Chapter 4 SCSI Commands
INQUIRY Command (12h)
DLT-S4 Interface Reference Guide
34
INQUIRY Command (12h)
4
The
INQUIRY
command allows the initiator to direct all attached devices
to return information about themselves. DLT-S4 devices respond by
providing a variety of information, including their World Wide Name
and other important characteristics. The DLT-S4 tape drive identifies
itself as a Sequential Access Storage Device.
The drive can provide different categories of data in response to an
INQUIRY
command:
•
Standard Inquiry Data
— contains basic data about the drive, including
vendor-specific inquiry data that precisely identifies the revision of
tape drive subsystem components.
•
Vital Product Data
— comprises several pages of additional data. Each
Vital Product Data page requires a separate
INQUIRY
command from
the initiator. To see a list of supported Vital Product Data pages (see
Supported Vital Product Data Page (00h)
on page 41
).
An
INQUIRY
command is neither affected by—nor does it clear—any
Unit
Attention
condition.
Figure 6
INQUIRY
Command
Descriptor Block — Data
Format
Note:
The tape drive does not need to access its tape medium to
respond to the
INQUIRY
command.
Bit
Byte
7
6
5
4
3
2
1
0
0
Operation Code (12h)
1
Reserved
Obsolete
EVPD
2
Page Code
3 — 4
(MSB)
Allocation Length
(LSB)
5
Control