HP Xw8200 LSI 20320A-R PCI: Ultra 320 SCSI to PCI-X Host Adapters Users Guide - Page 27

2.4 Terminating the SCSI Bus The SCSI bus contains all the devices that you connect with SCSI cables. When you connect the first and last physical SCSI devices on the ends of the SCSI bus, you must have termination active. You must remove or disable termination on all other SCSI devices on the same bus. If you connected only internal SCSI devices on a bus, the host adapter automatically terminates itself. If you connected only external SCSI devices on a bus, the host adapter also terminates automatically. Automatic termination occurs because the host adapter connection is at the end of the SCSI bus. If you connect both internal and external SCSI devices on a bus, the host adapter automatically disables its termination. This occurs because the host adapter is in the middle of the SCSI bus. 2.4.1 LSI20320 Host Adapter Termination The LSI20320, LSI20320H, LSI20320L, and LSI20320-R host adapters provide active termination with an automatic means of enabling and disabling the termination. When you connect SCSI devices to both the internal and external connectors, host adapter termination is automatically disabled. 2.4.2 LSI21320 Host Adapter Termination The LSI21320(-R) host adapter provides active termination with an automatic means of enabling and disabling the termination. When you connect SCSI devices to the internal and external connectors on Channel A, termination for Channel A is automatically disabled. Channel B has only one SCSI connector. Channel B termination is always enabled. 2.4.3 LSI22320 Host Adapter Termination The LSI22320(-R) host adapter provides active termination with an automatic means of enabling and disabling the termination. When you connect SCSI devices to both the internal and external connectors on a given channel, termination for that channel is automatically disabled. Terminating the SCSI Bus Version 2.1 Copyright © 2002-2003 by LSI Logic Corporation. All rights reserved. 2-11