ResScan S/W and S9 - Any computer guys decipher the files?

I have been using my S9 for a couple of weeks now and have been regularly downloading data into ResScan. A couple of things have me curious so thought I would see what the prevailing wisdom of the board is.

When downloading info a message displays that there is duplicate data and asks if you want to ignore it or overwrite the stored data. I am assuming this is because when you download data it doesn't delete it from the card, it just starts overwriting detailed info at some point. Is there a way to remove sleep data without losing the settings info? If you go to settings, you get a warning that all data will be erased, and it does just that- wipes everything off. Pressure settings, reminders, etc. all gone.

If you wipe the SD card after download, then put the card back in the machine it appears the settings (pressure etc) are retained, but what about reminders and such? Anyone played around or know the answer?


My other questions are about the files stored on the SD card...

In the Root Directory are:
A "DATALOG" directory
Two "Identification" files. The .tgt one seems to store machine info such as s/n model etc. Not sure what the .crc files are, they seem to be small in size, possibly some sort of checksum info?
Also "STR" files with .edf and .crc extentions. I am guessing this might be machine setting info?
Final root file is "Journal.dat" I have no idea what it is.

Looking at the data that is stored in the "DATALOG" folder, it appears there are a set of eight files for each sleep session. Anyone have any idea what is in each of the files? Again the .crc extension ones are very small size compared to the other files. The BRP.edf file tends to be the largest of the set, so I am guessing that is where the detailed data is stored. File names appear to be formatted with the date and start time of the session and the following suffixes and file extensions:

..._BRP.crc
..._BRP.edf -BReathing and Pressure info maybe?
..._EVE.crc
..._EVE.edf -EVEnt info maybe? Files seem to be smaller in size the lower my AHI is for a given session
..._PLD.crc
..._PLD.edf -Pressure (flow) Limitation info?
..._SAD.crc
..._SAD.edf -Snore info maybe?


As long as it all works I guess it doesn't really matter, I just like to know how stuff works sometimes. Any insight would be appreciated.

I can offer this tip.

When it offers the choice of overwrite or discard during download, always select discard.

It only stores detailed data for the previous 7 days on the card, overwrite will cause it
to replace the detailed sessions with the smaller summary data only.

WilsonVilleUSA, if you search for the many past threads/posts regarding the S9 "flow skew bug" you'll find some information regarding the SD card files that may be of interest to you. There's some info starting about here and continuing on subsequent pages: viewtopic.php?f=1&t=50578&p=472061#p472061.

Wilsonville,
You're correct about the content of the four files compiled during a sleep session. You can actually view the information in these files by opening them in a hex editor. The crc files as you suspected are checksum files. It appears that the ResMed programmers wrote their own 32-bit CRC generation code as their CRC files don't match any of the standard 32-bit generators as far as I can tell. So, while you can view and even change the data in a hex editor, any changes to the files wouldn't be accepted without a corresponding crc file.
Ken

kurth83 wrote:I can offer this tip.

When it offers the choice of overwrite or discard during download, always select discard.

It only stores detailed data for the previous 7 days on the card, overwrite will cause it
to replace the detailed sessions with the smaller summary data only.

With all respect, are you sure about the discard vs overwrite thing? I always select overwrite and my detail going back to day 1 is still there. I always assumed that it had to do with sleeping past the noon cut off of the machine (I go to bed late sometimes) and then starting a second sleep cycle during the same recording session. So, I get up at 1:00 PM pop the SD into my laptop, get an hours worth of data then go to bed at 5:00 AM. The next time I put the SD in the laptop, it will have an hours worth of data from the previous sleep session on the laptop plus more from sleep session 2. Re-reading this confused the heck out of me but but, I figured the software was asking me if I wanted to discard the previous data from the same day. I could definitely be wrong.

I always click on overwrite and all of my data, since day one,is stored in ResScan on my laptop. So, is this not the correct thing to do?