Power down to remove SD card on S9?

jhensley wrote:The reason I'm concerned is when I remove a SD (or CF) camera card thats connected to a computer without unmounting it, I always get an error message that says something to the effect that the disk was not ejected properly and data corruption could result.

You'll only get corruption if the system is writing to the card when you pull it out. Because the only writing you're going to do at your computer is to reformat the card, you probably don't need to bother to eject it.

Any thoughts on when the S9 writes to the SD card and how long it writes after completing treatment.

I believe it writes to the card more or less continuously during therapy, doubt it takes more than a few seconds to finish up after you hit stop. Unless you grab the card immediately after stopping the blower, I don't think you're likely to have a problem.

Pushing the card in to release it could alert the system that the card is about to come out, but I'm not sure that it does.

jhensley wrote:Thanks for all the input. Good information. It appears that different ResMed publications contradict each other.

The reason I'm concerned is when I remove a SD (or CF) camera card thats connected to a computer without unmounting it, I always get an error message that says something to the effect that the disk was not ejected properly and data corruption could result.

Any thoughts on when the S9 writes to the SD card and how long it writes after completing treatment.

I almost never turn off the S9 Autoset before removing/inserting the card. It does not complain one iota.

Based on my studies of S9 data, and other comment here in the past, I'm confident that all data writing is completed within seconds, and at most 1 minute, after hitting the stop button. Data is written to the card in full one minute increments. All four data files may or may not start at the same time, and in fact usually don't. If you hit the stop button 6 hrs, 14 min, 23 seconds after the data file was started, the last 23 seconds of data is never written to the card. Because of the different start times, which I have observed can be more than 30 seconds, you can have the situation where an apnea occurs during the last partial minute of flow and does not show up in the flow graph, but will be noted in the event file. You will see it in the Rescan event graph but not in the flow graph.

From back in the days of the S8s as I remember it we were always told (in the manual or not???) to wait at least 15 minutes after turning our PAP off before removing the card to check the data. I do remember checking the data via the LCD screen right after turning my Elite off and having a slight difference between that data and the data from a download 15 minutes later. (Arrgghh, how soon we forget!)

In terms of flash memory technology, there's no reason the machine should take more than a second to write data to the card. While the computer people sometimes refer to flash memory as "slow," that's in comparison to stuff that's really really fast.

My card has a couple of months data on it and only has 2 MB of data on it. Even the slowest SD cards can do 2 MB in one second.

Flash memory devices have a limited number of write cycles. If you write the data to the same memory location too often, the memory will eventually keep working. Because of this, some devices attempt to limit the number of times they write to memory.

It's possible that some of the manufacturers decided they're not going to write the data to the memory card unless the machine has been off for several minutes, so that they don't add a cycle every time you get up to take a bathroom break. I do NOT know that they do this, but it's possible.

archangle wrote:In terms of flash memory technology, there's no reason the machine should take more than a second to write data to the card. While the computer people sometimes refer to flash memory as "slow," that's in comparison to stuff that's really really fast.

My card has a couple of months data on it and only has 2 MB of data on it. Even the slowest SD cards can do 2 MB in one second.

Flash memory devices have a limited number of write cycles. If you write the data to the same memory location too often, the memory will eventually keep working. Because of this, some devices attempt to limit the number of times they write to memory.

It's possible that some of the manufacturers decided they're not going to write the data to the memory card unless the machine has been off for several minutes, so that they don't add a cycle every time you get up to take a bathroom break. I do NOT know that they do this, but it's possible.

From my observation the speed at which the card can be written has nothing to do with when the card is written. It's all in the S9 read/write algorithm which seems to be a little bit flaky to me.

Hi guys.

Is there a setting on the resmed machine to tell it to actually record events? I pulled the sd card from it, plugged it in and looked at the files. There are two directories (Datalog and Settings), but Datalog is empty. Whats up with that?
Thanks in advance.
Chris.

chohenwald wrote:Hi guys.

Is there a setting on the resmed machine to tell it to actually record events? I pulled the sd card from it, plugged it in and looked at the files. There are two directories (Datalog and Settings), but Datalog is empty. Whats up with that?
Thanks in advance.
Chris.

Sleep Quality in the clinical setup menu needs to be set to "On".
The Default from the factory is Usage...which is hours of use only.
Sleep Quality must be set to ON to get any further detailed data...how much data depends on the model.
The Escape has nothing but hours of use. The Escape Auto adds a very limited AHI to the hours of use.
Full efficacy data only by the Elite, AutoSet and VPAPs..