HP storageworks HSG80 Reference Manual page 216

Glossary
ECB
External Cache Battery. The unit that supplies backup power to the cache module in the event
the primary power source fails or is interrupted.
EIA
Electronic Industries Association. EIA is a standards organization specializing in the electrical
and functional characteristics of interface equipment.
EMU
Environmental Monitoring Unit. A unit that provides increased protection against catastrophic
failures. Some subsystem enclosures include an EMU which works with the controller to
detect conditions such as failed power supplies, failed blowers, elevated temperatures, and
external air sense faults. The EMU also controls certain cabinet hardware including DOC
chips, alarms, and fan speeds.
environmental monitoring unit
See EMU
ESD
Electrostatic Discharge. The discharge of potentially harmful static electrical voltage as a
result of improper grounding.
extended subsystem
A subsystem in which one or two enclosures are connected to the primary enclosure.
external cache battery
See ECB
F_Port
A port in a fabric where an N_Port or NL_Port may attach.
fabric
A group of interconnections between ports that includes a fabric element.
failback
The process of restoring data access to the newly-restored controller in a dual-redundant
controller configuration. See also failover.
Glossary–8 HSG80 Array Controller V8.7 Command Line Interface Reference Guide