2-11
Installation
Configuring SCSI Devices
Your host adapters can transfer data up to 40 MBytes per second on
each SCSI channel when connected to devices on a wide bus that
support UltraSCSI. UltraSCSI and non-UltraSCSI devices can coexist
on the same cable, and each device can transfer data at its own
negotiated or assigned transfer rate. However, to reliably transfer
data at the higher transfer rate of UltraSCSI, the following
requirements must be met:
■
Internal and external cables must be terminated with active
teminators, either provided by the SCSI device at the end of the
cable or by a separate terminating plug. The terminators on the
AHA-2940UW/OF and AHA-2944UW/OF are active
terminators.
■
For all SCSI devices connected to the host adapter, make sure
you use high-quality SCSI cables to ensure reliable data
transfer.
■
When four or more UltraSCSI devices are connected to the host
adapter, the combined length of all cables (internal and
external) must not exceed 1.5 meters for single-ended devices
or 25 meters for differential devices to ensure reliable
operation.
If fewer than four UltraSCSI devices are used the combined
cable length must not exceed 3.0 meters for single-ended
devices or 25 meters for differential devices.
