Log sense (4dh), Sense, 4dh) – Dell PowerVault TL2000 User Manual
Page 25
LOG
SENSE
(4Dh)
The
LOG
SENSE
command
allows
the
host
to
retrieve
statistical
information
maintained
by
the
media
changer
about
its
own
hardware.
The
statistical
information
is
divided
over
several
pages.
A
LOG
SENSE
command
will
retrieve
one
of
these
pages.
Bit
7
6
5
4
3
2
1
0
Byte
0
Operation
Code
(4Dh)
1
LUN
Reserved
PPC
(0)
SP
(0)
2
PC
Page
Code
3
Reserved
4
Reserved
5
(MSB)
Parameter
pointer
6
(LSB)
7
(MSB)
Allocation
length
8
(LSB)
9
Control
Field
descriptions:
PPC:
If
Parameter
Pointer
Control
bit
is
set,
the
target
terminates
the
command
with
Check
Condition
status.
The
sense
key
is
set
to
ILLEGAL
REQUEST,
and
an
additional
sense
code
of
INVALID
FIELD
IN
CDB.
SP:
Saving
Log
Parameters
(SP)
is
not
supported.
If
the
SP
bit
is
set,
the
command
is
terminated
with
Check
Condition
status
with
the
sense
key
set
to
ILLEGAL
REQUEST,
and
an
additional
sense
code
of
INVALID
FIELD
IN
CDB.
PC:
The
Page
Control
field
defines
the
type
of
parameter
value
to
be
returned.
This
field
should
either
be
set
to
00b
(Current
Threshold
Values)
or
01b
(Current
Cumulative
Values).
If
not,
the
command
is
terminated
with
Check
Condition
status
with
the
sense
key
set
to
ILLEGAL
REQUEST,
and
an
additional
sense
code
of
INVALID
FIELD
IN
CDB.
The
Current
Cumulative
Values
are
the
values
computed
since
the
last
reset
of
the
device
(either
by
power-cycling,
Bus
Device
Reset,
or
SCSI
Reset).
Note:
Only
Log
Sense
Tape
Alert
page
(2Eh)
supports
PC
being
set
to
Current
Threshold
Values.
Page
Code:
The
Page
Code
field
identifies
which
log
page
is
being
requested
by
the
initiator.
If
the
page
is
not
supported
then
the
command
terminates
with
a
Check
Condition
status
with
the
sense
key
set
to
ILLEGAL
REQUEST,
and
an
additional
sense
code
of
INVALID
FIELD
IN
CDB.
Supported
pages
are:
v
00h
-List
of
Supported
Pages
Page
v
07h
-Event
Log
Page
v
2Eh
-Tape
Alert
Page
v
30h
-Statistics
Counter
Page
v
33h
-Error
Log
Page
Parameter
Pointer:
The
Parameter
Pointer
field
allows
the
host
to
specify
at
which
parameter
within
a
Log
Page
the
requested
data
should
begin.
This
is
not
supported
in
any
Log
Sense
page
and
should
be
set
to
0.
Chapter
3.
Supported
SCSI
Commands
3-11