Siemens SITRANS TH400, Руководство по эксплуатации, Страница: 58 / 62

Glossary
SITRANS TH400
58
Operating Instructions, 06/2010, A5E01018688-02
Microcontroller
Microcontrollers (also written µControllers, µC, MCU) are single-chip computer systems
which have virtually all their components - such as main processor, program memory,
working memory and the input/output interfaces - accommodated on a single chip.
Non-volatile memory
→
EEPROM
Risk
The combination of probability of a damage occurring and its magnitude.
RS -232
RS: Recommended Standard
A recognized industry standard for serial data transfer. For cable lengths shorter than 15 m.
No differential evaluation. Transmit and receive on different lines.
Safety function
Defined function executed by a safety-instrumented system with the objective of achieving or
maintaining a safe system status taking into account a defined dangerous occurrence.
Example:
Limit pressure monitoring
Safety Instrumented Function
→ SIF
Safety Integrity Level
→
SIL
Safety-instrumented system
A safety-instrumented system executes the safety functions that are required to achieve or
maintain a safe status in a system. It consists of a sensor, logic unit/control system and final
controlling element.
Example:
A safety-instrumented system is made up of a pressure transmitter, a limit signal sensor and
a control valve.
Sensor
Converter that converts mechanical or other non-electrical variables into electrical signals.