Barracuda 18LP Family: ST39175LW/LC ST318275LW ... - Seagate
Barracuda 18LP Family: ST39175LW/LC ST318275LW ... - Seagate
Barracuda 18LP Family: ST39175LW/LC ST318275LW ... - Seagate
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<strong>Barracuda</strong> <strong>18LP</strong> Product Manual, Rev. E 37<br />
8.1.1 Function description<br />
J2<br />
jumper<br />
installation<br />
SE<br />
On<br />
Off<br />
Jumper function description<br />
Forces drive to use single-ended I/O drivers/receivers only.<br />
Drive can operate on the interface in low voltage differential mode or single-ended,<br />
depending on the voltage state of the I/O “DIFFSNS” line. Default is no jumper on.<br />
DS ME<br />
Off Off Spindle starts immediately after power up—Default setting.<br />
Off On Drive spindle does not start until Start Unit command received from host.<br />
On Off Spindle Startup is delayed by SCSI ID times 12 seconds after power is applied, i.e., drive 0<br />
spindle starts immediately when DC power connected, drive 1 starts after 12 second delay,<br />
drive 2 starts after 24 second delay, etc.<br />
On On Drive spindle starts when Start Unit command received from host. Delayed start feature is<br />
overridden and does not apply when ME jumper is installed.<br />
WP<br />
On<br />
Off<br />
PD<br />
On<br />
Off<br />
RES (2)<br />
Off<br />
Entire drive is write protected.<br />
Drive is not write protected. Default is no WP jumper installed.<br />
Parity checking and parity error reporting by the drive is disabled.<br />
Drive checks for parity and reports result of parity checking to host.<br />
Default is PD jumper not installed.<br />
Reserved jumper position. Default is no jumper installed.<br />
TP (“LW” model only)<br />
Off<br />
No terminator power is connected to drive terminators or SCSI bus I/O cable.* No jumpers<br />
on is factory default.<br />
On<br />
Drive supplies power to SCSI bus I/O cable.* A jumper on the TP position may be needed to<br />
power external terminators (see Section 9.8 and Figure 10).<br />
*See Figure 7c for pins used for Termpower.<br />
8.2 Drive orientation<br />
The balanced rotary arm actuator design of the drive allows it to be mounted in any orientation. All drive performance<br />
characterization, however, has been done with the drive in horizontal (discs level) and vertical (drive on<br />
its side) orientations, and these are the two preferred mounting orientations.<br />
8.3 Cooling<br />
Cabinet cooling must be designed by the customer so that the ambient temperature immediately surrounding<br />
the drive will not exceed temperature conditions specified in Section 6.4.1, “Temperature.” Specific consideration<br />
should be given to make sure adequate air circulation is present around the printed circuit board (PCBA)<br />
to meet the requirements of Section 6.4.1, “Temperature.”<br />
8.3.1 Air flow<br />
The rack, cabinet, or drawer environment for the <strong>Barracuda</strong> <strong>18LP</strong> drive must provide heat removal from the<br />
electronics and head and disc assembly (HDA). You should confirm that adequate heat removal is provided<br />
using the temperature measurement guidelines described in Section 6.4.1.