Optical Drive and Library SCSI-2 Command Reference

SCSI-2 Drive Command Set
Inquiry Command (12H)
Chapter 22-26
Inquiry Command (12H)
This command sends controller and drive information to the initiator.
EVPD (8X and 14X only). An enable vital product data bit of
1 specifies that the drive shall return the optional vital
product data specified by the page code field. An enable
vital product data bit of 0 specifies that the drive shall
return the standard INQUIRY data.
Page Code The page code field specifies which page of vital product
data information the drive shall return (Table 2-21).
Allocation
Length This field specifies the number of bytes that the
initiator has allocated for the return data. An Allocation
Length of 0 is not an error and indicates that no data
will be returned. The initiator will terminate the data in
phase when all available inquiry data has been
returned or when allocation length bytes have been
returned, whichever is less.
If an inquiry command is received from an initiator with
a pending UNIT ATTENTION (before the drive reports
CHECK CONDITION status), the drive performs the
INQUIRY command and does not clear the UNIT
ATTENTION condition.
Table 2-20 Inquiry Command CDB
Byte 7 6 5 4 3 2 1 0
0 Operation Code (12H)
1 Logical Unit
Number (0)
Reserved (0) EVPD
2 VPD Identifier
3 Reserved (0)
4 Allocation Length
5 Reserved (0) Flag Link