Chapter 4. PROFINET System Operation
GFK-2571N
May 2018
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4.4
Data Coherency
In a PACSystems PROFINET network, it is important to note that I/O data coherency is at the PROFINET
submodule level. The PROFINET Controller coherently transfers I/O data to and from the CPU on a PROFINET
submodule basis. This means that output data from a single CPU output scan for multiple PROFINET
submodules may not be transferred during the same PROFINET IO production cycle. Conversely, input data
consumed from a single PROFINET IO cycle by the PROFINET Controller may not be consumed during a single
CPU input scan.
