Hitachi 8450H/R - Manual (Page 53)

Ch 3: Installing Optional Devices
Hitachi PC VisionBase 8450H/R Server 49
Daisy Chain and Terminating Resistor
A maximum of seven SCSI devices can be serially connected to one SCSI controller. Such a serial connection is
referred to as a daisy chain connection. The SCSI devices at both ends of the daisy chain require a resistor called a
terminator (terminating resistor). If you attach a terminator onto another SCSI device, that SCSI device will not
operate normally.
NOTE: A terminating resistor is installed for the following devices supplied as standard in the Hitachi PC
VisionBase 8450H/R Server: the SCSI controller, the disk array controller board, and the platter board on
which internal hard disks are to be installed.
In Hitachi PC VisionBase 8450H/R Server you need not mount a terminating resistor onto removable
devices; the SCSI cable to be connected already has one mounted.
SCSI IDs
SCSI IDs are numbers used to identify SCSI devices; 0 to 6 are used. Make sure that 0 is used for the SCSI ID for
your starter hard disk. Be sure to set SCSI IDs so that there is no duplication within the group of SCSI devices (those
within the same daisy chain) connected with the same SCSI controller.
NOTE: The SCSI ID for the SCSI controller is set to 7.
In Hitachi PC VisionBase 8450H/R Server, up to six SCSI devices can be connected to one controller.
If the same SCSI ID is used the more than one SCSI device in a group of SCSI devices connected to the
same SCSI controller, the SCSI devices will malfunction.
SCSI board
(a terminating resistor is mounted)
Daisy chain image
SCSI
device
A terminating resistor is mounted here
SCSI cable