Siemens SIMATIC Box PC 840 Manual page 89

"Type" Field
The parameters you can select here are usually stored on the IDE drive. The 'Auto'
setting in the 'Type' field means that these values are automatically read from the
drive and written into memory (Autodetect).
If Type is selected for a drive that cannot be detected, a timer times out in
approximately 1 minute and the entries remain unchanged. You should always
check that the interfaces for which you select 'Auto' are in fact connected to drives.
Select "User" if you want to define the hard-disk type yourself, in which case
remember that you also have to set the other fields, including Cylinder, Heads,
Sectors/Track or other settings according to the type of hard disk.
"Multi Sector-Transfer" Field
The entry in the Multi-Sector Transfer field defines the number of sectors
transferred per interrupt. The value depends on the drive and should be set only by
setting the Type field to Auto.
Disabled
2,4,8,16
"LBA Mode Control" Field
If the LBA Mode Control field (enabled,disabled) is set to 'Enabled', the system
supports hard disks with capacities greater than 528 Mbytes. The value depends
on the drive and should be set only by setting the Type field to Auto.
"32 Bit-IO" Field
The setting in the 32 Bit I/O field defines the mode of access for the drive
"Transfer Mode" and "Ultra DMA Mode" Fields
The settings in these fields define the interface data-transfer rate. The value
depends on the drive and should be set only by setting the Type field to Auto.
Hit ESC to exit the submenu.
SIMATIC Box PC 840 Manual
A5E00085984-04
sectors
Disabled 16-Bit access
Enabled 32-Bit access
Configuring the SIMATIC Box PC 840
(default)
5-7