HP Surestore 160ex - Optical Jukebox, Руководство по обслуживанию, Страница: 205 / 230

Theory of Operation
SCSI Interface PCA
Chapter 6 6-13
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Figure 6-6 SCSI Interface PCA
The jukebox communicates to the PCA through a GPIO bus.
The differential and single-ended connectors are on the top of the PCA
and the single-ended bus connection to the jukebox is on the bottom. A
slider switch between the two external connectors selects which type of
input will be accepted.
Four jumpers select the configuration for termination alternatives
— J6 - enable/disable differential host TERMPOWER. PIN 1 and 2
jumpered together allows the PCA to provide TERMPOWER to
the differential external [host] SCSI bus (default).
— J5 - enable/disable internal bus TERMPOWER. PINS 1 and 2
jumpered together allows the PCA to provide TERMPOWER to
the internal SCSI bus (default).
— J4 - bus terminator configuration. PIN 1 and 2 jumpered together
enable bus termination (default). When enabled, active
termination is supplied for the internal bus at this PCA;
termination at the other end of the SCSI cable is by a clamp
terminator attached to the SCSI cable near the last drive
connection.
— J1 - enable/disable single-ended host TERMPOWER. PIN 1 and 2
jumpered together allows the PCA to provide TERMPOWER to
the single-ended external [host] bus (default).