Seagate ST36530N/W/WC manual Interconnect characteristics for single-ended I/O circuits

26 Medalist Pro Installation Guide, Rev. B

Figures 3a, 3b, 3c, and 3d show typical drive connections. The following table lists the maximum cable lengths and number of devices with single-ended I/O circuits allowed on a daisy-chain cable for <10 and <20 M transfers/sec I/O data transfer rates.

Table 4a. Interconnect characteristics for single-ended I/O circuits

	Maximum distance between
Number of attached SCSI	terminators (meters) [1] [3]
devices	Fast-5	Fast-10	Fast-20	Fast-40
1 to 4 maximum capacitance	6	3	3	N/A
(25pF) SCSI devices
5 to 8 maximum capacitance	6	3	1.5	N/A
(25pF) SCSI devices
9 to 16 maximum capacitance	6	3	[2]	N/A
(25pF) 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 T10/1302D 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.