Avidyne IFD540 Pilot's Manual page 209

fob. The second option ("Since Last") downloads the data logged
since the last time a download was completed. Since the logs
contain a large amount of data, the second option will be a
quicker option in almost every case.
Download times are highly dependent on the number and types
of logs being downloaded and the length of time since the last
download. Times can range from a few seconds to more than 15
minutes. The more often logs are downloaded, the shorter the
download times will be.
In order to provide an indication of download progress, a progress
bar will be presented with both a symbolic aircraft indicating
download in progress and a % complete estimate. The files to be
downloaded can have one of several states – "OK", "In
progress...", "Pending", "Skipped", "Active", "Failed".
When downloaded to the USB fob, the data logs will be saved in
.csv files. This can be imported into newer versions of Microsoft
Excel in a table format. The data can then be plotted or analyzed
by several third-party tools. Note that files can easily contain
50MB or more of data.
Data included in the files are as follows:
System Log
Date/Time stamp
Power On
OAT, if available
Localizer deviation
Glideslope deviation
Ground speed
Ground track
Crosstrack deviation
Vertical deviation
Display mode
Nav mode
GPS parameters
Magnetic Variation
6-33 General
GPSS state
OBS value
Desired track
Nav frequency
Course select value, if known
Nav type
VOR course
GPS altitude
Distance to active waypoint
FMS course
Active waypoint information
FLTA Status