Hello eng.hmk;

The following document contains many design hints to make sure that the Profinet network updates at the best possible time, given the number and type of I/O devices, the number of switches (question of network depth), the amount of data traffic...

Profinet system description:

https://support.industry.siemens.com/cs/ww/en/view/19292127

I have seen Profinet designs that are much more comples than what your schematics show. The extract below should give you reassurance.

Hope this helps,

Daniel Chartier