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An uneasy avionics feeling...

bmarvel

Well Known Member
Friend
Like other builders, I have avionics from several vendors in my -14A. My choices stemmed from cost, size, familiarity, capability, prior experience and other issues that everyone faces.
To date in the 325 hours on the airplane everything has worked together well. But a recent experience has led me to some concern about this mix and match setup. The trigger for it was the new software for Garmin?s GTN 650 (adding VNAV and along track offset) that is not seen by either my Dynon Skyview displays or the Dynon autopilot. Something needs to be done to make the two talk to each other. I am wondering what and by whom.

My question does not deal specifically with either Dynon or Garmin or with any other manufacturer. I mention them here only because they are the two players involved. I am wondering in general what degree of cooperation is required when a box manufactured by one company interfaces with a different box manufactured by another when a software upgrade is made by either of them.

Asked more directly:
1. In today?s software world, does Garmin have to actually give coding or other specific information to Dynon to make the interface work?
2. Or, is all necessary information automatically contained in the Garmin ARINC data that can be picked off and used by Dynon to implement the interface?
3. In the worst case, what if a manufacturer decides its upgrade is proprietary and thus only available to owners of its other boxes? Does this not penalize a customer who owns one box from them which interfaces with other boxes from other manufacturers?

You can substitute any company names you wish because this is a general question that is likely to occur in the future as more capability is added to different avionics.

My post is a shot in the dark to see if anyone familiar with this can address it. Is the concern legitimate?
 
I can't answer your questions, but I am getting the same uneasy feeling while currently shopping for avionics. Specifically, it appears that Dynon and Garmin both require their own brand of ADS-B "In" receivers. It appears that other vendors (GRT and MGL) allow a EchoUAT to provide "In" (traffic and weather) to display on the EFIS.

I understand why a vendor would want control of ADS-B "Out" components... but why "In"? And why can't a Skyview send airport codes to a Garmin GTR200 Com radio?
 
This is why ARINC came into being. To standardize avionics and interfaces.
(Airlines drove it)
If a manufacturer uses proprietary interfaces and protocols, it is usually to keep out competition. Draw your own conclusions.
 
Asked more directly:
1. In today’s software world, does Garmin have to actually give coding or other specific information to Dynon to make the interface work?
2. Or, is all necessary information automatically contained in the Garmin ARINC data that can be picked off and used by Dynon to implement the interface?
3. In the worst case, what if a manufacturer decides its upgrade is proprietary and thus only available to owners of its other boxes? Does this not penalize a customer who owns one box from them which interfaces with other boxes from other manufacturers?
?

1. Unless there is a contractual obligation, no.
2. No. For example, a Garmin TSO’d GPS can output the data needed for ADSB out. But that data is via a proprietary code.
3. Yes. Garmin has in the past changed its proprietary codes, causing heartburn for other small companies and owners of devices that had reverse engineered the code. Sometimes this has been done without explicit warning. Of course, you are not obligated to update software.

Companies in capitalist economies are supposed to maximize their profits. Some companies (GRT, for example) think they will do best if they work with as many other boxes as possible. Others(Garmin) think they will maximize profits if they force their buyers to go all-Garmin. Some (Dynon) seem to be in-between.
 
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This situation reminds me of the olden days of computers when each software program had to have a printer driver for your specific printer. Am I dating myself?
 
ARINC is an a industry standard format. The protocol and label definitions are available.
 
Question here also?

On this subject, is that not what the ARNIC box is intended for in the Garmin line of add-ons?
Yours, R.E.A. III # 80888
 
On this subject, is that not what the ARNIC box is intended for in the Garmin line of add-ons?
Yours, R.E.A. III # 80888

The ARINC box in Garmin’s lineup allows those that need it to interface with ARINC speaking devices. Those that don’t need it don’t have to pay for the add on.

ARINC is built into the GTN/GNS IFR Navigators.
 
Yes, but, to answer the OPs original question: Not all information is available via ARINC. e.g., data needed for adsb-out is not in the ARINC data stream. It is in an RS232 data stream, but in a proprietary format. The data stream that lets two 430?s share flight plans is proprietary. etc.
 
Take aways

I appreciate everyone's responses to my post. I think the "bottom line" here is:

1. The bullet proof solution is to assure that all avionics in your airplane that communicate with each other are made by the same manufacturer.

