User's Manual

DLT4000 SCSI Interface
8-50 DLT4000/DLT4500/DLT4700 Cartridge Tape Subsystem
8.4.9.2 MODE SELECT Pages
Following the Block Descriptor are the MODE SELECT pages, which set the device
parameters. Each page has a 2-byte header which identifies the page code and
indicates the number of bytes in that page.
The supported Page Codes are as follows:
Page Code Description Sense/Select
01h Error Recovery Page Both
02h Disconnect/Reconnect Both
0Ah Control Mode Page Both
0Fh Data Compression Page Both
10h Device Configuration Both
11h Medium Partition Both
3Eh EEPROM Parameter Both
Figure 8-31 MODE SELECT Pages Supported
PS Bit
For the MODE SELECT command this bit is reserved. For the MODE SENSE
command, a Parameters Savable (PS) bit of one indicates that the page can be saved in
nonvolatile memory by the drive. If the PS bit is zero, the supported parameters cannot
be saved. (Savable pages are not supported.)
Additional Page Length
This indicates the number of bytes in that page. However, the value does not include
bytes 0 and 1. The length is returned on MODE SENSE and must subsequently be set
to the same value when performing MODE SELECT. If the page length does not
match that expected by the drive, a CHECK CONDITION status is returned with the
sense key set to ILLEGAL REQUEST.
The drive also returns a CHECK CONDITION status with an ILLEGAL REQUEST
sense key if the host sends an unsupported Page Code, or a Page field with values not
supported or changeable. In this case, no parameters will be changed by the command.