SCSI Switches Information

DescriptionSCSI Switches


Small computer system interface (SCSI) switches connect test points or devices to instruments for the testing, measuring, or monitoring industrial systems.




SCSI is an intelligent peripheral bus with a standard, device-independent protocol that allows many peripheral devices to be connected to the SCSI port. SCSI switches are often used in peripheral sharing between two hosts, clustered peripheral configurations, multiple peripheral cross-platform disaster recovery, and business continuity applications.


SCSI switches are an excellent way to share expensive SCSI tape libraries and drives, RAID arrays, and peripherals such as printers and scanners. Redundant array of independent drives or disks (RAID) is a term for data storage schemes that divide or replicate data among multiple hard drives




SCSI switches are available with single-ended, high-voltage differential (HVD), and low- voltage differential (LVD) interfaces. They also come in both narrow and wide bus configurations. Normally, the configuration of a SCSI switch is specified as b x c, where b is the number of independent SCSI host buses to which the SCSI switch connects, and c is the number of SCSI channels. Typically, SCSI switches are available in the following configurations:


  • 1 x 2
  • 1 x 3
  • 1 x 4
  • 2 x 1
  • 2 x 2
  • 3 x 1
  • 3 x 2
  • 3 x 3
  • 4 x 1
  • 4 x 2
  • 4 x 3
  • 4 x 4
  • 5 x 4
  • 5 x 5
  • 6 x 4


Custom and specialized configurations for SCSI switches are also available.




SCSI SwitchesSpecifications for SCSI switches include the form factor, which indicates the size, shape, and functional type of the device.


Generally, SCSI switches come in one four formats:


Stand-alone SCSI switches are independent units that connect to a larger system.


Board-level switches are SCSI switches that are computer boards which are inserted into a carrier.


Application-specific integrated circuit (ASIC) switches are designed for a specific SCSI switch applications. They are manufactured by connecting existing circuits in new ways.


Rack-mounted SCSI switches are designed to be mounted in a rack together with other units.


Stand-alone switches, board switches, unlisted, specialized, and proprietary SCSI switches are also available. 




Image credit:


National Instruments