Helllo Jonathan;

Cocolino's link allows access to a few documents, one of which is CPU 31xC and 31x: Technical Specifications.

If you open this manual to the technical data of the CPU 315-2DP, you will see that you can configure up to 4 CP 342-5 on the rack.

Hope this helps,

Daniel Chartier

Hello Jonathan;

Toi already have links from out earliet replies that van vive you answer To such questions. 

The same Technical Daya manual I quoted ratlier shows data for all S7-300 CPUs, includong the m9st powerful, the S7-319-3PN/DP. Even that CPU only allows 4 CP 342-5 in its rack. However, since it has 2 integrated ports that can be used for Profibus-DP, it allows for up to 6 Profibus masyer and slaves on-board. And in your evaliation of this CPU as a solution you should take into account its price.

Another possible option (check the overall pricing first!) would be to use a S7-400 CPU. Even the smallest CPU of that family, the S7-412-1XJ05-0AB0, allows up to 10 Profibus-DP CP (CP 443-5 Extended) on its main rack.

https://support.industry.siemens.com/cs/ww/en/view/53385241/71381257867

Could uou describe your project briefly, so we can understand why you need so many Profibus interfaces in a single plant? How many nodes do uou plan to use as Profibus slaves in the field? Since most Profibus masters allow up to 125 slave nodes, it is unusual to have a S7-300 with such a large number ofslaves. Maybe a small sketch could clarify your topology, if you would care to have us examine it.

Hope this helps  

Daniel Chartier