Technical data

GL–5
Compaq HSG80 Array Controller ACS Version 8.3 Maintenance and Service Guide
dual-redundant
configuration
A controller configuration consisting of two active controllers operating as a
single controller. If one controller fails, the other controller assumes control
of the failing controller’s devices.
dual-simplex A communications protocol that allows simultaneous transmission in both
directions in a link, usually with no flow control.
DUART Dual universal asynchronous receiver and transmitter. An integrated circuit
containing two serial, asynchronous transceiver circuits.
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.
ECC Error checking and correction.
EDC Error detection code.
EIA The abbreviation for Electronic Industries Association. EIA is a standards
organization specializing in the electrical and functional characteristics of
interface equipment. Same as Electronic Industries Association.
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.
ESD Electrostatic discharge. The discharge of potentially harmful static electrical
voltage as a result of improper grounding.
extended subsystem A subsystem in which two cabinets are connected to the primary cabinet.
external cache
battery
See ECB.
failedset A group of failed mirrorset or RAIDset devices automatically created by the
controller.