Packard Bell ST8000, 5800 manual Option Cards, Introduction

D Option Cards

Introduction

The Ultra Extender and Differential Converter Option cards provide a single solution allowing the extension of device connectivity and/or cable length of the SCSI bus for the DEU subsystems.

When the Ultra Extender card is used, the circuitry functions as a SCSI bus repeater for multiple single- ended to single-ended cabling schemes while being electrically isolated from each other. When the Differential Converter card is used, the circuitry functions as a SCSI bus converter for differential to single-ended cabling schemes again while being electrically isolated from each other. As SCSI command and data passes from the source bus to the load bus, signal filtering and re-timing are employed to maintain the SCSI signal.

The cards feature TolerANT® technology, which includes active negation on the SCSI drivers and input signal filtering on the SCSI receivers. Active negation causes the SCSI Request, Acknowledge, Data, and Parity signals to be actively driven high rather than passively pulled up by terminators. The receiver technology improves data integrity in unreliable cabling environments, where other devices would be subject to data corruption. The TolerANT receivers filter the SCSI bus signals to eliminate unwanted transitions without long signal delays. This improved driver and receiver helps eliminate double clocking of data, the largest reliability issue with SCSI operations.

PRINTER NOTE: Page size 9” x 9.25”. Align this page to top, right hand corner. Back box bleeds off top and right edge. Left side of page extends to 9.25 inches.