3–4 Configuring the Pedestal
3.4 Internal SCSI Buses
Figure 3–3 shows the three internal SCSI bus configurations. Digital recommends that the
internal SCSI bus length be kept as short as possible.
The total internal SCSI bus cable length is distance from the controller terminator to the
pedestal terminator. To calculate this distance, add the following elements:
•
The distance from the controller terminator to the controller output connector
•
The pedestal input cable length (rear panel to connector J10)
•
The pedestal backplane SCSI bus length (either “A,” “B,” or “AB”) from either J10 or
J16 to the terminator (see Table 3–4).
Table 3–4 Determining SCSI Bus Lengths
Length
SCSI Bus Element
Bus
From
To
Meters
Inches
Upper Backplane
A
J10
J11
0.41
16.0
Lower Backplane
B
J16
J17
0.25
10.0
Backplane
AB
J10
J17
0.73
28.8
Cable, Input/Output
0.30
12.0
Cable, Jumper
0.07
2.8
Output Cable
0.30
12.0
BA35X–AA 5.25-Inch Device Option Kit
Cable, Input 5.25-inch device
0.64
25.0
Cable, Adapter, 68-pin to 50-pin
0.05
2.0
Figure 3–3 BA346–KB SCSI Bus Lengths
`
CXO-4477A-MC
BA346-AA
OPTION
J10
J11
J16
J17
SCSI ADDRESS 0
SCSI ADDRESS 1
SCSI ADDRESS 2
SCSI ADDRESS 3
SCSI ADDRESS 4
SCSI ADDRESS 5
SCSI ADDRESS 6
BUS
"A"
BUS
"AB"
BUS
"B"
CAUTION
The recommended cable lengths are when the total
internal SCSI is less than 1 meter (39 inches) for both
the controller and pedestal.
If the total internal bus length exceed 1 meter (see
Section 3.4), you must use a shorter cable for proper
SCSI bus operation.
Summary of Contents for BA346-K Series
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