External Scsi Cabling And Termination - Sun Microsystems Enterprise 250 Owner's Manual

External SCSI Cabling and Termination

Use the following cabling guidelines to ensure proper device cabling and termination
on the external SCSI bus:
4 In order to maintain UltraSCSI performance, all cables used must be
UltraSCSI-compliant.
4 The external SCSI bus must be correctly terminated. Most Sun devices use
autotermination. See the documentation supplied with the device.
4 If all external mass storage devices use 68-pin connectors, connect all non-Sun
devices to the system first and connect a Sun autoterminating device to the end of
the chain.
4 If external mass storage devices consist of 68-pin devices and 50-pin devices,
connect the Sun 68-pin devices to the system first and terminate the chain with a
50-pin device and its terminator. The 68-pin device connected to the 68-50 pin
adapter cable must be autoterminating in order to terminate the high-order bits.
Caution -
Do not connect 68-pin devices after 50-pin devices; SCSI bus errors
will occur.
The following figures provide a summary of the cabling guidelines.
Figure 5–13
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Hardware Configuration