jlk wrote:
I removed sd card, then erased data, re-inserted card, didn''t get erasing data screen, put sd card in puter and downloaded last nights data. Seems if you remove sd card before erasing data on S-9 you don't erase sd card. Sorry about your luck on that one, Idamtnboy, but thanks for the heads-up for me. john
I did remove it first. That's what was so consternating. I expected the S9 to read the data off the card and reload it's own memory. That didn't happen! I also found I out I messed up and set the day one day too far. That's why Nov 6 data is missing. Now I had no choice but to erase the data again to reset the clock correctly. I have a back up of each card iteration and just copied them to another SD card so I could make changes and see what Resscan would show.
Since the machine date was wrong I was going to end up with two sets of Nov 7 data. I loaded the first Nov 7 data into Resscan, printed a report, and then deleted the session. Today I loaded last night's data into Resscan, which is dated Nov 7 again. Now I'm all set except that I have no Nov 6 data in Resscan.
I found out you cannot muck with the data on the SD card and then have Resscan read it. I used a hex editor to revise the data in the STR.edf to change the date from Nov 7 to Nov 6. That meant the CRC value was no longer the same even though I only changed two numbers by an increment of 1. Yep, you guessed it. Resscan checks the CRC and would not recognize the data. No way to fool Resscan into accepting data that wasn't generated on the S9. I have no idea what kind of algorithm is used to generate the CRC, and it's probably a state secret at Resmed. Heartening to know that at least one part of our medical info is pretty secure from tampering!