Flashdisk

Some AC500 CPUs (e.g. PM592-ETH, PM595) are equipped with an non-removable and non-volatile flashdisk. It contains no moving parts. The flashdisk is designed for operation in industrial environments and applications. A wear levelling algorithm and a power-fail protected file system provide industrial robustness. To write on the flashdisk the CAA_File_Library: CAA_File Library Contents is required.

Attention

:strong:The flashdisk has a finite number \ of write cycles.

A warning will be generated when the flashdisk reaches 80 % of its max. number of write cycles. The flashdisk will be set into read-only mode to avoid data loss, when the max. number of write cycles is reached.

Important hints to PLC programmers:

• Programmer should keep the amount of cyclic written data low to assure long availability.
• To increase the number of write cycles, the programmer could choose to use only 90 %, 75 % or even 50 % of the flashdisk capacity. The disk space left free will automatically be used by the wear levelling algorithm.
• The wear levelling information of the flashdisk can be read from the PLC browser with the command diskcfg settings flashdisk. In applications with high data generating processes (typical more then 1,5 GByte/day) this information should be monitored during implementation.