Glossary
ATEX
ATEX is an abbreviation of the French term "Atmosphère explosible" (potentially explosive
atmosphere). ATEX stands for both EC directives in the area of explosion protection: ATEX
product directive 94/9/EC and ATEX operating directive 1999/92/EC.
Auxiliary power supply
Auxiliary power supply refers to an electrical supply or reference voltage which some electrical
circuits require apart from the standard supply. The auxiliary power supply can, for example,
be specially stabilized, have a particular level or polarity and/or other properties which are
important for the correct functioning of switch components.
Auxiliary voltage
Dangerous failure
Failure with the potential to switch a safety-instrumented system to a hazardous or non-
functioning safety state.
EEPROM
EEPROM (Electrically Erasable Programmable Read-Only Memory): a non-volatile, electronic
memory module.
EEPROMs are often used where individual bytes of data (e.g. configuration data or runtime
meters) change over time and must be stored safely in the event of a mains power failure.
Failure/Fault/Error
Failure:
A resource is no longer capable of executing a required function.
Fault/Error:
Undesired state of a resource indicated by its incapability of executing a required function.
Fault/Error
Final controlling element
Converter that converts electrical signals into mechanical or other non-electric variables.
SITRANS P320/P420 (mA/HART)
Operating Instructions, 06/2018, A5E44852162-AA
253