Autopilot wiring

[Brantel]

Is it safe to run the AP cables out to the wing and back to the back and not connect a servo to it?

I have pre-wired my plane but will not start out with the servos installed.

Will the DSAB bus not like having those long cables with nothing connected to them on the end? I am worried about noise etc.....

 

[dynonsupport]

An unterminated run like that isn't optimal for sure, but it probably won't cause any issues at those lengths.

 

[Brantel]

Would a terminating resistor be OK to ad? If so what value? I suppose I could just leave those disconnected from the buss till I really need them but I hate getting under that panel!!!!

 

[DBRV10]

Why not run a cable out to the wing and one to the tail.

We ran a 3 core and two core Shielded and twisted of course, to each destination, all terminated at the bus junction behind the panel.

No Comms problems......unlike DeviceNet

 

[Brantel]

I do have one each running to the tail and the wing all coming back to a central star point behind the sub panel.

I initially will not have the servos installed and I do not want the long flying leads to cause an issue....I also do not want to be back under that panel once I put the front top skin on for good so I would love to connect these lines to the star point and be done with it.

Dynon states that most likely they wont cause a problem but if a terminating resistor out on the ends would guarantee that, I would like to add them. I would just need to know what value to use.

 

[DBRV10]

fair enough, as you probably know many systems use 110ohms and I think DN240ohm so you could try it and see!

I doubt Dynon have ever been asked such interesting questions before......so Question of the month award goes to you!

 

[Brantel]

Yep, us Automation Engineers know bad things can happen when you do not terminate networks!!!!

Dynon has stated that there DSAB is a differential 2 wire RS485 based system so 110-120 ohms should do the trick????

 

[PhantomPholly]

This discussion reminds me of coax ethernet in the Novel 2.x days...

 

[jaba-who]

I don't want to be the bearer of bad tidings but.....

I don't think I have ever heard of a builder NOT having to get back behind the panel once the final install was made. I think in the real world you are going to be back under that panel more than you would like. So you you might as well just terminate them behind the panel and wait till you get the servos before connecting theme to the Dynon. That way you do decrease the risk of the wires causing some problem prior to connecting the servos to them.

John Martin

 

[DBRV10]

Hate to break the bad news to ya buddy, but our IFR panel went in, once and I have not been back in there in 150 hours, apart from getting some harness pins in the connector block reseated into the block.

And I can tell you I have no desire to get back into it either!

 

[jakej]

"I have not been back in there in 150 hours, apart from getting some harness pins in the connector block reseated into the block."

So you DID go back ;D

Jake J

 

[DBRV10]

Smarty pants!!!

Not because I wanted too, or to rewire things.......cheeky bugger!

Them tight harness coonectors as you know only too well!

 

[sangliervolant]

Servo power ?
I'm wiring autopilot harness to Skyview.
On my harness, wiring power and ground go to skyview display DB9.
On Dynon drawing, power go to a servo switch and breaker to aircraft power.
I plan wiring power with AWG20 and one 2A breaker per servo.
What is your advice ?

 

[dynonsupport]

I'm not sure what the question is exactly, but, you do need to provide separate power for the servos. They are higher current draw devices than the ADAHRS and EMS modules and require more power than SkyView is designed to provide itself. We'll actually have a servo harness out shortly, which will have all of the bits and pieces needed to connect things together, though none of the connectors will be attached so that you can route the wires where they need to go. It will have higher 20 ga wire vs the normal 22ga wire used everywhere else.

 

[dynonsupport]

The SV-NET-SERVO wiring kit is now available through normal channels (our online store, through dealers, etc.)

-Robert
Dynon Marketing

 

[jc2da]

Quick question here, in an all metal Van's RV, curious if it would be okay to ground the servos to a local ground point, essentially leaving the black wire unused in the servo wire harness?

Page 9-8 in the install guide, just says to wire to "aircraft ground" and doesn't say anything more specific about it.

Jae

 

[jc2da]

Bump. Any thoughts? Thanks!

 

[dynonsupport]

Yep, that's fine.

 

[BJohnson]

I installed my elevator AP servo SV-32 in the RV-9A fuselage 1.5 years ago, and now I am finishing the installation of the entire system. I wired the power and ground through a DB9 connector and used 22 gauge wire. The AC43.13b indicated that a load of 2 amps over 30 feet would drop the voltage 1V, and since the distance was more like 15 ft, I assumed that it was OK with a 2A fuse. Max current published for the SV32 was 1.33A. Reading the new documentation, the recommendation is 20 gauge and use a splice other than a DB9 connector.

Question: do I need to rewire the power and ground to meet the current recommendations, or am I OK with the smaller SV32 servo?

 

[gvines]

I have a similar question: I'm wiring my SV32 servo and have the net servo kit.  The kit comes with DB-9s and indicates they are only for the network connections, yet the power & disconnect wires will fit.  It comes with sufficient pins as well.

Can I run all the servo wires through the DB9 ?

The SV32 spec says 1.33A (max), the mil spec (MIL-W-5088B from the ITTcannon site) says 1.5A average max per wire (and a bunch of other limitations but I assume power & ground are the only two with significant current). So the connector seems OK. (but not for the SV42)

Any reason not to do this just at the servo? I can see how wiring the DB9 on the other end where it might connect to the main unit would cause a problem. But at the servo this seems the best way.

Thanks