HP CD-Writer Plus External 9200e Drive - Manual (Page 6)

6 How to Set the SCSI ID
The SCSI Card
A SCSI card (not included) and its software must be installed and
functioning properly before installing the CD-Writer Plus. Consult the
documentation that came with your SCSI card or your computer for
details.
If you purchase a SCSI card (also known as a host adapter or SCSI board)
for your computer make sure it is:
■ PCI Bus
■ SCSI-2
The SCSI Devices
SCSI IDs
Each device in a SCSI chain must have a different identifying number
between 0 and 7 called the SCSI ID (SCSI ID 7 is usually reserved for the
SCSI card). The SCSI ID for external devices is often set with a switch on
the back of the device.
Termination
The SCSI devices at either end of a chain must be terminated so the
computer knows that there are no more devices in the chain. External
devices are often terminated using a switch on the back of the device or
connecting a resistor. The CD-Writer Plus adjusts its termination
automatically.
If you do not have any internal devices, the SCSI card itself is one end of
the chain and must be terminated. Most newer SCSI cards adjust their
termination automatically.
How to Set the SCSI ID
Why might I need to change the SCSI ID?
A SCSI card may have several devices attached to form a SCSI chain. Each
device in the chain must have a different SCSI ID. You will need to
change the SCSI ID on the CD-Writer Plus if the ID set at the factory is
already in use by another device.