User Disk

The User disk is a volatile storage device located in the SDRAM. It can be used for any application purpose. If activated, the PLC’s web visualization is saved in the User Disk’s subdirectory WEBVISU. If configured, the symbol file is also stored in the User disk.

Size Product specific, see table Memory Sizes Introduction of AC500 Storage Devices for AC500 Products
IEC access CAA_File_Library: CAA_File Library
Diagnosis device number 17

Additional hint for the size of the User disk:

The web visualization’s size is the sum of the user’s visualization data plus the web visualization overhead (e.g. some Java applets (.jar files)). This means, the actual size of the User disk may differ from the offical documented size.

This difference can be recognized by comparing the sizes of the PLC browser command fdir userdisk and the information in the dialog File Sizes. This additional space is reserved for the web visualization’s overhead.

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To get detailed information on your web visualization files, click … in the File Sizes dialog.

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To get a summary of the various data which will be downloaded into the User disk, click … in line Used of the File Sizes dialog.

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Thus, the number in line Used of the File Sizes dialog, means “total sum of the web visualization in Bytes” and the number in line Maximum means “Maximum allowed user data for web visualization”. So, it is possible that Used becomes bigger than Maximum.