HP C2488A Technical Reference Manual page 67

Inquiry
Inquiry
The INQUIRY command requests that information regarding parameters of the Target be sent
to the Initiator.
The INQUIRY command will return a CHECK CONDITION status only when the Target
cannot return the requested Inquiry data. Inquiry data will be returned even though the
peripheral device may not be ready for other commands. The INQUIRY command will
execute even if the drive is reserved to another Initiator.
If an INQUIRY command is received from an Initiator with a pending UNIT ATTENTION
condition (before the Target reports CHECK CONDITION status), the Target will execute
the INQUIRY command and will not clear the UNIT ATTENTION condition.
Note
9
Byte
00
An INQUIRY command directed to an invalid LUN (
=I
0) will return a
Peripheral Device Type of 7FH (Logical Unit Not Present) in byte 0 of the
parameter list. This condition is not considered an error. The INQUIRY
command will be executed with no error reported even if the Target is
reserved by Ito a different Initiator.
Inquiry Command DeSCriptor Block (COB)
Bit
7
I
6
I
5
I
4
I
3
I
2
I
1
I
0
Opcode
=
12H
01 LUN (Logical Unit Nwnber)
I
Reserved
I
EVPD
02 VPD Page Code
03 Reserved
04 Allocation Length
05 Control Byte
EVPD (Enable Vital Product Data) and VPD Identifier. The status of the EVPD bit and the
VPD Identifier field determine the information to be returned to the Initiator. The supported
combinations are:
EVPD
bit
o
1
1
1
VPD
Page Code
OOH
OOH
SOH
EOH
Target Will Return:
Standard Inquiry Parameter Page
Supported VPD Page List
Unit Serial Number VPD Page
Manufacturing Information VPD Page
If EVPD is set to 0 (zero), and the VPD Page Code is set to 1 (one), the Target will return:
Status: CHECK CONDITION
Sense Key: ILLEGAL REQUEST
Additional Sense Code: INVALID FIELD IN CDB.
Allocation Length. This field specifies the number of bytes that the Initiator has allocated for
returned Inquiry data. An Allocation Length of zero indicates that no INQUIRY data will be
transferred. This condition will not be considered as an error. Any other value indicates the
DRAFT SCSI Command Descriptions A·11
1/18/93 09:58