Avago Technologies LSI53C140 - Manual (Page 14)

1-4 Using the LSI53C140
Ver. 2.1 Copyright © 1998–2001 by LSI Logic Corporation. All rights reserved.
Figure 1.3 shows two LSI53C140 expanders that configure three
segments. This configuration allows segments A and B to be treated as
a point-to-point segment. Segment C is treated as a load segment with
at least 8 inches between every node.
Figure 1.3 LSI53C140 Server Clustering
Figure 1.3 demonstrates how SCSI bus expanders are used to couple
bus segments together without any impact of the SCSI protocol or
software. Configurations that use the LSI53C140 in the Ultra2 mode
(LVD to LVD) allow the system designer to take advantage of the inherent
cable distance, device connectivity, data reliability, and increased transfer
rate benefits of LVD signaling with Ultra2 SCSI peripherals.
Table 1.2 shows the various distance requirements for each SCSI bus
mode.
Segment A Segment B
Segment C
Primary Server Secondary Server
Shared Disk Subsystem
SCSI Bus
Expander
SCSI Bus
Expander