Operation
6.8 PROFINET IO
Time synchronization and isochronous mode on PROFINET IO with IRTflex and IRTtop
In addition, a high-performance and isochronous connection to the application with low load
on the application CPU is also ensured. Isochronous data transfer with cycle times well
below one millisecond and with a deviation in the cycle start (jitter) of less than a
microsecond provide sufficient performance reserves for demanding motion control
applications.
In contrast to standard Ethernet and PROFINET IO with RT, the telegrams for PROFINET IO
with IRT are transmitted based on a schedule.
Sync domain
The sync domain can be configured in HW Config. SINAMICS S120 is an IO device and has
to be assigned to a sync master as a sync slave.
6.8.4.5
PROFINET IO with IRTflex
Description
For PROFINET IO with IRTflex, the largest IRT bandwidth requirement of a device plus a
reserve for the complete network is reserved. It is not defined when which telegram in the
IRT time window over which port will be transferred.
Figure 6-46
As for PROFINET IO with IRTtop, the synchronization of all devices on a shared Sync
master is necessary. All synchronized devices combined form a sync domain.
Send clock
A send clock of 0.5 ms (planned as of FW2.5 SP1))/1.0 ms, 2.0 ms and 4.0 ms can be
selected.
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Overview of communication with IRTflex
Drive converter cabinet units
Operating Instructions, 07/07, A5E00288214A