Avago Technologies eXtremeRAID 2000 - Manual (Page 30)

SCSI Termination Guidelines
2-8 eXtremeRAID 2000 Installation Guide
SCSI Termination Guidelines
To maintain proper voltage levels for SCSI control and data signals, each end
of a SCSI bus must be terminated. Termination devices can be built into a
controller, a SCSI device, or attached to the end of a SCSI bus.
The eXtremeRAID 2000 controller is equipped with automatic SCSI
termination circuitry. If the controller is at the end of a SCSI bus, it
automatically enables on-board termination. The controller can also detect
whether single-ended (SE) or low-voltage differential (LVD) termination is
required and can automatically configure the appropriate termination type.
If all SCSI devices for a channel are only connected to the internal or
external channel connector, the end of the SCSI bus farthest from the
eXtremeRAID 2000 controller must have a terminator installed. In this case,
the controller automatically enables on-board termination (Figure 2-3 and
Figure 2-4).
If SCSI devices for a channel are connected to both internal and external
connectors, each end of the SCSI bus must be terminated. In this case, the
eXtremeRAID 2000 controller automatically disables on-board termination
(Figure 2-5).
Figure 2-3. External Drive Termination Example