Seagate Barracuda ST11950N, Руководство по эксплуатации продукта

Страница: 74 / 94

64 Barracuda 1 and 2 Product Manual, Rev. C
SCSI I/O
Connector
DC Power
Connector
J4
J01
Pin 1
J5
Figure 24. ST11950W/WD and ST12550W/WD physical interface
11.7.1 Physical characteristics
This section defines the connectors, cables, signals, and terminators
needed to implement the SCSI interface.
11.7.1.1 Physical description
You can daisy chain multiple SCSI devices on a common cable if each
device has the same types of drivers and receivers (all single-ended or
all differential). Devices having single-ended interface circuits cannot
be on the same daisy chain with devices having a differential interface
circuit. All signals are common between SCSI devices. A maximum of
8 SCSI devices (including the host) may be daisy chained together
when using a non-wide bus and ST11950N/ND or ST12550N/ND drives.
A maximum of 16 SCSI devices (including the host) may be daisy
chained together when using a wide bus and ST11950W/WD or
ST12550W/WD drives.
Terminate both ends of the daisy chain, but do not terminate any intermediate
SCSI device. The single-ended (ST11950N, ST11950W, ST12550N, and
ST12550W) drives are equipped with permanently mounted IC terminators,
which you can turn on or off using the Enable SCSI Terminator jumper. See
Section 10.1 to locate the Enable SCSI Terminator jumper for each drive
model. The differential (ST11950ND, ST11950WD, ST12550ND, and
ST12550WD) drives do not have on-board terminators. You must provide
external termination to terminate a differential drive.
11.7.1.2 Cable requirements
Sections 11.7.1.2.1, 11.7.1.2.2, and 11.7.1.2.3 describe the single-ended,
differential, and general cable requirements for Barracuda 1 and 2 drives.