Configuring Mpi And Profibus Subnets; Overview; Basic Principles Of Mpi And Profibus Subnets - Siemens Simatic S7-300 CPU 31xC Series Installation And Operating Instructions Manual

Configuring
4.11 Planning subnets
4.11.2

Configuring MPI and PROFIBUS subnets

4.11.2.1

Overview

The next section contains all the information you require to configure MPI, PtP and
PROFIBUS subnets:
Contents
• MPI, PtP and PROFIBUS subnets
• Multi-Point Interface
• PROFIBUS DP
• MPI and PROFIBUS network components
• Example of networks - MPI
4.11.2.2

Basic principles of MPI and PROFIBUS subnets

Convention: device = node
All devices you interconnect on the MPI or PROFIBUS network are referred to as nodes.
Segment
A segment is a bus line between two terminating resistors. A segment may contain up to 32
nodes. It is also limited with respect to the permitted line length, which is determined by the
transmission rate.
Transmission rate
Maximum transmission rates:
• MPI:
• PROFIBUS DP: 12 Mbps
4-30
– CPU 315-2 PN/DP and CPU 317: 12 Mbps
– All other CPUs: 187.5 kbps
S7-300, CPU 31xC and CPU 31x: Installation
Operating Instructions, Edition 08/2004, A5E00105492-05