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Scsi bus lengths – LSI U80ALVD User Manual

Page 26

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2-8

Installing the LSIU80ALVD

You can connect up to four devices if they are evenly spaced on a
3-meter Ultra SCSI cable (0.75 m between devices). Your SE SCSI bus
should not exceed 3 meters (total internal and external cable lengths),
even with fewer than four devices.

For LVD applications, you can connect up to 16 devices including the
host adapter if they are evenly spaced on a 12-meter Ultra SCSI cable
(0.19 m minimum between devices).

Table 2.2

SCSI Bus Lengths

Maximum Bus Length, Meters

1

1. This parameter may be exceeded in point-to-point and engineered applications.

Maximum #

of Devices

SE

Differential

LVD

SCSI-1

6

25

12

8

Fast SCSI

3

25

12

8

Fast Wide SCSI

3

25

12

16

Ultra SCSI

1.5

2

2. Additional spacing rules apply.

25

12

8

Ultra SCSI

3

2

4

Wide Ultra SCSI

25

12

16

Wide Ultra SCSI

1.5

8

Wide Ultra SCSI

3

4

Ultra2 SCSI

Note

3

3. SE and high power differential are not defined at Ultra2 speeds.

Note

3

12

8

Wide Ultra2 SCSI

Note

3

Note

3

12

16