HP DAT 72e, Getting Started Manual

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15
Step 3: Connect the SCSI cable
A wide VHD-to-HD SCSI cable is provided to connect your HP StorageWorks DAT tape drive
to a VHD SCSI port on an LVD SCSI bus. If your server has an HD SCSI port, you must either
purchase and install a VHD-to-HD adapter or use an HD-to-HD cable instead of the supplied
cable. Refer to our web site for recommended products:
www.hp.com/go/connect
.
Caution
To avoid damaging the computer or tape drive, ensure that both are powered off while you
attach the SCSI cable.
1 Make sure you are connecting to a recommended SCSI bus type. See “Checking the SCSI
connection” on page 9. Do not connect the tape drive to the same bus as a RAID controller.
For optimum performance, we recommend that your HP StorageWorks DAT drive is installed
on a dedicated SCSI bus. If it is not, do not connect it to the same bus as your disk drive.
2 Perform a normal system shutdown and turn off the server and any connected peripherals.
3 Attach the VHD connection on the SCSI cable to the server’s external SCSI connector and
secure it by tightening the screws.
4 Attach the HD connection on the SCSI cable to one of the SCSI connectors on the rear panel
of the tape drive and secure it by tightening the screws. (See figure 5.)
5 Connect the multimode terminator to the drive’s other SCSI connector and tighten the screws to
secure it. The multimode terminator detects whether the host bus adapter is SE or LVD and
automatically provides the appropriate termination.
Why does the tape drive need a terminator?
Terminators are essential, as they provide the correct voltages on the SCSI bus and prevent
unwanted signal reflections from interfering with data transfers. The rule is:
There must be termination at both physical ends of the bus and only at the ends.
Normally the HBA forms one end of the SCSI bus and provides termination. You, therefore,
need to ensure that the other end of the bus is terminated. If the tape drive is at the end of
the SCSI bus, the terminator must be attached to the tape drive.
If you want to attach additional devices to the SCSI bus after the tape drive, you will need
to remove the SCSI terminator and attach the next device to this SCSI connector. Make sure
that you attach the terminator to the last device in the chain.
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