Adaptec AHA-2940UW User Guide - Page 23

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: s 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. s For all SCSI devices connected to the host adapter, make sure you use high-quality SCSI cables to ensure reliable data transfer. s 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. Downloaded from www.Manualslib.com manuals search engine 2-11