Please select Into the mobile phone version | Continue to access the computer ver.
DAT files / flight data not being stored on MPP
2236 18 2018-1-13
Uploading and Loding Picture ...(0/1)
o(^-^)o
cohaolain
lvl.1

Ireland
Offline

I'd like to check in to see if anybody else has had similar problems to me with their MPs or MPPs. This problem has been quite a scary one for me, my new MPP being my first drone of this calibre. The problems I've faced have resulted in me already having to send off my drone and controller to receive a new set under my warranty, and now I've unfortunately met the same problems again.

My problems began when I was flying my drone several months ago, when I noticed the drone, which had been hovering several metres away, was landing of its own accord. The controller was being unresponsive but appeared to still be connected, while my phone was stating that the aircraft had disconnected. It seemed almost as if the controller had frozen, or hung. Eventually, the controller switched to 'connecting' again and reconnected. However the same thing occured again several minutes later.
A few days later the same thing occured except the drone was about 40ft up, and maybe 20ft away. The controller once again appeared to hang (all info frozen on screen, completely unresponsive) and the aircraft ascended. The controller made no attempt to reconnect and the drone flew to home. The .txt files from my phone, when uploaded to airdata, state there were long periods of data loss when this occured.
I believe I saw in the log for the first time this occured that the controller had seemed to disconnect. However I was much more concerned when, after this last experience, I returned home to check the log out from the drone and noticed that it was simply absent.
I kept flying for a few days hoping the problem would correct itself, it seemed to happen almost randomly. Ultimately I believe the final straw was when the drone disconnected from the controller as it sat on a kitchen floor just a metre away from the controller in the same was as it had several times before. At this point I contacted DJI support and was told to calibrate the IMU, compass and controller. I did all these, and the drone did indeed appear to fly fine once again. However I soon realised that eventually the drone was not recording any logs anymore, for any flights whatsoever, or at least not showing them in DJI Assistant 2. At this point DJI asked me to file a repair case. I sent back the controller and the drone, and both were replaced under warranty.

I went away hoping that after several droneless weeks, all of my problems would disappear when the new one arrived. The new drone did appear to work without issue for a few days, however the problems began again just a few days ago.
Firstly, I took the drone up for a moment inside in the house. All went well, except I hit the props off the end of my bed and damaged two of them. This all seemed fine, and I simply replaced the two props. I noticed that airdata showed two moments of data loss for roughly a second before the crash, however the drone's log, which appeared without problem in DJI Assistant 2, showed no such connection loss from the controller. I assumed that the cable connecting my phone to the controller may have been loose, and accepted that the crash had been my fault.
Here's where the serious issues begin again: I went to take up the drone again in order to see if the 'data loss' recoccured. This is when the 'controller freezing' appeared to start again. I was having issues getting my phone to connect to the controller, and as it tried to load the DJI GO 4 app, it kept failing, and every time it did, the controller froze as before, and ceased to be able to control the drone. This kept happening repetivively over the course of several minutes. It seemed almost identical to the problems I'd faced before except even worse. After this went on for several minutes, I gave up, and connected my drone to my PC to check the logs. The log for the entire time the controller had started acting up was not there in DJI Assistant 2.
So this was annoying to say the least. I believed it may have been my phone or the OTG cable that was the issue (it's a OnePlus 3 running the latest android and DJI Go 4), however there is no way the phone, app or controller should be able to interfere with the flight data recorder on the aircraft that I'm aware of.
The next day I tried to fly it again, ensuring the cable was connected properly (I normally do, as in, just much more so than usual). Despite there being no connection problems, the prop guard got caught in something after the drone veered to the right. I went to grab the DAT file in DJI Assistant 2, and it was not there.

