Siemens SIMATIC PROFINET Function Manual page 203

Configuration
You specify whether or not a configuration can be used multiple times in the properties of the
IO system.
All other parameter settings for the configured devices are then set automatically by STEP 7
and checked during compilation.
Boundary conditions
To prevent a standard machine project from having dependencies on other devices outside
of the machine, observe the following:
● A standard machine project consists of an IO controller and the corresponding
IO devices. You should therefore configure only one CPU as IO controller and the
corresponding IO devices in the standard machine project.
● Do not use connection configured at both ends for the communication. Instead, use only
a connection configured at one end or unspecified connections if necessary.
Background: To configure the communication in a STEP 7 project, it is always possible to
set the IP address parameters in the project. For multiple use IO systems, however, this
strategy is not possible since the IP address parameters of the IO controller and the
assigned IO devices are assigned locally. At the time of the configuration, the IP address
parameters are therefore unknown.
If you nevertheless want to configure communication with devices on PROFINET, for
example with a central coordinator, you can only use communications mechanisms that
allow dynamic assignment of the IP address parameters in the user program.
Example: Open User Communication
If, for example, the device is configured as an active end point (initiator of the
connection), the IP address parameters can be stored, for example, in a data block. You
then supply the data block with the currently valid IP address parameters during
commissioning. For this dynamic type of IP address parameter assignment, there is no
system support; in other words, if you change the configuration of the system, the IP
address parameters are not automatically adapted.
You will find a description of handling instructions for Open User Communication under
this keyword in the STEP 7 online help.
PROFINET with STEP 7 V14
Function Manual, 09/2016, A5E03444486-AG
Functions
5.9 Standard machine projects
203