Quantum Instruments DLT 7000 - Manual (Page 112)

SCSI Commands
5-8 Quantum DLT 7000 Tape System
5.1.4 DATA-Phase Command Components
Many of the SCSI commands cause data to be transferred between the initiator
and the drive. The content and characteristics of this data are command-
dependent. Table 5–5 lists the information transmitted for all of the commands.
The "Length in CDB" column of Table 5–5 identifies the Command Descriptor
Block field used by the drive to determine how much command-related data are
to be transferred. The units (bytes or logical blocks) for the different Length
fields are implied by the Length Field Name as follows:
Field Name Units Implied
Allocation Length Bytes of data the drive is allowed to send to the initiator
Parameter List Length Bytes of data the initiator has available for the drive
Transfer Length Logical number of data blocks or data bytes the initiator
wants transferred or verified
Byte Transfer Length Bytes of data the initiator wants transferred
The DATA OUT column in Table 5–5 lists the information passed to the drive
by the initiator as part of the command. The DATA IN column lists the
information sent to the initiator by the drive. Numbers in parentheses after an
item indicate the item’s length in bytes. In some cases, additional length
information is communicated during the DATA phase.