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Chapter 4 SCSI Commands
MODE SENSE (6) / (10) Command (1Ah / 5Ah)
DLT-S4 Interface Reference Guide
161
Table 90
MODE SENSE
Data
Header — Field Descriptions
Field
Description
Mode Data Length Specifies the length in bytes of the
MODE SENSE
data that is available to be
transferred.
Note that the Mode Data Length does not include its own length.
Medium Type
The drive checks the media type, which can be one of the following:
Type
Description
00h
Unknown or not present
81h
Cleaning tape
86h
Super DLTtape I
1
87h
Super DLTtape II
1
, Super DLTtape II WORM
1
91h
DLTtape S4, DLTtape S4 WORM
WP
Write Protect. When set to 0, indicates that the tape is write-enabled. When set to 1,
indicates that the tape is write-protected.
Buffered Mode
When set to 0, the drive does not report a
GOOD
status on
WRITE
commands until it
actually writes the data blocks to tape.
When set to 1, the drive reports
GOOD
status on
WRITE
commands as soon as the
data block has been transferred to the buffer. This is the default configuration of the
drive. Note that if Buffered Mode is not used, the drive suffers a degradation of
performance and capacity.
Speed
Always set to 0, indicating the default speed.
Block Descriptor
Length
Specifies the length in bytes of all of the block descriptors. If the DBD bit in the CDB
is set to 0, this value is 8, indicating one Block Descriptor was sent. If the DBD bit in
the CDB is set to 1, this value is 0, indicating no Block Descriptors were sent.
1.
When these cartridges are mounted in the drive, the
MODE SENSE
information reports the Media Type and the
correct Density Code as detected on the tape and sets the Write Protect (WP) bit in the
MODE SENSE
header to
1. Any command that attempts to write to the medium (WRITE, WRITE FILEMARKS, ERASE) returns
CHECK
CONDITION
status with Sense Key set to
DATA PROTECT
(7) and the Additional Sense Code or Additional
Sense Code Qualifier set to
CANNOT WRITE MEDIUM - INCOMPATIBLE FORMAT
(30h/05h). The drive does
not update the medium.