Single-Ended I/O Module
5–4 UltraSCSI RAID Enclosure
Controlling the Internal SCSI Bus
The I/O module controls the internal SCSI bus in the following
manner:
•
Isolates the internal SCSI bus from the external SCSI bus
•
Provides single-ended SCSI bus termination for each internal bus
•
Disconnects the internal SCSI bus from the external SCSI bus
when directed by the EMU
•
Distributes TERMPOWER (+5 V dc) to the internal SCSI bus
•
Turns O
N
the green internal TERMPOWER LED when internal
TERMPOWER is present
•
Turns O
FF
the green internal TERMPOWER LED when there is
either an internal TERMPOWER overcurrent condition or no
TERMPOWER
Controlling the External SCSI Bus
The I/O module controls the external SCSI bus in the following
manner:
•
Provides single-ended SCSI bus termination for the external bus
•
Distributes TERMPOWER (+5 V dc) to the external SCSI bus
•
Turns O
N
the green external TERMPOWER LED when external
TERMPOWER is present
•
Turns O
FF
the green external TERMPOWER LED when there is
either an external TERMPOWER overcurrent condition or no
TERMPOWER
•
Disables the external bus termination when a cable is connected
to the right VHDCI connector