SL 40 to Skyview

[dynonsupport]

If mmarien is right and the A210 won't accept tuning commands from a Garmin handheld GPS, then it won't work from Dynon either.

 

[skypilot1104]

OK... Now I am very curious if this will work with the "New" GTR225 and/or the GNC255... These are the new replacements from Garmin for the SL30/40... Unfortunately I can't find an installation Manual for my GTR225 to get the pin out, and the harness sent with the COMM is the very basic... Can anyone help?

The Harness has a set of wires labeled:
2 conductor Shielded - RS232 Into Com
White - Data
Blue - Ground
1 Standard Wire - Com Remote Tune Up
1 Standard Wire - Com Remote Tune Down
1 Standard Wire - Com Remote Transfer

 

[dynonsupport]

Garmin says the new radios are compatible with the old protocol. Until someone tries it out, we'll just have to trust Garmin and assume it will work.

 

[GalinHdz]

GREAT, but I am out of serial ports.

1-Aera
2-SV-Xponder
3-SV-ADSB
4-G430W
5-SV-GPS

 

[dynonsupport]

3 GPS devices connected to one SkyView!

You really should hook that G430 up via ARINC, which will allow you to use the NAV/LOC/ILS functions of it with SkyView, as well as allowing it to be used for GPS approaches. That will free up a serial port.

 

[GalinHdz]

3 GPS devices connected to one SkyView!

You really should hook that G430 up via ARINC, which will allow you to use the NAV/LOC/ILS functions of it with SkyView, as well as allowing it to be used for GPS approaches. That will free up a serial port.

I forgot to mention the G430 is also connected via ARINC. Maybe I should just use that connection and free up one port. Will Skyview V6 also push data to a G430/530 like it will to an SL30/40?

 

[dynonsupport]

The 430/530 does not support external tuning so there's nothing we can do there.

 

[GalinHdz]

The 430/530 does not support external tuning so there's nothing we can do there.

Oops, overlooked that "minor" detail. 

 

[skypilot1104]

Just a FYI... I added RS232 capability to my GTR225 harness this evening.  Pin 1 - Tx, Pin 16 - Rx, Pin 31 RS232 Gnd, Setup my skyview Serial Port 2 for NMEA Basic 9600 baud, and matched the GTR225 serial port to NMEA, and data started to flow from the skyview to the GTR.  Since the GTR225 is COMM only, there was no serial input to the skyview at this point.  Garmin said the GTR supports the same audio format as the SL series... I am hopeful that Skyview and the GTR will work together.

 

[swatson999]

3 GPS devices connected to one SkyView!

You really should hook that G430 up via ARINC, which will allow you to use the NAV/LOC/ILS functions of it with SkyView, as well as allowing it to be used for GPS approaches. That will free up a serial port.

I forgot to mention the G430 is also connected via ARINC. Maybe I should just use that connection and free up one port. Will Skyview V6 also push data to a G430/530 like it will to an SL30/40?

Why do you have both ARINC *and* serial connections from the SV to the 430?

 

[GalinHdz]

3 GPS devices connected to one SkyView!

You really should hook that G430 up via ARINC, which will allow you to use the NAV/LOC/ILS functions of it with SkyView, as well as allowing it to be used for GPS approaches. That will free up a serial port.

I forgot to mention the G430 is also connected via ARINC. Maybe I should just use that connection and free up one port. Will Skyview V6 also push data to a G430/530 like it will to an SL30/40?

Why do you have both ARINC *and* serial connections from the SV to the 430?

It was available and easy to do. No such thing as excessive redundancy.

 

[swatson999]

interesting...what data is the 430 sending via serial, and is SV even using it? I just have the ARINC box and have had no issues, but I have several available serial ports....

What failure scenarios do you envision where this would serve as a backup?

 

[skypilot1104]

Just wanted to chime in... when I was setting up the GTR I saw a number of pre-configured Serial settings for the GNS430, I "believe" you can send Nav / GPS information to the Skyview display on the HSI... via Serial Connection.

 

[GalinHdz]

interesting...what data is the 430 sending via serial, and is SV even using it?  I just have the ARINC box and have had no issues, but I have several available serial ports....

What failure scenarios do you envision where this would serve as a backup?

I am getting everything (HSI) on my Skyview but I am not sure what G430 data is being received via ARINC vs Serial. If I loose my SV-GPS and AERA the G430 data should run my Skyview. 

 

[swatson999]

Well, here's the list of what's sent and received via ARINC

http://wiki.dynonavionics.com/SV-ARINC-429_Labels

The question is...if everything else, including ARINC, went away, would a serial connection to the 430 provide anything useful to Skyview that it actually uses?

The installation manual says you do not need to connect serial directly to SV, only to the ARINC box (in fact, it says NOT to connect it directly if you had it doing that before).

