MCDU Programming

[junebug172]

Anyone know what programming language(s) is/are used in the MCDUs? I've heard a different one was used for each side for redundancy.

[MrHorgy]

You say MCDU so I assume you refer to Airbus? Although I don't have a definitive answer to your question, I would suggest that it is incorrect. To write in two languages to me would seem to double the workload of subsequent upgrades, and also render the MCDU's non interchangeable for maintenance!

[safelife]

The FMGCs are programmed in the same language, they are actually running identical software on either side.
What uses this kind of redundancy are the FADECs, they have each two channels which are programmed using different languages by different programmers.

[junebug172]

What programming language is used?

[italia458]

What programming language is used?

I feel your pain! It's hard to get a straight answer around here, even for simple questions.

I don't know the answer to your question but I find the responses you're getting to be amusing.

[RunSick]

A secret one so it can´t be hacked.

[noughtsnones]

You may wish to chase Mr G. One MCDU supplier, Esterline CMC Electronics, recruitment seems to favour software engineers in particular with object oriented and C code skills.

I also opine that to deliver a single function in civil aircraft engine and avionics, dissimilar software and/or hardware is very rarely deployed.

[catiamonkey]

Almost certain it's written in Ada. This was in the 1980s where the US DoD was mandating everything they bought be written in Ada and as a result the entire aerospace industry switched. Although it's no longer a requirement, the vast majority of critical aerospace software is written in Ada to this day.

[FlightPathOBN]

FMS uses ARINC 739 and ARINC 758 and coupled with ACARS thru ARINC 724B

[ZFT]

I'm confused. ARINC define standards? Also thought 702 was FMS

[junebug172]

Thanks. That makes sense.

Looked it up on Wiki and they just happened to use an aviation-related example.

Ada (programming language) - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Ada_(programming_language)#.22Hello.2C_world.21.22_in_Ada)

[FlightPathOBN]

ZFT,

"700 Series ARINC Characteristics define digital systems and equipment installed on current-model production aircraft. They include definitions of form, fit, function, and interface for line replaceable units (LRUs) in a federated architecture."

I was answering the post, and it got blended a bit...739 is the MCDU protocol standard.

here is the complete ARINC list....

ARINC 700 Series (https://www.arinc.com/cf/store/catalog.cfm?prod_group_id=1&category_group_id=4)

For the most part, if you are looking at the operating system language, I know the standard for most is C++, especially for Airbus. Boeing still has some VxWorks hanging around, but the FMS that I have worked with, Honeywell, Smiths, and Thales all use C++.

ARINC protocols are the 'standard' for input output and the programming format for the navdatabase.

[fantom]

It's English.

You are all mad; I am the only sane one.

[FlightPathOBN]

Well, there you have it....English. :ok:

(now why didnt I understand the intent of the question :} )

[catiamonkey]

FlightPathOBN,

VxWorks is a operating system. It doesn't have anything to do with the language the system is written in. You can run C, C++ or Ada on top of VxWorks. VxWorks is popular but there's quite a bit using Green Hills INTEGRITY now because its DO-178B out of the box.

If you're talking about the FMS itself, Honeywell originally used Pascal, Pegasus is Ada (based on Pascal), Primus EPIC is C on a proprietary OS, and the A380 system is C++ on top of INTEGRITY.

Boeing likes Ada, 70% of the 777 is written in Ada. I confirmed the Airbus BSCU, FWC, FCDC is in Ada, and the A350 ADIRU will be Ada on INTEGRITY.

[FlightPathOBN]

catia,

Thanks...I only worked with the C++ part of the Smiths and Honeywell boxes, and only in a few areas such as the WGS84 database/lookup, great circle calcs, and some at/above issues. Some of the NDB extended features were causing internal issues as well.

I understand that it works on top of VxWorks, but I thought that VxWorks was on the order of a machine language...

I was never sure if the C++ part was complied into something else...but that C++ was much easier to work with (and find programmers for), than the other languages.

Thanks for the clarification.

[junebug172]

Thanks catia!

Had no idea vmworks was used on so many platforms.

VxWorks - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/VxWorks)

Link to other OS:

INTEGRITY Real-time Operating System (http://www.ghs.com/products/rtos/integrity.html)