Garmin GNC 255 and Skyview - limitations

scottmacintyre

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Hi All

I have tried searching but can't find the thread that was discussing the potential options available to this combination of units. I intend adding a 255 to my Skyview and would like to ensure the GPS data is available to the Garmin in order to allow the DME type info to be available as well as VOR functions.

I recall there was something of a decision to be made about sharing data but can't be sure what the issues were. Something like the GPS data could go across but not the frequencies from the Dynon - is this feature available now as I have not seen any screen grabs of it in action ?

Please can anyone confirm what is possible and expose any restrictions on the features of the units.

Many thanks.

Scott

Pulsar XP with 1x 7" Skyview
 

dynonsupport

Dynon Technical Support
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You can tune the radio directly from SkyView, but we don't send the continuous list of frequencies to it.

We can display the NAV data from the radio. We don't have a display of DME nor do we send anything about DME to the 255.

I'm not 100% sure what you are looking to do. Both the SkyView and 255 have a ton of features so it's hard to create a full list of exactly what can and can't be done.
 

jselesi1

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Hi All

Can somebody tell me, the list of known working features between SkyView and 255 depending on connection type (RS232 and/or ARINC 429)?
Thank you in advance.
 

dynonsupport

Dynon Technical Support
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For sure, you can do the following via RS-232:

Display the frequency of the COM active and standby at the top of the SkyView screen
Show you what these frequencies are for (KPAE ATIS, KAWO TWR) based on SkyView's database, on SkyView's screen
Display the VOR, ILS, and Glideslope needles on the HSI.
Tune the COM or NAV standby frequency via the TUNE button on SkyView
Set the course for the VOR with the CRS knob on SkyView.

There's no reason to connect one via ARINC-429.
 

scottmacintyre

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I am not trying to do anything complex - here's what I need to know:

The Garmin 255 needs GPS info to allow it to provide relevant nearest station frequencies (it will generate a list in the same way as the Skyview) and also it will then display DME type info (distance, time to etc). Would this be available as well as the 2 way frequency/VOR/GS information that seems to be confirmed as a working feature set if they are linked together ?

I think there was mention of a limitation on the exchange of information between the 2 units.

The information regarding all the frequencies associated with nearest airfields is already in the Garmin unit but it may be easier sometimes to select from the Dynon.

There has been a suggestion the single serial port on the Garmin and the configuration of the Dynon of what information is available on that port might be the issue. Is there a 255 profile or are we still to use SL30 setting ?

Hope that clarifies.
 

Dynon

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So ideally you want a single serial port to send GPS plus NAV/Frequencies, but SV does not currently have that option (but it's on our list to add). So currently you can choose between GPS so that the radio can do its fancy look-ups, or NAV/Frequencies for basic functionality. For now, you should choose the latter, because it's the only way we can set the ILS course on the head.
 

BMW_X6M

RV-9A O-320 Catto Prop. Dual HDX, ADSB GTN650
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Regarding this subject, but with a Garmin GTN-650. I have the GTN-650 connected with the ARINC-429. My question is I would now like to connect the GTN-650 using a serial port to obtain all of these nice radio tuning features so described for the 255. Has anyone reported this will work? It would just be nice to know before going to the trouble to connect it up. I would need the settings to place in both units also, if someone has. Thanks.
 

dynonsupport

Dynon Technical Support
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As far as we know, it is not possible to tune the Garmin GTN or GNS products externally. This is a limitation on the Garmin side, not on our side.
 

scottmacintyre

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The 'fancy lookup' isn't much of an advantage on the Garmin as the Skyview will provide a similar feature - but the distance to or from a VOR is useful. Not sure it's worthwhile upgrading just yet until the potential is unleashed between these 2 systems.
 

scottmacintyre

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You mentioned ARINC wasn't a worthwhile option but would this provide the additional data transfer ? What else would this type of connection give as far as functionality ?

I guess this is somewhat more of a Garmin issue than Dynon but now in the UK we can't fit any 25kHz radios to new builds there will be many people going for the 255 in place of an SL30 but not able to use the features on the new radio without it having a GPS stream available to it.
 

scottmacintyre

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I found out the solution as things stand at the moment - seems like the ARINC option would allow GPS position to be transferred from Skyview to Garmin with the frequency info being handled by the serial port. As the SV has a nearest list of frequencies it's not such an issue not having the Garmin know where you are. Later a software update might allow the serial port to transfer the info for both GPS and frequencies. Is this a possibility ?
 

paul330

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I started a thread on this about 6 months ago. You can configure the Serial port for the 255 as an SL30 using the legacy commands. That will give you radio tuning info, NAV freq, needles, HSI etc. The stream does not include GPS output back to the 255. Dynon, as I understand it, are working on this. Unfortunately, the 255 has only one serial port which is a big limitation on a piece of kit this expensive - blame Garmin, not Dynon!

I guess there would be a way to add a 429 module and transfer the GPS data that way but it strikes me as a very expensive option. I trust Dynon are going to come up with a new 255 protocol which will address all this, so I'm going to wait.
 

BMW_X6M

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I have just called Garmin, to ask why the GTN boxes cannot be remotely tuned in the same way as their stand alone radio's can. The guy there did not have an answer, but said he would submit it to engineering for review as a future software update to the GTN units. Maybe if enough customers request this, it will get implemented.
 

scottmacintyre

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I just noticed the post above which suggests Dynon are working on the serial connection providing both GPS and VOR data - is this a possibility ? Just trying to get an idea of what's going to be possible now I have cut a new panel.
 

dynonsupport

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Serial connection for GPS and VOR for what product? There have been a few mentioned in this thread.
 

scottmacintyre

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Sorry - I thought the name of this thread implied the Garmin GNC 255 was the device. The whole question was having to choose the VOR data or the GPS data from the serial port on the Skyview as the Garmin has a single port. Just hoping the capability might be there to allow both these data streams to be available on the one port.
 

Dynon

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It isn't possible to join those two feeds together today, but it's under consideration for a future software update.
 

scottmacintyre

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Just wondering if the above limitation has been resolved. We are currently swapping out a Com radio for the GNC255 and have the serial connection ready to hook up.
We hope we will be able to use the Nav functions and display LOC/GS/VOR info and use the HSI display - this is obtained from data received from the 255, I believe with the possibility of changing frequencies on the 255 by sending the data to the 255 - all achievable using 1 x 2 wire serial connection. Previously it seemed there was hope that GPS information would also become available to the 255 from the Skyview - has this been added to the firmware ?
 
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