If I want to upgrade the firmware on a CF card of CU320-2, is it enough to delete the content when opening it in windows explorerer (card in card reader to pc)?
Or is it better to als format the card? If so what format procedure do I use (FAT,FAT16,FAT32)?
What in the case of upgrading firmware on CF card of Simotion D (fi. D425-2)?

I read the text underneath in the D4X5-2 hardware and installation manual :

8.5.3 Formatting the CompactFlash card
You can format a faulty CF card, for example.
Before formatting the CF card, please observe the notes in Section Backup of the
CompactFlash card data (Page 353).
The procedure for formatting the CF card is as follows:
1. Insert the CF card into a CF card adapter connected to your PG/PC.
2. Format the CF card in Windows (FAT, FAT16 or FAT32 file system).
3. If the boot sector of the CF card is also defective, you will have to rewrite the boot loader.

Note
The CF card may not formatted with NTFS.
The following formats are permitted:
● For D410-2/D4x5-2: FAT, FAT16 and FAT32
● For D410/D4x5: FAT and FAT16

Because of the improved memory utilization on the CF card, FAT32 formatting is
preferable for the D410-2 and D4x5-2. As of Kernel/firmware V4.3, D410-2 and D4x5-2
CF cards supplied as standard with FAT32 formatting.FAT32 requires at least the boot loader version V3.02.

I have following questions :

1. Is it so that formatting the card on itself does not destroy the boot loader?
2. It is advised as you said not to format the card, but only delete it (with no hidden files visible).
   If I do format the card, are there direct (negative) consequences for the card, or long term consequences?
3. What diagnostics (fi led display) indicate that I should fprmat the card, rewrite the boot loader?