I've reasoned the phone may be the problem, so today I went to fly with an iPad Mini 4 using DJI Go 4. I had no problems, disconnections etc. over the course of two flights. What I did was: fly once for several minutes, land, power cycle the drone, fly again and then land. To the best of my knowledge this should've made two logs, one for each power cycle, appear in DJI Assistant 2, and also two logs appear on the iPad. Some flights have disappeared completely from DJI Assistant since yesterday, while one of today's flights is also missing. They are visible in DJI GO 4. Here is the result, sorry for the messed up order.
I really hope I've made a massive oversight somewhere and that I'm simply missing something obvious, but this has really been on my nerves and it is quite upsetting considering the money I spent on this piece of tech. I feel like missing flight records could result in an inability to make warranty claims, and that seems very dangerous. Thank you so much for all your help, and sorry for the long post!:

2nd flight, DOES appear in DJI Assistant

2nd flight, DOES appear in DJI Assistant




Top two flights in question from today in Kilcock

Top two flights in question from today in Kilcock

1st flight, DOES NOT appear in DJI Assistant

1st flight, DOES NOT appear in DJI Assistant

Ticked are one flight from yesterday and one today(despite multiple seen in other screenshot from ye ...

Ticked are one flight from yesterday and one today(despite multiple seen in other screenshot from ye ...

Only logs that are copied today

Only logs that are copied today

Extracting shows flight 50 and 55, with missing numbers

Extracting shows flight 50 and 55, with missing numbers

More flights shown in screenshot from the 12th than shown today. Some extracted logs have FLYXXX num ...

More flights shown in screenshot from the 12th than shown today. Some extracted logs have FLYXXX num ...
2018-1-13
Use props
DroneFlying
Captain
Flight distance : 10774613 ft
United States
Offline

I contacted DJI support and was told to calibrate the IMU, compass and controller

By any chance did they also ask you to upgrade to the latest firmware (or if you were already on it)? I'm guessing so as that seems to be part of their standard script.

Yes, this is a known problem that I believe it was introduced in the previous (v01.04.0100) firmware and as best I can tell anyone who has upgraded to it will be unable to see DAT files for their flights. Ironically enough, though, you apparently often can still see the mostly useless ones produced by just powering on without doing any flying.

I'm hoping that DJI has addressed this in the firmware released a couple of days ago (v01.04.0200), but as someone smarter than me pointed out earlier today, I'm probably being overly optimistic. In the meantime, look on the bright side: if the DAT files really aren't there then DJI's going to have a hard time demonstrating pilot error in a lot of these cases.
2018-1-13
Use props
cohaolain
lvl.1

Ireland
Offline

DroneFlying Posted at 2018-1-13 12:24
I contacted DJI support and was told to calibrate the IMU, compass and controller

By any chance did they also ask you to upgrade to the latest firmware (or if you were already on it)? I'm guessing so as that seems to be part of their standard script.

Indeed, they did tell me to 'refresh' the firmware on the AC and the RC for the first drone I had. I did, and it didn't help.
I'm currently on the  v01.04.0200 firmware you mentioned. That's the firmware that I flew with today, and the problem persisted. Well actually, it recorded the second of my two flights today. But it also appears to have wiped some records from yesterday. Whereas records from the first few flights with this drone (done on v01.04.0100 several weeks) are still present in their entirety.
You mentioned that this is a known problem, is there a thread discussing this already that I missed (because I have been searching for some time now), or is that the word from DJI?Edit: I should clarify, you said that on the 0100 firmware people weren't able to get DATs, however I was actually able to get all mine with no issue for my first few flights on that firmware. This issue cropped up once again yesterday on my replacement drone and seems random.
2018-1-13
Use props
DroneFlying
Captain
Flight distance : 10774613 ft
United States
Offline

cohaolain Posted at 2018-1-13 12:32
Indeed, they did tell me to 'refresh' the firmware on the AC and the RC for the first drone I had. I did, and it didn't help.
I'm currently on the  v01.04.0200 firmware you mentioned. That's the firmware that I flew with today, and the problem persisted. Well actually, it recorded the second of my two flights today. But it also appears to have wiped some records from yesterday. Whereas records from the first few flights with this drone (done on v01.04.0100 several weeks) are still present in their entirety.
You mentioned that this is a known problem, is there a thread discussing this already that I missed (because I have been searching for some time now), or is that the word from DJI?Edit: I should clarify, you said that on the 0100 firmware people weren't able to get DATs, however I was actually able to get all mine with no issue for my first few flights on that firmware. This issue cropped up once again yesterday on my replacement drone and seems random.

