I use the Portable PowerFLARM as my IGC flight recorder. Yesterday I
ran into a glitch: It created two files. The second one repeats the
last couple of minutes of the same flight (landing pattern), which also
appears in the first file. For that part of the flight, the two logs
superimposed (in SeeYou) are almost but not quite the same, looks like
the recording interval differs.

Perhaps I didn't give the FLARM enough time to decide it was a landing?
Right after landing I told it to do an "IGC readout". After that was
done, transferred the file to Tophat. Then the FLARM still said
"maintenance mode", I hit its button, and it told me it was doing a bit
more "IGC readout", maybe that's when it wrote the second file? I saw
the two files when I looked at the SD card plucked from the FLARM, it
was not shown by Tophat.

Perhaps this hints at a "prerecording" feature within the FLARM, i.e.,
when I got out of maintenance mode it thought it was starting a new
flight log, wrote the last few minutes' data into the new log, then
decided I've landed and closed that second file.

On 25/07/2021 16:06, Moshe Braner wrote:
> I use the Portable PowerFLARM as my IGC flight recorder.  Yesterday I
> ran into a glitch:  It created two files.  The second one repeats the
> last couple of minutes of the same flight (landing pattern), which also
> appears in the first file.  For that part of the flight, the two logs
> superimposed (in SeeYou) are almost but not quite the same, looks like
> the recording interval differs.
>
> Perhaps I didn't give the FLARM enough time to decide it was a landing?
> Right after landing I told it to do an "IGC readout".  After that was
> done, transferred the file to Tophat.  Then the FLARM still said
> "maintenance mode", I hit its button, and it told me it was doing a bit
> more "IGC readout", maybe that's when it wrote the second file?  I saw
> the two files when I looked at the SD card plucked from the FLARM, it
> was not shown by Tophat.
>
> Perhaps this hints at a "prerecording" feature within the FLARM, i.e.,
> when I got out of maintenance mode it thought it was starting a new
> flight log, wrote the last few minutes' data into the new log, then
> decided I've landed and closed that second file.

A Flight normally ends 5 minutes after movement has ceased, subject to
conditions defined in the specification:

3.7 End of an IGC file. The IGC file must not be ended until one of the
following conditions apply:
(1) if no horizontalor vertical movement has been detected for at least
5 minutes with no change of exact position (thresholds as in 3.5 above)
to allow for being static for a short time in ridge or wave lift;
(2) after the recorder is switched off by deliberate action,
(3)if power is lost in flight for more than one minute (the minute is to
allow for battery change-over in flight or other short-term power loss).
Also, for FRs with displays, when power is re-established, the previous
display mode shall continue, or;
(4) if the recorder is still powered after the flight, when the user
establishes a connection for downloading from the recorder.

On 7/25/2021 12:27 PM, Tim Newport-Peace wrote:
"A Flight normally ends ..., or;
(4) if the recorder is still powered after the flight, when the user
establishes a connection for downloading from the recorder."

- but I did do that point (4), and got a complete flight log that way.
It's just that afterwards it created a second file, pre-recording the
last couple of minutes of the flight that's already had a log finalized.

> "A Flight normally ends ..., or;
> (4) if the recorder is still powered after the flight, when the user
> establishes a connection for downloading from the recorder."

I have to allow for a post-flight wait period with my PowerMouse / Oudie2 combination for flight download. A minute or so after I land, the Oudie has a 'flight will finish' message. Below that message is a choice to 'end flight now'. If I choose to 'end flight now', the Oudie downloads an earlier flight from the PM vs the current one. Instead, if I wait ~10min for the Oudie to automatically begin the download process, the current flight will be captured. I assume the PM takes some amount of time to close/release the current flight file for download and needs the extra time (maybe the 5min rule?). It's a bit of PIA for me. I roll out near my tie down spot and have to patiently wait before post-flighting the cockpit for the Oudie wait and download process to complete. A few times, I haven't paid attention, killed the master and yanked the battery before it completed.
JJ