Siemens SITRANS SL Operating Instructions Manual page 208

Glossary
Div. 0
Area in which dangerous, potentially explosive gaseous atmospheres can form frequently,
constantly or over long time periods during the normal operation of a device. Div 0 (US
standard) corresponds to Zone 0 (European standard).
Div. 1
Area in which dangerous, potentially explosive gaseous atmospheres are permanently
present during the normal operation of a device. Div 1 (US standard) corresponds to Zone 0
and Zone 1 (European standard).
Div. 2
Area in which normally less dangerous, potentially explosive gaseous atmospheres form
during the normal operation of a device. Div 2 (US standard) corresponds to Zone 2
(European standard).
EEPROM
Electrically Erasable Programmable Read Only Memory
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.
Electro Magnetic Compatibility
Definition as per the EMC law:
EMC is the capability of a device to operate satisfactorily in an electromagnetic environment
without itself emitting electromagnetic signals which interfere with other devices in that
environment.
Endian
Date is sometimes saved in a different order in certain computer architectures. Intel-based
computers, for example, save the data differently from the Siemens controllers (S7), namely,
in reverse sequence. The byte sequence from Intel, termed Little Endian, is therefore the
reverse S7 byte sequence, Big Endian. The following applies to these two forms:
● Little Endian: The most significant byte is located at the right-hand end of a word.
● Big Endian: The most significant byte is located at the left-hand end of a word.
Ethernet
This is a specific type of local network that works according to a standard defined by Intel,
DEC and Xerox.
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Operating Instructions, 12/2010, A5E01132948-04
SITRANS SL