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Chapter 5 : Connecting Hard Disk Drives
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Chapter 5 : Connecting Hard Disk Drives
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Chapter 5 : Connecting Hard Disk Drives
SCSI cables
Cable length should be kept low. The total length of the SCSI daisy chain must not exceed
6m (20ft).
SCSI ID setting
The SCSI bus is a parallel type connection, and data on the bus is available to all devices.
However, communication will be between two devices only, so each device is allocated an
ID number, like an address number. In this way, only the device with the ID number that
is specified in the data will actually read and respond to the data.
If two devices share the same ID number, the system will probably crash, so make sure that
each device has a unique ID number. SCSI devices usually have a DIP switch or, like the
CBX-D3, a thumbwheel switch that you can use to set the ID. Refer to the instructions
supplied with the device.
The example above shows seven devices (computer and six peripherals) connected in a
SCSI daisy chain. Each device has a different ID number. Note that the last device in the
chain is terminated. In most cases SCSI ID 7 is reserved for use by the computer, and ID
0 for the internal hard disk. Do not use either of these IDs for any other SCSI device.
HARD DISK
1
CBX-D3
HARD DISK
2
SCSI
SCSI
SCSI
Total length of SCSI daisy chain must not exceed 6m (20ft)
HARD DISK
1
CBX-D3
HARD DISK
2
SCSI
SCSI
SCSI
ID No. 1
ID No. 2
ID No. 3
HARD DISK
3
SCSI
SCSI
DEVICE
SCSI
ID No. 4
ID No. 5
SCSI
DEVICE
SCSI
ID No. 6
This device is
terminated
