I'm using a CR1000 and changed the program and would like to know whether we can get the data from the other program I was using.
Refer to section 10.12 of the CR1000 manual. There is a chance you could recover some lost data.
If the CR1000 has a recent OS, you may use the data recovery wizard in DevConfig.
On older OS versions, you would have to use terminal commands.
so when i get a warning before programming a logger, can i still recover in the logger, the deleted data?
The warning provides a chance to abort changing the program, so you can collect data first.
If the warning was ignored, the data recovery wizard might be able to recover some of the old data.