IBM 25R0012 User Guide - Page 20

Sleep, Attachment, Physical, Characteristics, Interface, Speed

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Sleep Mode To conserve energy when circuit functions are not needed for drive operation, the drive features a power-management function that causes the drive's electronics to enter a low-power mode known as sleep mode. To enter sleep mode, the drive must be inactive for a minimum of 30 seconds (default value; this is programmable via the mode pages); to exit, the drive must receive a command across the SCSI interface, a command across the Library/Drive Interface (LDI or RS-422 interface), or a load or unload request. When in sleep mode, the drive's response time to commands that do not require media motion increases by up to ten microseconds. Commands that require media motion may be delayed an additional 100 milliseconds because the tape must be retensioned. SCSI Attachment To communicate with a server, the drive uses the Ultra160 LVD SCSI interface. Physical Characteristics of the SCSI Interface The drive contains a high-density, 68-pin, D-shell receptacle connector (HD68) for attachment to the server. The HD68 connector includes the connectors for the SCSI signal, the SCSI ID, and the drive's power. The drive supports LVD SCSI cables with HD68 connectors. Speed The Ultra160 LVD SCSI interface is compatible with older SCSI technology and is capable of data transmission at 160 MB/s. Ultra160 SCSI uses the three management features of the Ultra3 SCSI standard that specifically affect data transfer rate: v Double transition clocking - a data-transfer technique that enables data rates to double without increasing clock speed v Domain validation - a procedure that detects and adjusts SCSI configuration issues that might prevent interoperation between SCSI devices v Cyclic redundancy check (CRC) - an error-checking technique Because the cables, connectors, and terminators are the same for the Ultra160 and Ultra2 SCSI interfaces, devices with those interfaces can be mixed on the same bus and each device can operate at its fully rated speed. 4 IBM 400/800GB LTO3 Tape Drive User's Guide

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Sleep
Mode
To
conserve
energy
when
circuit
functions
are
not
needed
for
drive
operation,
the
drive
features
a
power-management
function
that
causes
the
drive’s
electronics
to
enter
a
low-power
mode
known
as
sleep
mode
.
To
enter
sleep
mode,
the
drive
must
be
inactive
for
a
minimum
of
30
seconds
(default
value;
this
is
programmable
via
the
mode
pages);
to
exit,
the
drive
must
receive
a
command
across
the
SCSI
interface,
a
command
across
the
Library/Drive
Interface
(LDI
or
RS-422
interface),
or
a
load
or
unload
request.
When
in
sleep
mode,
the
drive’s
response
time
to
commands
that
do
not
require
media
motion
increases
by
up
to
ten
microseconds.
Commands
that
require
media
motion
may
be
delayed
an
additional
100
milliseconds
because
the
tape
must
be
retensioned.
SCSI
Attachment
To
communicate
with
a
server,
the
drive
uses
the
Ultra160
LVD
SCSI
interface.
Physical
Characteristics
of
the
SCSI
Interface
The
drive
contains
a
high-density,
68-pin,
D-shell
receptacle
connector
(HD68)
for
attachment
to
the
server.
The
HD68
connector
includes
the
connectors
for
the
SCSI
signal,
the
SCSI
ID,
and
the
drive’s
power.
The
drive
supports
LVD
SCSI
cables
with
HD68
connectors.
Speed
The
Ultra160
LVD
SCSI
interface
is
compatible
with
older
SCSI
technology
and
is
capable
of
data
transmission
at
160
MB/s.
Ultra160
SCSI
uses
the
three
management
features
of
the
Ultra3
SCSI
standard
that
specifically
affect
data
transfer
rate:
v
Double
transition
clocking
-
a
data-transfer
technique
that
enables
data
rates
to
double
without
increasing
clock
speed
v
Domain
validation
-
a
procedure
that
detects
and
adjusts
SCSI
configuration
issues
that
might
prevent
interoperation
between
SCSI
devices
v
Cyclic
redundancy
check
(CRC)
-
an
error-checking
technique
Because
the
cables,
connectors,
and
terminators
are
the
same
for
the
Ultra160
and
Ultra2
SCSI
interfaces,
devices
with
those
interfaces
can
be
mixed
on
the
same
bus
and
each
device
can
operate
at
its
fully
rated
speed.
4
IBM
400/800GB
LTO3
Tape
Drive
User’s
Guide