Userdisk

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

Name	Userdisk
Description	User RAMdisk
Size	Product specific, see table Memory Sizes Introduction AC500 Storage Devices
IEC access	CAA_File_Library: CAA_File Library Contents
FTP access	FTP user = “userdisk”
Diagnosis device number	17

Additional hint for the size of the Userdisk:

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)), i.e. the actual size of the storage device “Userdisk” 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 CoDeSys dialog File Sizes. This additional space is reserved for the web visualization’s overhead.

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

To get a summary of the various data which will be downloaded into the Userdisk, click the … button in the dialog’s Used line.

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.