There's no one thread where it's discussed in any depth but there are a handful of them -- all recent and from people using the then-latest firmware -- where I asked someone to retrieve the DAT file for a flight but they couldn't. That's a pity as I think it's in everyone's best interest -- including DJI's -- if we can review the detailed flight information ourselves. Oh, well, I guess that's just one more reason people now have to downgrade to the older versions of firmware.
2018-1-13
Use props
cohaolain
lvl.1

Ireland
Offline

DroneFlying Posted at 2018-1-13 12:41
There's no one thread where it's discussed in any depth but there are a handful of them -- all recent and from people using the then-latest firmware -- where I asked someone to retrieve the DAT file for a flight but they couldn't. That's a pity as I think it's in everyone's best interest -- including DJI's -- if we can review the detailed flight information ourselves. Oh, well, I guess that's just one more reason people now have to downgrade to the older versions of firmware.

Definitely. It's an extremely strange issue, especially given that it happens sometimes and not others. And in my case that it started on the flight with the disconnections and then that some logs disappeared later on.
2018-1-13
Use props
cohaolain
lvl.1

Ireland
Offline

Yesterday was the first time this missing log issue occurred with the new replacement MPP as far as I know, and (by chance?) was on the first flight where a disconnection / controller hang occurred. It's extremely annoying that it seemed to stop logging as soon as a problem occurred, and that now the problem happens sometimes.

I don't know....
2018-1-13
Use props
DJI Elektra
DJI team
Hong Kong
Offline

cohaolain Posted at 2018-1-13 14:25
Yesterday was the first time this missing log issue occurred with the new replacement MPP as far as I know, and (by chance?) was on the first flight where a disconnection / controller hang occurred. It's extremely annoying that it seemed to stop logging as soon as a problem occurred, and that now the problem happens sometimes.

I don't know....

Sir, please provide me your DJI Account and the firmware of your drone. I would forward this situation for you. Thanks for your support.
2018-1-13
Use props
cohaolain
lvl.1

Ireland
Offline

DJI Elektra Posted at 2018-1-13 19:53
Sir, please provide me your DJI Account and the firmware of your drone. I would forward this situation for you. Thanks for your support.

Thanks, I just sent you a PM
2018-1-14
Use props
JensIR
lvl.4
Flight distance : 207631 ft
  • >>>
Norway
Offline

@cohaolain, I am experiencing the same issue as you: It appears that the log files (DAT) that are supposed to be available through DJI Assitant are missing when I check after a flight.
I first became aware of this on December 31st when I tried to investigate the cause of a sudden power shutdown and subsequent (light) crash. When I connected the Mavic to DJI Assistant I was unable to locate a log file corresponding to the flight. Also I noticed most of the other previous flights seemed to be missing.
The log files in the app are completely separate from the log files in the drone. The log files on the phone/tablet are created by the app from data transmitted from the drone but are supposed to contain a lot less information than the actual logs recorded in the drone itself. In my case, just like you, the log files on the phone were all there for all flights.
My experience is described in this thread: https://forum.dji.com/forum.php?mod=viewthread&tid=127191 . Check post #7 for details on this issue.
Also there is another thread discussing similar problems here: https://forum.dji.com/forum.php?mod=viewthread&tid=126879  , although the OP of this thread seems to have a slightly different issue from me. My contribution to that thread is mostly in post #21.
Due to lack of time and suitable flying condtions I have since not been able to do any more test flights to check if the logs are missing even now. So my issue remains in a state of uncertainty for the moment. Hopefully I will be able to conduct some test flight next week.
I also see there is a new firmware available since a few days ago. I may try to upgrade to see if there is a difference.

