NonStop S-Series System Expansion and Reduction Guide

Table Of Contents
Glossary
G-Series Common Glossary
Glossary-29
EMI
removes power from all computer equipment in the room. The EPO connectors prevent
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. HP 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 HP 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.
empty string. In C and C++ programs, a character string that begins with a null character.
This term is synonymous with
null string.
EMS. See Event Management Service (EMS).
EMS collector. An Event Management Service (EMS) process to which subsystems report
events.
enclosure. Similar to a cabinet in HP NonStop™ K-series systems. An enclosure can
contain components of a system or a peripheral. Base enclosures are placed on the
floor and can have other enclosures stacked on top of them. Stackable enclosures can
be placed on top of other enclosures. See also system enclosure
and peripheral
enclosure.
enclosure interleaving. On HP NonStop™ S-series systems, configuring a mirrored disk
volume to use two separate system enclosures. For internal disk drives, the two disk
drives of the mirrored volume can be in separate enclosures. For external disk drives,
the adapters connected to the two disk drives of the mirrored volume can be in
separate enclosures.