Seagate ST31250N Product Manual page 61

Barracuda 2LP Product Manual, Rev. D
ST31250W and ST32550W
ST31250WD/ST32550WD
ST31250W/WD and
ST32550W/WD
Block Pins Function
J1 1 & 2 Terminator power from the drive (drive
supplies terminator power to its own
terminators).
1 & 3 Terminator power to the SCSI bus (drive
supplies power to an external terminator)
2 & 4 Terminator power from the SCSI bus (drive
receives terminator power from the SCSI
bus–usually the host controller)
1 & 3 & Terminator power to the SCSI bus and drive
2 & 4 (drive supplies termination power to its own
terminators and to the SCSI bus)
5 & 6 Enable SCSI termination. Jumper installed
enables the internal termination on the drive.
Jumper removed disables the drive's internal
terminators.
J1 1 & 3 Terminator power to the SCSI bus
J2 1 & 2 Reserved
3 & 4 Reserved
5 & 6 Disable SCSI parity
7 & 8 Write protect
9 & 10 Enable motor start. Jumper installed causes
the drive to wait for the Start Unit command
from the SCSI host. No jumper installed
causes the drive to look at the Delay Motor
Start jumper. Default is no jumper.
11 & 12 Delay motor start. Jumper installed causes a
10-second delay for each SCSI ID number
plus a maximum power-up delay of 3 seconds
before starting the spindle motor automati-
cally. Default is no jumper.
13 & 14 Reserved
15 & 16 Reserved
17 & 18 Reserved
J4 1 SCSI ID bit 0; no jumper = 0; yes jumper = 1
2 Fault LED pin (–)
3 SCSI ID bit 1; no jumper = 0; yes jumper = 1
4 Vendor unique
5 SCSI ID bit 2; no jumper = 0; yes jumper = 1
6 SSREF(+) spindle sync
7 SCSI ID bit 3; no jumper = 0; yes jumper = 1
Example:
If SCSI ID is equal to three (3)
(3 x 10) +3 = 33
The drive's spindle motor starts
in 33 seconds.
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