2018-1-14
Use props
cohaolain
lvl.1

Ireland
Offline

JensIR Posted at 2018-1-14 03:57
@cohaolain, I am experiencing the same issue as you: It appears that the log files (DAT) that are supposed to be available through DJI Assitant are missing when I check after a flight.
I first became aware of this on December 31st when I tried to investigate the cause of a sudden power shutdown and subsequent (light) crash. When I connected the Mavic to DJI Assistant I was unable to locate a log file corresponding to the flight. Also I noticed most of the other previous flights seemed to be missing.
The log files in the app are completely separate from the log files in the drone. The log files on the phone/tablet are created by the app from data transmitted from the drone but are supposed to contain a lot less information than the actual logs recorded in the drone itself. In my case, just like you, the log files on the phone were all there for all flights.

I guess that means mine's not the only case of this happening then...

I took my drone out for another flight today. Once again, no disconnections with the iPad. I'll get back to that.

I plugged in my phone (OnePlus 3) to see how that acted now, and it immediately disconnected after take off. The RC's display acted as before, not showing any sort of error but instead just the last received data, and I required a manual restart of the RC in order to reconnect. All this time the drone was trying to land itself despite the RC being adamant it was still connected and in the air. Pressing the power button still changed the display as normal, so it's not 'frozen' in that sense, it just seems to be stuck in the idea that it's still connected to the drone with no problem.

Also, not on my phone but only on the iPad, I'm getting an ultrasound module error now immediately after every takeoff (although the clearance data is still showing up fine on the RC). This whole thing is unbelievable and I'm close to tears at this stage.
1) Logs aren't being recorded, some get wiped randomly, some reappear randomly
2) OnePlus 3 being connected as display appears to either cause logs not to be recorded, or perhaps even more seriously break the RC's connection and prevent it from reconnecting due to the apparent hang
3) Apparently my ultrasound module is broke now, and that will require a second shipment back to the Netherlands and several more weeks of waiting, despite the fact I'm paying for DJI Care Refresh as this goes on.

This has been an unbelievable upsetting experience so far.
2018-1-14
Use props
cohaolain
lvl.1

Ireland
Offline

Also I should note that on my first warranty repair I was also shipped a replacement RC, which is experiencing the same problems with my OnePlus 3 as the first RC. The phone should definitely not be able to break the connection between RC and drone, or hang the controller as it has several times!!
2018-1-14
Use props
cohaolain
lvl.1

Ireland
Offline

Apparently the drone recorded the log for the RC hang/disconnect this morning. Also, apparently the ultrasonic module stopped working last night directly after the FW update to v01.04.0200

Sorry I'm writing so many posts here, but this has been a really upsetting experience for me. My investment into this drone was very significant since I'm a student, and so far all I've really gotten is stress... I'd really like to get to the bottom of all this as soon as possible, maybe help fix some bugs or whatever, and start enjoying the drone like I've experienced it at its best.
2018-1-14
Use props
DJI Elektra
DJI team
Hong Kong
Offline

cohaolain Posted at 2018-1-14 03:38
Thanks, I just sent you a PM

Thanks for your quick response. If there is any news, we would update here.
2018-1-18
Use props
djiuser_larry
lvl.3
Flight distance : 70200 ft
United States
Offline

I see more or less what you see on the DJI Assistant flight data page. The DAT''s near the bottom are 300MB files and contain 'real' looking flight information.  (I think the flight file sizes max out at 300MB and a longer flight will have more than one of these files associated with it.) Files for the newer flights are much smaller and don't show anything that looks like a real flight.

