Siemens SINAMICS G150 - Real-Time (RT) and Isochronous Real-Time (IRT) Communication

Operation
6.9 Communication via PROFINET IO
Converter cabinet units
Operating Instructions, 07/2016, A5E03347396A
357
Note
CU320-2 DP and inserted CBE20
The cyclic process data channel for PROFIBUS DP is initially deactivated for a CU320
-2 DP
and inserted CBE20. However, it can be reactivated with parameter p8839 = 1 at any time
(see "Parallel operation
of communication interfaces").
References
Note
References
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 Organizat
ion e. V.
Haid
-und-Neu-Straße 7,
D
-76131 Karlsruhe
http://www.profibus.com,
Order Number 3.172, spec. Chp. 6
•
IEC 61800-7
6.9.2.2
Real-time (RT) and isochronous real-time (IRT) communication
Real-time communication
When communication takes place via TCP/IP, the resultant transmission times may be too
long and not defined to meet the production automation requirements. When communicating
time-critical IO user data, PROFINET IO therefore uses its own real-time channel, rather
than TCP/IP.
Real time means that a system processes external events over a defined period.
Determinism
Determinism means that a system will react in a predictable ("deterministic") manner.
With PROFINET IO with IRT, it is possible to precisely determine (predict) transmission
times.