Exabyte 230D Library Installation And Operation Manual page 246

Appendix B
If the library or any of the tape drives is the last device on the SCSI
bus, you must attach a terminator to the appropriate SCSI
connector at the back of the library.The SCSI terminator must
match the SCSI bus configuration (single-ended, LVD, or HVD;
wide or narrow).
Termination can be active or passive. If your host can transfer data
at more than 5 MB per second, use active termination. If your host
limits data transfer to 5 MB per second or less, use either active or
passive termination. For best results on a single-ended bus, use
active termination.
Each device on the SCSI bus must have a unique ID. The host
computer uses these IDs to identify each device. The SCSI ID also
determines which device has priority when more than one device
is trying to communicate with the host. The lower the ID, the
lower the priority of the device.
If you have one tape drive installed, the library uses two SCSI IDs,
one for the library itself and one for the tape drive. If you have
two drives installed, the library uses three IDs. Separate IDs allow
the library and tape drives to operate as independent devices,
receiving different sets of SCSI commands from the host.
232
Exabyte testing has shown that older passive termination
does not provide rising edge transitions that are fast or
clean enough at fast SCSI speeds.
The SCSI ID does not depend on physical location. For
example, the last device on a multi-device SCSI bus can
have a SCSI ID of 2.
Exabyte 230D