Aircraft Disconnected error

5000msl · Sep 2, 2018

Out stretching my flight "legs" this morning with the M2P. As I'm a new pilot I thought I'd try the QuickShots first in a wide open area. No problems.

I was free flying later just to get practice. Wasn't really aware of it but apparently reached the Max Distance setting (whatever the default was; 480m?) - got a prompt, but it's hard for these old eyes to read the small text (I've got a tablet holder now on order.) It was far away, but within LOS. Didn't notice any breakup of return video. I probably kept my thumb on the stick, but when the screen went dark with a red status bar stating Aircraft Disconnected that got my attention.

A pop-up offered some information, but all I could focus on with my heart racing was a prompt for Return to Home which I accepted. The 2P flew back to me, though the screen stayed black, and never reconnected even when it got close - is that normal? I landed OK. Turned the 2P off then back on and it reconnected. I took a couple short flights after this with no issues.

Suggestions? Recommendations? Comments? TIA

Noleafclover1337 · Sep 2, 2018

Could have had some interference. I’ve had a few disconnects with my M2P under a mile away. I think there’s some major firmware’s updates needed for the M2P..

5000msl · Sep 2, 2018

Noleafclover1337 said:
Could have had some interference.

I was in the middle of nowhere. No power lines within a couple miles or anything else I can think would interfere, but possible, I suppose.

sar104 · Sep 2, 2018

Retrieve the logs (mobile device txt and DAT) if you want to see what happened.

5000msl · Sep 2, 2018

sar104 said:
Retrieve the logs (mobile device txt and DAT) if you want to see what happened.

Thanks, that's a good idea, however I'm not sure I know how to get anything meaningful...

I looked at Flight Records in the Go4 app, but about all I can tell from that is that I was 795' from home point at 49' height, traveling at 29mph, and an estimated 7min left on the battery when the track abruptly ends. No record of flight from that point back to home point.

I tried connecting the M2P via USB cable to my desktop and started DJI Assistant 2, latest version, to see if that would provide additional information. When I clicked the aircraft, then Flight Records, the spinner spun, and it said Cannot retrieve flight records. Retry? No amount of retrying helped. I tried starting the controller with phone attached, but same result. Nada.

I'd "saved" the records from the app, but couldn't find where they were on the iPhone. Did a Google... opened apps via iTunes save FlightRecords, FlightLogs, and ExportFlightRecords. The first is a bunch of unreadable data. FlightLogs lists the prompts from the screen during the flight - the last for the flight in questions states the aircraft has reached Maximum Distance. ExportedFlightRecords is a .csv file containing a long list of number, lat, long, number - not particularly helpful in this instance.

Anything I missed? Is this the extent of the records?

I did take the opportunity to sync my flight records. Anyway to view those from my DJI account? I didn't see any way, myself. I guess syncing is so you can use multiple devices or refresh if you delete and reinstall the app.

sar104 · Sep 2, 2018

5000msl said:
Thanks, that's a good idea, however I'm not sure I know how to get anything meaningful...

I looked at Flight Records in the Go4 app, but about all I can tell from that is that I was 795' from home point at 49' height, traveling at 29mph, and an estimated 7min left on the battery when the track abruptly ends. No record of flight from that point back to home point.

I tried connecting the M2P via USB cable to my desktop and started DJI Assistant 2, latest version, to see if that would provide additional information. When I clicked the aircraft, then Flight Records, the spinner spun, and it said Cannot retrieve flight records. Retry? No amount of retrying helped. I tried starting the controller with phone attached, but same result. Nada.

I'd "saved" the records from the app, but couldn't find where they were on the iPhone. Did a Google... opened apps via iTunes save FlightRecords, FlightLogs, and ExportFlightRecords. The first is a bunch of unreadable data. FlightLogs lists the prompts from the screen during the flight - the last for the flight in questions states the aircraft has reached Maximum Distance. ExportedFlightRecords is a .csv file containing a long list of number, lat, long, number - not particularly helpful in this instance.

Anything I missed? Is this the extent of the records?

