Siemens sinamics dcp - 7.6.3 RT classes for PROFINET IO

Operation
7.6 Communication via PROFINET IO
SINAMICS DCP
Operating Instructions, 09/2019, A5E34382853K
263
7.6.3 RT classes for PROFINET IO
PROFINET IO is a scalable real-time communication system based on Ethernet technology.
The scalable approach is expressed with three real-time classes.
RT
RT communication is based on standard Ethernet. The data is 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 update cycle in which cyclic data is 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"
is not supported by SINAMICS DCP.
● IRT "high performance"
Software preconditions for configuring IRT:
● STEP 7 5.4 SP4 (HW Config)
Note
F
or further information about configuring the PROFINET interface for the I/O controller and
I/O device, please refer to the following document: SIMOTION SCOUT Communication
System Manual.
IRT "high flexibility"
Note
IR
T "high flexibility" is not supported by SINAMICS DCP.
The telegrams are sent cyclically in a deterministic cycle (Isochronous Real Time). The
telegrams are exchanged in a bandwidth reserved by the hardware. One IRT time interval
and one standard Ethernet time interval are created for each cycle.