Whether the drone is actually storing flight information I don't know, but the retrieval part of the DJI Assistant program is FUBAR. I'm just not worrying about it at this time. It's DJI's problem whether they can retrieve information if I crash. The logs that are recorded to the GO4 app are good enough for me.

As far as GO4 app disconnects I've seen those, especially with my older tablet and on hot days, but I don't think I have seen the RC itself disconnect (just the app). I'm still not flying the MP too far away where I can't see what it is doing.

My DJI Assistant is the Mac version and was the latest version at the end of the year. I did not do any upgrades after that prior to my January vacation but now maybe I'll test out the new firmwares.
2018-1-23
Use props
DroneFlying
Captain
Flight distance : 10774613 ft
United States
Offline

djiuser_larry Posted at 2018-1-23 22:37
I see more or less what you see on the DJI Assistant flight data page. The DAT''s near the bottom are 300MB files and contain 'real' looking flight information.  (I think the flight file sizes max out at 300MB and a longer flight will have more than one of these files associated with it.) Files for the newer flights are much smaller and don't show anything that looks like a real flight.

Whether the drone is actually storing flight information I don't know, but the retrieval part of the DJI Assistant program is FUBAR. I'm just not worrying about it at this time. It's DJI's problem whether they can retrieve information if I crash. The logs that are recorded to the GO4 app are good enough for me.

I think the flight file sizes max out at 300MB and a longer flight will have more than one of these files associated with it

No, they don't; I've analyzed DAT files well over 1GB many times. In fact, I've never really paid much attention, but I believe it's more the norm than an exception for them to be over a gigabyte.

Files for the newer flights are much smaller and don't show anything that looks like a real flight.

Yes, unfortunately that's what other people on recent firmware versions are seeing.

Whether the drone is actually storing flight information I don't know, but the retrieval part of the DJI Assistant program is FUBAR.

It appears  that the problem lies in the firmware, though I'm not sure whether the files aren't being created or if they're created but somehow just aren't accessible through Assistant.
2018-1-24
Use props
JensIR
lvl.4
Flight distance : 207631 ft
  • >>>
Offline

For what it is worth: I updated the Mavic firmware to the latest version yesterday, but the situation is still the same: No real flight data available in the DJI Assistant.
So how long is it going to take to fix this quite basic issue?
2018-1-24
Use props
Jimmy GB
lvl.1
Flight distance : 1362949 ft
United Kingdom
Offline

I have this issue of missing logs as well, there are 10 on the internal card from 4 months ago, but 50+ missing since then. A small log seems to be created when I boot up the Mavic when it's connected to the PC, but not in normal flight conditions. Did anyone overcome this problem? Latest firmware etc all up to date.
2018-5-29
Use props
DeuceDriv3r
First Officer
Flight distance : 4698533 ft
United States
Offline

Jimmy GB Posted at 5-29 04:46
I have this issue of missing logs as well, there are 10 on the internal card from 4 months ago, but 50+ missing since then. A small log seems to be created when I boot up the Mavic when it's connected to the PC, but not in normal flight conditions. Did anyone overcome this problem? Latest firmware etc all up to date.

does this have a resolution yet..

I am on a mavic pro and both .4..0100 and .04.0300 firmwares .. I was getting logging until a point then it stopped..

I had another atti moment today and can't retrieve the log? very strange.. almost like it fills the storage but then instead of getting rid of old .dat files and continuing . .. it has stopped logging new flights?
2018-11-21
Use props
BMGD
lvl.1
Flight distance : 255814 ft
South Africa
Offline

DeuceDriv3r Posted at 11-21 11:33
does this have a resolution yet..

I am on a mavic pro and both .4..0100 and .04.0300 firmwares .. I was getting logging until a point then it stopped..

Also have missing .dat logs, and the dates of those there are all either 2018-01-01 or 2018-12-05?
2018-12-7
Use props
Advanced
You need to log in before you can reply Login | Register now

Credit Rules