Is it possible to upload and download in PM571??
It is possible to upload and download code to any AC500 series controller with an SD card. But you cannot upload and recreate the controller source code from the CPU or flash memory.
The SD card stores the application source code - and for long term storage is probably the best way to make sure that the end user does not accidentally lose the source code. Allways remember to manually update the Application in the SD card before you leave site. You can also remove the SD card from the PLC and plug it into the engineering PC to do this.
The AC500 controller memory (ie the boot project) is compiled code, and hence cannot be translated back into application source code.