Compaq AA-RHGWB-TE manual Using Scsi Bus Signal Converters, Types of Scsi Bus Signal Converters

9.1 Using SCSI Bus Signal Converters

A SCSI bus signal converter allows you to couple a differential bus segment to a single-ended bus segment, allowing the mixing of differential and single-ended devices on the same SCSI bus to isolate bus segments for maintenance purposes.

Each SCSI signal converter has a single-ended side and a differential side as follows:

•DWZZA — 8-bit data path

•DWZZB — 16-bit data path

•DS-BA35X-DA 16-bit personality module

______________________ Note _______________________

Some UltraSCSI documentation uses the UltraSCSI "bus expander" term when referring to the DWZZB and UltraSCSI signal converters. Other UltraSCSI documentation refers to some UltraSCSI products as bus extender/converters.

For TruCluster Server there are no supported standalone

UltraSCSI bus expanders (DWZZC).

In this manual, any device that converts a differential signal to a single-ended signal is referred to as a signal converter (the DS-BA35X-DA personality module contains a DWZZA-on-a-chip or DOC chip).

A SCSI signal converter is required when you want to connect devices with different transmission modes.

9.1.1 Types of SCSI Bus Signal Converters

Signal converters can be standalone units or StorageWorks building blocks (SBBs) that are installed in a storage shelf disk slot. You must use the signal converter module that is appropriate for your hardware configuration.

For example, use a DWZZA-VA signal converter to connect a wide, differential host bus adapter to a BA350 (single-ended and narrow) storage shelf, but use a DWZZB-VW signal converter to connect a wide, differential host bus adapter to a non-UltraSCSI BA356 (single-ended and wide) storage shelf. The DS-BA35X-DA personality module is used in an UltraSCSI BA356 to connect an UltraSCSI host bus adapter to the single-ended disks in the UltraSCSI BA356. You could install a DWZZB-VW in an UltraSCSI BA356,

9–2Configurations Using External Termination or Radial Connections to Non-UltraSCSI Devices