Seagate ST34501N, ST34501WD, ST34501DC, ST34501WC manual Drive termination

Page 24

22

Cheetah 4LP Installation Guide, Rev. B

the case, change the ID so that each device on the SCSI chain has its own unique ID. Also check your system or controller user’s manual to ensure that you have not violated its SCSI ID numbering recommendations.

Drive termination

If you are installing a Cheetah drive in a system that has other SCSI devices installed, terminate only the end devices on the SCSI chain. A SCSI “device” is any disc drive, scanner, tape backup unit, or other piece of hardware connected to your sys- tem using the SCSI bus.

The top example in Figure 2 shows an internal hard disc at one end of the SCSI bus with the SCSI controller at the other end (both are terminated). The bottom example shows two additional SCSI devices connected externally—this means the SCSI con- troller is no longer on the end of the SCSI chain and should not be terminated.

Note. Some controllers prefer to remain terminated even if they are in the middle of the chain. Also, some controllers treat the internal and external chains as separate logical buses. This means you may need to terminate both the first and last devices on both logical buses to achieve proper termination. If necessary, refer to your system or controller documentation to see how this is handled in your particular system.

For information about how to terminate your drive, refer to the appropriate drive-specific section.

Image 24
Contents ST34501N/W/WC/WD/DC Contents Preface Electrostatic discharge protection Important safety information and precautions Cheetah 4LP Installation Guide, Rev. B Wichtige Sicherheitshinweise Cheetah 4LP Installation Guide, Rev. B Page Regulatory agency compliance Electromagnetic susceptibilityElectromagnetic compliance Electromagnetic compliance for the European Union Australian C-TickSeagate technical support services Online servicesSeagate CompuServe forum FAX services SeaFAXDirect-support services Seagate technical supportCustomer service centers Manufacturer’s representativesGeneral description Drive characteristics Additional drive characteristics DC power requirements Amps ST34501 WC models WD, DC models +12V8 +5V8 Voltage regulation5 ± 5% ± 5%2Dimensions of the drive Drive models General informationScsi ID jumpers Drive termination Terminator power Circuits and data path widthsCable characteristics for single-ended circuits Pin I/O connection to drive Multiple drive connection to host adapter Multiple-drive connection to host adapter Scsi I/O Providing adequate cooling Kühlung des Systems Suggested air flow Abbildung 4. Empfohlener LuftstromverlaufMounting the drive and connecting cables Installation des Laufwerkes und Anschluß der KabelPage Pin Power Pin GleichstromHinweis Cheetah 4LP Installation Guide, Rev. B Mounting configuration dimensions Formatting the drive Quick reference desktop system notesSetting the Scsi ID jumpers Setting the Scsi ID on model N drivesTerminating the drive Terminating the driveSetting terminator power jumpers Other applicable jumper options Additional jumper optionsWD drives Model W and WD drive alternate ID select and LED connection Terminating the drive W model shown Drive Front Other option jumpers are available as illustrated below WC/DC drives Applicable jumper options Jumper optionsDrive Active indicator Drive Active LED indicator connectionsPage Page