Rt Classes For Profinet Io - Siemens Sinamics S110 Function Manual

Communication
9.4 Communication via PROFINET IO
Connecting the IO supervisor
You can go online with the STARTER in a number of ways, which are illustrated below:
Figure 9-40
9.4.3

RT classes for PROFINET IO

PROFINET IO is a scalable realtime communication system based on Ethernet technology.
The scalable approach is expressed with three realtime classes.
RT
RT communication is based on standard Ethernet. The data are transferred via prioritized
Ethernet telegrams. Because standard Ethernet does not support any synchronization
mechanisms, isochronous operation is not possible with PROFINET IO with RT! The real-
time capability is comparable with the present PROFIBUS DP solutions with 12 MBaud, i.e. a
sufficiently large bandwidth portion is available for the parallel transmission of IT services on
the same line.
The real update cycle in which cyclic data are exchanged depends on the bus load, the
devices used and the quantity framework of the I/O data. The update cycle is a multiple of
the send cycle.
IRT
Two options are available with this RT class:
● IRT "high flexibility"
● IRT "high performance".
624
Connecting the IO supervisor
Function Manual, 01/2011, 6SL3097-4AB10-0BP3
Function Manual