Polyrack Tech-Group - Glossary from E to H

EMC

Electromagnetic compatibility is the ability of an electrical device to
function satisfactorily in its electromagnetic environment without affecting
this environment and other devices that may be present in it.
Three European standards define the basis for electromagnetic compatibility.
The EN 50081 deals with emitted interference in residential, commercial, industrial
and small business areas.
The EN 50081 deals with the interference immunity in the same areas.
The standard 550222 defines the limit values and measuring methods for radio
interference for information technology devices.

EN

Abbreviation for "European Norm"

EN 55022

European specification defining standards for information technology equipment and essentially covers the topics of radio interference as well as defining limits and measuring methods.

EN 60950

European specification defining the security of equipment for information technology.

ESD

1. Abbreviation for “Electrostatic Discharge”. This is the process of charge equalization between solid, liquid or gaseous media that have different electrostatic charges. The charge equalization is usually accompanied by a spark or other sign of discharge.
2. Abbreviation for “Electrostatic Sensitive Devices”

ETSI

Abbreviation for "European Telecommunications Standards Institute“. Members of the ETSI include parts of the EU administration, European manufacturers and development institutes. ETSI Standards are referred to as ETS (European Telecommunication Standards).

Euroboard

The euroboard is a circuit board according to a DIN standard. The card measures 100 x 160 mm.

HP

Abbreviation for "Horizontal Pitch" or standard width measurement which defines the width for plug-in modules in the 19” construction system. One HP equals 5.08 mm.

Hot Swap

Hot Swap
Refers to the exchange of computer components while the computer is running. There are three defined stages:
1. Basic hot swap: the component that is going to be changed has to be deactivated or the computer configuration has to be changed first.
2. Full hot swap: software in the component to be changed or in another component takes care of the activation or deactivation automatically.
3. High availability model: a separate hot swap controller takes control. This allows for failed boards to be deactivated automatically and therefore prevents the computer from crashing.

Heatsink

Heatsinks allow excessive heat that is given off by components to be dissipated into the environment through an enlargement of the surface.