2. A backup position is to insure that companies making different boxes that communicate with each other in your plane are companies which work together. The problem is that business being business, such collegial arrangements can dissipate over time.

3. In the situation I mentioned in my initial post, the ideal solution is for Garmin and Dynon to cooperate in any needed communications required for compatibility. After all, I am of customer of each, and each stands to benefit from making their products work together. As before, I offer no criticism of them or anyone else since in full disclosure I also have a GRT box in my panel. And yes, there is a reason for each one.

4. This compatibility matter between flight displays, navigators, transponders, autopilots, etc. appears a work in progress where there is not yet agreement on how to accomplish it across the board.
 
This is exactly why I'll be choosing all Garmin. I'm building an IFR panel and consequently I want all boxes speaking the same language. An integrated system if you will.

The mix and match method may work or it may not, depending on the whims of the individual manufactures and that's a game I'm unwilling to play.
 
Exactly

....and this is EXACTLY what Garmin wants. That being said, the industry needs competition to keep the players investing in innovation which drives prices and features that we so desire. I wouldn?t be too concerned with going with same manufacturer. Places like Stein and other contributors can help you get what you want to play nicely with all the components. Years ago when building a home stereo system, the turntable (what?s that hahahah) was one mfg, the amp another, speakers another, and so on. If I recall, it was kinda fun too. For certified GPS boxes, you currently have Avidyne and Garmin. Maybe there will be some others to enter the market before we get too old to fly. It?s a great time to be in the experimental avionics marketplace. Good luck on your project!

This is exactly why I'll be choosing all Garmin. I'm building an IFR panel and consequently I want all boxes speaking the same language. An integrated system if you will.

The mix and match method may work or it may not, depending on the whims of the individual manufactures and that's a game I'm unwilling to play.
 
....and this is EXACTLY what Garmin wants. .......

If Dynon wants to compete for panel space in an IFR environment, then they better provide a complete solution. Right or wrong, for better or worse...that's what Garmin does.

And as far as Stein's making things play nice together, your right. Except that ignores the point of a possible upgrades that takes it out of Stein's hands whether the different boxes will continue play nice.

Your also right this is a great time to be in the experimental marketplace. Hopefully the other manufactures will catch up to Garmin with fully integrated mature systems but that probably won't happen anytime soon.

Edit: This is not to say it’s Garmin or nothing....Dynon and the rest make fantastic stuff and I would be proud to have any of these other brands in my panel.
 
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Golden gun

1. The bullet proof solution is to assure that all avionics in your airplane that communicate with each other are made by the same manufacturer.

It may seem bullet proof because it's worked for 1000 hours for you and a few buds. But proving the absence of integration bugs is next to impossible. I know of at least one case where all displays from the same manufacturer went blank on a wide body during approach. Not cool. I've caught very subtle bugs in software that have been flying jets for a decade. And I gaurentee the boxes you put in your RV are not tested to the rigor of the hardware I work on.

I've been building and testing avionics for everything from the CEO magic carpets to twin isle wide bodies for almost 20 years. The robust solution I'll be going with is a small standby from a different mfr. They will share pitot/static connections and that's it. It's not the right way, but what I feel best with knowing how hard it is to test software.
 
It may seem bullet proof because it's worked for 1000 hours for you and a few buds. But proving the absence of integration bugs is next to impossible. I know of at least one case where all displays from the same manufacturer went blank on a wide body during approach. Not cool. I've caught very subtle bugs in software that have been flying jets for a decade. And I gaurentee the boxes you put in your RV are not tested to the rigor of the hardware I work on.

I've been building and testing avionics for everything from the CEO magic carpets to twin isle wide bodies for almost 20 years. The robust solution I'll be going with is a small standby from a different mfr. They will share pitot/static connections and that's it. It's not the right way, but what I feel best with knowing how hard it is to test software.
+1
Me too. Even has its own battery.
 
bugs

... The robust solution I'll be going with is a small standby from a different mfr. They will share pitot/static connections and that's it. It's not the right way, but what I feel best with knowing how hard it is to test software.
Agreed, manufacturer diversity can be good. My backups are those old round black things that only need pitot and static and no electricity. All software has bugs, they sometimes rear their ugly heads at exactly the wrong moment. :D
 
If Dynon wants to compete for panel space in an IFR environment, then they better provide a complete solution. Right or wrong, for better or worse...that's what Garmin does.
Snip...