I did take the opportunity to sync my flight records. Anyway to view those from my DJI account? I didn't see any way, myself. I guess syncing is so you can use multiple devices or refresh if you delete and reinstall the app.

DJI Flight Log Viewer - Phantom Help

How to retrieve a V3.DAT from the tablet

If DJI Assistant 2 showed "Flight Records" then you are not using the latest version, which you need for the M2. That will say "Log Export" instead. Not that it will help, because the aircraft DAT files are encrypted.

5000msl · Sep 2, 2018

sar104 said:
DJI Flight Log Viewer - Phantom Help

How to retrieve a V3.DAT from the tablet

If DJI Assistant 2 showed "Flight Records" then you are not using the latest version, which you need for the M2. That will say "Log Export" instead. Not that it will help, because the aircraft DAT files are encrypted.

Thanks for the log view link! I tried it out. It mostly provides the same info as in the Go4 app, but nicely formatted and with the addition of battery voltages (which might be useful if one's battery is developing problems.) Didn't see anything suspicious.

I'm using v2.0.0 which is the version listed on the DJI Mavic 2 downloads page. If there is a newer version, where do I find it?

sar104 · Sep 2, 2018

5000msl said:
Thanks for the log view link! I tried it out. It mostly provides the same info as in the Go4 app, but nicely formatted and with the addition of battery voltages (which might be useful if one's battery is developing problems.) Didn't see anything suspicious.

I'm using v2.0.0 which is the version listed on the DJI Mavic 2 downloads page. If there is a newer version, where do I find it?

That's strange. "Flight Records" was in previous versions, but now I see this:

gnirtS · Sep 2, 2018

Sounds like a standard DJI Go or USB cable issue.

Did the RC itself disconnect or just the app?

5000msl · Sep 2, 2018

sar104 said:
That's strange. "Flight Records" was in previous versions....

You are right. I mis-remembered what I saw. Sorry for the confusion. I still get no records, though.

5000msl · Sep 2, 2018

gnirtS said:
Sounds like a standard DJI Go or USB cable issue.

Did the RC itself disconnect or just the app?

Not sure. The camera view went black, but the app was still running and displayed a red status bar at the top that said AIRCRAFT DISCONNECTED. It prompted me if I wanted to return to home and I chose YES which implies some communication. As I'm a new pilot and was flustered, I didn't pay attention to the display on the controller unfortunately. If this happens again I'll try to take a deep breath and check the RC display.

Thanks for your reply.

sar104 · Sep 2, 2018

sar104 said:
That's strange. "Flight Records" was in previous versions, but now I see this:

View attachment 45033

Anyway - what you need is the DAT file from the mobile device, (see link above) not the aircraft.

5000msl · Sep 2, 2018

sar104 said:
Anyway - what you need is the DAT file from the mobile device, (see link above) not the aircraft.

I was able to download the DAT files using iTunes, but don't know how to read them as they appear to be pure data files. Is there an app or site that will interpret them? Thanks.

gnirtS · Sep 2, 2018

If you have some sort of control like that and just no picture or app it hints the app or usually its the USB cable at fault.

sar104 · Sep 2, 2018

5000msl said:
I was able to download the DAT files using iTunes, but don't know how to read them as they appear to be pure data files. Is there an app or site that will interpret them? Thanks.

If you followed the instructions in post #6 to get the file then the instructions on how to convert and view the contents was also there:

DatCon Introduction

Cslucas34 · Sep 2, 2018

gnirtS said:
If you have some sort of control like that and just no picture or app it hints the app or usually its the USB cable at fault.

That or he lost video signal but still had control signal, they are two separate signals.

gnirtS · Sep 2, 2018

At the distance quoted i'd say more likely a shoddy USB cable. Its not as if the DJI ones are any good!

DanMan32 · Sep 30, 2018

I get the same 'Failed to get log list' on Assistant 2.0.0 and 2.0.2 as well. Using DJi's own cable on my desktop PC. I haven't tried my laptop.
Is anyone successful with it running on a PC and connecting to an M2?