Functionalities¶
| No. | Device | Description | Up from CPU firmware | Functionality |
|---|---|---|---|---|
| 1 | RAMdisk | System RAM disk. Only For internal firmware use! |
V2.0.2 | Load / save boot project Firmware update Internal system files |
| V2.1.3 | Files via FTP server (e. g. firmware update) | |||
| 2 | Userdisk | User RAM disk | V2.0.2 | WEB visu files and JAVA applet for WEB server Symbol file for OPC server and CP600 panels |
| V2.1.3 | JAVA script files for WEB server User data via CAA_File_xxx.lib CAA_File_Library: CAA_File Library Contents Files via FTP server |
|||
| 3 | SRAMdisk | Battery buffered RAM disk | V2.1.3 | User data via CAA_File_xxx.lib CAA_File_Library: CAA_File Library Contents Files via FTP server |
| 4 | Flashdisk | Internal flash disk | V2.1.3 | User data via CAA_File_xxx.lib CAA_File_Library: CAA_File Library Contents Files via FTP server |
| 5 | SD Memory Card (removable) | SD Memory Card (removable) | V2.0.2 | Firmware update Load / save boot project Source code of user project load / save User data via POUs SD_WRITE: SD_WRITE SD_WRITE and SD_READ: SD_READ SD_READ Retain data Persistent data |
| V2.1.3 | User data via CAA_File_xxx.lib CAA_File_Library: CAA_File Library Contents Files via FTP server |
Note
Unlike the PLC’s memory areas like %M or Retain, where 1 Byte actually consumes 1 Byte, all storage device utilize a file system.
That means there is a difference between a files size and its size on the disk.
On disks files are stored in so-called clusters which are a group of disk sectors. “Size on disk” refers to the amount of cluster(s) a file is taking up, while “file size” is an actual byte count of the file data. So you will usually find that the size on disk is larger than the file size. This is not an error, but a result of the disk organization via a file system. Since sector and cluster sizes vary depending on a disk’s size and the used file system, the ratios between the size on disk and the file size also vary between the various storage devices.