Chapter 4 SCSI Commands
WRITE Command (0Ah)
DLT-S4 Interface Reference Guide
336
Table 190
WRITE
Command
Data
—
Field Descriptions
Exception Conditions
4
If the drive detects End of Tape (EOT) while writing, it finishes writing
any buffered data. The command terminates with
CHECK CONDITION
status. Within the Sense Data, the EOM field is set, the Sense Key is set to
NO SENSE
, and the Additional Sense Code and Additional Sense Code
Qualifier fields are set to
EOM / P DETECTED
. The drive attempts to
complete any subsequent writes, returning a
CHECK CONDITION
status in
each case.
If the drive encounters the physical EOM when attempting a
WRITE
, it
returns a
CHECK CONDITION
status. Within the Sense Data, the EOM and
Valid fields are set, and the Sense Key field is set to
VOLUME OVERFLOW
.
The Information fields contain the residue count and the Additional
Sense Code and Additional Sense Code Qualifier fields are set to
EOM / P
DETECTED
. The drive physically positions the tape at
EOM / P.
Field
Description
Fixed
Sets both the meaning of the Transfer Length field.
When set to 0, a single block is transferred from the initiator and is written to the
drive beginning at the current logical tape position. Upon successful termination, the
drive logically positions the tape after this block on the EOM / EOP side. The
Transfer Length specifies the length of block in bytes.
When set to 1, the Transfer Length field specifies the number of blocks to be
transferred to the drive and written to the medium beginning at the current tape
position. This form of WRITE is valid only if the drive is currently operating in fixed-
block mode, as indicated by the Block Size field in the Mode Parameter Block
Descriptor (see
Mode Parameter Block Descriptor
on page 104). The current block
length is the block length defined in the
MODE SELECT
command. Upon termination,
the drive logically positions the tape after these blocks.
Transfer Length
Contains the length of the data transfer in bytes or blocks depending on whether
fixed- or variable-block mode is selected.
When set to 0, no data is transferred and the current position on the drive is not
changed.