Yep - Garmin does a lot of stuff and I?m thrilled we have options other than Garmin.

I have just purchased another GTN-650 to go in the new project, not because I wanted a piece of Garmin in the panel but because the other options were even less viable. I will, again, use it with a full SkyView install. I have a lot of hard IFR time flying SkyView and would not want to change to anything else.

I don?t care how people spend their money, but your post may lead new builders to believe that they have to buy Garmin or fall out of the sky.

We can only hope companies like Dynon take the step to produce a TSO GPS navigator to keep Garmin in check. Competition is a wonderful thing.

Carl
 
Yep - Garmin does a lot of stuff and I’m thrilled we have options other than Garmin.

I have just purchased another GTN-650 to go in the new project, not because I wanted a piece of Garmin in the panel but because the other options were even less viable. I will, again, use it with a full SkyView install. I have a lot of hard IFR time flying SkyView and would not want to change to anything else.

I don’t care how people spend their money, but your post may lead new builders to believe that they have to buy Garmin or fall out of the sky.

We can only hope companies like Dynon take the step to produce a TSO GPS navigator to keep Garmin in check. Competition is a wonderful thing.

Carl

I’m sorry, I didn’t mean to give the impression that it was Garmin or nothing. I edited my previous post to clarify my position. The non Garmin choices are fantastic and we truly are in a golden age of experimental avionics.

My point really only relates to a mixed manufacturers system possibly not being compatible in a hypothetical future update.

This is what’s driving my decision but if Dynon wanted to sponsor me I would certainly not turn them down :D
 
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I ran Dynon for my main panel, with a Garmin 430W for the certified IFR receiver, because the 430W has been around long enough that Garmin is not likely to jack around with the software and change the protocols at this point, and it cooperates just fine with the Dynon ARINC today.

With new tech, there is always the danger that a new tweak or software update will upset the apple cart. I don't need any of the new features of the GTN series, the old 430W does everything I really need and it's not likely to get jacked with at this point, so that's where I went.
 
We can only hope companies like Dynon take the step to produce a TSO GPS navigator to keep Garmin in check. Competition is a wonderful thing.

That?s exactly what Avidyne has done. They are, imho, a very viable company with, in many ways, an equal or superior product to the Garmin line.

As for compatibility, there is very little function in an IFR navigator like the Garmin GTN line that is more functional with a G3X system than with a Dynon system.

Sometimes you are better off with a setup with different manufacturers so a software bug doesn?t take your entire panel down. This has happened on Garmin panels as well as other manufacturers.

Garmin, Dynon and AFS are all great systems that I would recommend. GRT is much like AFS in that it is compatible with a whole lot of 3rd party products. I would avoid MGL. TruTrak makes a great auto pilot that is compatible with the above-mentioned systems to differing degrees, but can be used as a completely stand-alone ?keep me alive when I have no clue what is happening when my system fails? unit.
 
Australian Prospective

Adding to Jesse's great summary,

Garmin may have a lot going for it in Domestic USA but they have limitations in other countries.

A simple thing like having mapping (VNC WAC etc ) on those shinny new G1000's and G3X have eluded Garmin users for what ever reason here in Australia. Each year they say they will have it resolved and then another year passes. Hopefully soon for the many G users in Australia.

Meanwhile Dynon /AFS has had full mapping with wifi transfer capability for over 4 years in Australia with Avplan.

I like Garmin and have a GTN750, but right now in Aus the best choice would be Dynon/AFS with an Avidyne and Avplan software .
 
Sorry for the thread drift...
Jesse, I?m curious why you mentioned TruTrak but not Trio. IMHO it?s superior to the TT in most ways, except for needing more panel space. But in a ?main efis just failed? emergency, that bigger display (which means more knobs, fewer knobs doing multiple things) might be an advantage.
 
Sorry for the thread drift...
Jesse, I?m curious why you mentioned TruTrak but not Trio. IMHO it?s superior to the TT in most ways, except for needing more panel space. But in a ?main efis just failed? emergency, that bigger display (which means more knobs, fewer knobs doing multiple things) might be an advantage.

I didn?t mention Trio because I don?t have a lot of experience with them. I know most people with them are happy with them, so that could be added to a list, but I can?t add it to my list due to lack of experience with it. I think TruTrak is a little more compatible with the EFIS systems out there.
 
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