Quantum LTO 4, User Manual

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SCSI Commands: 17BINQUIRY Page 29
3.5 INQUIRY
The INQUIRY command requests that the drive return information about itself. If an
INQUIRY command is received from an Initiator with a pending Unit Attention
Condition (before the drive reports Check Condition status), the drive performs the
INQUIRY command and does not clear the Unit Attention Condition.
3.5.1 INQUIRY Command Descriptor Block
Byte
Bits
7 6 5 4 3 2 1 0
0 Operation Code (12h)
1 Ignored Reserved CmdDt EVPD
2 Page or Operation Code
3 Reserved
4 Allocation Length
5 Control
3.5.1.1 INQUIRY Command Field Descriptions
Field Bytes Bits Description
Operation
Code 0 The Operation Code for INQUIRY is 12h.
Ignored
Logical
Unit 1 5-7 The LUN field is vestigial from the SCSI-1 standard and is ignored.
CmdDt 1 1 Command Support Data (CmdDt) bit
0 = Requests INQUIRY data
1 = Requests command support data specified by operation code.
EVPD 1 0 0 = Requests Standard INQUIRY Data.
1 = Requests data page specified by the Page Code.
Page
Code 2 00h = Requests Supported Vital Product Data Page
80h = Requests Unit Serial Number Page
83h = Requests Device Identification Page
B0h = Requests Sequential Access Device Capabilities Page
C0h = Requests SCSI Firmware Revision Page
C1h = Requests Servo Firmware Revision Page
C2h = Requests Head Assembly Serial Number Page
C3h = Requests Reel Motor 1 Serial Number Page
C4h = Requests Reel Motor 2 Serial Number Page
C5h = Requests Board Serial Number Page
C6h = Requests Base Mechanical Serial Number Page
Operation
Code 2 Command Descriptor Block operation code when CmdDt is set to
one.
Allocation
Length 4 Specifies the amount of data to be returned, in bytes. A value of 0 is
a valid entry and returns no data.
The drive transfers the number of bytes specified up to the total
bytes in the requested page.
Reserved All reserved bits must be 0.
Control 5 See SCSI Command Control Byte Format on page 25.