Overview

AC500 PLCs offer a variety of storage devices. The following table gives a short overview and a description on these storage devices:

Note

IEC access means that the storage device can be accessed by Function Blocks of an IEC program.

FTP access means that the device can be accessed via FTP server on the PLC (if available).

Component	Description	IEC Access	FTP Access	CPUs (AC500 V2)
RAM disk	System RAM disk Volatile storage device placed in the SDRAM Used by the firmware during its operation For internal firmware use only!	No	Yes FTP user = “ramdisk”	All
User disk	User RAM disk Volatile storage device placed in the SDRAM Can be used for any application purpose	Yes	Yes FTP user = “userdisk”	All
SRAM disk	Battery-buffered, non-volatile RAM disk placed in the SRAM Can be used for any application purpose	Yes	Yes FTP user = “sramdisk”	All Processor Modules for AC500 (Standard) V2 Device List: Device List: Processor Modules (CPUs)
Internal Flash	PLCs persistent memory Used for storing firmware, user application and user data	Yes	No	All
Flash disk	Internal persistent mass storage device Can be used for any application purpose	Yes	Yes FTP user = “flashdisk”	PM592-ETH PM595-4ETH
sdcard	SD memory card (removable) Removable persistent mass storage device Can be used for any application purpose	Yes	Yes FTP user = “sdcard”	All Processor Modules with SD memory card slot Device List: Device List: Processor Modules (CPUs)