Questions tagged [arinc-429]

ARINC 429 is both an electrical bus standard and a data transfer standard for aircraft avionics.

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What could cause an air data computer interfaced via A429 to only display integer values?

I'm working with a Shadin 2000 air data computer interfaced via ARINC 429 to an Avidyne IFD 550. For some reason, the airspeed tape is flipping between discreet values, and not gradually increasing/...
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How are ARINC 429 BCD dd:mm:yy labels encoded?

Label 260 (Date) has a dd:mm:yr format, which requires 6 characters. How is this label typically coded? Here is my best guess based on the range of each digit: Bit # Another header 1-8 Label (260) ...
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What is the format for standard ARINC 429 labels with 20 sig bits?

Certain standard labels in the ARINC 429 specification have 20 significant bits. For example, Label 110 (GNSS Latitude) has a range of +/- 180 degrees, with a resolution of .000172 degrees. In order ...
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Are there any standards for defining your own ARINC 429 labels?

Is anyone aware of any ground rules or best practices for defining your own ARINC 429 labels? Are there certain ranges of labels that correspond to groups of parameters like engine temps, rpms, etc? ...
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Negative number in ARINC-429

I'm a little bit confused by representation of negative number in ARINC-429. Let's consider the following example: Significant bits is equal to 7 (it does not count sign bit), Resolution is equal to ...
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How to identify transmit labels for a particular equipment in ARINC429?

As i can see, each equipment has a set of labels which the equipment may supposed to be received. Say if i am Equipment 03Ch (Tire pressure monitoring system), i will be configured to receive below ...
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Should I use given resolution or calculate resolution based on the max range and number of sig bits?

In ARINC429, Should I use given resolution or calculate resolution based on the max range and number of sig bits given? ForeExample, to calculate Ambient Static Pressure (Label-203, Equipment ID - 10A)...
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ARINC429 - Encoding and Decoding of BINARY DATA

In ARINC429 protocol, how to encode and decode FAN DISCHARGE STATIC PRESSURE (LABEL - 127). Range is 1.5 to 30.0 No of Sig. Bits - 11 Resolution is 0.016 What should be the value to be loaded into the ...
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Does ARINC 429 have any error correction methods?

I'm currently studying the application of ARINC 429, and have noticed that ARINC 429 doesn't have an error correction but an Error detection set in the parity bit (bit-32). Are there any means for ...
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Best Way to certify DO-178 Communications Stack?

We currently have a piece of hardware running an RTOS that needs the communication stack to be certified to DAL-B. Everything has already been developed for non commercial aerospace applications, ...
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Does the Flight Acquisition Unit on the Boeing 737 NG stream data?

I noticed on B737-800 entering the flight deck on the right side there is a port Data Loader and I think this is the Flight Acquisition Unit. Is this port used exclusively for loading data to FMCs etc ...
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Does the civil industry use the CAN FD bus?

Does anyone know if commercial aircraft are using the CAN FD communication bus?
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How is DME station ident coded in ARINC 429?

I understand that labels 242,244, 246, 247 are set for DME Station Id or DME Station Ident. they are marked as discrete. How should I convert the station code from alphabet to these 'discretes'? The ...
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How different is ADFX/ARINC 664 router from normal Router?

ADFX or ARINC 664 is a protocol that is derived from the Ethernet protocol. What I understand it is Point to Point (no routing of data) Deterministic used VLAN for addressing I just wonder do we ...
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Why does the SSM decoding vary between different A429 label types

For A429 there are different label types, for example: BCD, BNR, Discrete... These types have their corresponding SSM (Sign/Status Matrix) that is unique, for example an SSM of "00" represents a ...
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USB interface for FDR?

Currently I am investigating the feasibility of transmitting a limited amount of FDR data via radio link for domestic flights within continental USA. I am working on building a prototype system in ...
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What are the major aircraft systems (LRUs) using the ARINC429 Protocol?

I want to know the different aircraft systems (LRUs) using ARINC429 protocol. Why is it used instead of the ARINC 629 ? How is it different from the different ARINC protocols like 629 and AFDX(664)?
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What is the purpose of the selected altitude/airspeed in ARINC 429?

What is the purpose of the selected altitude and airspeed fields in ARINC 429?
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How many labels are defined in ARINC 429 for calibrated altitude?

How many labels are defined in ARINC 429 for calibrated altitude?
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Is it possible to communicate an everyday computer with the ARINC bus? [closed]

Lately I've been wondering if it's possible to interface an everyday computer with the ARINC buses (either 429 or AFDX). This would be very useful for simulation, testing and prototyping purposes. ...
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What is the "true static pressure"?

