StorCase Technology S20A108 - Manual (Page 25)

StorCase Technology, Inc. S20A108 User's Guide - Rev. A02
18 Appendix B - Factory-Installed Options
Appendix B - Factory-Installed Options
Data Express Ultra160 Isolator/Repeater Board
The Data Express Ultra160 Isolator/Repeater Board (Figure B-1) is an upgrade attachment for
the S20A108 receiving frame. This attachment provides a bus-isolating repeater function as
described below.
Bus-Isolating Hot Swap Function
The Isolator/Repeater Board provides an enhanced, bus-isolating hot swap function by
allowing the installation, removal or exchange of DE200 carriers while the computer system
is operating by monitoring and protecting the computer system and other peripheral devices
on the SCSI bus. The Isolator/Repeater Board eliminates the need to shut down the system
when adding or removing a SCSI device by performing two functions:
1. Delays power up/down of the drive until the time period between SCSI bus cycles.
This prevents the interruption of any SCSI bus activity by other devices on the bus.
2. Prevents drive power sequencing from generating noise on the SCSI bus, thus
preventing data transfer corruption on other devices.
Please note that, whereas UNIX and Apple-based systems provide mount/dismount drive
commands, most PC systems do not provide such a feature. When using one of these operating
systems, it may be necessary to reboot the computer after adding or changing a drive. This
reboot activity will force the SCSI host adapter to rescan its SCSI bus for physically attached
drives, and will then be able to access the new or changed drive.
Repeater Function
Specifically in LVD/Single-Ended implementations, unknown system components and their
combinations may produce impedance mismatches, excessive capacitance loading and/or
noise interference within the system, potentially introducing intermittent incompatibility issues.
To minimize these unpredictable effects caused by varying system specifications, StorCase
recommends the Data Express Isolator/Repeater Board on all Ultra160 Data Express receiving
frames. This Isolator/Repeater Board provides a signal repeater function that allows the Data
Express drive enclosure to contribute to improved signal quality to and from the drive.
For more information and data, please refer to the Repeater Board Benefits and Downward
Compatibility technical papers on our web site at: http://www.storcase.com/tools
Attaching the Isolator/Repeater Board
The S20A108 may be purchased with the Isolator/Repeater Board factory-installed. If the
board has not already been attached to the S20A108 receiving frame, follow the instructions
below to add the board. Otherwise, proceed to the section "Using the Isolator Board" for usage
instructions.