Real-Time (Rt) And Isochronous Real-Time (Irt) Communication - Siemens sinamics dcp Operating Instructions Manual

Cycle communication using PROFINET IO with IRT or using RT is possible on all drive units
equipped with a PROFINET interface. This means that problem-free communication using
other standard protocols is guaranteed within the same network.
Note
PROFINET for drive technology is standardized and described in the following document:
PROFIBUS Profile PROFIdrive – Profile Drive Technology
Version V4.1, May 2006,
PROFIBUS User Organization e. V.
Haid-und-Neu-Strasse 7
D-76131 Karlsruhe
Link: (www.profibus.com)
Order no. 3.172, spec. Chapter 6
• IEC 61800-7
NOTICE
Inserting the CBE20 Communication Board deactivates the cyclic PZD channel for
PROFIBUS DP.
8.6.2.1

Real-time (RT) and isochronous real-time (IRT) communication

Real-time communication
When communication takes place via TCP/IP, the resulting transmission times may be too
long and non-deterministic to meet production automation requirements. When
communicating time-critical IO user data, PROFINET IO therefore uses its own real-time
channel, rather than TCP/IP.
Determinism
Determinism means that a system will react in a predictable ("deterministic") manner.
With PROFINET IO, it is possible to precisely determine (predict) transmission times.
PROFINET IO with RT (Real Time)
Real time means that a system processes external events over a defined period.
Process data and alarms are always transferred in real time (RT) within the PROFINET IO
system. RT communication provides the basis for data exchange with PROFINET IO. Real-
time data is treated with a higher priority than TCP(UDP)/IP data. Transmission of time-
critical data takes place at guaranteed time intervals.
SINAMICS DCP
Operating Instructions, 05/2016, A5E34382853K
8.6 Communication via PROFINET IO
Operation
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