Siemens SITRANS SL, Руководство по эксплуатации, Страница: 211 / 212

Glossary
SITRANS SL
Operating Instructions, 12/2010, A5E01132948-04
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STEP 7
STEP 7 is programming software for the S7-300 and S7-400 controller families
STL
Statement list -> User program in which control functions are listed in the form of statements.
Termination
The termination (lat. terminare for "end") used in telecommunications technology describes
the completion of a signal path. The termination results in minimization of signal reflections
which could otherwise lead to interferences. The termination is normally used at the physical
end of a signal path.
Zone 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.
Zone 1
Area in which a dangerous, potentially explosive gaseous atmosphere occasionally forms
during the normal operation of a device.
Zone 2
Area in which a dangerous, potentially explosive gaseous atmosphere usually doesn't form,
or only for a short time period, during the normal operation of a device.