data word label
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QUESTION/ANSWER

19. ARINC 429
Q.2 A message consists of a start-of-
transmission signal, up to -------- words?
A.2 253 data words.
Q.3 The first bit is the---------?
A.3 Parity bit (used for error detection).
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QUESTION/ANSWER

20. ARINC 429
Q.4 What is the major limitation of ARINC 429?
A.4 The major limitation of ARINC 429 is that it
has a simplex architecture.
Q.5 There are multiple sinks for ------------ in
ARINC 429?
A.5 One source.
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QUESTION/ANSWER

21. ARINC 429
Q.6 Which technique used in ARINC 429 for
modulation?
A.6 ARINC 429 uses a return-to-zero modulation
technique.
Q.7 Data transfer in ARINC 429 is not ----------?
A.7 Bi-directional.
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QUESTION/ANSWER

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