Protocol analysis
R&S
®
RTE
678User Manual 1326.1032.02 ─ 20
13.10 ARINC 429 (option R&S RTE-K7)
13.10.1 ARINC 429 basics
The ARINC 429 is a specification that defines the characteristics of an avionic data bus
used on commercial and transport aircraft.
In an ARINC 429 system, a single transmitter/source is connected to 1 to 20 receivers/
sinks on one twisted wire pair. The bus uses differential signals. The ARINC 429 stan-
dard uses a simplex communication - data may be transmitted in only one direction.
The information is transmitted over the bus in defined series of words.
Word Format
Figure 13-49: Structure of an ARINC 429 word
An ARINC 429 word is 32-bits and consists of the following parts (see Figure 13-49):
●
Parity: the most significant bit (MSB). Checks if there are bit errors during the trans-
mission. The total number of logic 1 bits for the word shall be odd.
●
Sign/Status Matrix (SSM): the value of these bits depends on the data type. It may
be used to report the status of hardware equipment.
●
Data:
– Binary (BNR): stores the data as a binary number.
– Binary Coded Decimal (BCD): uses 4 data field bits to represent a decimal
digit.
– Discrete data: a combination of BNR and/ or BCD or individual bits that express
specific equipment conditions.
– Maintenance data and acknowledgment
– Williamsburg / Buckhorn protocol: a bit-oriented protocol that is used for file
transfer.
●
Source/Destination Identifier (SDI): indicates the intended receiver or the transmit-
ting subsystem.
●
Label: gives information about the word's data type.
For comfortable analysis, you can load an editable label list, to interpret transferred
numeric values as meaningful text labels.
ARINC 429 (option R&S
RTE-K7)
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