With the same version of the DJI Assistant (1.1.6) I managed to update the FW with I'm unable to get the DAT files out from the craft. The only thing that happens when going to that option is a screen with nothing basically. I would have expected the flight logs showing up?

Why do you want the.dat files?    The .txt files from the app are much more user friendly.

The txt files just tell a fraction compared with the DAT files.  And I need to analyze  a couple of events that has happened. So question is, does anyone else have this issue with getting the DAT files?

Background is. I have a new P4A. Compass is calibrated at the same spot all my other drones got their compass calibrated. During my first test flight with it I got what's seen in the first picture. And I have never seen that from my other Phantoms / Mavic / Inspire at the same place* I thought it might had to do with the flight mode I happened to test at that time, draw mode. I made another flight and the issue did not occur but on the other hand I did not try out any other flight mode. So i thought it might be related to that mode.

During my third flight at a place I have never flewn before I got a more serius error related to the compass, pic 2. I made 2 more flight at the same place but no errors. And no flight modes were involved in any of those flights.

So I was start wondering if it's something wrong with my new P4A and also thought I might get more data out of the DAT file.

* I had compass errors there, and every place i flew with an old phantom 3 pro I got replaced as there was something wrong with it. Therefore my suspicions it might be something wrong with my new P4a.

Håkan K Posted at 2017-9-22 19:57
The txt files just tell a fraction compared with the DAT files.  And I need to analyze  a couple of events that has happened. So question is, does anyone else have this issue with getting the DAT files?

Background is. I have a new P4A. Compass is calibrated at the same spot all my other drones got their compass calibrated. During my first test flight with it I got what's seen in the first picture. And I have never seen that from my other Phantoms / Mavic / Inspire at the same place* I thought it might had to do with the flight mode I happened to test at that time, draw mode. I made another flight and the issue did not occur but on the other hand I did not try out any other flight mode. So i thought it might be related to that mode.

You say you need more info and you are using Airdata?
Airdata doesn't show flight dta, just a brief summary.
It's no use when you want to see what's going on.
Try uploading our .txt file to http://www.phantomhelp.com/LogViewer/Upload/
Follow the instructions there to upload your flight record.
Come back and post a link to the report it provides.

Looking at what you've posted, I'd have to ask what surface are you launching from?

First flight. No (known) things to cause magnetic interference. And as said, I haven't got any compass errors there with any of my phantoms, inspire or mavic. (Except a P3Pro which was ovbiosly something wrong with as it throw that error 30 sec to 1 mnt in air and released the GPS lock, replaced)

First compass error

Second flight. Thinking about it, an old abondoned mine. Probably a lot of iron in the ground:

Second error

Thanks for looking into it. And let me know what extra info you can see from this compared with flightdata, Except a higer sampling rate? (Just want to understand this better)

Håkan K Posted at 2017-9-22 19:57
The txt files just tell a fraction compared with the DAT files.  And I need to analyze  a couple of events that has happened. So question is, does anyone else have this issue with getting the DAT files?

Background is. I have a new P4A. Compass is calibrated at the same spot all my other drones got their compass calibrated. During my first test flight with it I got what's seen in the first picture. And I have never seen that from my other Phantoms / Mavic / Inspire at the same place* I thought it might had to do with the flight mode I happened to test at that time, draw mode. I made another flight and the issue did not occur but on the other hand I did not try out any other flight mode. So i thought it might be related to that mode.

I have a new P4A. Compass is calibrated at the same spot all my other drones got their compass calibrated.
....  I thought it might had to do with the flight mode

First up, the flight mode used would not cause compass issues.
The compass should be working the same way in any flight mode.

2nd .. There was no need to calibrate the compass of your new P4 Advanced.  The manual doesn't suggest it at all.
This might or might not be a factor but it's impossible to tell.

What shows up in your first flight is unusual.
At 10:41 you get indications of a compass error for 5 seconds and again at 11:57 for 4 seconds.
But the Phantom doesn't slip into Atti mode at all and the flight continued with no problems.
The compass error messages almost appear to be a false alarm (but I've never seen false alarms for compass errors.

The other flight is more serious with a yaw error (which is similar to a compass error) appearing at 1:17 - 1:24 and not coming back for the rest of the flight.
This time your Phantom dropped into atti mode which is what normally happens with a compass or yaw error because the Phantom can't handle the conflicting data from compass and GPS.

I'm not sure what the cause of either incident was.  They are not what is commonly seen for these errors.
A yaw error is usually due to launching from on top of a steel or reinforced concrete surface.

If it was my Phantom, I'd go somewhere different and recalibrate the compass again and give it a few test flights to see if that improves things or if you have a problem drone.

Labroides Posted at 2017-9-23 16:18
I have a new P4A. Compass is calibrated at the same spot all my other drones got their compass calibrated.
....  I thought it might had to do with the flight mode

I agree not to calibrate the compass except when moving far distances to compensate for the deviation. And in this case it came from China.

I had three  successful flights Sunday.  I think the second case above was due to a lot of Iron in the ground.  The first, although not that serious as it kept the GPS lock is still a mystery.  I will calibrate the compass again as I notice the craft won't fly straight. I.e with no input on left stick (mode 2) and flying forward it will turn a bit left. And the RC is calibrated. I saw the same bahavior with my Inspire and it was fixed by a compass calibration.

It's somewhat complicated but look  here

http://www.datfile.net/DatCon/retrieveV3Dat.html

to see how to retrieve a .DAT using DJI Assistant 1.1.6

BudWalker Posted at 2017-9-25 16:43
It's somewhat complicated but look  here

http://www.datfile.net/DatCon/retrieveV3Dat.html

The DAT file problem is not to hook up the assistant. They are just not visible after connection. And I did upload using the same assistant so it's indeed connected..

Håkan K Posted at 2017-10-6 20:44
The DAT file problem is not to hook up the assistant. They are just not visible after connection. And I did upload using the same assistant so it's indeed connected..

Would the firmware update have deleted the files from aircraft ?

BudWalker Posted at 2017-9-25 16:43
It's somewhat complicated but look  here

http://www.datfile.net/DatCon/retrieveV3Dat.html

There's also the DJI data analyser :-

https://forum.dji.com/thread-114810-1-1.html