Tech Notes: Seagate Barracuda 9 ST19171W/WC Hard-Disk Drives
Tech Notes: ST19171W/WC Hard-Disk Drive
Installation | Formatting | SCSI
Interface | Cabling
Requirements | Termination | Terminator Power | Mounting
- If multiple devices are on the bus, set
the drive’s SCSI ID to one that is not being used by
other devices on the bus.
- If the drive is the only device on the
bus, attach it to the end of the SCSI bus cable. You must
enable permanently installed terminators on the model W
drive by using jumper plug TE if termination is not
provided by the host equipment. On the model WC drive,
external terminators must be provided. On Dell servers,
this termination is provided by the SCSI backplane.
- If the drive is attached to a bus that
contains other devices and the new drive is not attached
to the end of the bus, you should remove the TE jumper
from the new drive.
- Set all appropriate option jumpers for
desired operation before applying power to the drive.
- It is not necessary to low-level format
this drive. The drive is shipped from the manufacturer
low-level formatted in 512-byte sectors.
- Reformat the drive if a different spare
sector allocation scheme is selected.
The drives can be daisy-chained together or
with other compatible SCSI devices. Both ends of the cable must
be terminated. On the model W drive, remove the TE jumper on J2;
do not remove the TP jumpers.
The 80-pin connector option is intended for use
with drives that plug directly into a PCB or a wall- or
bracket-mounted connector in the host computer. Installations
with connectors on cables are not recommended.
For 68-pin drives only high-quality cables are
recommended that do not exceed a total length of 1.5 m.
Internal hard-disk drive termination consists
of active circuits in an LSI module that is permanently mounted
on the PCB. All single initiator/single-target (not
daisy-chained) applications require that the initiator and
hard-disk drive be terminated.
In multitarget systems peripherals between the
host and the end of the cable must not be terminated.
Where terminators are not required, remove the
TE jumper that enables the drive terminators. Removing the
terminator power-source selection jumper, TP, does not disconnect
the terminators from the circuit.
ANSI SCSI-2 alternative active terminators
should be used for daisy-chained applications. Do not mix active
and passive terminators on the same SCSI bus.
ST19171WC drives do not have internal
terminators available. You must provide external active
terminators when termination is required. On Dell servers, this
termination is provided by the SCSI backplane.
The model W drive can be configured as follows:
- Accept terminator power from the SCSI bus
- Supply power to the SCSI bus
- Provide terminator power for internal
termination circuits from the drive power connector
- Provide power to its own terminators and
to the SCSI bus terminator power line
The drive can provide power both to its own
terminators and to the power line for the SCSI bus terminator if
both sets of TP pins are jumpered (recommended configuration).
TERMPWR has the following characteristics:
- V TERM = 4.25 V to 5.25 V
- 1500-mA minimum source drive capability
- 3.0 A maximum
The model WC drive cannot furnish terminator
power, because no conductors in the 80-pin I/O connector are
devoted to terminator power.
The balanced rotary-arm actuator design of the
drive allows it to be mounted in any orientation. However, all
drive performance characterization was done with the drive in
horizontal and vertical orientations, which are the preferred
orientations.
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