FUJITSU C150-E049-02EN - Manual (Page 60)

M3099GX/GH OEM Manual 3-27
INTERFACE
Commands (See
ANSI SCSI-2 7) A command is communicated by sending a command descriptor
block to the target. For several commands, the command descriptor
block is accompanied by a list of parameters sent during the DATA
OUT phase. The command descriptor block always has an operation
code as its first byte and a control byte as its last byte.
Reserved (See ANSI SCSI-2 7.1.1)
Reserved bits, fields, bytes, and code values are set aside for future
standardization. Their use and interpretation may be specified by
future extensions to ANSI SCSI standard. A reserved bit, field, or
byte shall be set to zero, or in accordance with a future extension to
this standard. A target that receives a reserved bit, field, or byte that
is not zero or receives a reserved code value shall terminate the
command with CHECK CONDITION status and the sense key
shall be set to ILLEGAL REQUEST.
Logical Unit Number
The logical unit number is defined in the IDENTIFY message. The
target shall ignore the logical unit number specified within the
command descriptor block if an IDENTIFY message was received.
This scanner supports Logical Unit Number 000b only. Followings
shows target’s response to selection of invalid logical unit.
• In response to an INQUIRY command, the target shall return the
INQUIRY data with the peripheral qualifier set to the value
required.
• In response to any other command except REQUEST SENSE, the
target shall terminate the command with CHECK CONDITION
status.
• In response to an REQUEST SENSE command, the target shall
return sense data. The sense key shall be set to ILLEGAL
REQUEST and the additional sense code shall be set to
LOGICAL UNIT NOT SUPPORTED.
#03.pm5 98.2.22, 1:31 PM 27