Siemens SINAMICS S120 Function Manual page 776

Communication
10.3 Communication via PROFINET IO
Set the RT class
The RT class is set by means of the properties of the controller interface of the IO controller.
If RT class IRT "high performance" is set, it is not possible to operate any IRT "high
flexibility" devices on the IO controller and vice versa. IO devices with RT can always be
operated, regardless of the IRT class setting.
You can set the RT class in the HW Config for the associated PROFINET device.
1. In HW Config, double-click item PROFINET interface in the module.
2. Select the RT class under RT class on the "Synchronization" tab.
3. Once you have selected "IRT", you can also choose between option "high flexibility" and
4. Confirm with "OK".
Synchronization domain
The sum of all devices to be synchronized form a synchronization domain. The whole
domain must be set to a single, specific RT class (real-time class) for synchronization.
Different synchronization domains can communicate with one another via RT.
For IRT, all IO devices and IO controllers must be synchronized with a common
synchronization master.
RT allows an IO controller to communicate with a drive unit outside a synchronization
domain or "through" another synchronization domain. As of version 5.4 SP1, STEP 7
supports multiple synchronization domains on a single Ethernet subnet.
Example:
● Synchronization domain IRT: SIMOTION2 with SINAMICS
● SINAMICS, which is assigned to the IO system of SIMOTION1, is arranged in the
774
The "Properties" dialog box opens.
"high performance".
topology in such a way that its RT communication must be established through the IRT
synchronization domain.
Figure 10-44 RT communication across the limits of synchronization domains
Function Manual, (FH1), 01/2013, 6SL3097-4AB00-0BP3
Drive functions