It's an interesting failure analysis...if the SV GPS went off-line, would the GPS data from the ARINC box allow SV to show the map, etc., based on THAT GPS?

I still don't see what the serial line directly from the 430 to SV does for you, though...(that is, what does it get you that the ARINC connection doesn't?)...unless you're using a second serial line from the 430 as a backup to the ARINC box failing?

 

[dynonsupport]

The only thing you can get over serial from an 430W is en-route horizontal GPS guidance.

It doesn't have ANY data from the VOR/LOC, any GPS vertical data, nor gain information for CDI gain which is needed for approaches.

So basically, it's exactly like a handheld GPS. Given the airplane already has a handheld GPS and the Dynon GPS, that's a lot of backup.

 

[GalinHdz]

So basically, it's exactly like a handheld GPS. Given the airplane already has a handheld GPS and the Dynon GPS, that's a lot of backup.

That is what I thought. Hey, it was available, free and easy to connect so I did it. "There is no such thing as excessive redundancy". 

 

[dynonsupport]

I would disagree that there is no such thing as excessive redundancy. We don't all fly airplanes with two, three, or four engines, and we don't all require our planes to have two pilots on board. We also don't run two circuit breakers and wires to every electrical load to deal with failed breakers or broken wires. That's because we make logical trade-offs between redundancy and reality. So what you really mean is that you think free redundancy is never bad.

Even in your case, it wasn't free. You added weight from the extra wire, you added one more path for something to go wrong, and you added operational complexity. You have a GPS0, GPS1, GPS2, and GPS3 in your plane, and two of them are the same source, yet one has a lot less operational capability. This increases workload on the pilot, which inherently is a risk and is a downside. The Pilot could see waypoint KABC on the HSI and think it must be right since the G430W shows KABC, but they are using the highly wounded serial connection and don't realize it.

It also caused you to claim you were out of serial ports

While this is a minor case, it's just an example of why just adding redundancy all day is not always good. All redundancy inherently increases the complexity of a system, and at some point that makes the system unusable.

Just a point of view from a guy that thinks about redundancy in our systems every day...

--Ian Jordan
Dynon Avionics

 

[swatson999]

Ian beat me to the punch...well said.

The way we plan for mitigations (in my job, that is) is to determine the failure mode or failed item, *then* decide what the mitigation is.  In this case, you can have:

Failed 430W
Failed ARINC device
Failed SV
(as some examples)

If the 430 fails, then the SV GPS could back it up (albeit not for approaches, but at least for mapping, course guidance, flight planning, etc.), and comm 2 for communications (assuming you have a second radio or a handheld)
If the ARINC failed, then SV GPS for mapping, 430 for course guidance and approaches, each operating independently
If SV failed, then 430 for course guidance, and backup PFD or AI/ALT/DG

There are other failure cases to consider, but in every one, we're at least single-fault tolerant without the extra complexity and without losing capability (serial ports) unnecessarily. 

It's important to have a set of design principles to use when building any reasonably complex system...

 

[GalinHdz]

I would disagree that there is no such thing as excessive redundancy. We don't all fly airplanes with two, three, or four engines, and we don't all require our planes to have two pilots on board. We also don't run two circuit breakers and wires to every electrical load to deal with failed breakers or broken wires. That's because we make logical trade-offs between redundancy and reality. So what you really mean is that you think free redundancy is never bad.

We don't fly with multiple engines/pilots/circuits but some do. Triple redundancy is not uncommon in aviation. Redundancy is a design trade off between required and available. So OK, FREE redundancy is not a bad thing. 

Even in your case, it wasn't free. You added weight from the extra wire, you added one more path for something to go wrong, and you added operational complexity. You have a GPS0, GPS1, GPS2, and GPS3 in your plane, and two of them are the same source, yet one has a lot less operational capability. This increases workload on the pilot, which inherently is a risk and is a downside. The Pilot could see waypoint KABC on the HSI and think it must be right since the G430W shows KABC, but they are using the highly wounded serial connection and don't realize it.

Adding maybe 1/2oz on a 2500lb aircraft is about a 0.0000125% increase. A failure of this free "extra" path does not reduce any capability. Both instances completely inconsequential.

Now I agree it might give the pilot an increased workload, at least until DYNON lets us assign "nicknames" to the ports. 

It also caused you to claim you were out of serial ports

Now THIS is an excellent reason to re use this port for an SL-40.

While this is a minor case, it's just an example of why just adding redundancy all day is not always good. All redundancy inherently increases the complexity of a system, and at some point that makes the system unusable.

Sorry I don't agree, in any way shape or form, that this system is so complex it is unusable in this form.

Just a point of view from a guy that thinks about redundancy in our systems every day...

--Ian Jordan
  Dynon Avionics

Point taken and considered especially coming from someone in your position.

Now, I am going to move that connection and use it for the SL-40. THIS is an excellent reason especially now that I am going to install an SL-40 which I didn't have before.

THANKS!