uploading from PM590
i came to know that we cannot upload the program backup from PM590 that doesnt have a SD card
Why is that?
where is the program stored in the PLC that doesnt have SD card. and how is it possible that if a powe failure occurs the program stays in there.
in PLC's of other brands you can easily upload the program without the fact that the PLC has SD card installed or not. the program is in the internal memory of the PLC and it stays there...
so what is the phenomena of this PLC where does it stores the program?