Communication
11.2 PROFINET
S7-1200 Programmable controller
944 System Manual, V4.2, 09/2016, A5E02486680-AK
Procedure: Adjusting the real-time settings
To ensure that all IO controllers and shared devices are operated with the appropriate send
clock and that the update times are calculated correctly based on the communication load,
you must adjust and check the following settings:
1. Select the project whose IO controllers have access to the PROFINET interface and the
ports of the shared device.
2. Select the interface module of the shared device in the network view.
3. In the Inspector window, navigate to the "PROFINET interface > Advanced options >
Real time settings > IO cycle" area.
4. In the "Shared device" area, set the number of project-external IO controllers. The
maximum number depends on the IO device (specification in GSD file).
5. You must set the same send clock for each IO controller that has access to modules and
submodules of the shared device:
● If you configure the IO controller with STEP 7 (TIA Portal):
– Open the corresponding project.
– Select the PROFINET interface of the IO controller.
– Select the "Advanced options > Real time settings > IO communication" area in the
Inspector window and set the shared send clock.
● If you configure the IO controller with a different engineering tool:
– Select the PROFINET interface of the shared device in STEP 7 (TIA Portal) and read
out the send clock on the shared device ("Advanced options > Real time settings"
area).
– Enter the read send clock in the engineering tool.
Note
If you configure all IO controllers
that have access to the shared device in STEP 7
Portal), you can set shorter send clocks on the IO controller than supported by the
shared device (send clock adaptation).
You must compile the configurations for the different IO controllers and load them to the
CPUs one after the other.
Due to the distributed configuration with separate projects, STEP 7 does not output
consistency errors in the case of incorrect access parameter assignment. These are
examples of incorrect access parameter assignment:
● Several IO controllers have access to the same module
● IP address parameters or send clocks are not identical
These errors do not show up until controller operation and are output as configuration errors.