IBM Netfinity 6000R User Reference Manual page 121

SCSI cabling requirements
If you plan to attach external SCSI devices, you must order additional SCSI cables. To
select and order the correct cables for use with external devices, contact your IBM
reseller or IBM marketing representative.
For information about the maximum length of SCSI cable between the terminated
ends of the cable, refer to the ANSI SCSI standards. Adhering to these standards will
help ensure that your server operates properly.
Setting SCSI IDs
Each SCSI device connected to a SCSI controller must have a unique SCSI ID. This ID
enables the SCSI controller to identify the device and ensure that different devices on
the same SCSI channel do not attempt to transfer data simultaneously. SCSI devices
that are connected to different SCSI channels can have duplicate SCSI IDs. The
following table lists the SCSI IDs for devices that are connected to one channel. Note
that the hot-swap hard disk drive bay numbers are from bottom to top.
Drive bay 1:
SCSI ID 0
Drive bay 2:
SCSI ID 1
Drive bay 3:
SCSI ID 2
Backplane:
SCSI ID 8
The hot-swap-drive backplane controls the SCSI IDs for the internal hot-swap drive
bays. However, when you attach a SCSI device to the external SCSI connector, you
must set a unique ID for the device. Refer to the information that is provided with the
device for instructions to set its SCSI ID.
SCSI connector pin-number assignments
The following table shows the pin-number assignments for the 68-pin SCSI
connectors.
Pin Signal
1 +Data 12
2 +Data 13
3 +Data 14
Table 13. 68-pin SCSI connector pin-number assignments
Standard Optional
Drive bay 4:
SCSI ID 12
Drive bay 5:
SCSI ID 13
Drive bay 6:
SCSI ID 14
Backplane:
SCSI ID 9
Table 12. SCSI IDs for hot-swap hard disk
drives and backplanes
34
68
Pin
35 -Data 12
36 -Data 13
37 -Data 14
1
35
Signal
Chapter 6. Installing options
107