18 | Elite 23 Installation Guide, Rev. A |
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 Elite 23 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.