Barracuda 18LP Family: ST39175LW/LC ST318275LW ... - Seagate

Barracuda 18LP Product Manual, Rev. E 37
8.1.1 Function description
J2
jumper
installation
SE
On
Off
Jumper function description
Forces drive to use single-ended I/O drivers/receivers only.
Drive can operate on the interface in low voltage differential mode or single-ended,
depending on the voltage state of the I/O “DIFFSNS” line. Default is no jumper on.
DS ME
Off Off Spindle starts immediately after power up—Default setting.
Off On Drive spindle does not start until Start Unit command received from host.
On Off Spindle Startup is delayed by SCSI ID times 12 seconds after power is applied, i.e., drive 0
spindle starts immediately when DC power connected, drive 1 starts after 12 second delay,
drive 2 starts after 24 second delay, etc.
On On Drive spindle starts when Start Unit command received from host. Delayed start feature is
overridden and does not apply when ME jumper is installed.
WP
On
Off
PD
On
Off
RES (2)
Off
Entire drive is write protected.
Drive is not write protected. Default is no WP jumper installed.
Parity checking and parity error reporting by the drive is disabled.
Drive checks for parity and reports result of parity checking to host.
Default is PD jumper not installed.
Reserved jumper position. Default is no jumper installed.
TP (“LW” model only)
Off
No terminator power is connected to drive terminators or SCSI bus I/O cable.* No jumpers
on is factory default.
On
Drive supplies power to SCSI bus I/O cable.* A jumper on the TP position may be needed to
power external terminators (see Section 9.8 and Figure 10).
*See Figure 7c for pins used for Termpower.
8.2 Drive orientation
The balanced rotary arm actuator design of the drive allows it to be mounted in any orientation. All drive performance
characterization, however, has been done with the drive in horizontal (discs level) and vertical (drive on
its side) orientations, and these are the two preferred mounting orientations.
8.3 Cooling
Cabinet cooling must be designed by the customer so that the ambient temperature immediately surrounding
the drive will not exceed temperature conditions specified in Section 6.4.1, “Temperature.” Specific consideration
should be given to make sure adequate air circulation is present around the printed circuit board (PCBA)
to meet the requirements of Section 6.4.1, “Temperature.”
8.3.1 Air flow
The rack, cabinet, or drawer environment for the Barracuda 18LP drive must provide heat removal from the
electronics and head and disc assembly (HDA). You should confirm that adequate heat removal is provided
using the temperature measurement guidelines described in Section 6.4.1.