Seagate ST34573N/W/WD/LW/WC/LC Installation Manual page 27

Barracuda 9LP Installation Guide, Rev. E
Figures 3a, 3b, 3c, and 3d show typical drive connections. The
following tables list the maximum cable lengths and number of
devices allowed on a daisy-chain cable for I/O data transfer rates
shown.
Table 4a. Cable characteristics for single-ended I/O
circuits
Number of attached SCSI
devices
1 to 4 maximum capacitance
(25 pF) SCSI devices
5 to 8 maximum capacitance
(25 pF) SCSI devices
9 to 16 maximum capacitance
(25 pF) SCSI devices
[1] For environments where all elements of the bus (cables, device inter-
faces, environmental noise and other parameters) are controlled to
be better than minimally required, it may be possible to extend the
path length and device count.
[2] Extending the device count beyond eight requires specification con-
trol beyond the minimum specified in the ANSI T10/1142D docu-
ment. It is recommended that the devices be uniformly spaced
between terminators with the end devices located as close as possi-
ble to the terminators.
[3] Values specified by data rate shall apply even if a slower data rate is
negotiated.
Maximum distance between
terminators (meters) [1] [3]
Fast-5 Fast-10 Fast-20 Fast-40
6 3
6 3
6 3
25
3 N/A
1.5 N/A
[2] N/A