What is true static pressure? How do we define it? Is it same as corrected static pressure for installation and errors? ARINC 429P1-18 defines Static pressure as corrected and uncorrected where in ...
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What is the criteria for selecting BNR or BCD as data encoding in ARINC429

I was going through ARINC429 part1-18 and found all the labels that are defined along with transmission bit and data encoding. What is the criteria for choosing BNR or BCD for data encoding ? Why are ...
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Why apply resolutons in data words for ARINC 429 bus

Data words transported over the ARINC 429 bus are defined and built-in units, ranges, refresh rates, number of significant bits, and resolution. Why is it necessary to include resolution? Does ...
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What is the difference between Body Pitch Rate and Inertial Pitch Rate?

ARINC 429 specifies two series of attitude rate labels for ADIRS/AHRS/IRS systems: Body 326 : Body Pitch Rate 327 : Body Roll Rate 330 : Body Yaw Rate Inertial 336 : Inertial Pitch Rate 337 : ...
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How to set frequency and distance in ARINC 429?

How can I set frequency & read distance in ARINC 429? For example can you give an example to tune a 1105.5 MHz and read 25786 ft. ...
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How to encode an altitude in ARINC429?

How can I encode an altitude (ft) in ARINC429? I didn't understand if I just need to transform it in binary number and then use the "Bipolar Return-to-Zero". Like for example with an altitude of 25 ...
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In the ARINC specification, why is baro altitude (label 204) measured in Knots?

I am currently designing a system that reads the baro altitude (on label 204) from an LRU. Ultimately in my software I would like to display the baro altitude reading in real-time using a graphical ...
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Why use different data bus for civil and military avionics?

There are various type of data bus in aviation, the two most common in the '90 were ARINC 429 for civil aviation and Mil 1553 for military applications. They are not very different one for the other, ...
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In ARINC 429 where are the bits indicating the hex value of Equipment ID?

I'm a newbie in ARINC-429 standard; the following might be a very simple issue for you. In ARINC 429 the LABEL field is covered by the bits 1 through 8; which bits are covering the Equipment ID? For ...
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Numerous questions regarding ARINC429 protocol [closed]

I recently made significant progress in my understanding on the ARINC429 thanks to a user on this site, but I after reading more into it, I may have confused myself a little bit. Any help on any of ...
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How to decode ARINC 429 data?

I am looking for some help regarding decoding ARINC 429 data. I have a CSV document that contains sequentially stored ARINC 429 labels. My overall goal is to be able to scan for 4 specific labels and ...
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What is the Scaling Factor in ARINC 429?

I'm a newly appointed engineer in an avionics company and have been tasked with preparing a report on ARINC429. I understand most of it, and I certainly find it simpler that 664, but I still can't ...
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Are the discrete I/O considered to be part of the ARINC interface?

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 ...
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What is the technical term for ARINC 429 data injected into a heartbeat stream going to an LRU?

I am going to describe a type of communication protocol that I've seen used with ARINC 429 and would like to know if there is a proper name and classification for this type of communication... Anyway, ...
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Can an ARINC 429 controller set to receive messages on high-speed (100kHz) see 12.5kHz messages?

I am working with an ARINC 429 controller which is currently set to receive messages at 100kHz. When the transmission line sends messages that are 12.5kHz (standard ARINC 429 low speed) the controller ...
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How are the BNR and BCD data formats identified in an ARINC-429 message?

I'm a newbie in ARINC-429 standard. How does the receiver identify which data is in BCD format and which is BNR? I understand that labels indicate the message data carried information, but it does not ...
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In the ARINC specification, does "sig bits" include the sign bit?

In the ARINC specification, there are sections where all of the different labels (and their pay-loads) are described. In each of the tables where the labels are defined, there is a column called sig ...
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Is there an ARINC label/data that can be associated with a gyroscope's precession?

I am looking to read the precession of a gyroscope off of an ARINC bus, is there an ARINC label that can be associated with the gyroscope's precession value? My thoughts are, that it might have ...
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Is there a such thing as an ARINC label for the yaw angle?

Is there a way to check the yaw angle on the ARINC bus? If so, what is the associated ARINC-429 label?
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What is the encoding difference between ARINC 429 BNR and BCD formats?

I think I have an understanding of the differences between the types of ARINC word formats, but would just like to get some input to see if my understanding is correct. In the ARINC 429 specification, ...
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