Glossary
ET 200S
Manual, Edition 10/2005, A5E00514527-01
Glossary-7
Provider-consumer principle
Unlike PROFIBUS DP, both partners on PROFINET IO are independent providers for
transmission of data.
Real time
Real time means that a system processes external events within a defined time.
Determinism means that a system responds in a predictable (deterministic) manner.
Both requirements are important for industrial networks. PROFINET satisfies these
requirements. Thus, as a deterministic real-time network, PROFINET is designed as follows:
•
The transfer of time-critical data between different stations via a network is guaranteed
within a defined interval of time.
•
To this end, PROFINET has an optimized communication channel for real-time
communication: Real time (RT).
•
The time of transfer can be accurately determined.
•
It is ensured that seamless communication can take place in the same network by means
of other standard protocols, such as industrial communication for PG/PC.
Reference data companions
A value is assigned to every peripheral module in the input or output data telegram which
gives evidence about the quality of this reference date. For example outputs of a module can
thus be switched off without influencing other modules.
Reference potential
Potential from which the voltages of the circuits involved can be observed and/or measured.
Reversing starter
A reversing starter is a → motor starter that determines the direction of rotation of a motor. It
consists of a circuit breaker and two contactors.
Segment
The bus line between two terminating resistors forms a segment. A segment contains 0 to 32
→ bus nodes. Segments can be interconnected by means of RS 485 repeaters.
SELV
Safety Extra Low Voltage
Slave
A slave can only exchange data with a → master when requested by it to do so. By slaves we
mean, for example, all DP slaves such as ET 200X, ET 200M, ET 200S, etc.
Содержание Simantic ET 200S
Страница 8: ...Table of contents ET 200S viii Manual Edition 10 2005 A5E00514527 01 ...
Страница 242: ......
Страница 270: ...Glossary ET 200S Glossary 10 Manual Edition 10 2005 A5E00514527 01 ...