Adaptec 1821900 User Reference - Page 31

Connecting SCSI Devices The following example shows two Ultra160/Ultra2 SCSI devices connected to the external connector. As in the previous diagrams, the last device on the SCSI bus must use an LVD/SE terminator plug in order to operate at its maximum speed. Terminated T device Maximum Cable Lengths The total length of cabling (internal and external) on the SCSI bus cannot exceed the maximum lengths listed in the following table. The third column lists the maximum number of SCSI devices you can connect to the SCSI card. Maximum Cable Length Data Transfer Rate Maximum Devices Supported 25 m (82.0 ft) Ultra160 SCSI (160 MBytes/sec) 1 and Ultra2 SCSI (80 MBytes/sec) 12 m (39.4 ft) Ultra160 SCSI (160 MBytes/sec)1 15 and Ultra2 SCSI (80 MBytes/sec) 3 m (9.8 ft) Fast Wide SCSI 15 (20 MBytes/sec) 3 m (9.8 ft) Fast SCSI 7 (10 MBytes/sec) 3 m (9.8 ft) Ultra SCSI 4 (40 MBytes/sec for 16-bit, 20 MBytes/sec for 8-bit) 1.5 m (4.9 ft) Ultra SCSI 5-72 (40 MBytes/sec for 16-bit, 20 MBytes/sec for 8-bit) 1 Mixing Fast/Ultra devices with Ultra160 and Ultra2 SCSI devices causes the entire SCSI bus to default to Ultra SCSI speeds and cable length requirements. 2 Ultra SCSI data transfer rates do not currently support more than seven devices connected to the SCSI card. ❒ 25