Logic SCSI to PCI Host Adapter User's Guide

3-10 Ultra160 SCSI to PCI Host Adapter Characteristics
3.3 Cabling SCSI Devices
The cable provided in your host adapter kit is matched to the host
adapter board and its operation. The Ultra160 SCSI cable also has
built-in multimode (LVD/SE) termination because most Ultra160 hard disk
drives are not made with on-board LVD termination.
Table 3.3 lists standard cable specifications.
3.3.1 Internal SCSI Cables
You can make internal SCSI bus connections to your Ultra160 SCSI host
adapter with an unshielded, 68- or 50-conductor ribbon cable. Some
internal cables come with an LVD/SE terminator on one end. This end
must be farthest from the host adapter. Figures 3.8 through 3.10 provide
examples of internal cables.
Table 3.3 Cable Specifications
STA Term
Maximum Bus Length, Meters
1
1. This parameter may be exceeded in point-to-point and engineered
applications.
Maximum DevicesSE LVD
Ultra SCSI 1.5 see note
2
2. LVD was not defined in the original SCSI standards for this speed. If all
devices on the bus support LVD, then 12-meter operation is possible at
this speed. However, if any device on the bus is SE only, then the entire
bus switches to SE mode, and the distances in the SE column apply.
8/4
Wide Ultra SCSI 1.5/3 see note
2
8/4
Ultra2 SCSI see note
3
3. SE and High Voltage Differential (HVD) are not defined at greater than
Ultra speeds.
12 8
Wide Ultra2 SCSI see note
3
12 16
Ultra160 see note
3
12 16