Interfaces - Siemens SIMATIC S7-300 Hardware And Installation Manual

Recommended MPI address n
Reserve PROFIBUS address "0" for a service PG that you can subsequently
connect briefly to the PROFIBUS subnet if required. Therefore, assign unique
PROFIBUS addresses to PGs integrated in the PROFIBUS subnet.
PROFIBUS DP: Electrical conductor or optical waveguide?
Use optical waveguides instead of copper conductors if you want your field bus to
cover greater distances regardless of the transmission rate and be insensitive to
external noise fields.
Equipotential bonding
For information on what to take into account relating to equipotential bonding when
you configure your network, refer to the corresponding chapter in the appendix.
Also note ...
the section referring to communication in the relevant CPU manual.

5.10.3 Interfaces

MPI interface
Availability: In all the CPUs described in this document.
MPI (Multi-Point Interface) represents the interface between the CPU and a PG/OP
or for communication in an MPI Subnet.
The typical (default) transmission rate is 187.5 Kbps. You can also specify 19.2
Kbps for communication with an S7-200. Other transmission rates are not possible.
The CPU automatically broadcasts its bus parameter configuration (e.g.
transmission rate) via MPI interface. A programming device, for example, can then
automatically retrieve the correct parameters and connect to an MPI Subnet.
Note
In RUN mode, you may only connect PGs to the MPI Subnet.
Other stations (e.g.. OP, TP, ...) should not be connected to the MPI subnet while
the PLC is in run mode. Otherwise, transferred data might be corrupted as a result
interference or global data packages be lost.
S7-300 Programmable Controller Hardware and Installation
A5E00105492-02
Configuring
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