Chapter 1. Product Description
EK–SMCPP–UG. A01
1–15
1.3.3 Power Verification and Addressing (PVA) Module
Proper operation of the subsystem, whether it be a master or an expansion
enclosure, requires both a PVA module and an EMU module. The PVA (Figure
1-10) and its associated EMU ensures that all major UltraSCSI components are
functioning properly. When an error condition occurs, these modules notify the
user that a problem exists. The controller identifies the specific problem. The
PVA and EMU LED displays identify possible causes of the problem.
The PVA mounts in the lower right section of the enclosure, directly above the
controller. The PVA and EMU have the same physical dimensions, use the same
type connectors, and are mounted next to each other – the EMU on the left and
the PVA on the right (see Figure 1-6). They are not interchangeable.
Figure 1–10 Power Verification and Addressing (PVA) Module
As shown in Figure 1-10, the major user-accessible components of the PVA
include the following:
•
The dc power shutoff switch includes a green power status LED
•
The UPS connector (RJ-45) for future expansion
•
The enclosure SCSI address switch that establishes the enclosure address
and thereby the SCSI bus Ids for each storage device
