Sleepyhead with backup machine

[on the virge]

I just purchased a backup APAP PRS One 550 which I plan to use on trips, as well as backup. I use Sleepyhead. When I use my backup machine do I: 1) take my data card out of my primary machine (PRS One 560) and put it in the backup or 2) use the data card already in the backup?
My wife also has a PRS One 560. Can she also use the data card in the backup or do we need to keep separate data cards for the backup?

[PaulaO2]

I'd use a second card. Every time you put it in the backup machine, the second machine is going to re-write the card. You'll lose everything on it. Then when you put it back in your usual one, it will get re-written again. All that re-writing may or may not shorten the life of the card.

When you input the data into SH, just use the same profile. It will sort out the machine for you. You can test it first and create a test profile. Download data from one card, then the other, and see what happens. Then just delete that test profile (and its data) then do it for real.