'RC Input Packets lost' & Code 38/30 on VPlane log

Good morning – I am having issues with 2 NEOS loaded with VPlane on a first gen (non-touch) VControl.. Both planes are nitro powered models, and have Neos with VPlane loaded onto them. Both Neos had zero issues/no crashes.

On the first plane while I was airborne, I lost transmitter signal for a second or two. After landing, I found the Vbar log contained line items that read Code 38 and Code 39 See attached photo. I then updated both the Vcontrol and Neo. On my next flight, I did not lose signal while in the air, but after landing did find that the Vbar log showed Code 38 and Code 39 again.

On the second Nitro plane, I updated the Neo to the latest firmware, and after flying a single flight found that the Vbar log shows a ‘RC packets lost’ error.

I would like to know what the issue is, and why it is occurring. IT would seem this is a major issue and that the planes should not be flown until the problem is fixed.

Other information:
-I’m using a non-touch VBC with the latest updates loaded, and have never had any issues with this unit. I also use this VBC on multiple electric and nitro helis without any issues.
-Both Neos I’m using with VPlane have no had any issues or crashed and are running the latest firmware (1.4.90)

WWG1WGA

Hi,

38 and 39 mean input packets lost and fail safe.
Basically what you saw after the update, on the second plane.
Not good.

Please check the antenna status display in your radio, and let us know what you find.

How/where are the NEOs mounted/located, and how are the antenna wires laid out?
What models are these, made from what materials?

Photos could help understanding

Kind regards

Eddi

Born to fly ...
forced to work.

Hi Eddi - thanks so much for your prompt response! It is greatly appreciated.

Both planes are balsa-built nitro-powered biplanes. The Neos are mounted with 3M double sided tape just as with my helis.

The Neos are mounted upside down near the CG on both planes - on with wires facing after, and the other with wires facing forward.

I do have pics, but cannot upload them due to the (apparent) file size of the pictures.

Perhaps I can email the pictures?

WWG1WGA

Hi Tim,

got the pics on e-mail, thank you.

Was there anything common, between the incidents?
At which distance/altitude/orientation did it happen, if you can recall?

A fellow pilot of ours reported an interesting observation (and logical, and explainable):

He had packet losses.
He suspected like everything, even drones flying close by.
Then, he added a 2nd NEO as an Extender, with two extra antenna wires, and laid them out differently.
And ... problem gone. Even at (GPS tracked) 1.3 km distance / 1.4 km altitude, which makes almost 2 km distance.

Especially on nitro and jet planes, the tanks, the fuel are very badly dampening the signal reception.
2.4 GHz is microwave, and you need several hundred watts to heat up liquids.
We have only 100 mW radio power, but put the antennas close to a huge 'chunk' of liquid.
That absorbs almost everything without even blinking ...

As our developer put it, there's only 20 db difference in signal gain, between good and bad reception, or between 200 m and 2,000 m range.
If the antennas stick out of the fuselage, it's best. But hardly anybody does it, looks are rated higher than function/safety.
Back in the day, you had the antenna suspended between wing and rudder, I wonder why

Cheers

Eddi

Born to fly ...
forced to work.



1 mal bearbeitet. Zuletzt am 19.05.2021 09:56 von Eddi E. aus G..

Eddi,

All flying between the two planes is near identical. I only lost signal on one of the two planes for a split second (seemed much longer). At that time I was coming from left to right inverted about 30 ft off the ground. I will perform another range test next time I fly - I think I can view the signal strength on the VCB while in the air (or have a spotter watch it).

Regarding the 2nd Neo unit as an extender - must it be a full blown Neo or would a VBasic receiver work?

The cost involved in adding another Neo wouldn't be worth it to me, as I would likely switch radio systems.

Also, what type of plane was this pilot you referred to flying? Gas, Nitro, Electric? Large or Small?

*interesting data point: previous to this, I flew VPlane (Vbar Mini + Vsat) in an electric speed plane (Extreme Flight Pantera), and a nitro mono plane (Great Planes Ultra Sport 40) with VPlane on an Silverline +Vsat without any issues at all per the Vbar flight log. Is it possible the second wing (my signal issues are with BIPLANES) has anything to do with signal interference?

WWG1WGA

Hi,

VBasic is sufficient. In the future, once VBar NEO mini hits the marked, I heard rumors that a 'satellite' or VBasic version of it could happen, which would cut costs a bit more. But that's still up in the air, with the slow supply of electronic items these days.

