I want to know how many S7-400H PLCs can be used in a Plant Bus. (The maximum number of CPU to use in plant bus)

The topology used is Server/Client.  (2x Server   4x Client   1x EWS )
Software: STEP 7 v5.5  Wincc v7 sp3

I need  a Source (Manual) to  present this issue to the Client.

Hi dear,

Sub: Clarification on CPU Limitation in Plant Bus

There is no specific mention of a limitation or maximum number of CPUs in the Plant Bus. However, based on my observations and a previous project, we used around 20 CPUs in the Plant Bus. I believe the limitation is primarily based on the available IP addresses rather than a fixed number of CPUs.

For your reference, please find the link/thread below, which provides some insights into connection limitations when using CP cards, Softnet, or Hardnet.

Link:

https://support.industry.siemens.com/forum/kw/en/posts/maximum-allowable-number-of-connections-in-wincc/62699

I hope my response helps clarify your query. Please provide your feedback or suggest any corrections if needed.

Hi,

EverySIEMENS network BUS(Plant BUS, Terminal BUS, etc.) has a node limitation of64 nodes.
You can extend it usingSCALANCE switches, but the usual limit is64 nodes.

As a source, I suggest checking: SIMATIC Fault-tolerant systems S7-400H