Third HDX Display Wiring

[PYoder]

Dynon has a document detailing the wiring of a third HDX display (network hub for ethernet etc) - I have misplaced the one they provided to me some time ago - anyone have this document?

 

[Rhino]

I'm not sure what you mean by "network hub for ethernet etc." The SV-NET-HUB is serial. You can't combine it with ethernet. Adding a third display to the serial network would be as simple as plugging it into an SV-NET-HUB. Adding it to ethernet would be a different story, requiring an ethernet hub or switch. Making a physical ethernet connection between displays that way would be easy. But I'm not sure if anything else would be needed to make them talk to each other, because I don't know if the displays are configured to work that way. And, since two displays connect directly over an ethernet cable now, a crossover cable might be needed.If Dynon has a way to do that, I'm not aware of what it is. But if they do, maybe you should contact them and ask.

 

[PYoder]

I'm not sure what you mean by "network hub for ethernet etc." The SV-NET-HUB is serial. You can't combine it with ethernet. Adding a third display to the serial network would be as simple as plugging it into an SV-NET-HUB. Adding it to ethernet would be a different story, requiring an ethernet hub or switch. Making a physical ethernet connection between displays that way would be easy. But I'm not sure if anything else would be needed to make them talk to each other, because I don't know if the displays are configured to work that way. And, since two displays connect directly over an ethernet cable now, a crossover cable might be needed.If Dynon has a way to do that, I'm not aware of what it is. But if they do, maybe you should contact them and ask.

I understand the SV-NET-HUB connection - and that is not an issue. However the two existing displays are connected via Ethernet also - utilizing a crossover cable and that cannot be utilized to connect a third - an Ethernet hub is required - and while AC-powered hubs are common, 12volt hubs are not so common. In addition. A third display requires ‘splicing’ all of the data lines in with the two existing displays.
Dynon, at one time, sent to me a diagram outlining all of these issues - but they aren’t responding this week and I thought someone on this forum might respond more quickly.

 

[Rhino]

Then you'd just use an unmanaged hub or switch with standard cables, and ditch the crossover. I don't have the diagram for the rest. Sorry. I could come up with one, but I imagine Dynon will have replied by the time I finished it, and I have no desire to reinvent the wheel, so.....

If it's not something on their site though, it might be helpful if you post it here when you get it. That way, others could maybe benefit from it in the future.

 

[Marc_J._Zeitlin]

I understand the SV-NET-HUB connection - and that is not an issue. However the two existing displays are connected via Ethernet also - utilizing a crossover cable and that cannot be utilized to connect a third - an Ethernet hub is required - and while AC-powered hubs are common, 12volt hubs are not so common. In addition. A third display requires ‘splicing’ all of the data lines in with the two existing displays.
Dynon, at one time, sent to me a diagram outlining all of these issues - but they aren’t responding this week and I thought someone on this forum might respond more quickly.

So I don't know crap about having a 3rd display - I only have two. But you already know what you need to do for the SV-NET and for all the data lines (splice the third into the other two). For the Ethernet, see page 2-32 of rev. AT of the installation manual - it says:

Dynon Avionics strongly recommends “Low Smoke Zero Halogen” Ethernet cables for use in aircraft,but any Ethernet cable – whether it is a “crossover” or normal “straight” type Ethernet cable - will technically work. Low Smoke Zero Halogen Ethernet cables are available from Dynon Avionics (SV-ETHERNET-3CC). Aircraft containing more than two SkyView displays will need an Ethernet switch with enough ports to connect all SkyView displays together.​

So it seems as though ANY cable - straight or crossover - will work, and all you need is a 12V switch, like this one:

https://www.amazon.com/Industrial-3-Port-Gigabit-Ethernet-Switch/dp/B0DHFWCG2B

I'm sure there are a zillion others. Doesn't look very complicated... The hardest part will just be splicing in all bazillion data wires to the existing harness.

 

[Rhino]

A crossover cable has pins reversed from a standard ethernet cable, so they are not interchangeable. Dynon uses a crossover cable because the displays are normally hooked directly together, and crossovers are commonly used for directly connected equipment. For instance, you use a crossover cable when you connect two computers together directly, without a hub or switch. But when going through an ethernet hub or switch, you cannot use a crossover cable. The hub or switch assumes all connections are standard cables, and internally routes the data accordingly. The Dynon recommendation is because, no matter which configuration cable you use, a Low Smoke Zero Halogen is preferred due to better safety in the case of a fire.

 

[Marc_J._Zeitlin]

My point was, with a $40 switch and a couple of ethernet cables, the OP can have what he wants. Seems simple enough.

 

[Rhino]

I agree. It's patching in all the other stuff he wants that will be his biggest challenge. I knew what you were getting at. But you appeared to say any cable, including a crossover, would work with a switch, and it won't. I just didn't want anyone to mistakenly assume it would.