The plane was a jet afaik, tests were also made with woodies (like your Biplanes, I guess).
I'd say sufficiently big, to be able to see it 2 km out :-)

Maybe Lars can add some more info about the planes here.

About the previous planes, let's have a look at the differences: RX Sat, with some wire so it can be in a different position, and extending the overall length to the antenna tips—were the wires laid out significantly different than in the photos (loops to the tank and back, in one, and close to the RX battery, in the other)?

I'd say the number of wings has no influence _unless_ they were made from or covered by shielding materials, like some mesh, creating a partial faraday cage or screen. The normal wood, paper, film or glass fiber as well as the normal Bowden cables or servos and wires in the wing(s) won't do much harm.

If you do range checks on the ground, stand the model on it's nose, tail up, walk around it so the wings get in between the radio and the NEO, see if it's different than in normal flight attitude (standing on it's wheels) or in flight around you (careful).

Kind regards

Eddi

Born to fly ...
forced to work.

Eddi,

The other planes I'm using VPlane have similar sets ups: the Vsat receiver antenna are near the fuel tanks. The electric plane obviously doesn't have a fuel tank, but the Vsat antenna is near the battery.

Would it be possible to connect a VSAT receiver to the NEO in the planes I'm having signal issues with? I do have a Vsat receiver that is not currently in use.

Otherwise, I may try to re-position the antenna on the Neo units in the planes having the signal issues. That seems to be the simplest solution to the issue.

The weather here will not allow flying this weekend, so I have time to work on a solution to my problem.

I'm interested in your thoughts!

WWG1WGA

Hi,

well, my thoughts would be, route the antenna wires out of the fuselage, shortest way, or let them stick down through the mount, or only one, the other one points left or right, with maximum possible distance.
Or use longer antenna wires.
The last 3+3 cm are 'where the music plays'.

Add a second NEO if possible, and if it was only temporarily, use one from a model which you don't fly frequently, anyway.

We can disable VLink on any serial no. (2nd. generation NEO), you update, then you can use a satellite.
They use the same radio module layout and components, they have the same sensitivity and signal gain, but they can be mounted in a different position, obviously. Possible disadvantages, the additional wire can pick up noise, too, and the external receiver is on the same power bus as the servos, so it can be affected by power surges or back voltages more easily.

Even with similar setups, a small difference can make a huge difference. I mean, take RFID: you can potentially read credit card information from your wallet from your back pocket, from a couple of feet away. Put a metal or carbon plate inside your wallet, nothing active or powered, and it dampens the signal gain sufficiently so you can sell 'shielded' wallets at a lovely fee :-)

I'm not a radio expert, but from everything I've seen, ham radio, CB radio, radio control, WiFi, whatever, the antenna layout has the biggest effect, then come surroundings, or even kind of a virtual amplification like a ground plane antenna.
Not as you might expect, sheer power. And we're limited to 100 mW anyway, and have frequencies which can not penetrate liquids, carbon, metal, for example, which get pretty easily dampened or absorbed.

I wish I could tell you, do this, problem goes away ... closest thing would be, try a different antenna layout, use longer antennas, use an Extender and place it away from the main NEO, to add diversity.

—Eddi

Born to fly ...
forced to work.

Thank you Eddi - understand it's not a A+B=C type of fix.

Can I use a regular gray Vsat receiver for additional reception rather than a 2nd Vlink Neo?

I have just such a receiver that I could use if that is an option.

WWG1WGA

WWG1WGA

NCSWIC

17!!

WTF?
IDGAF!

42!

Our sat is not like a Spektrum sat, it's meant to provide VLink to legacy VBars or 1st generation non VLink NEOs which can not be changed to VLink.
So you definitely need at least a NEO VBasic, install the Extender firmware, connect it via Interbus, and enable Interbus in the Macrocell settings of the main VBar.

—Eddi

Born to fly ...
forced to work.

Sounds good Eddi - appreciate the info.

The reason I asked about the VSat is that - several years ago - I had a non-Vlink Neo that I had to use a VSat with for use with my VBar Control. I figured perhaps adding a Vsat to the Vlink Neo may have been an option for signal diversification.

I'll let you know if antenna repositioning has any effect.

WWG1WGA