Rockwell Automation 1757-SWKIT4000 ProcessLogix R400.0 Installation and Upgrade Guide - Manual (Page 266)

Publication 1757-IN040B-EN-P - March 2002
11-14 Performance and Capacity Specifications
Since ProcessLogix permits almost totally generalized
intercommunications paths, the two devices can be under or on:
•
the same H1 link,
•
different nets of the same 1757-FIM,
•
different nets of the same IO chassis,
•
different IO chassis of the same controller,
•
different controllers of the same server
As the configuration moves from 1, co-residency on the same H1 link,
to 2 to 3 to 4 to 5 to 6, more nodes and more networks get involved,
increasing the load on each node and network and adding additional
delays to the signals. Therefore, the interacting equipment should be
co-located in the pyramid when the plant instrumentation and control
networks are laid out. The number of communication circuits between
points of differing controllers should be small (less than 2–5% of the
total number of circuits.)