DEC DS-HSZ22-AA, User Manual

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Chapter 1. Product Overview
EK–SMCPO–UG. A01 1–7
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Per LUN write cache/write back selection
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Configuration/Maintenance via RS-232 or host SCSI channel using SWCC
(StorageWorks Command Console)
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Update of firmware via host channel
1.4.3 Pedestal Power Supplies
The pedestal has two interchangeable, air-cooled, AC power supply modules lo-
cated at the rear of the unit. The power supplies provide redundant power if one
of the units should malfunction. Each supply pr5 and +12 Vdc to power
the RAID controller, EMU, and the storage SBBs in the pedestal. In addition,
each unit contains a high-speed fan for pedestal cooling. The upper power supply
is designated as "A" and the lower as "B". The unit contains an ac power recep-
tacle, a power status LED, a fan, and a latching slider switch to secure the supply
in the pedestal.
1.4.4 Uninterruptable Power Supply (UPS)
The UPS is separate and free-standing unit designed to protect the pedestal from
problems associated with poor quality AC power or a complete loss of AC
power. The UPS is connected between the AC outlet and the line input of the
pedestal power supply “B” to provide battery backup power.
The major features of the UPS include Cell Saver Technology (doubles battery
life and speeds recharge time), hot-swap batteries, and network surge protection.
The front panel display has user controls (LEDs and control buttons) and the rear
panel contains a COMM port, which provides UPS status to the EMU in the ped-
estal. The rear panel also contains the network surge protector, a reset button,
and four power receptacles. An audible alarm is activated when input power
fails, as a Low Battery Warning, or whenever the UPS is in need of servicing.
The UPS automatically recharges its battery when power is returned following a
power failure. Recharge time is four to six hours depending on the energy re-
quirements of your load and the length of the power outage.
Its own installation, operation, and service manual support the UPS. The manual
describes the UPS in detail and is part of the documentation set enclosed with
your subsystem.