NonStop System Glossary

electrostatically shielded transformer
A transformer that has a metallic shield placed between the primary and secondary windings. This
shield diverts high-frequency signals to ground.
ELF
See Executable and Linkable Format (ELF) or extended link format (ELF).
eInspect
The name of the command used to start the Native Inspect product.
emergency power off (EPO)
Describes equipment used to automatically disconnect all electrical power to connected equipment
if an emergency occurs. A computer room’s main EPO system shuts off all room equipment (except
for lighting and fire-sensor equipment) if a fire occurs. An equipment zone EPO shuts off power to
all connected computer equipment if the EPO switch is activated.
emergency power-off (EPO) connector
A two-pin connector on the service side of a NonStop S-series system enclosure that allows an
external signal to disable the batteries in the enclosure during emergency conditions. A cable is
attached from the connector to a relay band or push button typically located near the door of a
computer room. Pushing the EPO button removes power from all computer equipment in the room
and prevents the batteries from powering the server after power is removed. EPO capabilities are
required in the United States when a server is installed in a computer room designed to comply
with the special construction and fire protection provisions of the United States’ national electrical
code (or at other sites as required by local regulations).
EMI
See electromagnetic interference (EMI).
emitter-coupled logic (ECL)
A logic that expresses digital signals in differential negative voltage levels, from -8 volts to -1.8
volts. NonStop S-series servers containing ServerNet expansion boards (SEBs) use ECL ServerNet
cables. An ECL plug-in card (PIC) allows the modular SEB (MSEB) and I/O multifunction (IOMF)
2 customer-replaceable unit (CRU) to use ECL ServerNet cables.
emitter-coupled logic (ECL) plug-in card (PIC)
A plug-in card (PIC) for the modular ServerNet expansion board (MSEB) and I/O multifunction
(IOMF) 2 customer-replaceable unit (CRU) that supports the emitter-coupled logic (ECL) interface.
See also emitter-coupled logic (ECL) and plug-in card (PIC).
emitter-coupled logic (ECL) ServerNet cable
A ServerNet cable that uses emitter-coupled logic (ECL). Before the modular ServerNet expansion
board (MSEB) was introduced, ECL was the only ServerNet cable technology used by NonStop
S-series servers. You can connect an ECL ServerNet cable directly to a ServerNet expansion board
(SEB) or to an MSEB using an ECL plug-in card (PIC).
empty directory
In the Open System Services (OSS) file system, a directory that contains only an entry for itself and
an entry for its parent directory.
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